Table 4.

Definition and classification of surgical complications

Grade	Definition
Grade 1	Any deviation from the normal postoperative course without the need for pharmacological or surgical, endoscopic and radiological interventions.
Grade 2	Requiring pharmacological treatment with drugs other than such allowed for grade 1 complication. Blood transfusions and total parenteral nutrition are also included.
Grade 3	Requiring surgical, endoscopic or radiological intervention.
3a	Intervention not under general anaesthesia.
3b	Intervention under general anaesthesia.
Grade 4	Life-threatening complication (including CNS complications)* requiring IC/ICU management.
4a	Single-organ dysfunction (including dialysis).
4b	Multiorgan dysfunction.
Grade 5	Death of a patient
Suffix	If the patient suffers from a complication at the time of discharge, the suffix ‘d’ is added to the respective grade of complication. This label indicates the need for a follow-up to fully evaluate the complication.

*Cerebral haemorrhage, ischaemic stroke, subarachnoid haemorrhage, but excluding transient ischaemic attacks.

CNS, central nervous system; IC, intermediate care; ICU, intensive care unit.