16. The ASA Physical Status Classification Dr. Andrew Ferguson ASA 1 Normal healthy patient Mortality ASA 2 Mild systemic disease - no impact on daily life 0.1% ASA 3 Severe systemic disease - significant impact on daily life 0.2% ASA 4 Severe systemic disease that is a constant threat to life 1.8% ASA 5 Moribund, not expected to survive without the operation 7.8% ASA 6 Declared brain-dead patient - organ donor 9.4% E Emergency surgery
23. Dr. Andrew Ferguson Independent Predictors of Difficult Mask Ventilation and Intubation Difficult Mask Ventilation P-value Beard 0.0001 History of snoring 0.001 BMI > 30 0.0001 Mallampati III or IV 0.001 Age > 50 0.01 Severely limited jaw protrusion 0.03 Difficult Mask Ventilation & Intubation Severely limited jaw protrusion 0.0001 Thick neck/mass 0.02 History of sleep apnoea 0.04 BMI > 30 0.05 History of snoring 0.05
25. Dr. Andrew Ferguson Physical Examination - Risk Factors for Difficult Intubation Risk Factor Detail Level of Risk Weight < 90 kg 0 90-110 kg 1 > 110 kg 2 Head & Neck Movement > 90 o 0 Approx 90 o 1 < 90 o 2 Jaw movement IG = Interincisor gap Slux = mandibular subluxation IG > 5 cm or Slux > 0 0 IG < 5 cm or Slux = 0 1 IG < 5 cm or Slux < 0 2 Receding Mandible Normal 0 Moderate 1 Severe 2 Protruding maxillary teeth Normal 0 Moderate 1 Severe 2
28. NYHA Functional Class Dr. Andrew Ferguson Class I No limitation of physical activity; ordinary activity does not cause fatigue, palpitations or syncope Class II Slight limitation of physical activity; ordinary activity results in fatigue, palpitations or syncope Class III Marked limitation of physical activity; less than ordinary activity results in fatigue, palpitations or syncope; comfortable at rest Class IV Inability to do any physical activity without discomfort; symptoms at rest
29. Metabolic Equivalents (METs) 1 MET = 3.5 ml O 2 utilisation/kg/min Tolerance < 4 METs = higher risk Dr. Andrew Ferguson Activity METS min METS max Cycling 5 mph 2 3 Cycling 10 mph 5 6 Cycling 13 mph 8 9 Ballroom Dancing 4 5 Swimming 8 10 Tennis 4 9 Walking 1 mph 1 2 Walking 2 mph 2 3 Walking 3 mph 3 3.5 Walking 4 mph 5 6 Activity METS min METS max Bed making 2 6 Carrying heavy bags 5 7 Cleaning windows 3 4 Dressing 2 3 General housework 3 4 Grocery shopping 2 4 Painting/decorating 4 5 Sexual intercourse 3 5 Showering 3 4 Vacuuming 3 3.5 Walking up stairs 4 7
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32. Evaluating Respiratory Disease Dr. Andrew Ferguson Established Risk Factors for Pulmonary Complications Urea > 10.7 mmol/L (30 mg/dL) [OR 2.29] Partially or fully dependent [OR 1.92] Age > 70 [OR 1.91] COPD [OR 1.81] Neck, thoracic, upper abdominal, aortic or neurological surgery Prolonged procedures (> 2 hours) Emergency surgery [OR 3.12] Hypoalbuminaemia (< 30 g/L) [OR 2.53] Exercise tolerance < 1 flight of stairs / 100 yards BMI > 30
33. Dr. Andrew Ferguson VAMC Respiratory Failure Risk Index [Arozullah Ann Surg 2000;232:242-53] Preoperative Predictor Point Value Abdominal aortic aneurysm surgery 27 Thoracic surgery 21 Neurosurgery, upper abdominal, peripheral vascular surgery 14 Neck surgery 11 Emergency surgery 11 Albumin < 30 g/L 9 Urea > 10.7 mmol/L (30 mg/dL) 8 Partially or fully dependent status 7 COPD 6 Age > 70 6 Age 60-69 4 Class Point total N (%) Predicted PRF Actual PRF Phase 1 Actual PRF Phase 2 1 < 10 39,567 (48%) 0.5% 0.5% 0.5% 2 11-19 18,809 (23%) 2.2% 2.1% 1.8% 3 20-27 13,865 (17%) 5% 5.3% 4.2% 4 28-40 7,976 (10%) 11.6% 11.9% 10.1% 5 >40 1,502 (2%) 30.5% 30.9% 26.6%
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39. Dr. Andrew Ferguson Preop Medicines Management Stop 48 hours pre-op NSAIDs Stop 4 days pre-op Warfarin (convert to enoxaparin) Stop 7 days pre-op Clopidogrel Aspirin 75 mg usually continued (check with consultant) Herbal remedies HRT
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41. Fasting Guidelines Dr. Andrew Ferguson Time before anaesthesia Food or fluid intake Up to 8 hours Unrestricted Up to 6 hours Light meal Up to 4 hours Breast milk Up to 2 hours Clear liquids only (no solids, no fat) 2 hours pre-anaesthesia Nothing permitted