Pre-Operative Medical Assessment : in Healthy Patients

1. Pre-Operative Medical Assessment :in Healthy Patients Mazen Badawi Medical Resident 1/2010

2. 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

3. 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?

4. Things to remember • Keep no. of recommendations to a minimum • Clarify the specific reason for the consult request • Adherence to recommendations is greater for consults requested early • Follow patients through the postoperative period • Don’t say “cleared” , say “Average risk”

5. 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

6. ASA classification

7. Anesthesia risk • Drugs : Stress response, interaction, SE • Mechanical and operational errors • Cardiac : • Inhalational agents are mycardial depressant  Accentuated hypotensive response…

8. 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

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

10. Assessment of healthy indiv. • High false +ve , ? • Questionnaire • If 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

11. Questionnaire for healthy people • 13 questions • General : past serious illnesses • Resp, CVS: exertional SOB, anginal chest pain, cough, wheeze, ankle swelling • Rx: pills in the last 3 months (incl. excess alcohol) • Allergies • Anesthetic in last 2 months, problem with anesthesia (pt. or relative)

12. 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

13. 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.

14. Clinical assessment 2- Medication use : Including OTC, complementary, alternative

15. 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

16. Clinical Assessment 3- Age: <60 yr  1.3% mortality 80-89 yr  11.3% • Age 70 as turning point

17. 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

19. 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.

20. 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

21. 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

22. 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%

23. 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

24. 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

25. LFT • Only 0.3% of healthy ppl. Have abnormal LFTs •  routine LFT pre op. in healthy ppl isn’t recommended

26. 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

27. 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

28. 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

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

30. 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.

31. 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

32. 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

33. Thank you..