Preoperative Testing Guidelines

1. Preoperative Testing Guidelines Antonio Alan S. Mangubat

2. Clinical Pathway

3. Clinical Pathway

4. MEDICAL CONDITIONS • Cardiovascular System • Hypertension • Cardiac Murmur • Angina Pectoris, Arryhthmias, Cardiac failure • Pacemaker • Triple vessel disease

5. CV conditions • Hypertension • Newly diagnosed: Refer to IM • Poorly controlled: Refer to IM • Postpone operation if BP > 180/110 with less than two weeks to optimized • Inform surgeon, allow 2 weeks for BP control

6. Hypertension • Stage 1 or 2 hypertension is not an independent risk factor for perioperative cardiac complications • Mild/moderate hypertension with no associated CV/metabolic abnormalities  not beneficial to delay surgery

7. Hypertension • Continue all anti-hypertensive medications except ACE inhibitors and ARBs (controversial) • Continue beta-blockers and clonidine up to the day of operation because of the risk of rebound hypertension • May use IV beta-blockers or transdermalclonidine in patients unable to take oral medications

8. Hypertension • For SBP > 180 and DBP > 110 without any other associated s/s  risk benefit of postponing the surgery should be weighed • Evidence is inconclusive • IV anti-hypertensives can bring down the BP to manageable levels in a few hours • IV beta-blockers seem to be the most effective agents

9. CV conditions • Cardiac murmur • Refer to cardio for 2D-echo if murmur is unlikely to be functional (functional murmurs are soft and change/disappear with changes in posture) • Severe AS needs cardio assessment

10. CV conditions • Angina Pectoris, Arryhthmias, Cardiac failure • Follow guidelines for referral to cardiology

11. CV conditions • Pacemaker • Refer to cardio to check function of pacemaker if on poor follow-up or asymptomatic • Refer if pacemaker spikes are absent on ECG

12. CV conditions • Triple vessel disease (refuses CABG) • Refer to cardiology • Inform of risk if proceeding with surgery

13. Guidelines for referral to cardiology • Patients with Major clinical predictors • Require intensive management, and will result in delay or cancellation of surgery unless emergent • Recent MI < 30 days • Unstable/severe angina • Decompensated congestive heart failure • Signigicant arrhythmia • High-grade AV block • Severe valvular disease

14. Clinical Predictors(Risks of MI, heart failure, death) • Major: • Unstable coronary syndromes • AMI < 7 days, recent MI < 30 days • Unstable/severe angina • Decompensated CHF • Significant arrhythmias • High-grade AV block • Symptomatic ventricular arrhythmias with underlying heart diseass • Supraventricular arrhythmia with uncontrolled ventricular rate • Severe valvular disease

15. Clinical Predictors • Intermediate (Increase periop cardiac risk and require careful assessment of current status) • Mild angina pectoris • Prior MI > 1 month by history of pathologic Q waves • Compensated or previous CHF • DM • Renal insufficiency

16. Clinical Predictors • Minor • Elderly • Abnormal ECG (LVH, LBBB, ST-T changes) • Rhythm other than sinus • Stroke • Uncontrolled hypertension

17. Effort tolerance • Poor (1-4 Mets) • Eating • Dressing • Walking around the house • Washing dishes • Moderate to Good (4-10 Mets) • Climbing one flight of stairs • Walking on level ground at 6.4 kms/hour • Running a short distance • Scrubbing the floor • Playing a game of golf

18. Surgical Risks • High (reported death > 5%) • Aortic/other major vascular surgery • Peripheral vascular surgery • Prolonged procedures with massive fluid shifts and blood loss • Emergent major operation, especially in the elderly

19. Surgical Risks • Intermediate (cardiac risk < 5%) • Carotid endarterectomy • Head and neck surgery • Intraperitoneal/ intrathoracic surgery • Orthopedic surgery • Prostate surgery • Low (Cardiac risk < 1%) • Endoscopic/superficial procedures • Cataract surgery • Breast surgery

20. Respiratory Conditions

21. Endocrine System

22. Diabetes Mellitus • Mild hyperglycemia is preferable to hypoglycemia. • Patients should not take oral hypoglycemics on the day of the procedure. • Patient should not take short-acting insulin bolus the morning of procedure. • Long-acting or intermediate insulin may be used to cover basal insulin needs; 50%-100% of usual dose is often reasonable. • Insulin pumps should be continued but only to provide basal insulin coverage. • The details of the insulin recommendations are influenced by the insulin sensitivity of the patient, the timing of the procedure, the length of the procedure, and how long the patient will need to be NPO following the procedure.

23. Hematologic System

24. Renal Diseases

25. Obesity/OSA • Clinical diagnosis of OSA • Daytime somnolence (easily falls asleep during quiet times or Epworth score of > 14) • Snoring with arousal • BMI 30 or more • Neck circumference 42 cms. or more • Small receding mandible • Hypertension (> 140/90)

26. Obesity/OSA • Determination of Severity of OSA based on Clinical s/s • Determination of Severity of OSA based on Sleep Study

27. Obesity/OSA • Scoring of Invasiveness of Anesthesia or Surgery • Scoring of Opioid Requirement

28. Obesity/OSA • Determination of Peri-Operative Risk of OSA OSA severity + Invasiveness OR post-op opioids (1-3) (0-3) (0-3) • 4 or less: OPD acceptable but inpatient preferable • 5 or more: significantly increased perioperative risk

29. Obesity/OSA • Perioperative risk 4 or less • Monitoring in PACU for 3 hours longer than non-OSA patients in an unstimulated environment • Sp02 should be at baseline and with no airway obstruction • Perioperative risk 5 or more • Continuous postoperative Sp02 monitoring in ICU or high-dependency unit

30. Epworth Sleepiness Scale

31. Rheumatology

32. Coagulation System

33. Allergies

34. Preoperative Laboratory Examinations • ASA I

35. Preoperative Laboratory Examinations • ASA II and III

36. Guidelines for Preop Investigations • ECG • Age > 50 years • ASA II or more • High risk surgery • Cardio-respiratory symptoms or signs

37. Guidelines for Preop Investigations • CXR • ASA II with cardiorespiratory symptoms or signs • ASA III or more • High risk surgery • s/s of active respiratory disease • History of pneumonia within the last 6 months • History of pneumothorax • History of childhood tracheostomy • Large multinodular goiters • Thorascopic procedure or thoracotomy • Cervical lymph node biopsy under GA • Extremes of age, smoking, stable pulmo/cardio disease, resolved recent URTI are not considered unequivocal indications

38. Guidelines for Preop Investigations • Biochemistry • ASA I and age > 65 • ASA II or more • Moderate risk surgery and age >50 • High risk surgery • Drug history of: • Diuretics • Theophylline • Digitalis • Systemic steroids

39. Guidelines for Preop Investigations • CBC • Age > 65 • ASA II or more • Moderate and high-risk surgery • NSAID use within past 6 months • History of anemia within the past year • Pallor on PE • Polycythemia • CAD • Malignancy • Recent radiation or chemotherapy • Severe coexisting disease or unstable condition – renal failure, liver disease, poorly controlled HPN, malnutrition • Female with menorrhagia

40. Guidelines for Preop Investigations • Coagulation profile • High risk surgery • Moderate risk surgery (except for ASA I and age <50) • Patients with: • History or symptoms of bleeding diathesis • Severe active liver disease or renal disease • Anticoagulation therapy • Sepsis severe malnutrition or malnutrition syndrome • Vascular procedure

41. Guidelines for Preop Investigations • Liver function tests • Known or suspected cirrhosis • Potential active hepatitis • Therapy with hepatotoxic drugs

42. Guidelines for Preop Investigations • Other investigations • Pregnancy test for females who are unable to exclude pregnancy • Thyroid function test: only free T4 required, TSH no needed if patient is clinically euthyroid

43. Validity of Tests • In the absence of new clinical changes: • blood tests are valid for a period of 3 months • ECG for 6 months • CXR for 1 year

44. Thank you!