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PersistentLowPltPostSplenectomyforITP
Idiopathic(immune)thrombocytopenicpurpura(ITP)isthemostcommonindicationforelectivesplenectomy.
Itisanacquireddisorderinwhichautoantibodiesareproducedagainstaplateletglycoprotein.
Thespleenisthemajorsitefortheproductionofantiplateletantibodiesandalsoservesastheprincipalsiteofplateletdestruction.
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PersistentLowPltPostSplenectomyforITP
Children usuallypresentwithacuteITP,oftenassociatedwitharecent
viralsyndrome.
In90%ofcases,thediseasespontaneouslyremitswithin6to12months. Onlyrefractorycasesrequiresplenectomy.
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PersistentLowPltPostSplenectomyforITP
Adults TypicallypresentwithamorechronicformofITPthatismuchless
likelytospontaneouslyremit.
Asymptomaticpatientswithplateletcountsgreaterthan50,000/mm3maysimplybefollowed.
Symptomaticpatientsorthosewithcountslessthan30,000/mm3shouldbetreatedwithoralglucocorticoids.
Greaterthan50%ofpatientsrespondtoglucocorticoids. Inrefractorycases,orinpatientswithbleeding,intravenousimmunoglobulin(IVIG)isused,althoughtheeffectsaretransient. Indicationsforsplenectomyarefailuretorespondtomedicaltherapy
andintolerablesideeffectsfromsteroidadministration.
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PersistentLowPltPostSplenectomyforITP
Patientswhofailsplenectomyorrelapseafteraninitialresponseshouldbeinvestigatedfor
accessorysplenictissue.
Aperipheralsmearandmagneticresonanceimaging(MRI)ornuclearmedicinestudieswithtechnetium(Tc)-99mlabeledheat-damagedredcellsareindicated.
Ifaccessorysplenictissueisfound,re-explorationshouldbeconsidered(NEnglJMed2002;346:995)
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VentilatoryComplicationsinBurns.
Thermalinjurytotheairwaygenerallyislimitedtotheoropharynxorglottis. Theglottisgenerallyprotectsthesubglotticairwayfromheat,unlessthe
patienthasbeenexposedtosuperheatedsteam.
Edemaformationcancompromisethepatencyoftheupperairway,mandatingearlyassessmentandconstantre-evaluationoftheairway.
Gasescontainingsubstancesthathaveundergoneincompletecombustion(particularlyaldehydes),toxicfumes(hydrogencyanide),andcarbon
monoxidecancausetracheobronchitis,pneumonitis,andedema.
Mortalitymaybeincreasedbyasmuchas20%inthesepatients.
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VentilatoryComplicationsinBurns.
Carbonmonoxideexposureissuggestedbyahistoryofexposureinaconfinedspacewithsymptomsof:
Nausea Vomiting Headache Mentalstatuschanges Cherry-redlips.
Carbonmonoxidebindstohemoglobinwithanaffinity249timesgreaterthanthatofoxygen.
Resultsinextremelyslowdissociation(t1/2250min)onR.A.NirHus
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VentilatoryComplicationsinBurns.
W/100%O2thet1/2dropto40minviaN.R. Thearterialcarboxyhemoglobinlevelisobtainedasa
baseline,andifitiselevated(>5%innonsmokersor>10%
insmokers),oxygentherapyshouldcontinueuntilnormallevelsareachieved.
Theincreasedventilation-perfusiongradientandthereductioninpeakairwayflowindistalairwaysandalveoli
canbeevaluatedusingaxenon-133ventilation-perfusionlungscan.
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VentilatoryComplicationsinBurns.
Majorinjuriesrequireendotrachealintubationwithalarge-boretube(7.5to8mm)tofacilitatepulmonarytoilet
ofviscoussecretionsandmechanicalventilationwithpositivepressure.
Decreasedpulmonarycomplianceisoftenseenafterinhalationinjuryandcanleadtoiatrogenicventilator-associatedlunginjury.
Aconstrictingtruncalescharcanlimitchestexcursion. Escharotomiescanbeusedtorelievetheconstrictionand
allowadequatetidalvolumes.
ThisneedbecomesevidentinapatientmaintainedonaNirHus
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CharacteristicsLithogenicBile Theprimarybilesaltsare:
Cholate Chenodeoxycholate
Synthesizedintheliverbycholesterol. Theyareconjugatedintheliverwithtaurineandglycine. 95%ofthebileacidpoolisreabsorbedandreturned
throughtheenterohepaticsystemtotheliver.
Theremaining5%isexcretedinthestool.NirHus
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CharacteristicsLithogenicBile Thekeytomaintainingcholesterolinsolutionisthe
formationofmicelles,abilesaltphospholipid-cholesterol
complex,andcholesterol-phospholipidvesicles.
Instatesofexcesscholesterolproduction,theselargevesiclesmayalsoexceedtheircapabilitytotransportcholesterol,andcrystalprecipitationmayoccur.
butthecholesterol-phospholipidvesiclescarrythemajorityofbiliarycholesterol.
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CharacteristicsLithogenicBile Pigmentstonescontainlessthan20%cholesterolandare
darkowingtothepresenceofcalciumbilirubinate.
Blackpigmentstones(duetounconjugatedbilirubin)aresmallandtarry,andarefrequentlyassociatedwithhemolyticconditionssuchashereditaryspherocytosisand
sicklecelldiseaseorcirrhosis.
Notassociatedwithinfectedbile. Locatedalmostexclusivelyinthegallbladder
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CharacteristicsLithogenicBile Brownpigmentstonesaresoftandearthyintextureand
aretypicallyfoundinbileducts,especiallyinAsian
populations.
ContainmorecholesterolandcalciumpalmitateandoccurasprimarycommonductstonesinWesternpatientswithdisordersofbiliarymotilityandassociatedbacterialinfection.
E.colisecrete-glucuronidasethatcausesenzymatichydrolysisofsolubleconjugatedbilirubinglucuronidetoproduceinsolublefreebilirubin,whichthenprecipitateswithcalcium.
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