Pre-Operative Medical Assessment :in Healthy Patients

Mazen BadawiMedical Resident1/2010

Introduction

Goal : decrease risk of surgery : Identify unrecognized co-morbid disease

and risk factors for medical complications of surgery

Optimize preoperative medical condition Understand, recognize, and treat potential

complications Work as a team with surgeon and

anesthesiologist

Questions to answer in each case

Why was the consult requested?What is the benefit to the patient of the

proposed procedure?May one substitute a lower risk

procedure?What are the known risks?What is the balance of risk-benefit?What are the patient's goals?

Things to remember

Keep no. of recommendations to a minimumClarify the specific reason for the consult

requestAdherence to recommendations is greater for

consults requested earlyFollow patients through the postoperative

period Don’t say “cleared” , say “Average risk”

Anesthesia factor

Patient and surgical factors are more important risk predictors than anesthetic considerations (JAMA 1988;260:2859)

ASA (Dripps) Classification is a powerful predictor of overall perioperative mortality. It also predicts cardiac and pulmonary morbidity

ASA classification

ClassSys. Disturb.Mortality

1Healthy patient with no disease outside of the surgical process <0.03%

2Mild-to-mod. systemic disease caused by the surgical condition or by other pathologic processes

0.2%

3Severe disease process which limits activity but is not incapacitating 1.2%

4Severe incapacitating disease process that is a constant threat to life 8%

5Dying patient not expected to survive 24 hours with or without an operation

34%

ESuffix to indicate an emergency surgery for any class Increased

Anesthesia risk

Drugs : Stress response, interaction, SE

Mechanical and operational errors

Cardiac : • Inhalational agents are mycardial depressant

Accentuated hypotensive response…

Anesthesia risk

Pulm. :• Vital capacity decreased by 50%• Decreased Fun.Resd.C below closing volumes

atelectasis and V/Q mismatch• Decreased mucociliary clearance• Depression of response to hypoxia and

hypercarbia• Diaphragmatic dysfunction

Anesthesia risk

Spinal vs. epidural : No difference in cardiac mortality. Probable decrease in the risk of pulm.

complications

Assessment of healthy indiv.

High false +ve , ?QuestionnaireIf all answered “NO” no need for

complete Hx, Ex

Wilson, ME, Williams, MB, Baskett, PJ, et al. Assessment of fitness for surgical procedures and the variability of anaesthetists' judgments. Br Med J 1980; 1:509

Questionnaire for healthy people

13 questionsGeneral : past serious illnessesResp, CVS: exertional SOB, anginal chest

pain, cough, wheeze, ankle swellingRx: pills in the last 3 months (incl. excess

alcohol)AllergiesAnesthetic in last 2 months, problem with

anesthesia (pt. or relative)

Q. To determine need for anesth. App.

17 Q Resp, CVS : SOB, chest pain when climbing 2 flight

of stairs, hx of heart attack, angina, HF, asthma, bronchitis

Renal disease Neuro: stroke, epilepsy Anesthesia : previous problems in family Thyroid disease Liver disease Joint pain, stiffness esp. neck and jaw DM and insulin use

Clinical assessment

1- Exercise capacity :

poor if symptomatic with walking 4 blocks or climbing 2 flights of stairs doubles the risk for post op. complications, CVS complications but not pulm.

Clinical assessment

2- Medication use :

Including OTC, complementary, alternative

Clinical assessment

3- Obesity : surprisingly, it is not a risk factor for most major adverse postoperative outcomes there was no difference in postop.

complication rates between patients whose BMI was > or < 30 incl. pulm.

But it still a major risk for postop. DVT & PE

Clinical Assessment

3- Age: <60 yr 1.3% mortality

80-89 yr 11.3%Age 70 as turning point

Labs

Routine lab inv. Aren’t usually recommended in healthy indiv.

In a study of 2000 patients undergoing elective surgery, 60 %of routinely ordered tests would not have been performed if testing had only been done for recognizable indications; only 0.22 % of these revealed abnormalities that might influence perioperative management

Chest X-Ray

ECG

CBC

Type/Screen

INR/PT

LytesUrea

Creat.Blood

glucose

AST/ALP/BILI

Sickle Cell

ScreenMF

Surgical Procedure on Type & Screen List No of Units

Age: <45

45-70

>70

Cvs, HTN

Pulmonary disease

Malignancy

Hepatic disease/ETOH

Renal disease

Blood disorders

Diabetes

Smoking >20 pack years

Use of Digoxin, Diuretics, ACE inhib.

Use of Steroids

Use of Anticoagulants

CNS disease

Sickle Risk*

CBC

Anemia is present in 1% of asymptomatic ppl

In a study of 2000 pt, 30 days mortality= Pre op. Hb >= 12 1.3% mort. Pre op. Hb < 6 33.3% mort.

CBC

Conclusion: CBC is recommended in:

All pt. >65 yr before major surgery All pt. <65 yr before major surgery with

expected significant blood loss All pt with symptoms of anemia before

minor surgery

Electrolytes

Frequency of unexpected electrolyte abnormalities is low, 0.6%

No solid relation of abnormalities with periop. complications

Hints easily collectable from hx routine electrolyte determinations are

NOT recommended

Renal funct.

Mild to moderate renal impairment is usually asymptomatic

High Cr among asymptomatic patients with no history of renal disease is only 0.2% ,rises in > 46 yrs to reach 9.8%

Renal funct.

Ass. Of Cr >177 with cardiac, pulm., and post op mortality

Cr level is recommended esp. in >50 yr Hypotension expected Nephrotoxic Rx

B.S

25% of >60 yr have abnormal b.s level.incidence of asymptomatic hyperglycemia is

unknown. No relationship between op. risk and DM

except in vascular & CABG (but not asymp. hyperglycemia)

routine measurement of b.s is not recommended in healthy ppl before surgery

LFT

Only 0.3% of healthy ppl. Have abnormal LFTs

routine LFT pre op. in healthy ppl isn’t recommended

Hemostasis

routine preoperative tests of hemostasis are NOT recommended.

should be restricted to patients with a known bleeding diathesis or an illness associated with bleeding tendency

Urinalysis

Done to: identify unsuspected renal disease UTI

It is not necessary for the detection of asymptomatic renal disease if a serum creatinine measurement is Normal

relationship between asymptomatic UTI and surgical infection is unclear

not recommended as routine

ECG

Guidelines : Men > 45 years Women > 55 years Known cardiac disease Clinical evaluation suggesting the possibility of

cardiac disease Patients at risk for electrolyte abnormalities, such

as diuretic use Systemic disease associated with possible

unrecognized heart disease, such as DM, HTN Patients undergoing major surgical procedures

CXR

Recommended in: >50 yr undergoing major surg. Suspected cardiac or pulm. disease

PFT

not indicated for healthy patients prior to surgery

reserved for patients who have SOB that remains unexplained after careful clinical evaluation

Clinical findings are more predictive of the risk of postop. Pulm. complication than are spirometric results : decreased breath sounds, prolonged expiratory phase, added sounds.

Summary : for healthy pt.

screening questionnaire for all patients Hx of exercise tolerance for all patients Blood pressure and pulse for all patients Hx + Ex if one of the above is abnormal, in patients

over 60 years, or in those undergoing major surgery Pregnancy test for women who may be pregnant HCT for all patients undergoing surgery with

expected major blood loss and for patients 65 years or older undergoing major surgery irrespective of potential for perioperative blood loss

Summary

Serum Cr if major surgery, hypotension is expected, nephrotoxic drugs will be used, or the patient is above age 50

ECG recommendations as above, unless obtained within the previous month

Chest x-ray for patients over 50 years undergoing major surgery, or those with suspected cardiac or pulmonary disease, unless one has been performed within the past six months

All other tests only if the clinical evaluation suggests a likelihood of disease

Thank you..