PRE ANAESTHETIC ASSESSEMENT & EVALUATION

Dr.G.VIJAYA .MD

• What are the goals of pre op evaluation?

• Pre op risk assessment-ASA classification

• History

• General examination

• Assessment of functional capacity of the pt

• Airway assessment

Assessment for mask ventilation

Assessment for laryngoscopy/intubation

• Evaluation of co existing disease

CVS,RS,LIVER ,RENAL DISORDER

HEMATOLOGY,ENDOCRINE,CNS&

MUSCULOSKELETAL DISORDER

GOALS

• To obtain pertinent information regarding patients current & past medical history

• To formulate an assessment of the patient’s intra operative risk

• To decrease surgical morbidity

• To minimize expensive delays

• Avoid cancellations on the day of surgery

• To increase the peri operative efficiency

ASA 1Healthy pt without organic ,biochemical or psychiatric disease

ASA 2Pt with mild systemic disease (eg. mild asthma or well controlled HT)

No significant impact on daily activity Unlikely to have impact on surgery or anesthesia

ASA 3

Significant severe systemic disease that limits normal activity (renal failure on dialysis or class II CCF)

Significant impact on daily activity /probable impact on surgery or anesthesia

ASA 4Severe disease that is constant threat to life or requires intensive therapy

(eg acute MI, respiratory failure)serious limitation of daily activity (major impact on surgery or anesthesia)

ASA 5Moribund pt who is equally likely to die in next 24 hrs with or without

surgery

ASA 6 Brain dead organ donor

E – PRE FIXED FOR EMERGENCY TILL ASA 4 (ASA 4 E)

PRE OP RISK ASSESSEMENT ASA PHYSICAL STATUS classification

(1941 by Meyer Saklad )

• History And Physical examination Are The Most Important Assessors Of Disease And Risk

Why does the patient need an operation now?

• Is it acute/chronic illness?

• Presenting symptoms?

e.g. anaemia, cachexia, pain, seizures etc

• What are the pathophysiological consequences?e.g. thyroid mass

– Local - stridor, SVC obstruction

– Systemic - hypo/hyperthyroidism

PRESENTING COMPLAINT

ASSOCIATED MEDICAL CONDITIONS

Given the presenting problems are there any other conditions I am worried the patient could have?

• Bowel ca. - liver mets with abnormal LFTs, abnormal coagulation, impaired drug metabolism

• Peripheral vascular disease - IHD, carotid disease, HT, renal disease, COAD

OTHER MEDICAL CONDITIONS

Any other problems that may affect

perioperative morbidity and mortality?

• cardiac disease

• respiratory disease• arthritis• endocrine disease - diabetes, obesity etc

• Heart burn/reflex disease

FUNCTIONAL CAPACITY

• MET-metabolic equivalent of task

• 1 MET Can you dress yourself?

• 4 MET Can you climb a flight of stairs?

• 10 MET Can you participate in strenuous activities (swimming,

tennis,football)

FUNCTIONAL CAPACITYMET Functional Level Of Exercises

1 Eating.,Working At Computer, Dressing

2 Walking Downstairs ,Cooking

3 Walking 1-2 Blocks

4 Raking Leaves, Gardening

5Climbing 1 Flight Of Stairs(20steps Of 6 Inches Ht),

Dancing,bicycling

6 Playing Golf, Carrying Clubs

7 Playing Tennis

8 Rapidly Climbing Stairs, Jogging Slowly

9 Jumping Rope Slowly, Moderate Cycling

10 Swimming Quickly,running Or Jogging Briskly

11 Skiing Cross Country, Playing Full Court Basket Ball

12 Running Rapidly For Moderate To Long Distance

GENERAL HISTORY/ASSESSMENT

• Family history

• Previous anaesthetics

– PONV

– allergy

–malignant hyperpyrexia

– difficult airway

– difficult IV access

Rule out obstructive sleep apnea

HISTORY OF

• Snoring

• Day time sleepiness

• Hypertension

• Obesity

• Large neck circumference (>17 inches in men , >16 inches in women)

DRUG HISTORY

Very useful, often forgotten

• Current medications

• ALLERGY

• Medic alert bracelets

• Smoking/alcohol history

• Other drugs of abuse!

PHYSICAL EXAMINATION

• HR,RR,BP,SPO2,

• Height,wt,BMI

• CVS

PULSE VOLUME ,RHYTHM ,

Auscultate for murmurs, signs of volume over load

S3/S4

JVP, ascites , pedal edema

• RS

wheezing

Decrased breath sounds

Abnormal breath sounds

Cyanosis/clubbing

Use of accessory muscles

Effort of breathing

AIRWAY ASSESSMENT

• History –Prev surgery,anesthesia

• Congenital airway difficulties- pierre robin syndrome,klippel feil syn, down synd etc

• Acquired –rheumatoid arthritis , still’s disease,ankylosing spondylitis, acromegaly,pregnancy , diabetes

• Iatrogenic- surgery on TMJ, cervical spine fusion, oropharyngeal readio therapy,laryngeal surgery

EXAMINATION

• Small mouth , receding chin,high arched palate,large tongue,obesity ,large breasts

• Head . Neck burns,tumors,abscess,restrictive scars

• Loose teeth, protruding teeth,dentures

ASSESSMENT IN RELATION TO MASK VENTILATION

• BONES

• B-bearded individual

• O-obesity

• N-no teeth

• E-elderly

• S-snorer

• MOANS

• M-mask seal –difficult in receding mandible,facial anomalies

• O-obesity

• A-advanced age

• N-no teeth

• S-snorer

• MALLAMPATTI GRADING

• Original – 3 classifiaction

• Samson & Young’s Modification

Have 4 Classifications

MALLAMPATTI CLASSIFICATION

• Have patient sit up, and stick out tongue without phonating

• May be unable to properly assess this in an emergent field situation

• Performed with patient in a sitting position, head neutral, mouth open wide and tongue protruding to the maximum

• RELATES TO TONGUE SIZE TO PHARYNGEAL SIZE

MALLAMPATTI CLASSIFICATION

INTER INCISORS GAP

• 4.6 cm or more – normal –easy insertion of laryngoscope blade

• <3 cm – difficulty in intubation

• < 2.5 cm – LMA insertion difficult

PROTRUSION OF MANDIBLE

• Class A – able to protrude lower incisors anterior to the upper incisors

• Class B – lower incisors can just reacjh the margin of upper incisors

• Class C –lower incisors cannot protrude to the upper incisors

• Class B & C –difficult laryngoscopy

THYROMENTAL DISTANCE (PATIL TEST)

• Distance from tip of thyroid cartilage to tip of mandible (neck fully extended)

• >7 cm –normal

• <6cm -75% difficult laryngoscopy

STERNOMENTAL DISTANCE (SAAVA TEST)

Distance from upper border of the manubrium to the tip of mandible (neck fully extended,mouth closed)

• <12.5 cm –difficulty intubation

CERVICAL & ATLANTO OCCIPITAL JOINT FUNCTION

• Intubation position-early morning sniffing / magill’s position

• Ask the pt to touch his manubrium sterni with chin – assures flexion of 25-30 °

• Ask the pt to loof at ceiling with out raising eye brows to test AO joint(well extension 85°)

• If 2/3 rd or complete reduction of extension at AO joint –difficult laryngoscopy

DELILKAN TEST

• Ask the pt to sit in neutral position/you stand behind the pt

• Place your index finger of left hand under chin

• Index finger of right hand on occipital tuberosity

• Ask the pt to look ceiling

• If left index finger higher than right-normal

• If both are in same level –moderate limited mobilty

• If left is below than right –severe limitation

Evaluation of co existing diseases

CVS

• Rule out HT-(if 2 or more readings >140/90mmhg)

• Causes-essential / pheochromocytoma/ hyperthyroidism/ coccaine,amphetamines

• Post pone if BP >200/115mmhg

• Drug history-diuretics,digoxin,calcium channel blockers,beta blockers,ACEI etc

GOLDMAN CARDIAC RISK INDEX FOR NON CARDIAC

SURGERY

GOLDMAN CARDIAC RISK INDEX FOR NON CARDIAC

SURGERY

REVISED CARDIAC RISK INDEX

• High risk surgery (intra peritoneal , Intrthoracic,suprainguinal

vascular surgeries)

• IHD

• H/O congestive heart failure

• H/O CVA

• Diabetes mellitus on insulin

• Creatinine >2.0mg/dl

INVESTIGATIONS

• ECG – recent q waves, conduction abnormailities,arrythmias

• Normal ECG –doesn’t exclude cardiac disease

• Echo cardiogram

• Angio gram – if needed (to know shunt fraction ,left atrial pressure etc )

CARDIAC EVALUATION FOR NON CARDIAC SURGERY

Step1:EMERGENCY SURGERY

Proceed to surgery with medical risk reduction & perioperative surveillence

STEP 2:ACTIVE CARDIAC CONDITIONS •UNSTABLE ANGINA /RECENT MI•DECOMPENSATED HEART FAILURE•SIGNIFICANT ARRHYTHMIAS•SEVERE VALVULAR HEART DISEASES

POST PONE SURGERY UNTIL STABILISED OR CORRECTED

Step 3: low risk surgery •Superficial or endoscopic•Cataract/breast•Ambulatory

Proceed to surgery

Step 4-functional capacity Good >4 mets

Proceed to surgery

Step5:clinical predictors •IHD•Compensated heart failure•CVA•DM•Renal insufficiency

No clinical predictors

1-2 predictors

>3 predictors

Proceed to surgery

Vascular /intermediatesurgery

Proceed to surgery with HR control/consider non invasive testing if it will change management

consider testing if it will change management

Vascular surgery

RS

• H/O SMOKING

• RULE OUT BRONCHIAL ASTHMA

• RULE OUT COPD

• EVALUATE FOR RESTRICTIVE LUNG DISEASE

• RULE OUT PULMONARY HYPERTENSION

PULMONARY DISORDER EVALUATION

• SIMPLE CHEST X RAY PA VIEW

• PFT – IF NEEDED

(in case of thoracic surgery,bronchial asthma ,copd pt,if pt posted fot kyphoscoliosis correction)

• BED SIDE PULMONARY FUNCTION TESTS

• ABG –IF NEEDED

BREATH HOLDING (SABRASEZ)TEST

• Pt asked to take deep breath and hold it for as long as possible

• >30 sec –normal

• <15 sec-reduced vital capacity

• Normal person – hold up to 1 min

SNIDERS MATCH BLOWING TEST

• Lighted match stick held at 6 inches (15 cm ) from pt mouth

• Pt asked to blow out the match with out pursing lips

• Rough estimate of exp capacity /MBC

• If cant –MBC <60 L/MIN OR FEV1 <1.6L

• IF NOT ON 8 CMS DISTANCE –FEV 1<1L

Risk factors for pulmonary complications

• H/O smoking

• ASA >2 GRADE

• AGE >70 yrs

• COPD

• Neck ,thoracic,upper abdominal surgery,neuro surgery

• >2 hrs procedures

• Albumin <3 gm/dl

• Exercise capacity <1 flight

• BMI>30

HEPATOBILIARY DISORDER

• H/o-hepatitis-alcoholic,viral

• Obstructive /hemolyric jaundice

• Cirrhosis

• Portal hypertension

• Hepatic encephalopathy

• Wilson’s disease

• Hemochomatosis

• Hepato cellular carcinoma/secondaries

• LFT

• USG

• COAGULATION PROFILE

• SERUM PROTEINS

PUGH‘S MODIFICATION OF CHILD GRADING-chronic liver disease

Clinical & Biochemical Clinical & Biochemical variablesvariables

POINTS POINTS

11

SCOREDSCORED

22 33

Serum albumin (g/L)Serum albumin (g/L) >35>35 28-3528-35 <28<28

Serum bilirubin (µmol/L)Serum bilirubin (µmol/L)

[Mg /dl][Mg /dl]

<35<35

< 2< 2

35-6035-60

2 -32 -3

>60>60

> 3> 3

PT (seconds) prolongedPT (seconds) prolonged

from controlfrom control

1-41-4

INR [ < 1 .7]INR [ < 1 .7]

4-104-10

INR [1.7 -INR [1.7 -2.3]2.3]

1010

INR >2.3INR >2.3

AscitesAscites NoneNone MildMild ModerateModerate

EncephalopathyEncephalopathy AbsentAbsent Grade I – Grade I – IIII

Grade III – Grade III – IVIV

RENAL DISORDER

• Cause of renal failure-hypertension.diabetes

• Cardiovascular complications+

• Electrolyte imbalance

• Acute or chronic renal failure

• Associated coagulopathy due to platelet dysfunction

• Anemia due to decreased erythropoetin prodution

• Renal function tests

• HB/ Hematocrit

• Platelet count

• Coagulation profile

• Creatinine clearence (24 hrs)

• ABG

Pre Renal Vs Intrinsic Renal ARF

Diagnostic IndexPrerenal Azotemia

Intrinsic Renal Azotemia

Fractional excretion of sodium (%)a

•UNa x PCr/PNa x UCr x 100 < 1 >1

Urine sodium concentration (mmol/L) < 10 >20

Urine creatinine to plasma creatinine ratio >40 >20

Urine urea nitrogen to plasma urea nitrogen ratio >8 < 3

Urine specific gravity >1.018 < 1.015

Urine osmolality (mosmol/kg H2O) >500 < 300

Plasma BUN/creatinine ratio >20 < 10-15

Renal failure index•UNa/UCr/PCr

< 1 >1

Urinary sediment Hyaline castsMuddy brown granular casts

CREATININE CLEARENCE

• COCKCROFT –GAULT formula

Creatinine clearance = (140-age ) × wt (kg) ×(0.85 if female)

72 ×serum creatinine (mg/dl)

ENDOCRINE DOSORDER-DIABETES MELLITUS

• Duration

• oral hypoglycemic drugs,insulin

• Rule out micro & macro vascular /end organ damage

• Diabetic nephropathy

• Silent ischemia

• Autonomic neuropathy-orthostatic hypotension(>20/10mmhg difference)

• Stiff joint syndrome –difficult intubation

• Fasting blood glucose to be <110mg/dl

• FBS,PPBS

• HB A1C(<7% CARRYS LOW RISK)

• URINE ACETONES

• RFT, ELECTOLYTES

• ECG

• ECHO

ENDOCRINE-THYROID

• Hyper /hypo thyroidism

• Rule out pericardial effusion ,myxoedema-hypothyroidism

• palpitations, tachycardia

• Arrhythmia-hyperthyroidism

• Ask for anti thyroid,betablockers,steroids

• Eltroxin

• Thyroid function test

• Clinically symptoms /signs - should be improved

• ENT opinion to rule out pre existing vocal cord palsy

• X ray neck – to rule out tracheal compression

OTHER ENDOCRINES

• Parathyroid –hyper or hypo calcemia

• Adrenal insufficiency –due to HIV/TB

• Multiple endocrine neoplasia(MEN syndrome ) to be ruled out

• Pheocromocytoma

CNS

• CVA

• Seizure disorder-treatment/drugs

• Multiple sclerosis

• Cerebral aneurysms

• Neuromusculat junctions disorder

• Muscular dystrophies/myopathies-prone for malignant hyperthermia.neurolept malignant syndrome

• Intracranial tumours-relative C/I to central neuroxial block

HEMATOLOGY

• Anemia

• Target >10gm/dl for normal pt

• Desire pre op /intra op blood transfusion

• Rule out Jehovah Witnesses

ConditionIncreased mortality/morbidity below

hemoglobin (g/100 ml)

Old age <11 g/100 ml

Heart valve operation <12 g/100 ml

Heart failure <11 g/100 ml

PTCA <10 g/100 ml

COPD <13 g/100 ml

HEMATOLOGY –RULE OUT IF SUSPECTED

• Sickle cell disease

• Coagulopathies

• Hemophilias

• Von willibrands disease

• Thrombocytopenia

• Thrombocytosis

• Polycythemia –risk of thrombosis

MUSCULO SKELETAL

• Rheumatoid arthritis,ankylosing spondylitis

• SLE

• Kyphoscoleosis

• All these can complicate in difficult intubation/difficulty in regional block

• Associated cardiovascular/pulmonary dysfunction will be there

RULE OUT

• Malignancy-metastasis /complications

• Transplanted organ –sepsis/steroids /chemotherapy

• Obesity/OSA

• HIV

• Drug abuse

• H/O pseudo cholinesterase deficiency

• H/O malignant hyperthermia

ASSESSMENT IN PEDIATRICS

• Airway assessment not reliable

• H/O-freq URI/LRI or snoring-indicate obstructed airways

• Rule our adenoid/tonsillar enlagement

• Cheat indrawing –indicate lower airway obstruction

• Go thro prev records/anesthesia charts

• Assess for IV line accessebilty

PRE OP ADVICE

• Risk the pt according to ASA grade

• Advice to continue all the drugs except

anti coagulants,OHA

• Switch over to regular insulin

• Continue steroids

• Pre medications to be advised

• Blood requirements

• Clotting time ,bleeding time not at all reliable

CURRENT IE PROPHYLAXIS AHA 2007 RECOMMENDATIONS

• Prosthetic valves

• Prev IE

• CONGENITAL HEART DISEASE

1.Unrepaired Cyanotic Heart Disease including palliative shunt/conduits

2.Compltely repaired CHD with prosthetic material

3.Repaired CHD with residual defects

4.Cardiac transplantation receipients

CURRENT RECOMMENDATIONS FOR ANTICOAGULATION AND CENTRAL NEUROXIAL

BLOCK

RECOMMENDATIONS LABORATORY

ANTIPLATELETS ASPIRIN/NSAIDS NONE NONE

TICLOPIDINE STOP 14 DAYS PRIOR NONE

CLOPIDOGREL 7 DAYS PRIOR NONE

ABCIXIMAB/EPTIFIBATIDE/

TIROFIBAN

AVOID NEUROXIAL BLOC

ANTICOAGULATNS WARFARIN

STOP 4-5 DAYS PRIORMONITOR FOR 24

HRS AFTER REMOVAL OF

EPIDURAL CATHETER

PT/INR BEFORE AND AFTER NEUROXIAL

BLOCKINR TO BE <1.5

RECOMMENDATIONS LABORATORY

HEPARINIF ON SUB CUT

HEPARINDELAY UNTIL BLOCK

>4 DAYS –CHECK

PLATELETES

IV HEPARIN

DELAY UNTIL 1 HR AFTER BLOCK

REMOVE CATHETER AFTER 2-4 HRS OF

LAST DOSE

DO PTT

LMWH

PRE OP – BLOCK AFTER 12 HRS OF

LAST DOSE (DELAY 24 HRS IF HIGH DOSE

THE PT GIVEN)REMOVE 12 HRS

AFTER LAST DOSE AND WAIT 2 HRS TILL

NEXT DOSE

TO CONCLUDE

• Discuss and explain the pt about anesthetic technique

• Explain the risk

• Discuss with surgeon if needed

• Plan well about the anesthetic technique and reduce the morbidity and mortality during intra op as well in the post op period also

REFERENCES

• MILLER 7 TH EDITION• OXFORD HAND BOOK• RASHID KHAN –AIRWAY MANAGEMENT

THANK YOU