Management of the High-Risk Surgical Patient
Cardiothoracic anaesthesia and emergency anaesthesia are considered elsewhere (Chs 33, 34 and 37), and this chapter will concentrate on the patient undergoing scheduled major non-cardiac surgery. However, the principles of treatment, particularly fluid management, generally apply also to the patient undergoing an emergency procedure.
RISK PREDICTION SCORING SYSTEMS
Shoemaker’s Criteria
Previous severe cardiorespiratory illness (acute MI, COPD, stroke)
Extensive ablative surgery planned for carcinoma
Severe multiple trauma (more than three organs or two body cavities involved)
Massive acute blood loss (more than 8 units)
Age over 70 years with limited physiological reserve
Shock (mean arterial pressure less than 60 mmHg)
Acute abdominal catastrophe with haemodynamic instability (pancreatitis, bowel infarction, perforated viscus, GI bleeding)
Revised Cardiac Risk Index
POSTOPERATIVE PULMONARY COMPLICATION RISK PREDICTORS
LABORATORY INVESTIGATIONS FOR RISK ASSESSMENT
Cardiopulmonary Exercise Testing (CPET)
Anaerobic Threshold
AT is identified as the point at which there is onset of lactate production through the activation of anaerobic pathways. The lactate produced is buffered by bicarbonate to produce water and carbon dioxide. The net effect is an increase in the slope of the graph of carbon dioxide production relative to oxygen uptake (Fig. 23.1