The Clavien-Dindo classification of surgical complications
| Grade | Definition |
| Grade I | Any deviation from the normal postoperative course without the need for pharmacological treatment or surgical, endoscopic and radiological interventions. Allowed therapeutic regimens are: drugs as antiemetics, antipyretics, analgetics, diuretics and electrolytes and physical therapy. This grade also includes wound infections opened at the bedside. |
| Grade II | Requiring pharmacological treatment with drugs other than such allowed for grade I complications. Blood transfusions and total parenteral nutrition are also included. |
| Grade III | Requiring surgical, endoscopic or radiological intervention. |
| Grade-IIIa | Intervention not under general anaesthesia. |
| Grade-IIIb | Intervention under general anaesthesia. |
| Grade IV | Life-threatening complication (including CNS complications)* requiring IC/ICU-management. |
| Grade-IVa | Single organ dysfunction (including dialysis). |
| Grade-IVb | Multiorgan dysfunction. |
| Grade V | Death of a patient. |
Adapted from the study by Dindo et al.39
*Brain haemorrhage, ischaemic stroke, subarachnoidal bleeding, but excluding transient ischaemic attacks.
CNS, central nervous system; IC, intermediate care; ICU, intensive care unit.