Clavien-Dindo Classification

Grading Summary

Grade	Definition	Examples
0	No complication	Uneventful recovery
I	Deviation from normal course; only Grade I drugs allowed. Wound opened at bedside.	Wound seroma drained at bedside, antiemetic use, fever treated with paracetamol
II	Pharmacological treatment beyond Grade I drugs	Antibiotics for SSI, blood transfusion, TPN, UTI requiring antibiotics
IIIa	Intervention required; NOT under general anaesthesia	CT-guided drain, endoscopic haemostasis, ERCP for bile leak
IIIb	Intervention required UNDER general anaesthesia	Return to theatre for anastomotic leak, laparotomy for bleeding
IVa	Life-threatening; ICU admission; single organ failure	Respiratory failure requiring ventilation, acute renal failure requiring dialysis
IVb	Life-threatening; ICU admission; multi-organ failure	Septic shock with multi-organ dysfunction
V	Death	30-day or in-hospital mortality

Suffix "d" (disability) can be appended to any grade if a complication results in permanent disability at discharge.

Standardised reporting: The Clavien-Dindo classification is the international standard for reporting post-operative complications in surgical trials and audits. Required by most high-impact surgical journals.
Timing: Grade complications from day of surgery to hospital discharge. For outpatient procedures, use a 30-day window.
Grade I drugs (allowed without upgrading): Antiemetics, antipyretics, analgesics, diuretics, electrolyte replacement, physiotherapy. Wound infection opened at bedside without anaesthetic = Grade I.
Grade II trigger: Any antibiotic prescription (even oral) upgrades a wound infection from I to II. Blood transfusion = Grade II minimum.
Grade III distinction: The subgrades (IIIa vs IIIb) depend entirely on whether general anaesthesia was needed for the intervention. Bedside pleural tap = IIIa. Return to theatre = IIIb.
Comprehensive Complication Index (CCI): When multiple complications occur, the CCI calculates a weighted aggregate score using individual CD grades — more informative for complex patients.
Quality metric: Proportion of Grade ≥ IIIb complications is used as a surrogate for major surgical morbidity in hospital quality reporting.

Dindo D, Demartines N, Clavien PA. Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg. 2004;240(2):205–213.
Clavien PA, et al. The Clavien-Dindo classification of surgical complications: five-year experience. Ann Surg. 2009;250(2):187–196.
Slankamenac K, et al. The comprehensive complication index: a novel continuous scale to measure surgical morbidity. Ann Surg. 2013;258(1):1–7.