Table 1

The Clavien-Dindo classification of postoperative complications

GradeDefinition (examples listed in italics)
IAny deviation from the normal postoperative course without the need for pharmacological (other than the ‘allowed therapeutic regimens’), surgical, endoscopic or radiological intervention
Allowed therapeutic regimens are: selected drugs (antiemetics, antipyretics, analgesics, diuretics and electrolyte replacement), physiotherapy and wound infections opened at the bedside but not treated with antibiotics
Examples: Ileus (deviation from the norm); hypokalemia treated with sando K; nausea treated with cyclizine; acute kidney injury treated with intravenous fluids
IIRequiring pharmacological treatment with drugs beyond those allowed for grade I complications. Blood transfusions and total parenteral nutrition are also included
Examples: Surgical site infection treated with antibiotics; myocardial infarction treated medically; Deep venous thrombosis treated with enoxaparin; pneumonia or urinary tract infection treated with antibiotics; blood transfusion for anaemia
IIIRequiring surgical, endoscopic or radiological intervention
Examples: Return to theatre for any reason; therapeutic endoscopic therapy (do not include diagnostic procedures); interventional radiology procedures
IVLife-threatening complications requiring critical care management; neurological complications including brain haemorrhage and ischaemic stroke (excluding TIA).
Examples: Single or multiorgan dysfunction requiring critical care management, e.g. pneumonia with ventilator support, renal failure with filtration; SAH; stroke
VDeath of a patient
  • TIA, transient ischaemic attack.