chapter 11 surgical complications

8/13/2019 Chapter 11 Surgical Complications

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CHAPTER 11 - Surgical Complications Josef E. Fischer

Elliott Fegelman

Jay Johannigman

OPERATIVE RISK

Operative ris is !efine! as the s"m total of a#normalities of all organ systems an!

their interactions that !etermine the o"tcome of an operation. The approach "se! in

!etermining operative ris is to i!entify the patient at ris$ i!entify the organ

system%s& at ris$ prevent or protect against the complication or the fail"re of that

organ system %especially those aspects of organ insta#ility or ina!e'"acy that are

reversi#le&$ an! improve the o"tcome. The organ systems that !etermine o"tcome

incl"!e( %)& car!iac$ %*& p"lmonary$ %+& renal$ %,& hepatic$ %-& hemostatic$ %&

n"tritional/imm"nologic$ an! %0& vasc"lar.

1ar!iac RisOne means of estimating car!iac ris is to "se 2ol!man3s car!iac ris in!e4 %Ta#le

))/)&. The foc"s of the 2ol!man classification in patients "n!ergoing general

anesthesia is the history of a previo"s myocar!ial infarction. If the patient has not ha!

any previo"s myocar!ial infarction$ the ris of car!iac !eath is #et5een ) an! ).*

percent. If more than months has elapse! #et5een the car!iac infarction an! the

c"rrent operation$ there is a percent ris. If a transm"ral infarct has occ"rre! less

than + months #efore operation$ the ris of car!iac !eath is #et5een ) an! +0

percent.

Factors that pre!ispose to the occ"rrence of life/threatening car!iac events in the

perioperative perio! incl"!e a history of any of the follo5ing( %)& infarction 5ithin months$ %*& congestive heart fail"re$ %+& arrhythmias$ %,& aortic stenosis$ %-&

emergency or ma6or s"rgery$ %& age greater than 07 years$ an! %0& poor me!ical

con!ition.

Significant peripheral vasc"lar !isease sho"l! alert the s"rgeon to consi!er the car!iac

ris. If the patient gives a history of angina pectoris$ it sho"l! #e !etermine! 5hether

there has #een ne5 onset of "nsta#le angina.

The electrocar!iogram %E12& an! hematocrit level are significant. A car!iac stress

test is in!icate! to i!entify those patients at coronary ris. A positive car!iac stress

test incl"!es any or all of the follo5ing( an ST !epression of more than 7.* mV$ an

ina!e'"ate heart rate response to stress$ or hypotension. The most sensitive

e4amination of car!iac ris is the ina#ility to perform a #icycle e4ercise for * min an!

achieve a heart rate higher than )77. 8ata from rest an! e4ercise ra!ion"cli!e

ventric"lography provi!e little a!!itional information #"t can provi!e "sef"l

information.

The principal form of treatment for patients 5ith car!iac ris #eca"se of an antece!ent

myocar!ial infarction is %if possi#le& to !elay operating for appro4imately months

after the myocar!ial infarction. Some patients sho"l! #e a!mitte! to the intensive care

"nit the !ay #efore operation$ an! o4ygen cons"mption$ o4ygen !elivery$ mi4e!veno"s o4ygen sat"ration$ an! car!iac o"tp"t sho"l! #e optimi9e!. In patients 5ith


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significant angina$ angioplasty or coronary #ypass proce!"re may #e necessary #efore

any ma6or s"rgical proce!"re is "n!ertaen. In some sit"ations sim"ltaneo"s

car!iovasc"lar revasc"lari9ation an! caroti! en!arterectomy are performe!.

For patients in congestive fail"re$ the "se of calci"m channel #locers or #eta

#locers$ !igitali9ation 5ith car!iac glycosi!es$ an! !i"resis are part of thetherape"tic armamentari"m. Patients 5ith rapi! atrial fi#rillation sho"l! have their

car!iac rates controlle!. If the car!iac rhythm cannot #e ret"rne! to normal sin"s

rhythm 5ith the "se of glycosi!es$ '"ini!ine$ or procainami!e hy!rochlori!e

%Pronestyl&$ car!ioversion sho"l! #e consi!ere!. If car!ioversion is attempte!$ the

patient sho"l! first #e given anticoag"lants to prevent em#oli9ation.

P"lmonary Ris

P"lmonary ris factors incl"!e smoing$ o#esity$ a!vance! age$ an! in!"strial

e4pos"re. The patient at p"lmonary ris can #e i!entifie! #y simple f"nctional tests

s"ch as 5aling "p a flight of steps or #lo5ing o"t a match 5ith "np"rse! lips from a

!istance of : to )7 inches %*7;*- cm&. If arterial #loo! is !ra5n 5ith the patientinspiring room air$ it is not the re!"ce! PO * that i!entifies a patient significantly at

ris #"t rather a P1O * of greater than ,- mm1 is a highly s"#6ective test$ !epen!ing on

the patient an! the enco"ragement of the e4aminer e4horting the patient to #reathe

ma4imally. Patients 5ith p"lmonary artery

press"re higher than +7 mmeca"se most l"ng !amage is a res"lt of smoing or in!"strial poll"tion$ cessation of

smoing is essential for patients 5ho are to "n!ergo long elective proce!"res :

5ees cessation preoperatively is re'"ire! for ma4imal #enefit. P"lmonary physical

therapy may improve the operative ris. E4pectorants$ physical therapy$ incentive

spirometry$ h"mi!ifie! air %h"mi!ifie! o4ygen is not necessary&$ an!$ in the case of

#ronchiectasis$ anti#iotics #ase! on c"lt"res of the patient3s sp"t"m flora are all

appropriate to improve operative ris. Cith goo! preparation$ thoracotomy can #e

carrie! o"t in patients 5ith an FEV ) of less than ).7 ? an! an =>1 of +- to ,7

percent.


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Renal Ris

Renal a#normalities are reflecte! #y elevations in #loo! "rea nitrogen %>BD& an!

creatinine levels. Ser"m a#normalities are not manifest "ntil more than 0- to 7

percent of the renal reserve is lost %Fig. ))/)&. An elevation of >BD or creatinine that

is not #eca"se of !ehy!ration generally means that renal f"nction is compromise! #y

0- to 7 percent. Increase! levels of >BD or ser"m creatinine in a hy!rate! patientsho"l! #e '"antifie! #y meas"ring creatinine clearance(

1l1r %),7 / age& G 5eight %g&%m?@min& @ 0* G 1r %ser"m& mg@!?

Reversi#le ca"ses of renal ins"fficiency sho"l! #e i!entifie! an! correcte!. These

incl"!e infection$ "ncontrolle! hypertension$ o#str"ction$ an! !ehy!ration. The

patient sho"l! #e a!mitte! preoperatively to a monitore! #e! the night #efore s"rgery$

a p"lmonary artery catheter place!$ an! the patient hy!rate! 5ith intraveno"s saline

sol"tion to the optimal filling press"re in or!er to protect the i!neys.

Aminoglycosi!es sho"l! #e avoi!e! 5hether a!ministere! systemically or for #o5el

preparation.

In the postoperative perio!$ if severe hyperalemia s"pervenes %greater than 0.-

mE'@?&$ 5ith accompanying E12 changes$ intraveno"s calci"m sho"l! #e

a!ministere! an! follo5e! shortly thereafter #y -7H !e4trose$ )7 "nits of ins"lin$ an!

intraveno"s #icar#onate. So!i"m polystyrene s"lfonate %Kaye4alate& can #e given #y

mo"th or #y enema - g sho"l! #e a!ministere!. Essential amino aci!s an! hypertonic

!e4trose sol"tion$ given as total parenteral n"trition %TPD&$ may lo5er the potassi"m

level. As potassi"m enters the cells$ it might #e necessary to a!! potassi"m. If the

>BD level approaches )77mg@!?$ there are !iffic"lties 5ith clotting factors an!

platelets are !ysf"nctional$ res"lting in gastrointestinal #lee!ing$ 5hich f"rther

elevates the >BD level. Peritoneal$ hemo!ialysis$ or contin"o"s "ltrafiltration

occasionally is re'"ire!.

$

an! #et5een *7 an! -7 percent or higher for 1lass 1 categories. Chen the #loo!

ammonia concentration is higher than )-7 ng@!?$ an :7 percent mortality can #ee4pecte!. Chen the al#"min level is #elo5 *.7 g@!?$ a similar mortality is anticipate!.

Fe5 patients 5ith a #ilir"#in level higher than , mg@!? as a res"lt of hepatic

!ysf"nction s"rvive an operation re'"iring a general anesthetic. Similarly$ 5ith a

prothrom#in time prolonge! more than * secon!s$ a mortality of ,7 to 7 percent can

#e e4pecte!. A point system for patients 5ith liver !isease "n!ergoing nonsh"nt

operations "ses ser"m al#"min concentration$ prothrom#in time$ the presence of

encephalopathy$ an! a history or presence of varices %Ta#le ))/,$ Fig. ))/*&. Patients

5ith hepatic !ysf"nction generally !ie of a high/o"tp"t car!iovasc"lar fail"re an! lo5

peripheral resistance.

In an elective sit"ation$ a#stinence from alcohol$ 5here alcohol is the !amaging agent$is pro#a#ly the most important feat"re for improving hepatic f"nction. Patients 5ith


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cirrhosis receive a large proportion of calories from car#ohy!rate$ especially from

alcohol$ a cycle that it is necessary to #rea. These patients often are intolerant to the

protein that they nee! #eca"se they are hypercata#olic$ re'"iring ).) g of amino

aci!s@g@*, h$ instea! of the normal 7.-- g of amino aci!s@g@*, h. Protein tolerance

may #e improve! #y the "se of #ranche!/chain amino aci!;enriche! n"tritional

mi4t"res or #ranche!/chain amino aci!s alone. In patients 5ith ascites$ the conversionof "ncontrolla#le ascites to ascites that can #e controlle! 5ith me!ications

s"#stantially improves the operative ris. Spironolactone %Al!actone& an! f"rosemi!e

%?asi4& com#ine! 5ith fl"i! restriction to )-77 m?@!ay are therape"tic. Restriction of

so!i"m to -77 mg@!ay is !esira#le #"t rarely achieva#le 5itho"t the "se of salt/ free

foo!s. A so!i"m limit of * g@!ay is more realistic.


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hypoglycemia if overtreate!$ an! also #eca"se of the associate! inci!ence of

generali9e! small/vessel vasc"lar !isease.

Pathophysiology

The #asic !efect in !ia#etes is a lac of meta#olically effective circ"lating ins"lin.

The elevate! #loo! gl"cose level is a res"lt of !eficient "tili9ation on the part ofperipheral tiss"es an! increase! o"tp"t of gl"cose #y the liver. In !ia#etes the

#rea!o5n of fatty aci!s is increase!. =eta#olism of the etone #o!ies is limite!$

acc"m"lating in the #loo!stream an! eliminate! via the i!neys. 2lycos"ria pro!"ces

an osmotic !i"resis that is enhance! #y the presence of etone #o!ies 5ith the

associate! loss of so!i"m an! potassi"m. Eval"ation of !ecompensate! !ia#etes

incl"!es not only meas"ring the #loo! gl"cose level #"t also meas"ring ser"m acetone

an! electrolyte levels$ car#on !io4i!e com#ining po5er$ an! #loo! p


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gl"cose level in the perioperative perio!s$ partic"larly in the el!erly an! in car!iac

patients. In the patient 5ith postoperative hypotension$ #loo! gl"cose level sho"l! #e

meas"re! to r"le o"t hypoglycemia as a ca"se.

Patients 5ith mil! !ia#etes mellit"s fre'"ently !o not re'"ire ins"lin$ an! !ietary

control is s"fficient. The cornerstone of all !ia#etic management is the !ietary orparenteral intae. The preoperative !ia#etic intae sho"l! contain ),7 to *77 g of

car#ohy!rates$ 7 to )77 g of protein$ an! 5ith a!e'"ate vitamins an! minerals sho"l!

f"rnish )*77 to *)77 cal !aily. If parenteral fl"i!s are re'"ire!$ there is some

a!vantage to "sing fr"ctose or sor#itol$ 5hich can #e taen in amo"nts "p to -7 g

!aily in the !ia#etic patient$ #"t fr"ctose can ca"se lactic aci!osis. The goal of the

!ietary or parenteral fl"i! regimen is to eep the patient free of aceton"ria 5itho"t

e4cessive hyperglycemia. Patients "sing oral agents 5ith 5ell/controlle! !ia#etes

sho"l! contin"e the "se of these !r"gs "ntil the !ay #efore operation$ partic"larly if

the me!ication is tol#"tami!e or phenformin. Cith longer/acting agents$ s"ch as

chlorpropami!e$ the !r"g sho"l! #e !iscontin"e! 0* h preoperatively if the

a!ministration of ins"lin is contemplate!. Patients 5ho tae tol#"tami!epreoperatively "s"ally re'"ire ins"lin !"ring an! imme!iately after a ma6or operation.

Patients receiving chlorpropami!e "s"ally !o not re'"ire ins"lin !"ring the imme!iate

perioperative perio!.

Ins"lin Therapy

Several protocols for the a!ministration of ins"lin have #een propose! %Ta#le ))/-&.

One pop"lar metho! of treatment "ses a regimen in 5hich the !aily car#ohy!rate

re'"irement is !ivi!e! into fo"r e'"al !oses an! given parenterally as -;)7H !e4trose

in 5ater every h. This initiation of the parenteral gl"cose inf"sion is accompanie!

#y the s"#c"taneo"s in6ection of "nmo!ifie! reg"lar ins"lin in !oses e'"al to

appro4imately one/ fo"rth the !ose of ins"lin that the patient re'"ire! prior to

operation. Brine is chece! reg"larly$ an! s"pplementary !oses of crystalline ins"lin

are given as in!icate!. 8epen!ing on the e4tent of glycos"ria$ , to )7 "nits of

a!!itional ins"lin is provi!e! for each "nit of positivity. ?arger !oses may #e

in!icate! 5hen aceton"ria$ severe stress$ infection$ or mare! hyperglycemia is

present. The a!vantage of this metho! is that gl"cose an! ins"lin are given at reg"lar

intervals$ permitting a!6"stment in the !ose !"ring the !ay. It is prefera#le to monitor

#loo! gl"cose levels. The ma6or !isa!vantage of this regimen is that ina!vertent

interr"ption of gl"cose inf"sion may res"lt in hypoglycemia. Cith this regimen$ slight

glycos"ria is prefera#le provi!e! there is no aceton"ria.

The secon! #asic regimen is for patients 5hose !ia#etes is "n!er control 5ith single/

in6ection therapy "sing long/acting ins"lin an! in 5hom a complicate! postoperative

co"rse is not anticipate!. On the !ay of operation$ the patient receives -7 g of gl"cose

in )777 m? of sol"tion. Chen the intraveno"s sol"tion is starte!$ ins"lin is

a!ministere! at one/ half the !aily !ose of that previo"sly re'"ire!. After operation

an! ret"rn to the recovery room or 5ar!$ the remain!er of the "s"al !aily !ose of

ins"lin is given s"#c"taneo"sly. The amo"nt of ins"lin given on the !ay of operation

appro4imates that given the previo"s !ay. On the !ay after operation$ the "s"al !ose

of ins"lin is given in the morning #efore #reafast or at the same time that an

intraveno"s inf"sion is starte!. =o!ifications of this approach "se small !oses of

reg"lar ins"lin s"#c"taneo"sly !"ring the postoperative perio! #ase! on the e4tent ofglycos"ria or$ prefera#ly$ the ser"m gl"cose level. In patients treate! 5ith single !aily


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in6ections #"t 5hose !ia#etes is not "n!er control #efore operation$ conversion to a

regimen of sol"#le ins"lin is in!icate!.

Severe hyperglycemia in patients "n!ergoing ma6or operations is more effectively

manage! 5ith intraveno"s reg"lar ins"lin. The pro#lem of ins"lin a#sorption #y the

fl"i! container has #een overcome #y the "se of plastic containers$ highconcentrations of ins"lin$ small amo"nts of al#"min$ an! fl"shing the system. A

specific inf"sion protocol is o"tline! in Ta#le ))/.

A simplifie! protocol has #een propose! #y Coo!r"ff an! associates. The patients

receive their evening !ose of ins"lin the preoperative !ay$ #"t no s"#c"taneo"s ins"lin

on the morning of s"rgery. The patient is sche!"le! as the first case of the !ay. Ins"lin

an! gl"cose are controlle! 5ith t5o separate inf"sion p"mps one p"mp inf"ses -H

!e4trose in lactate! Ringer3s sol"tion at * m?@g@h$ an! the other !ispenses ins"lin

from a plastic #ag containing *-7 m? so!i"m chlori!e to 5hich -7 "nits of B/)77

reg"lar ins"lin has #een a!!e!. The rate of ins"lin inf"sion is #ase! on the ser"m

gl"cose level. T5enty "nits per ho"r is inf"se! for gl"cose levels a#ove *77 mg@!?$#"t no ins"lin for levels #elo5 :7 mg@!?. The s"rgical proce!"re is not #eg"n "ntil

the level is #elo5 *77 mg@!?. Ins"lin therapy !"ring emergent s"rgery or s"rgery

complicate! #y infection re'"ires greater amo"nts of ins"lin to maintain ser"m

gl"cose levels #elo5 *77 mg@!?. In e4treme cases$ #ol"s in6ection of 7.) to 7.,

"nit@g may #e re'"ire! as an a!!itive.

Ketoaci!osis

The preparation for s"rgical treatment of a patient 5ith etoaci!osis is critical.

Ketoaci!osis may mas'"era!e as a s"rgical emergency. The patient 5ith fran

!ia#etic coma is no can!i!ate for s"rgical treatment regar!less of the in!ication.

1rystalline ins"lin sho"l! #e "se! in all cases to esta#lish control. Page an! associates

reporte! effective management of !ia#etic coma 5ith contin"o"s lo5/!ose ins"lin

inf"sion "sing an average of 0.* "nits@h. Plasma gl"cose$ etone #o!ies$ an! free fatty

aci!s !ecrease! -: percent in , h. The associate! !ehy!ration an! electrolyte

a#normality m"st #e correcte! most patients 5ith a!vance! coma re'"ire an average

of * to , liters of fl"i! to overcome the !ehy!ration. The ser"m potassi"m

concentration sho"l! #e !etermine! at to : h intervals. Potassi"m is a!!e! to the

fl"i! in '"antities of ,7 mE'@? a!ministere! at a rate no higher than *- mE'@h. The

nee! for potassi"m "s"ally !oes not e4cee! :7 mE'. There generally is no nee! to a!!

gl"cose to intraveno"s fl"i! "nless the #loo! gl"cose level falls #elo5 normal. 2astric

atony is a fre'"ent accompaniment of !ia#etic etoaci!osis$ an! s"ction fre'"ently isre'"ire! to minimi9e p"lmonary aspiration. It is possi#le to correct etoaci!osis in

s"fficient time that the patient3s s"rgical stat"s is not compromise!.

Donetotic


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given to !etermine responsiveness. So!i"m an! potassi"m also m"st #e given #eca"se

large amo"nts of these ions are lost in the "rine.

2EDERA? 1ODSI8ERATIODS

The response to in6"ry an! s"rgical proce!"res incl"!es anti!i"resis$ an increase in

e4travasc"lar vol"me$ fever$ an! tachycar!ia. These are no5n to #e the res"lt of therelease of cytoines an! other agents. In patients "n!ergoing general anesthesia$ fever

on the first postoperative night is "s"ally attri#"te! to atelectasis$ #"t is pro#a#ly the

res"lt of a resetting of the central thermostat to com#at the hypothermia that occ"rs in

the operating room. As heat preservation techni'"es #ecome more 5i!esprea!$ it is

possi#le that s"ch fever 5ill #e eliminate!.

Brine o"tp"t falls$ normally #eca"se of the release of anti!i"retic hormone %A8eca"se the

!egra!ation rate of al#"min normally is relate! to the amo"nt in the e4travasc"lar

space$ the o"tflo5 of al#"min from the intravasc"lar space to the interstices res"lts in

increase! cata#olism of al#"min.

Ile"s of the colon an! stomach persists for * to - !ays after open intraa#!ominal

proce!"res$ #"t for a consi!era#ly shorter perio! after minimally invasive s"rgery.

Ret"rn of intestinal motility is one area in 5hich minimally invasive s"rgery appears

to have a !istinct physiologic a!vantage$ e4plaining the shorter length of hospital stay.

After open a#!ominal proce!"res$ the small #o5el contin"es to f"nction thro"gho"t

the postoperative perio!$ allo5ing the "se of enteral n"trition in the imme!iate

postoperative perio!.

Co"n! pain can #e severe for appro4imately ,: to 0* h. A consi!era#ly re!"ce!

re'"irement for pain me!ication can #e achieve! #y the "se of a s"#c"tic"lar clos"re

reinforce! 5ith Steri/Strips. The meta#olic response to s"rgery an! the postoperative

5o"n! pain can #e improve! #y the "se of a!e'"ate amo"nts of local anesthesia$ even

if the patient is "n!ergoing general$ epi!"ral$ or spinal anesthesia. Bse of these agents

at the #eginning of the proce!"re !ecreases the meta#olic response to s"rgery. Chen

"se! at the en! of the proce!"re$ a mi4t"re of short/ an! long/acting agents !ecreasesthe "se of pain me!ication in the imme!iate postoperative perio!$ an! in small

incisions may completely o#viate the "se of narcotics.

Postoperative fatig"e may #e the res"lt of general anesthesia as m"ch as the operation.

It is essentially a#sent in patients in 5hom the afferent nerves have #een severe!$ e.g.$

patients 5ith paraplegia. In the el!erly$ it may tae "p to * or + months for the

patient3s fatig"e to ameliorate. A#sence of physical activity !"ring convalescence

res"lts in e4ten!e! fatig"e. Infection or other "nto5ar! events in the postoperative

perio! also res"lt in a prolongation of fatig"e.

FEVERPathophysiology


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Fever is a !isor!er of normal #o!y thermoreg"lation that is controlle! #y the anterior

hypothalam"s. 1ore temperat"re an! its !i"rnal variation are centere! on a set point$

normally #et5een : an! F %+01&. There is spec"lation that the evol"tion of fever

arose as a protective mechanism to com#at infection. It is recogni9e! that certain

organisms$ s"ch as #acteria an! vir"ses$ are heat/sensitive an! can #e !estroye! in

vivo #y artificially in!"cing fever. Vario"s pathophysiologic mechanisms$ s"ch aspyrogens$ are responsi#le for the generation of fever. Pyrogens may arise from

infectio"s agents s"ch as vir"ses$ #acteria$ or f"ngi as a res"lt of s"#stances release!

#y these organisms or #eca"se of the presence of these organisms. In a!!ition$

antigen/anti#o!y comple4es$ steroi!s$ an! other inorganic s"#stances have #een

!emonstrate! to pro!"ce e4perimental fevers.

All pyrogens appear to evoe a common me!iator$ en!ogeno"s pyrogen or

interle"in/)$ a monoine pro!"ce! #y le"ocytes. Temperat"re/sensitive preoptic

ne"rons resi!e 5ithin the hypothalam"s. Interle"in/) generates fever #y altering the

activity of temperat"re/sensitive ne"rons locate! in the anterior hypothalam"s. Chen

the set/point is raise!$ the #o!y3s mechanisms for increasing temperat"re$ incl"!ingheat conservation an! increase! heat pro!"ction$ are #ro"ght into play. The act"al

#o!y temperat"re reaches that point a fe5 ho"rs after the set/ point has raise!.

Interle"in/) is e4tremely potent only a fe5 nanograms can affect the hypothalam"s

an! increase core temperat"re.

Chen the hypothalamic thermostat is s"!!enly raise! to a higher setting #y pyrogen$

the #loo! temperat"re remains relatively lo5. The in!ivi!"al feels chills an! the sin

is col! #eca"se of the vasoconstriction in!"ce! to conserve #o!y heat. Shivering can

occ"r$ a po5erf"l mechanism of heat pro!"ction. This contin"es "ntil the #loo!

temperat"re reaches the set/ point. If the set/point !rops s"!!enly$ the patient then

goes thro"gh the fl"sh phase$ or crisis. 8"ring this phase the #o!y attempts to ri!

itself of e4cess heat #y vaso!ilatation an! s5eating. >efore the a!vent of anti#iotics$

physicians an4io"sly a5aite! the fl"sh phase$ no5ing that the fever 5o"l! soon

resolve.

Fever per se "s"ally is not a significant physiologic pro#lem "nless core temperat"re

is elevate! a#ove )7-F. The most important role for fever in a critically ill s"rgical

patient is provi!ing an early/5arning sign for infection or inflammation. Potential

so"rces incl"!e in6"ry$ catheters$ "rinary tract$ l"ngs$ s"rgical sites s"ch as 5o"n!s or

anastomoses$ or throm#ophle#itis in the pelvic veins. 8r"g reactions are another

common ca"se of fever.

Perioperative Fever

%Ta#le ))/0&. >et5een *0 an! -: percent of patients !evelop a fever for at least *, h

after an operative proce!"re of mo!est magnit"!e. Persistence of a fever for *, h is

not ca"se for alarm "nless it is high an! associate! 5ith systemic symptoms s"ch as

rigor$ hypotension$ !ist"r#ances in mentation$ !ecreases in "rine o"tp"t$ or septic

shoc. If the fever persists for ,: h$ it is consi!ere! significant. Fever in the

imme!iate postoperative perio! "s"ally is not serio"s$ is not very high$ an! is self/

limite!. It is more liely that the postoperative fever is the res"lt of overcompensation

of the set/point in a patient 5ho 5as col!.


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The presence of fever on the first postoperative night is common$ "s"ally ascri#e! to

atelectasis$ #"t the "s"al so"rces of serio"s fever$ 5hich incl"!e 5o"n! cell"litis$

"rinary tract infection$ pree4istent central veno"s catheter fever$ or !rainage sprea! of

an infecte! foc"s sho"l! not #e !isregar!e!. A !elaye! transf"sion reaction$ allergic

in nat"re$ can #e the ca"se of fever.

=alignant


11/65

In patients 5ho are afe#rile !"ring the first 0* h$ fever "s"ally is a manifestation of a

significant complication. Fever can #e relate! to throm#ophle#itis$ especially in

patients 5ith previo"s episo!es of throm#ophle#itic complications.

The most common ca"se of fever after 0* h is 5o"n! infection$ 5hich may #e latent

or may #e associate! 5ith increase! 5o"n! pain. Brinary tract infections sho"l! also#e s"specte!$ partic"larly in patients 5ith catheters. ?ess common infectio"s

complications incl"!e pne"monitis$ ac"te cholecystitis %especially acalc"lo"s

cholecystitis in patients 5ho are immo#ile or have receive! large vol"mes of #loo!&$

i!iopathic postoperative pancreatitis %tho"gh this occasional complication "s"ally is

manifest in the imme!iate postoperative perio!&$ an! !r"g allergy. Bn"s"al

nosocomial infections can occ"r in imm"nocompromise! patients$ especially

transplant patients. An occasional patient s"stains liver necrosis from a chlorinate!

hy!rocar#on$ #"t "s"ally these are evi!ent in the early postoperative perio!. $ hepatitis 1$ cytomegalovir"s$ an! other viral illnesses may !evelop after

transf"sion.

1an!i!iasis may complicate intraveno"s total parenteral n"trition. 1an!i!a may not

gro5 o"t on initial #loo! c"lt"res 5hile the patient is ill. If 1an!i!a is !iscovere!

gro5ing from one or t5o other sites$ s"ch as sin$ sp"t"m$ or "rine$ the patient sho"l!

#e treate! 5ith amphotericin >$ an! the TPD line sho"l! #e remove!.

Fever occ"rring after ) 5ee is almost al5ays an in!ication of serio"s complications

"nless it is the res"lt of a !r"g allergy. ?ate infections can #e the res"lt of a leaing

anastomosis$ an a#scess a!6acent to the anastomosis$ or a !eep 5o"n! infection that is

s"ppresse! #y anti#iotics.

COBD8 1O=P?I1ATIODS

Co"n! Infection

Pre!isposing Factors

Co"n! contamination occ"rs in the operating room$ #"t not all 5o"n!s har#oring

#acteria #ecome infecte!. Chile m"ch of the contamination taes place 5ithin the

operative fiel! %e.g.$ a violate! hollo5 visc"s&$ the other ma6or so"rce of 5o"n!

contamination is the environment. Efforts sho"l! #e taen to re!"ce the #acterial

co"nt in the operating room. 8eterrents incl"!e #arriers$ changes of clothing$

appropriate covering of facial an! other hair$ an! the "se of scr"# s"its that minimi9e

the she!!ing of personal #acteria. Shoe covers also can #e 5orn$ #"t their efficacy is

'"estiona#le. Floors an! 5alls sho"l! #e moppe! !o5n #et5een cases 5ith antisepticsol"tion to !ecrease the #acteria am#ient in the operating room. Bltraviolet light at

entrances to sterile areas may #e efficacio"s fre'"ent air changes to *7 times a

min"te are important.

Sterili9ation sho"l! #e a!e'"ate. >reas in techni'"e are partic"larly important. The

contamination of go5ns$ gloves$ an! instr"ments sho"l! #e promptly reme!ie!.

2loves sho"l! #e imme!iately change! 5hen holes are !etecte!. It is important to

5all off the 5o"n! an! viscera an! to eep them moist$ especially !"ring long

proce!"res.

Staphylococc"s a"re"s is the most fre'"ently involve! offen!ing organism. Entericorganisms fre'"ently contaminate 5o"n!s 5hen #o5el operations are performe!.


12/65


13/65

Systemic anti#iotics sho"l! #e given imme!iately #efore the incision is ma!e an!

ser"m levels maintaine! thro"gho"t the proce!"re a#ove the minimally inhi#itory

concentration. Re!osing is necessary in long proce!"res. Ta#le ))/)7 lists appropriate

anti#iotics. There is !isagreement over contin"e! "se of anti#iotics after the 5o"n!

clos"re. =any #elieve that this is not necessary e4cept in massive contamination$ in

5hich case prophylactic anti#iotics #ecome therape"tic. Some a"thorities #elieve thatthe infection rate after a clean elective operation can #e halve! from , to * percent

5ith a single !ose of a first/generation cephalosporin others are concerne! a#o"t the

sprea! of resistant organisms an! #elieve that 5i!esprea! prophyla4is is "nnecessary.

=etic"lo"s techni'"e$ hemostasis$ an! gentle han!ling of tiss"es contri#"te to a lo5er

infection rate. Tiss"es sho"l! #e ept 5arm an! moist$ especially !"ring long

proce!"res. Evi!ence s"ggests that 5o"n! infections might #e prevente! if

hypothermia !oes not occ"r. Chile 5arming techni'"es have improve!$ they have not

completely o#viate! hypothermia. All e4pose! parts of the patient sho"l! #e covere!$

an! a 5arming pa! sho"l! #e place! #efore the proce!"re. A!ministere! fl"i!s an!

irrigation sho"l! #e 5arme!.

Co"n!s re'"iring !rainage are more liely to #ecome infecte! %)) percent vers"s -

percent in "n!raine! 5o"n!s&$ #"t it cannot #e concl"!e! that the !rains are

responsi#le for the infection. The !rains may have #een "se! #eca"se of concern for

a!e'"ate hemostasis.

1linical =anifestations

Co"n! infections are classifie! as minor$ e.g.$ p"r"lent material aro"n! sin s"t"re

sites$ or ma6or$ e.g.$ !iscrete collections of p"s 5ithin the 5o"n!. S"perficial

infections are limite! to the sin an! s"#c"taneo"s tiss"e !eep infections involve

areas of the 5o"n! #elo5 the fascia.

1linical manifestations of a 5o"n! infection incl"!e r"#or$ calor$ t"mor$ an! !olor.

The patient may have pain %!olor& that is "n"s"ally severe given the magnit"!e of the

proce!"re or the length of time it remains after the proce!"re. The 5o"n! may #e

5arm to the to"ch %calor&$ it may #e s5ollen an! e!emato"s %t"mor&$ an! there may

#e s"rro"n!ing re!ness an! cell"litis %r"#or&. If !rainage is not prompt$ the res"lting

5o"n! a#scess may #e accompanie! #y s"#stantial cell"litis. Fever to )7);)7*F %to

+1& "s"ally is present 5ith some increase in p"lse rate.

Co"n! infections "s"ally are evi!ent #et5een the fifth an! eighth postoperative !ays.Chen patients have receive! anti#iotics$ 5o"n! infections may #ecome manifest

5ees after an operative proce!"re. In cases of severe necroti9ing fasciitis or

clostri!ial myositis$ manifestations may occ"r 5ithin *, h.

=anagement

=anagement of 5o"n! infections !epen!s on the e4tent of !estr"ction an! the type of

5o"n! infection. A simple collection of p"r"lent material in the sin an!

s"#c"taneo"s tiss"e 5itho"t ma6or s"rro"n!ing cell"litis is treate! #y opening the

incision. The incision is opene! eno"gh to provi!e a!e'"ate !rainage$ an! a 5ic is

place! in the 5o"n! to prevent the sin an! s"perficial s"#c"taneo"s tiss"e from

closing #efore complete !rainage.


14/65

Opening the 5o"n! alone is ins"fficient in severe clostri!ial myositis or necroti9ing

fasciitis 5ith loss of via#ility of the fascia or m"scle. Ra!ical !e#ri!ement is

necessary to save the patient3s life. 8ischarge of !ish5ater p"s sho"l! alert the

s"rgeon to the possi#ility of necroti9ing fasciitis. A 2ram stain 5ill reveal a mi4e!

flora of gram/negative ro!s an! gram/ positive cocci. 1lostri!ial myositis is manifest

#y crepit"s %gas in the tiss"es&$ 5hich also may #e present in necroti9ing fasciitis$ an!vesicles on the sin. In #oth sit"ations$ the patient is more sic than e4pecte! 5ith a

simple 5o"n! infection. Chen 5o"n! infections are associate! 5ith s"rro"n!ing

cell"litis an! e!ema$ the "se of anti#iotics in a!!ition to opening an! !e#ri!ing the

5o"n! is necessary. A 2ram stain may i!entify some of the offen!ing organisms. In

the a#sence of specific information$ the 5o"n! sho"l! #e c"lt"re! an! the patient

place! on ampicillin %or clin!amycin&$ gentamicin$ an! metroni!a9ole or a

com#ination of anti#iotics that covers the organisms most liely to #e present. If

hemolytic streptococc"s is the offen!ing organism$ penicillin sho"l! #e a!ministere!

for ) 5ee.

8ia#etic patients are prone to Fo"rnier3s gangrene$ 5hich is a form of necroti9ingfasciitis of the perine"m or groin. These patients re'"ire 5i!e !e#ri!ement. Fo"rnier3s

gangrene often is fatal$ 5ith mortality rates of +7 to 0- percent.

Co"n!


15/65

!iscovere! in the postoperative perio!$ repeate! aspiration is in!icate!$ or$ prefera#ly$

close!/ s"ction !rains are place! perc"taneo"sly "ntil fl"i! no longer acc"m"lates$

an! the sin flaps are allo5e! to a!here. Press"re !ressing may #e helpf"l in

con6"nction 5ith aspiration an! contin"o"s close!/s"ction !rainage.

Co"n! 8ehiscence8ehiscence is separation 5ithin the fascial layer$ "s"ally of the a#!omen$ 5hereas

evisceration in!icates e4tr"sion of peritoneal contents thro"gh the fascial separation.

The inci!ence of 5o"n! !isr"ption is #et5een 7.- an! +.7 percent$ averaging *.

percent 5hen all a#!ominal proce!"res are consi!ere!. 8ehiscence occ"rs in ).+

percent of patients "n!er ,- years of age$ an! -., percent of patients over ,- years of

age. =any patient characteristics may contri#"te to a fascial !ehiscence$ #"t generally

!ehiscence is ca"se! #y a technical factor. Patient characteristics that contri#"te to

fascial !ehiscence sho"l! sensiti9e the s"rgeon to tae preca"tions "sing a mass

clos"re or anterior fascial retention s"t"res$ 5hich may not prevent !ehiscence #"t

may prevent evisceration.

=aln"trition$ hypoproteinemia$ mor#i! o#esity$ malignancy 5ith imm"nologic

!eficiency$ "remia$ !ia#etes %especially 5ith poorly controlle! #loo! gl"cose levels&$

co"ghing 5ith increase! a#!ominal press"re$ an! remote infection are contri#"tory

factors. 8ehiscence occ"rs in over - percent of patients 5ith cancer$ compare! 5ith

less than * percent in patients 5ith #enign con!itions. Ja"n!ice has #een associate!

5ith an increase! inci!ence of 5o"n! !ehiscence$ #"t it is "nclear 5hether this is a

!irect effect of the #ilir"#in or is the effect of all of the !eficiencies that are associate!

5ith en!/stage liver !isease. Preoperative #iliary !rainage !oes not res"lt in a

!ecrease in 5o"n! complications or !ehiscence. Ascites increases the inci!ence of

5o"n! !isr"ption.

?ocal factors increasing 5o"n! !isr"ption incl"!e hemorrhage$ infection$ e4cessive

s"t"re material$ an! poor techni'"e. Series are contra!ictory as to 5hether !ehiscence

is increase! in vertical as compare! 5ith hori9ontal incisions$ #"t all agree that 5hen

a stoma is #ro"ght o"t thro"gh an incision the inci!ence of !isr"ption is increase!.

A m"lticenter$ ran!omi9e!$ prospective trial compare! interr"pte! vers"s contin"o"s

polyglycolic aci! s"t"re clos"re of mi!line a#!ominal incisions. The overall

!ehiscence rate 5as ). percent in the contin"o"s s"t"re gro"p an! *.7 percent in the

interr"pte! s"t"re gro"p. The !ehiscence rate 5as significantly higher in the

interr"pte! s"t"re gro"p 5hen 5o"n!s 5ere contaminate!. =onofilament s"t"reshave a lo5er inci!ence of !isr"ption than #rai!e! s"t"res.

Vitamin 1 is essential for collagen synthesis an! fi#ro#last formation$ #acterial

!estr"ction$ an! s"pero4i!e pro!"ction #y ne"trophils. =any el!erly patients are

s"#clinically scor#"tic$ a con!ition associate! 5ith an eightfol! increase in the

inci!ence of 5o"n! !ehiscence. Linc is a cofactor for vario"s en9ymatic an! mitotic

processes$ partic"larly of the epithelial cells an! the fi#ro#lasts. Patients 5ith

!iarrhea$ hepatic ins"fficiency$ or chronic stress may #e s"#6ect to 9inc !eficiency that

is associate! 5ith poor healing. Steroi!s$ a!ministere! topically or systemically$ have

a !eleterio"s effect on 5o"n! healing$ interfering 5ith 5o"n! healing at every level$

incl"!ing inflammation$ 5o"n! macrophage f"nction$ capillary proliferation$ an!fi#roplasia. Vitamin A may co"nteract these effects.


16/65

1hemotherape"tic agents inhi#it 5o"n! healing. In patients 5ith neoplastic !isease$

chemotherape"tic agents sho"l! not #e "se! !"ring the first 5ee an! pro#a#ly also

!"ring the secon! an! thir! 5ees after operation. In #reast !isease$ the "se of -/

fl"oro"racil in the first postoperative 5ee res"lts in an increase! inci!ence of sin

!ehiscence an! !elaye! healing. A trial of -/fl"oro"racil in patients 5ith colon cancer$a!ministere! !"ring an! after operation$ ho5ever$ !i! not have a !eleterio"s effect on

5o"n! healing. Ra!iation is no5n to affect 5o"n! healing a!versely #eca"se of a

variety of factors$ incl"!ing interference 5ith normal protein synthesis$ mitosis$

migration of inflammatory factors$ an! mat"ration of collagen. Ra!iation therapy also

res"lts in o#literation of the small vasc"lat"re an! fi#rosis$ 5hich contri#"te to the

vicio"s cycle of local hypoperf"sion an! hypo4ia.


8ehiscence 5itho"t evisceration can #e !etecte! #y the classical appearance of

salmon/ colore! fl"i! !raining from the 5o"n!$ 5hich occ"rs in a#o"t :- percent of

cases a#o"t the fo"rth or fifth postoperative !ay. Cith the appearance of s"ch fl"i!$the patient sho"l! #e ret"rne! to the operating room an! the 5o"n! opene! "n!er

sterile con!itions. 8ehiscences may #ecome manifest 5hen sin s"t"res are remove!

an! evisceration of a#!ominal contents occ"rs. If evisceration occ"rs$ moist sterile

to5els are applie! to the e4tr"!e! intestines or oment"m an! the patient ret"rne! to

the operating room. 8ehiscence presents late as an incisional hernia.

Treatment

=anagement !epen!s on the patient3s con!ition. In some circ"mstances$ if there is no

evisceration$ it is prefera#le to treat the patient nonoperatively 5ith a sterile occl"sive

5o"n! !ressing an! #in!er$ accepting a postoperative hernia. Repair of !ehiscences

varies #"t generally involves a mass clos"re. There is little reason to attempt to re!o a

clos"re in 5hich s"t"res$ appropriately place! ) cm apart$ have p"lle! thro"gh.

Perioperative %prefera#ly #roa!/spectr"m& anti#iotics sho"l! #e given. The mortality

associate! 5ith 5o"n! !isr"ption has #een re!"ce! from over +7 percent to #elo5 )

percent. The inci!ence of reporte! postoperative hernia is inacc"rate #"t is pro#a#ly

over +7 percent.

1O=P?I1ATIODS OF T


17/65

"rinary retention( *) percent in the treate! gro"p$ compare! to - percent in the

control gro"p.

Another infl"ence on "rinary retention$ especially in ol!er patients$ is the vol"me of

inf"se! fl"i!. A minimal vol"me of fl"i! sho"l! #e inf"se! in sit"ations in 5hich

#loo! loss is liely to #e minimal an! the patient is not !ehy!rate!.

In "rinary retention$ patients e4perience "rgency$ !iscomfort$ an! f"llness$ an! an

enlarge! #la!!er can #e perc"sse! a#ove the p"#ic symphysis. Straight catheteri9ation

is "n!ertaen initially an! then "s"ally a secon! time. The #la!!er sho"l! not #e

allo5e! to !isten! #eyon! h$ #eca"se this 5ill impair the patient3s a#ility to voi!

5hen the catheter is remove!. If catheteri9ation is re'"ire! more than t5ice$ a Foley

catheter is place! an! left to !rain for at least * to 0 !ays.

Ac"te Renal Fail"re

Etiology

Ina!e'"ate Res"scitationIn the presence of hypotension$ catecholamine release an! norepinephrine stim"lation

#y the sympathetic nervo"s system !ecreases renal #loo! flo5. In a!!ition$ the renin/

angiotensin system is activate! 5ith sh"nting of #loo! a5ay from the afferent

arterioles$ !epriving the corte4 an! the t"#"les of #loo! flo5. A #asic !ict"m in the

care of emergency patients is ens"ring significant an! a!e'"ate "rine o"tp"t #efore

going to the operating room an!$ if there is time$ res"scitating s"ch patients. In the

el!erly$ it sho"l! #e remem#ere! that it is not rapi! rehy!ration or transf"sion$ #"t

overhy!ration an! overtransf"sion that are responsi#le for congestive fail"re. If there

is any '"estion in the s"rgeon3s min! a#o"t the patient3s vol"me stat"s #efore going to

the operating room$ a p"lmonary artery catheter sho"l! #e passe!$ the patient3s fl"i!

an! vol"me stat"s optimi9e!$ an! the operation !elaye! so that "rine o"tp"t is

a!e'"ate #efore general anesthesia is in!"ce!. In the presence of transf"sion reaction$

sepsis$ myocar!ial !ysf"nction$ or cr"sh in6"ry$ !i"resis sho"l! #e esta#lishe! "sing

mannitol an! f"rosemi!e %the latter given only 5hen vol"me stat"s is restore!&.

>icar#onate sho"l! also #e a!ministere! to alalini9e the "rine. Other ca"ses of ac"te

renal fail"re are liste! in Ta#le ))/)).

8r"g To4icity

A secon! important ca"se of ac"te renal fail"re in the s"rgical setting is the "se of

nephroto4ic !r"gs$ most commonly the aminoglycosi!es$ vancomycin$ amphotericin

>$ an! occasionally high !oses of penicillin 2 or s"lfonami!es. Pharmacoineticmonitoring is "se! to !etermine the minimal inhi#itory concentration in the plasma

re'"ire! for the organism in '"estion. Pharmacoinetic monitoring !oes not prevent

an! may not s"#stantially !ecrease vesti#"lar to4icity or the inci!ence of renal fail"re.

BD/to/creatinine ratio of *7() or greater.

This is commonly o#serve! 5ith !ehy!ration$ e.g.$ after a #o5el preparation orf"lminant !iarrhea$ or "n!erres"scitation of patients #efore or after an operative


18/65


19/65

Postrenal Fail"re

Postrenal fail"re is rare in the s"rgical setting #"t may res"lt from "reteral clots or

stones. 1hronic postrenal o#str"ction may res"lt from #enign prostatic hypertrophy.

Prolonge! Foley catheter int"#ation can res"lt in a posterior "rethral strict"re.

Prevention of Ac"te Renal Fail"re

For patients 5ith chronic "rinary tract infection$ specific anti#iotics selecte! on the

#asis of c"lt"res an! sensitivities sho"l! #e a!ministere! to era!icate the infection.

Patients 5ith chronic o#str"ction from #enign prostatic hypertrophy sho"l! #e treate!

5ith preemptive #alloon !ilatation or trans"rethral resection. In patients 5ith chronic

renal impairment$ saline loa!ing an! a!e'"ate !i"resis are esta#lishe! #efore general

anesthesia. A p"lmonary artery catheter is place! after the patient is a!e'"ately

hy!rate! an! so!i"m/containing fl"i!s a!ministere! "ntil a "rine o"tp"t of -7 to )77

m?@h is o#taine!. A patient 5ith ina!e'"ate "rine o"tp"t sho"l! not #e s"#6ecte! to

general anesthesia$ #eca"se ac"te t"#"lar necrosis can res"lt.

If an angiographic 5or"p is necessary$ it is #est performe! several !ays #efore the

operation so that if renal fail"re complicates the angiogram the effect is minimi9e!.

Bse of ra!iographic contrast agents has an inci!ence of renal fail"re of ) to )7

percent. In6"ry is !"e to !irect nephroto4ic effect an! hypovolemia from osmotic

!i"resis. Prest"!y hy!ration is partially protective. If possi#le$ anti#iotics that are not

nephroto4ic sho"l! #e "se!.

In lo5/flo5 states$ mannitol$ #icar#onate$ an! !i"resis in!"ce! #y f"rosemi!e sho"l!

#e "se!. =annitol is no5n to increase renal cortical #loo! flo5 an! pro!"ce an

osmotic !i"resis. It may protect the t"#"les #y preventing precipitation of meta#olites

5ithin them. Renal perf"sion may #e increase! #y a renal !ose !opamine of * to -

mg@g@min. If there is any '"estion concerning the vol"me stat"s$ central veno"s

press"re monitoring or$ prefera#ly$ monitoring of left/si!e! filling press"re 5ith a

p"lmonary artery catheter is appropriate.

=anifestations

Ac"te renal fail"re "s"ally presents in the postoperative perio! as olig"ria 5ith a "rine

o"tp"t of 7., to 7.- m?@g@h in an a!"lt. An"ria$ 5hile "ncommon$ as a manifestation

of ac"te t"#"lar necrosis pro#a#ly is the res"lt of renal artery throm#osis or

o#str"ctive "ropathy. The !iagnosis of ac"te t"#"lar necrosis is ma!e #y spot

meas"rement of "rinary so!i"m an! potassi"m levels an! osmolality. The fractionale4cretion of so!i"m %FEDa& is calc"late! "sing levels of so!i"m an! creatinine in the

"rine or plasma as follo5s(

FEDa BDa G V @ PDa G %B1r G V @ P1r& G )77H

5here(

BDa "rinary so!i"m

PDa plasma so!i"m

B1r "rinary creatinine


20/65

P1r plasma creatinine

V "rine vol"me in m?

An FEDa of greater than ) in!icates intrinsic renal !amage. =eas"rement of "rinaryspecific gravity may #e helpf"l in the a#sence of pigment or contrast "rinary specific

gravity in ac"te t"#"lar necrosis is appro4imately ).7)7. A "rinary so!i"m level of

less than )7 mE'@? in!icates a prerenal ca"se or intrinsic liver !isease. >BD an!

creatinine levels also are elevate!. In the case of renal fail"re$ t"#"lar cells an! casts$

re! #loo! cells$ an! 5hite #loo! cells on "rinalysis are !iagnostic. The "rinary so!i"m

level "s"ally is greater than ,7 mE'@?$ the potassi"m level is a#o"t the same fig"re$

osmolality is appro4imately #et5een +77 an! +-7$ an! the fractional secretion of

so!i"m is greater than +. The >BD/to/creatinine ratio is less than *7. The follo5ing

form"la may #e "se! to calc"late the creatinine clearance( 11r V G B1r@P1r$ 5here

V vol"me$ B1r "rinary creatinine$ an! P1r plasma creatinine.

=anagement

The management of renal fail"re can #e !ivi!e! into t5o perio!s$ the first 5hen the

!iagnosis is "ncertain$ an! the secon! 5hen the !iagnosis has #een ma!e. If the

patient is olig"ric an! tho"ght to #e hypovolemic$ a vol"me challenge is in or!er. If

the initial vol"me challenge res"lts in elevation of 6"g"lar nec veins$ sin t"rgor$ an!

eye#all !epth$ a p"lmonary artery catheter sho"l! #e place! to meas"re the patient3s

tr"e vol"me stat"s. Once a!e'"ate vol"me stat"s has #een esta#lishe!$ f"rosemi!e %*7

to ,7 mg& sho"l! #e given to improve "rine o"tp"t. =annitol can #e given to increase

renal cortical #loo! flo5$ provi!e! the patient is not vol"me overres"scitate!.

Ethacrynic aci! or a f"rosemi!e !rip can #e "se! to prevent renal fail"re an! perhaps

5ash o"t those t"#"les in 5hich "rine flo5 can #e reesta#lishe!. Renal !ose

!opamine also may #e "se! in con6"nction 5ith !i"retics #icar#onate is given in an

attempt to slightly alalini9e the patient. Any nephroto4ic !r"gs %see Ta#le ))/)*&

sho"l! #e stoppe! imme!iately.

=anagement of Esta#lishe! Renal Fail"re

Chen the patient has #een !iagnose! 5ith renal fail"re$ there are a n"m#er of goals(

%)& Avoi! overhy!ration$ 5hich res"lts in congestive heart fail"re an! the nee! for

hemofiltration or !ialysis.

%*& Avoi! !ialysis if possi#le.

%+& Avoi! to4ic ionic !amage$ s"ch as hyperalemia.

%,& Provi!e n"tritional s"pport.

The most imme!iate threat in many patients 5ith ac"te renal fail"re is hyperalemia.

Ser"m electrolyte levels sho"l! #e monitore! fre'"ently. Chen ser"m potassi"m level

reaches -.- mE'@ !?$ there is nee! for concern$ #eca"se rapi! rises to the point 5here

E12 changes occ"r can happen very '"icly. E12 changes incl"!e peae! T 5aves

5ith progression to a sin"s #ra!ycar!ia an! a sine 5ave rhythm$ 5ith hypotension an!!eath. 8eaths from hyperalemia are avoi!a#le. The emergency treatment of


21/65

hyperalemia incl"!es the inf"sion of calci"m$ hypertonic !e4trose sol"tion$ an!

ins"lin. Thereafter$ so!i"m polystyrene s"lfonate %Kaye4alate& - g as enema or #y

mo"th sho"l! #e a!ministere!. Inf"sion of hypertonic !e4trose sol"tion an! essential

amino aci!s in the form of total parenteral n"trition 5ill lo5er the ser"m potassi"m

level. A!ministration of fl"i!s sho"l! #e limite! to #elo5 meas"re! an! calc"late!

losses.

=aintenance of n"trition is an essential part of the treatment of patients 5ith ac"te

t"#"lar necrosis. D"trition can #e a!ministere! enterally or parenterally. Increase!

s"rvival in patients 5ith ac"te t"#"lar necrosis has #een !emonstrate! only 5ith

intraveno"s n"tritional s"pport. An intraveno"s 2ior!ano/2iovannetti !iet of

essential amino aci!s an! hypertonic !e4trose sol"tion$ 5ith a minim"m of fat$

!ecreases mortality in patients 5ith ac"te t"#"lar necrosis. The most significant

improvement is seen in the more severely affecte! patients 5ith complications an! in

those 5ith olig"ric renal fail"re re'"iring !ialysis. There is some$ #"t not statistically

significant$ improvement in patients 5ith non/olig"ric renal fail"re. D"tritional

s"pport may !elay the nee! for !ialysis or cell"lar filtration #eca"se it minimi9es thefree 5ater pro!"ce! #y m"sc"lar #rea!o5n. It is not clear 5hether semiessential

amino aci!s$ s"ch as arginine an! histi!ine$ sho"l! #e incl"!e! in this essential amino

aci! !iet. Chile it is tr"e that these amino aci!s may #ecome !eficient 5ith chronic

!ialysis$ plasma amino aci! patterns in patients 5ith ac"te renal fail"re !o not reveal

any evi!ence of amino aci! !eficiency.

8ialysis is "n!ertaen in patients 5ith ac"te renal fail"re for critical ionic e4cesses$

vol"me overloa!$ or a >BD concentration higher than :7 to )77 mg@!?. Vol"me

overloa! may #e prevente! #y contin"o"s hemofiltration. Bn!er most circ"mstances$

hemo!ialysis is the proce!"re of choice$ #"t chronic peritoneal !ialysis may #e

s"ccessf"l after the retroperitone"m is seale!.

8ialysis is not innoc"o"s it has an ann"al mortality of - to )7 percent. The

hypotension that "s"ally is seen at the termination of the !ialysis r"n$ 5hen patients

are !ehy!rate!$ can #e in6"rio"s to the i!neys. There is an a!vantage to !elaying

!ialysis "ntil patients are hemo!ynamically sta#le. Once patients are on chronic

!ialysis$ essential an! nonessential amino aci!s are given #y TPD or$ prefera#ly$

enterally.

RESPIRATORM 1O=P?I1ATIODS

PathophysiologyRespiratory complications are among the most common complications of s"rgery an!

the most lethal$ responsi#le for - to +- percent of postoperative !eaths. Bpper

a#!ominal an! thoracic incisions res"lt in a significant !ecrease in vital capacity an!

f"nctional resi!"al capacity$ most prominently in the first *, h after operation. After

"pper a#!ominal s"rgery$ vital capacity may #e re!"ce! #y as m"ch as -7 to 7

percent$ 5hile f"nctional resi!"al capacity is re!"ce! #y appro4imately +7 percent.

The ca"se of these changes is m"ltifactorial. Postoperative pain alters the mechanics

of respiration "pper a#!ominal an! thoracic incisions have the greatest impact.

Darcotic analgesia carries it o5n inherent riss #eca"se it eliminates sighing an!

promotes atelectasis. Even if pain is eliminate! #y epi!"ral anesthesia$ there remains a

!emonstra#le !ecrease in vital capacity an! f"nctional resi!"al capacity$ ano#servation that has le! some to s"ggest !iaphragmatic !ysf"nction. 8iaphragmatic


22/65

inhi#ition can res"lt from inhi#itory refle4es arising from sympathetic$ vagal$ or

a#!ominal receptors.

1losing vol"me %l"ng vol"me at 5hich air5ay clos"re is first !etecta#le& !ecreases in

the postoperative perio!. ?oss of f"nctional resi!"al capacity$ elimination of sighing

%#y narcotic analgesics&$ an! the change to a postoperative #reathing pattern of smallfre'"ent #reaths com#ine to lo5er the en!/ti!al point to a level that falls #elo5

closing vol"me. This res"lts in a rapi! loss of alveolar vol"me an! s"#se'"ent

alveolar collapse. This pre!ilection is accent"ate! in smoers$ 5ho characteristically

have a higher closing vol"me as a res"lt of their !isease! air5ays.

In a!!ition to altere! mechanics an! !ecrease! closing vol"me$ other physiologic

ca"ses that contri#"te to respiratory ins"fficiency incl"!e !iff"sion !efects$

a#normalities in the ventilation/perf"sion ratio$ re!"ction in car!iac o"tp"t 5ith

concomitant persistent sh"nt$ alterations in the hemoglo#in level an! persistent sh"nt$

an! sh"nting that is anatomic or relate! to atelectasis.

=eas"rements of ventilation an! o4ygenation have #een applie! to assess the

pathophysiologic events. Ventilatory mechanics are eval"ate! #y meas"ring the

ventilatory rate$ the vital capacity %V1&$ total vol"me %VT&$ an! !ea! space %V8&.

V8@VT$ 5hich also is infl"ence! #y car!iac o"tp"t$ is "se! to assess 1O* elimination.

1ompliance is a meas"rement of the !istensi#ility of the l"ng.

The partial press"re of 1O* in arterial #loo! %Pa1O *& can #e consi!ere! as a

reciprocal f"nction of ventilation an! is normally ,7 mm


23/65

Smoing

The s"rgeon sho"l! !isting"ish chronic parenchymal l"ng changes from the short/

term$ potentially reversi#le effects. Patients 5ho smoe are enco"rage! to stop #efore

their operation. A patient m"st a#stain from smoing for at least : 5ees to achieve

any !emonstra#le #enefit. Patients 5ho have stoppe! smoing for more than : 5ees

#efore s"rgery have as lo5 a ris of p"lmonary complications as patients 5ho havenever smoe!. ?ess than *7 percent of patients 5ho are re'"este! to stop smoing

preoperatively act"ally are a#le to !o so.

Age

It is !iffic"lt to !etermine the ris attri#"ta#le to age in!epen!ent of the associate!

changes that accompany the aging process. A!vance! age alone sho"l! not govern the

!ecision for or against s"rgery. Overall poor physical stat"s$ rather than a!vance! age$

is the most important ris factor in !etermining perioperative respiratory

complications.

O#esityThe pre!ilection for !evelopment of postoperative respiratory complications in o#ese

patients is relate! to the "n!erlying p"lmonary !ysf"nction characteristic of this

patient pop"lation. Patients 5ho e4cee! their i!eal #o!y 5eight #y more than +7

percent have a !emonstra#le !ecline in their f"nctional resi!"al capacity$ 5hich is the

res"lt of a re!"ction in chest 5all compliance. This intrinsic loss of f"nctional resi!"al

capacity$ 5hen com#ine! 5ith s"pine positioning$ ren!ers the o#ese patient

partic"larly prone to hypoventilation an! hypo4emia in the postoperative perio!.

1hronic O#str"ctive P"lmonary 8isease %1OP8&

Patients 5ith pree4isting p"lmonary !isease are at increase! ris of postoperative

complications. P"lmonary f"nction tests provi!e a means to '"antify o#6ectively

e4isting p"lmonary a#normalities. Specific fin!ings on p"lmonary f"nction tests that

sho"l! alert the s"rgeon incl"!e a#normalities in FEV )$ force! vital capacity %FV1&$

pea e4piratory flo5 rate$ an! FEV)@FV1 ratio %see Ta#le ))/*&.

In patients 5ith recogni9e! 1OP8$ the s"rgeon m"st plan to improve the lielihoo! of

a s"ccessf"l o"tcome. This incl"!es caref"l planning of the incision$ "se of local

anesthetic agents$ caref"l clos"re of the 5o"n!$ placement of gastrostomy t"#e$ an!

postoperative p"lmonary toilet techni'"es. A transverse incision is prefera#le to a

vertical incision. Bse of local anesthetics s"ch as li!ocaine or #"pivacaine !ecreases

intraoperative an! postoperative incisional pain. In selecte! patients it is possi#le toplace a small catheter for contin"o"s inf"sion of li!ocaine in the intram"sc"lar layers

of the incision to ren!er the incision anesthetic. This simple mane"ver may

significantly improve a patient3s p"lmonary f"nction. Co"n! clos"re in the patient

5ith 1OP8 sho"l! emphasi9e a sec"re clos"re 5ith minimal postoperative pain$ s"ch

as a s"#c"tic"lar clos"re. Pain control$ s"ch as the "se of an epi!"ral catheter$ is a

significant improvement. In the a#sence of a postoperative epi!"ral catheter$ patient/

controlle! analgesic !evices res"lt in fe5er respiratory complications. A gastrostomy

%rather than a nasogastric& t"#e is "sef"l in patients 5ith 1OP8$ as m"ltiple st"!ies

have sho5n that a nasogastric t"#e in the postoperative perio! is the one clinical

factor associate! 5ith a statistically increase! inci!ence of respiratory complications.

1ar!iac 8isease


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The most o#vio"s e4ample of car!iac !isease complicating postoperative respiratory

f"nction is congestive heart fail"re 5ith accompanying p"lmonary e!ema. Patients

5ith 6"g"lar veno"s !istention$ a thir! heart so"n!$ or previo"s history of p"lmonary

e!ema are most liely to !evelop this complication. Patients 5ith significant car!iac

!ysf"nction an! s"rgical patients 5ho receive large amo"nts of fl"i!s !"ring their

res"scitation sho"l! #e o#serve! closely for the !evelopment of p"lmonary e!ema inthe postoperative perio!.

Atelectasis

Atelectasis$ the collapse of alveoli 5ith ongoing perf"sion$ is the res"lt of changes in

the normal !ynamics of p"lmonary f"nction res"lting from anesthesia$ !iaphragmatic

!ysf"nction$ postoperative incisional pain$ an! patient positioning. Emphasis sho"l!

#e on prevention rather than treatment. Atelectasis res"lts in a percepti#le increase in

sh"nt fraction. Once collapse!$ the alveol"s is !iffic"lt to rerecr"it. This may #e !"e

to the loss of s"rfactant #"t also is a physical property #eca"se of the s"rface tension

consi!erations of the p"lmonary parenchyma. Secretions may acc"m"late in the

collapse! alveol"s$ 5ith potential #acterial overgro5th.

?"ng inflation in the postoperative perio! prevents an! reverses atelectasis. The most

fre'"ently "se! techni'"es incl"!e co"ghing an! !eep #reathing %18>&$ chest

perc"ssion an! post"ral !rainage %1PP8&$ incentive spirometry$ intermittent positive

press"re #reathing %IPP>&$ an! contin"o"s positive air5ay press"re %1PAP&. Each

techni'"e employs a !ifferent metho! to achieve the same goal of l"ng inflation.

Vario"s st"!ies s"pport the "se of any of these techni'"es as s"perior to no

postoperative therapy. The techni'"es of co"ghing$ !eep #reathing$ an! incentive

spirometry are ine4pensive an! not la#or/intensive. 1PP8$ IPP>$ an! 1PAP re'"ire

significant la#or$ machinery$ or a com#ination of #oth. Patients 5ho are at lo5 ris

for the !evelopment of respiratory complications$ s"ch as those "n!ergoing a lo5er

a#!ominal incision or e4tremity s"rgery$ pro#a#ly !o not re'"ire specific therape"tic

interventions. For patients 5ho have mo!erate ris of !eveloping perioperative

respiratory complications$ co"ghing an! !eep #reathing or the "se of incentive

spirometry "s"ally 5ill s"ffice.

Three gro"ps of me!ications have #een applie! to the prophyla4is an! therapy of

atelectasis( %)& e4pectorants$ to provi!e more li'"i! an! less visco"s secretions$ %*&

!etergents an! m"colytic sol"tions$ to alter the s"rface tension of secretions an!

ren!er their elimination more liely$ an! %+& #roncho!ilators$ "se! primarily #y

inhalation$ to increase the si9e of the tracheo#ronchial tree an! eliminate#ronchospasm. The m"colytic agents$ s"ch as ="comist or Alevaire$ are in!icate!

#eca"se inhale! air 5ith a relative h"mi!ity lo5er than 07 percent inhi#its ciliary

activity an! ten!s to !esiccate secretions.

Pne"monitis

Pne"monitis is a nosocomial infection seen 5ith increasing inci!ence on s"rgical

services. Chile pne"monitis is the thir! most common nosocomial infection %after

5o"n! an! "rinary tract infections&$ it is associate! 5ith the highest mor#i!ity an!

mortality. The organisms involve! are po5erf"l pathogens an! incl"!e Pse"!omonas$

Serratia$ Kle#siella$ Prote"s$ Entero#acter$ an! Streptococc"s. There is an emerging

pre!ominance of gram/ negative organisms$ partic"larly in patients in intensive care"nits. This may #e a reflection of the 5i!esprea! "se of


25/65

therapy. Bse of these agents res"lts in #rea!o5n of the aci! #arrier$ allo5ing

overgro5th an! coloni9ation of the stomach #y intestinal flora. This sit"ation is

f"rther aggravate! #y the placement of a nasogastric t"#e an! the "se of s"pine

positioning in the postoperative perio!. F"ngal pne"monia is "ncommon$ #"t 5ith the

increasing "se of ever #roa!er spectr"m anti#iotic regimens$ the emergence of this

pathogen in the f"t"re is liely.


Patients 5ith pne"monia manifest fever$ pro!"ctive co"gh$ !yspnea$ ple"ritic chest

pain$ an! a p"r"lent sp"t"m. >loo!staine! sp"t"m is rare #"t may #e e4acer#ate! #y

repeate! s"ctioning attempts. =o!erate hypo4emia is common$ #"t severe hypo4emia

is "n"s"al "nless the pne"monia is severe an! 5i!esprea!. The presence of

hypotension "s"ally in!icates a gram/negative pne"monia. A"sc"ltation reveals

#ronchial #reathing$ areas of !"llness to perc"ssion$ an! the presence of rales.

=anagement

=anagement !epen!s on correctly i!entifying the responsi#le organism. The propertechni'"e for o#taining an a!e'"ate respiratory specimen for the !iagnosis of

pne"monia is controversial. In the int"#ate! patient$ there is increasing emphasis on

o#taining a #ronchoscopic/g"i!e! alveolar lavage specimen or the "se of a protecte!/

#r"sh catheter techni'"e. ="ltiple st"!ies in patients 5ho are int"#ate! have

!emonstrate! that c"lt"res o#taine! via ro"tine en!otracheal s"ctioning have little

pre!ictive #enefit in correctly i!entifying the pathogen responsi#le for nosocomial

pne"monia. 2iven the increasing inci!ence of gram/negative nosocomial infections in

the intensive care setting$ anti#iotic therapy 5ith an aminoglycosi!e an! an

antipse"!omonal penicillin sho"l! #e initiate! 5hen the !iagnosis is ma!e. Anti#iotic

"sage m"st #e eval"ate! 5ith c"lt"re res"lts an! mo!ifie! if necessary.

Aspiration

Aspiration can #e a cataclysmic$ instantaneo"sly lethal event associate! 5ith large

amo"nts of partic"late/la!en aci! contents "nless e4pe!itio"sly manage! #y s"ction$

lavage of the respiratory tree$ protection of the air5ay 5ith an en!otracheal t"#e$ an!

contin"e! p"lmonary toilet "ntil all partic"late matter has #een remove! from the

tracheo#ronchial tree. The "se of steroi!s to ameliorate the progression of the clinical

syn!rome of aspiration has #een !emonstrate! to #e effective only 5hen they have

#een given #efore the aspiration event. The most liely setting of massive aspiration is

!"ring the emergency in!"ction of anesthesia$ partic"larly in patients 5ith

gastroesophageal refl"4 or a hiatal hernia. It is commonly ass"me! that a nasogastrict"#e prevents aspiration$ #"t this is not al5ays the case. If a nasogastric t"#e is

improperly positione! or maintaine!$ its presence may facilitate rather than prevent

aspiration.


The clinical se'"elae of aspiration "s"ally are not s"#tle$ 5ith the presence of gastric

contents in the mo"th follo5e! #y 5hee9ing$ hypo4ia$ #ronchorrhea$ an! cyanosis. In

the conscio"s patient$ co"gh pro!"ctive of partic"late matter may #e present. In the

"nconscio"s patient$ aspiration may present as a ma6or air5ay o#str"ction. S"ctioning

reveals gastric aspirate in the oropharyn4 an! trachea. If aspiration is "ntreate!$ or if it

is significant in vol"me$ the res"lts resem#le that of a p"lmonary #"rn$ 5ith e!ema$5hee9ing$ cyanosis$ an! tachycar!ia. 1hest ra!iographs !emonstrate progression of


26/65

local !amage an! infiltration. Ac"te respiratory fail"re res"lts. In over -7 percent of

patients 5ho s"ffer aspiration$ the initial chemical pne"monitis res"lts in #acterial

coloni9ation 5ith s"#se'"ent !evelopment of pne"monia.

=anagement

The only effective treatment of aspiration is prevention #y emptying the stomach an!ne"trali9ation of gastric contents. Evi!ence has s"ggeste! that ne"trali9ation strategies

that "se histamine roncho!ilating agents may help in relieving o#str"ction in those

patients 5ith a"!i#le 5hee9ing from reactive air5ay response. Positive/press"re

ventilation %PPV& an! positive en!/ e4piratory press"re %PEEP& are often necessary$

an! a p"lmonary artery catheter is "sef"l in !etermining vol"me stat"s.

P"lmonary E!ema

P"lmonary e!ema res"lts 5hen p"lmonary/capillary hy!rostatic press"re e4cee!s

plasma oncotic press"re. The res"lt of this im#alance is fl"i! trans"!ation into the

alveol"s. The most common ca"ses of p"lmonary e!ema in the s"rgical patient are

fl"i! overloa! or myocar!ial ins"fficiency secon!ary to myocar!ial

infarction@ischemia. A!!itional ca"ses of p"lmonary e!ema incl"!e sepsis$ valv"lar

!ysf"nction$ ne"rogenic stim"lation$ an! hepatic fail"re.

Increase! capillary permea#ility also can res"lt in a trans"!ation of fl"i! into the

alveol"s. 1ommon ca"ses of increase! capillary permea#ility incl"!e sepsis$ ac"te

respiratory !istress syn!rome %AR8S&$ an! ac"te pancreatitis.


There are t5o pea phases of occ"rrence of p"lmonary e!ema in the s"rgical patient.

The first occ"rs !"ring res"scitation. If res"scitation is too aggressive or overreplaces

intravasc"lar vol"me$ p"lmonary e!ema may res"lt. The secon! pea inci!ence of

p"lmonary e!ema is in the postoperative perio! 5hen fl"i! mo#ili9ation occ"rs. If the

patient3s car!iovasc"lar an! renal systems !o not maintain an a!e'"ate pace to off/

loa! the mo#ili9e! fl"i!$ p"lmonary e!ema may res"lt$ partic"larly in the el!erly

patient. Chen vol"me stat"s is in !o"#t$ placement of a p"lmonary artery catheter is

val"a#le #eca"se it allo5s for a!e'"ate estimation of vasc"lar vol"me an! of en!points of res"scitation$ an! it ai!s in the phase of fl"i! mo#ili9ation.

The patient 5ith p"lmonary e!ema manifests !yspnea at rest$ tachypnea$ an! air

h"nger. In the el!erly or imm"nocompromise! patient$ changes in mental stat"s$

incl"!ing lethargy an! !isorientation$ may occ"r. Chee9ing an! signs of

#ronchospasm may #e a"!i#le. In a!!ition$ rales that often are "p to the clavicles on

posterior a"sc"ltation$ !isten!e! nec veins$ cyanosis$ an! peripheral pitting e!ema

may #e present. 1hest ra!iographs may reveal progression of p"lmonary e!ema$

vasc"lar prominence$ septal lines %Kerley3s > lines&$ an! peri#ronchial an!

perivasc"lar c"ffing.

=anagement


27/65

=anagement !epen!s on the inciting ca"se. For patients 5ith a vol"me overloa!$

simple therapy incl"!ing o4ygen an! !igitali9ation can significantly improve the

clinical con!ition. In most instances$ the placement of a p"lmonary artery catheter

significantly ai!s in the !iagnosis an! management. The initial fin!ings reveal an

elevate! p"lmonary artery occl"sion press"re in the range of ): to *- mm


28/65

The release of marro5 s"#stance an! fat from the !amage! marro5 allo5s the

intravasc"lar passage of these s"#stances to the p"lmonary/capillary #e!. Fat em#oli

recovere! from the l"ngs of patients 5ho !ie! 5ith fat em#olism presente! a lipi!

profile similar to that of fat in #one marro5. Posttra"matic lipemia$ the coalescence of

chylomicra$ an! other meta#olic !erangements are also consi!ere! ca"ses of the fat

em#olism syn!rome.

?arge em#oli may ca"se mechanical o#str"ction of the ma6or an! secon!ary

p"lmonary vessels. =o!alities that increase the activity of lipoprotein lipase$ releasing

free fatty aci!s$ 5hich are tho"ght to #e a to4in$ ca"se a more e4plosive an! !amaging

syn!rome. The pathophysiologic agent is pro#a#ly a s"#stance s"ch as oleic aci!$

5hich has serve! as the classic mo!el for the pro!"ction of ac"te respiratory !istress

syn!rome in the la#oratory. Other researchers have s"ggeste! that once fat em#oli are

lo!ge! in the p"lmonary vasc"lat"re$ they are coate! 5ith platelets that s"#se'"ently

lyse$ releasing inin/lie s"#stances an! vasoactive s"#stances$ s"ch as serotonin.

It is more !iffic"lt to e4plain the fin!ings s"ch as petechia an! lesions in the #rain inthese patients given the filtering f"nction of the p"lmonary/ capillary #e!. Other

e4planations to reconcile these fin!ings incl"!e coalescence of the chylomicra that

give rise to the fat em#olism syn!rome$ or #ypassing the p"lmonary filter in

precapillary sh"nts that have opene! #eca"se of increase! p"lmonary artery press"re.

Since the histologic feat"res of the cere#ral lesions consist of petechial hemorrhages

of the cortical 5hite matter$ #rainstem$ an! spinal cor!$ these 5ill #e self/limite! an!

are reversi#le provi!e! the patient can #e s"pporte! !"ring this perio!.


Bp to 0- percent of patients 5ith fat em#olism syn!rome manifest some !egree of

respiratory ins"fficiency. This "s"ally occ"rs soon after the in6"ry #"t occasionally as

long as ,: to 0* h after5ar!. 1hest ra!iographic fin!ings incl"!e characteristic

#ilateral alveolar infiltrates. The syn!rome may evolve into ac"te respiratory !istress

syn!rome$ an! a minority of patients re'"ire int"#ation an! respiratory s"pport.

1entral nervo"s system %1DS& involvement occ"rs in the ma6ority %as many as :

percent& of these patients #"t !oes not !evelop in the a#sence of p"lmonary

a#normalities. De"rologic impairment may prece!e the p"lmonary fin!ings #y to )*

h. The most common ne"rologic presenting symptoms incl"!e conf"sion an!

!isorientation 5ith event"al progression to coma.


29/65


30/65

Etiology an! Pathophysiology

Attention has foc"se! on the concept of an a#normal cytoine response to in6"ry.

Chat is not esta#lishe! is 5hether the e4tent or components of this response are

a#normal. Important components of this a#normal response incl"!e some activation

of the complement casca!e$ activation of the throm#o4ane/le"otriene path5ay$

!isor!ers in nitric o4i!e pro!"ction$ !egran"lation of ne"trophils$ an! pro!"ction ofincrease! permea#ility factors #y macrophages. All of these vario"s factors have #een

implicate! in the res"ltant trans"!ation of fl"i! an! reactive materials that are the

hallmar of the alveolar floo!ing that characteri9es AR8S.

The signat"re of AR8S is a ventilation@perf"sion mismatch. Alveolar hypoventilation

occ"rs #eca"se of collapse$ e4pansion of the alveolar mem#rane$ or presence of

e4"!ate an! fl"i! 5ithin the alveolar spaces that are still availa#le for perf"sion. This

alveolar #loc$ 5hen com#ine! 5ith changes in perf"sion relationships$ res"lts in

the increase! hypo4emia manifeste! as a sh"nt as 5ell as increase! !ea! space. Sh"nt

fraction$ a reflection of the magnit"!e of ventilation@perf"sion a#normality$ is

calc"late! #y the form"la 1c / 1a@1c / 1v$ 5here 1c is p"lmonary capillary O*content$ 1a is arterial O*content$ an! 1v is mi4e! veno"s O*content. Bn!er normal

circ"mstances$ less than - percent of the #loo! flo5 across the p"lmonary #e! is a

sh"nt fraction. In severe cases of AR8S$ this sh"nt fraction can e4cee! ,7 percent.

The classic ra!iographic appearance of 5hiteo"t on chest ra!iograph implies a

"niform l"ng in6"ry in AR8S. 1omp"te! tomography %1T& scans have !emonstrate!

that this concept is mislea!ing. 1T scans of a patient 5ith significant AR8S

characteristically !emonstrate regional changes in l"ng f"nction an! normal areas of

l"ng intersperse! 5ith mare!ly !isease! portions of l"ng. 8epen!ent l"ng regions

s"ffer the most significant consoli!ation$ 5hile the non!epen!ent regions remain air/

fille!. The s"ggestion is that in some areas regional l"ng compliance is not re!"ce!

!"ring AR8S #"t that l"ng vol"me is !rastically !iminishe!.

A ne5ly !escri#e! concept of ventilator l"ng in6"ry has #een terme! vol"tra"ma.

Vol"tra"ma is !ifferent from #arotra"ma an! refers to the mal!istri#"tion of inspire!

ti!al vol"me secon!ary to positive/press"re ventilation an! the heterogeneo"s nat"re

of l"ng in6"ry in AR8S. >arotra"ma is simply e4tra alveolar air. Vol"tra"ma !oes not

res"lt in !issection of air from the alveol"s #"t rather is characteri9e! #y !irect tiss"e

!amage at the alveolar@capillary interface.

The mechanism of in6"ry in vol"tra"ma is tho"ght to #e over!istention or stretchingof the alveol"s #eyon! its normal ma4im"m. This over!istention res"lts in capillary

fract"re an! parenchymal inflammation. This initial overstretching may #e the

primary ins"lt$ 5hich res"lts in a casca!e of in6"ry lea!ing to increase! capillary

permea#ility an! c"lminating in hypo4emia. The tra!itional therapy for AR8S may

lea! to a clinical syn!rome that act"ally resem#les AR8S. The heterogeneo"s nat"re

of AR8S promotes the mal!istri#"tion of !elivere! ti!al vol"me s"ch that the

ma6ority of ventilation an! press"re is transmitte! to normal alveolar "nits rather

than to the !isease! areas of the l"ng. >ase! on the relationship of normal l"ng

vol"me an! transp"lmonary press"re$ the ma4im"m alveolar press"re sho"l! remain

less than +- cm


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1"rrent mechanical ventilation strategies have emphasi9e! the nee! to re!"ce

vol"tra"ma. These incl"!e( %)& early "se of PEEP a!6"ste! to the inflection point$ %*&

press"re/limite! ventilation 5ith platea" press"res less than +- cm


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prospective ran!omi9e! trials comparing the mor#i!ity$ mortality$ ventilator !ays$ an!

length of stay in the intensive care "nit for patients manage! 5ith permissive

hypercapnia vers"s tra!itional strategies in AR8S have provi!e! s"ggestive$ #"t not

"ne'"ivocal$ evi!ence of its #enefits.

In the 5eaning process$ the first priority is to re!"ce the FIO * to less than 7.- toavoi! maintaining the collapse of the alveoli. De4t$ the n"m#er of intermittent

man!atory ventilation %I=V& #reaths sho"l! #e !ecrease! to a level that permits a

normal p< an! a Pa1O * of +- to ,- mmeca"se

perfl"#ron is immisci#le 5ith most s"#stances$ it facilitates removal of cell"lar !e#ris

an! m"c"s.

1AR8IA1 1O=P?I1ATIODS

=yocar!ial Infarction

Perioperative myocar!ial infarction %=I& pro#a#ly is the lea!ing ca"se of !eath in the

el!erly after noncar!iac s"rgery. =ortality from perioperative =I ranges from -,

percent to : percent :7 percent of the !eaths occ"r 5ithin ,: h of operation. This is

s"rprising$ consi!ering that the mortality rate for ac"te =I 5itho"t shoc$"nassociate! 5ith operation$ is appro4imately )* percent.

The presence of coronary artery !isease increases the inci!ence of perioperative =I

from the control level of 7.) to 7.0 percent to ).) percent after operation. In patients

over ,7 years of age$ 5ith or 5itho"t coronary artery !isease$ the infarction rate is ).:

percent. In patients 5ith previo"s =I$ the reinfarction rate ranges from - to : percent.

The most important varia#le in a patient 5ith a previo"s =I is the time that has

elapse! since that =I. For patients 5ho are operate! on 5ithin + months the

reinfarction rate is *0 percent$ #et5een + to months the rate is )) percent$ an! after

months the reinfarction rate sta#ili9es at - percent.

I!entification of the Patient at Ris


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The most 5i!ely "se! criteria an! comp"tation for the m"ltifactorial in!e4 score to

estimate car!iac ris in noncar!iac s"rgery is that originally p"#lishe! #y 2ol!man

%see Ta#le ))/)&. In!ications on physical e4amination incl"!e 6"g"lar/veno"s

!istention an! an S+ gallop$ more than -@min premat"re ventric"lar #eats$ rhythm

other than sin"s$ age over 07 years$ an! transm"ral or s"#en!ocar!ial infarction in the

previo"s months. Emergency operation$ intrathoracic$ intraperitoneal$ or aortic sitesof s"rgery$ evi!ence for important valv"lar aortic stenosis$ an! poor general me!ical

con!ition also are in!icators. On the #asis of the comp"tational score$ patients 5ith

more than *- points %1lass IV$ the highest/ ris class& have a mortality rate from

car!iac ca"ses of - percent an! a mor#i!ity rate of ** percent 5ith life/threatening$

nonfatal car!iac complications.

The history is important in eval"ating the ris of myocar!ial infarction. A history of

!yspnea on e4ertion$ orthopnea$ paro4ysmal noct"rnal !yspnea$ peripheral e!ema$

an! partic"larly angina pectoris %especially at rest& sho"l! lea! the s"rgeon to o#tain a

more !etaile! history an! a car!iac eval"ation. A preoperative e6ection fraction of less

than 7.+- !etermine! #y ra!ion"cli!e imaging an! ventric"lography is associate! 5itha 0- to :- percent inci!ence of perioperative =I$ compare! to a *7 percent inci!ence

in patients 5ith an e6ection fraction greater than 7.+-.


=ost cases of perioperative =I occ"r on the operative !ay or !"ring the first +

postoperative !ays. Altho"gh infarction has #een associate! 5ith all anesthetics$ the

inci!ence is higher after general anesthesia for a#!ominal or pelvic s"rgical treatment.

The most important precipitating factor is shoc$ either !"ring the operation or in the

early postoperative phase. The more prolonge! the shoc$ the greater the ris of

coronary throm#osis an! myocar!ial ischemia. The E12 may sho5 ST !epression

an! T/5ave flattening 5ith the loss of as little as -77 m? of #loo! in patients 5ith

previo"s coronary occl"sion.

8iagnosis can #e !iffic"lt #eca"se chest pain often is a#sent or o#sc"re! #y narcotics.

1hest pain occ"rs as a primary manifestation in only *0 percent of patients$ 5hich is

less than the 0 percent generally reporte! in patients in 5hom a coronary occl"sion is

not relate! to s"rgery. It is appropriate to consi!er ro"tinely monitoring patients 5ith

previo"s infarction in an intensive care "nit. The s"!!en appearance of shoc$

!yspnea$ cyanosis$ tachycar!ia$ arrhythmia$ or congestive fail"re sho"l! #e an

in!ication of the !iagnosis. 8yspnea$ cyanosis$ an! arterial hypotension re'"ire a

!ifferential !iagnosis #et5een car!iac an! respiratory pro#lems. The E12 mayprovi!e the !iagnosis 5ith a characteristic infarction pattern$ #"t this is not an

"ne'"ivocal fin!ing. In ol!er patients$ ST/segment an! T/ 5ave changes may #e

associate! 5ith myocar!ial ischemia$ an! the same changes may #e o#serve! 5ith

postoperative shoc. A st"!y of arterial gases may provi!e a !ifferential !iagnosis of

respiratory pro#lems. ?eft ventric"lar fail"re 5ith p"lmonary e!ema generally is not

accompanie! #y car#on !io4i!e retention$ an!$ in contrast to air5ay o#str"ction an!

alveolar hypoventilation$ there "s"ally is a re!"ction in arterial 1O*tension an!

respiratory alalosis 5hen car!iac fail"re accompanies =I. The 1PK/ => isoen9yme

is the most precise metho! for !etection of myocar!ial necrosis after operation. If =I

is s"specte!$ serial st"!ies$ incl"!ing E12 an! meas"rements of aspartate

transaminase %S2OT& an! 1PK/=>$ sho"l! #e !one !aily. Isotope scanning of themyocar!i"m "sing techneti"m pyrophosphate may !etect a recent ac"te infarction.


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=anagement

Preoperative preparation of patients 5ith signs of car!iac ins"fficiency sho"l! incl"!e

!igitali9ation for patients 5ith enlarge! hearts or histories of previo"s car!iac fail"re.

Ro"tine !igitali9ation is not in!icate!. Anemia$ if present$ re'"ires treatment$ an!

attention sho"l! #e !irecte! to5ar! the reg"lation of fl"i! an! electrolyte #alance an!hypovolemia. Patients on propranolol sho"l! contin"e to receive the !r"g "ntil the

morning of the operation. Operation is contrain!icate! for a perio! of at least +

months$ an! prefera#ly months$ after myocar!ial ischemia or infarction$ e4cept in

an emergency. 8"ring the operation$ a #roa! array of factors precipitating =I sho"l!

#e avoi!e!. These incl"!e hypo4ia$ hypotension$ hemorrhage$ !ehy!ration$ electrolyte

!ist"r#ance$ an! arrhythmias. The reg"lation of #loo! press"re !"ring anesthesia

pro#a#ly is the most important meas"re in the prevention of myocar!ial ischemia an!

infarction. Chen #loo! press"re falls significantly in the a#sence of #loo! loss$ the

prompt correction of hypo4ia #y a!e'"ate ventilation 5ith o4ygen an! the

a!ministration of vasopressors is in!icate!. 8igitali9ation may #e re'"ire! 5hen

shoc is com#ine! 5ith heart fail"re. The a!ministration of #loo! or fl"i! is in!icate!to maintain #loo! vol"me.

Treatment of =I itself consists of relief of pain an! an4iety "sing morphine an!

se!ation. Relief of hypo4ia is accomplishe! 5ith ++ to -7 percent o4ygen !elivere!

via a mas or nasal catheter. S"ctioning of the tracheo#ronchial tree may #e re'"ire!

to clear o#str"cting secretions. 1ritically ill patients are #est manage! in an intensive

care setting 5ith invasive monitoring "sing arterial lines an! a p"lmonary artery

catheter. Shoc is treate! #y vasopressor agents. Promptness in instit"ting vasopressor

therapy increases the chance of its effectiveness. Rapi! !igitali9ation is applica#le in

the treatment of shoc 5hen the myocar!ial ins"fficiency may #e responsi#le for the

severe hypotension. 8igitali9ation also is in!icate! for the treatment of heart fail"re$

5hich is a fre'"ent manifestation of postoperative =I. In a!!ition to !igitali9ation$

parenteral !i"retic therapy may #e "se! in the treatment of car!iac fail"re. Some have

a!vocate! the "se of anticoag"lant therapy after the !anger of e4cessive #lee!ing

from an operative site has passe!. Chen ac"te =I is !etecte!$ early emergency

car!iac catheteri9ation$ angioplasty$ or stenting may reverse an evolving =I. Rarely$

emergency coronary artery #ypass s"rgery may #e in!icate!.

Arrhythmias

If arrhythmia is !efine! as a se'"ence of a#normal #eats s"staine! for more than +7 s$

an overall inci!ence of 0+ percent of intraoperative car!iac arrhythmias has #eenreporte! in one series an! * percent in another. The inci!ence 5as higher in

int"#ate! patients an! in patients 5ho ha! "n!ergone ne"ros"rgical an! thoracic

proce!"res. T5enty/one percent 5ere ventric"lar in origin. In another st"!y$ :,

percent of patients e4perience! significant arrhythmias. The ma6ority 5ere associate!

5ith the int"#ation an! e4t"#ation phase of anesthesia. Of these$ ,+ percent 5ere

ventric"lar arrhythmias. Once anesthesia is over$ the inci!ence of arrhythmias in

noncar!iac s"rgery is appro4imately *., percent$ an! the ma6ority of patients are

asymptomatic.

Sin"s tachycar!ia$ not an arrhythmia$ is #y far the most common !ist"r#ance in

rhythm$ follo5e! #y premat"re ventric"lar contractions an! sinoatrial arrhythmia$


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5hich can #e a normal variant. >ra!ycar!ia an! trigeminy also have #een reporte! in

a significant n"m#er of patients.

Cith car!iac proce!"res$ the inci!ence of arrhythmias is appro4imately -7 percent$

5hile thoracic proce!"res have an inci!ence of *7 to +7 percent. Pne"monectomy has

#een associate! 5ith an arrhythmia rate of +7 to ,7 percent$ lea!ing to the practice of!igitali9ing the patient #efore pne"monectomy. In one report$ the inci!ence of

s"praventric"lar tachycar!ias$ incl"!ing s"praventric"lar tachycar!ia$ atrial fl"tter$

an! fi#rillation$ after pne"monectomy 5as ** percent. Of these$ more than half

occ"rre! 5ithin the first 0* h of operation$ an! one/thir! occ"rre! on the first

postoperative !ay.

Etiology

The ca"ses of arrhythmia incl"!e intrinsic car!iac !isease$ perioperative release of

catecholamines #eca"se of stress or pain$ an! organ manip"lation that stim"lates a

refle4 response.

Electrolyte A#normalities an! =eta#olic 8ist"r#ances


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Appro4imately ++ percent of patients 5ith preoperative arrhythmias "n!ergoing

peripheral vasc"lar s"rgery !evelop car!iac complications$ as compare! 5ith

percent of the patients 5ith normal sin"s rhythm. Chen the preoperative eval"ation is

accomplishe! 5ith E12$ rhythm strip$ an!$ if necessary$ *,/h contin"o"s


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heart rate of more than )77 #eats@min&$ hemo!ynamic insta#ility may res"lt$

especially 5hen ventric"lar response rates of )+7 to ),7 #eats@min are achieve!.

Sin"s Tachycar!ia

Sin"s tachycar!ia is not a !ysrhythmia #"t may #e mistaen for one an! can ca"se

alarm 5hen the heart rate is mare!ly elevate!. Sin"s tachycar!ia "s"ally s"ggestssympathetic stim"lation #y a variety of con!itions$ incl"!ing pain$ hypovolemia$

hypo4ia$ aci!osis$ sepsis$ congestive heart fail"re$ hypoperf"sion$ or hypercapnia.

Chile thyroto4icosis may ca"se sin"s tachycar!ia$ partic"larly in thyroi! storm$ an

atrial !ysrhythmia is more common. Treatment sho"l! incl"!e * to , liters of

o4ygen@min an! is !irecte! at i!entification an! correction of the "n!erlying ca"se.

Paro4ysmal S"praventric"lar Tachycar!ia

The paro4ysmal s"praventric"lar tachycar!ia !ysrhythmias$ 5hich are reentry in

nat"re$ have a ventric"lar rate #et5een )-7 an! *-7 #eats@ min. They may #e ca"se!

#y hypo4ia$ myocar!ial ischemia or infarction$ congestive heart fail"re$ or

thyroto4icosis. Cith a rapi! ventric"lar response$ synchroni9e! !irect/c"rrentco"ntershoc is in!icate!. 1aroti! sin"s massage or Valsa

chapter 11 surgical complications

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