Table 1 Clinical criteria for high-risk surgical patients (Reproduced with permission from Boyd O, Jackson N. Clinical review: How is risk defined in high-risk surgical patient management? Critical Care 2005, 9:390–396, Copyright Springer Nature)

Previous severe cardiorespiratory illness — acute myocardial infarction, chronic obstructive pulmonary disease, or stroke

Late-stage vascular disease involving aorta

Age > 70 years with limited physiological reserve in one or more vital organs

Extensive surgery for carcinoma (e.g. oesophagectomy, gastrectomy cystectomy)

Acute abdominal catastrophe with haemodynamic instability (e.g. peritonitis, perforated viscus, pancreatitis)

Acute massive blood loss > 8 units

Septicaemia

Positive blood culture or septic focus

Respiratory failure: PaO2 < 8.0 kPa on FIO2 > 0.4 or mechanical ventilation > 48 h

Acute renal failure: urea > 20 mmol/l or creatinine > 260 mmol/l