Table 4.

Criteria used during the retrospective chart review to identify morbidities occurring during the postoperative period (adapted from that described by Bennett-Guerrero et al. [16])

System	Morbidities
Respiratory	New requirement for supplemental oxygen New requirement for respiratory support
Immunological	Antimicrobial therapy Pyrexia
Renal	Oliguria < 500 mL/24 h Rise in serum creatinine, either ≥ 26.4 μmol/L from baseline, or a greater than 1.5-fold rise from baseline Urinary catheter in situ
Gastrointestinal	Unable to tolerate enteral diet for any reason
Cardiovascular	Tests or therapy for any of: - New myocardial infarction or ischaemia - Hypotension (requiring fluid therapy > 200 mL/h or pharmacological therapy) - Atrial or ventricular arrhythmias - Cardiogenic pulmonary oedema - New thrombotic event requiring anticoagulation
Neurological	New focal neurological deficit, confusion, delirium or coma New postoperative pain requiring parenteral opioids or regional analgesia
Haematological	Requirement for blood product transfusion: - Red cell concentrate - Platelets - Fresh frozen plasma - Prothrombin complex concentrate - Fibrinogen
Wound	Wound dehiscence requiring surgical exploration, or drainage of pus from wound