Table 2.

The refinement proposal to the Accordion classification of postoperative complications [10] (text marked by the italic type presents the modified points in the classification).

Gradea	Definition of postoperative complication
Grade I	Requires only minor invasive procedures that can be done at the bedside, such as insertion of intravenous lines, urinary catheters, and nasogastric tubes, and drainage of wound infections. Physiotherapy and antiemetics, antipyretics, analgesics, diuretics, electrolytes, and physiotherapy are permitted. It includes cases requiring a doubly prolonged postoperative stay b to treat conditions which otherwise are considered as sequel
Grade II	Requires pharmacologic treatment with drugs other than such allowed for minor complications, for example, antibiotics. Postoperative blood transfusions and total parenteral nutrition are also included
Grade III	No general anaesthesia: requires management by an endoscopic, interventional procedure or reoperation without general anaesthesiac,d
Grade IV	General anesthesia or single-organ failure
Grade V	General anesthesia and single organ failure or multisystem organ failure (>2 organ systems)
Grade VI	Death within 30 postoperative days or up to discharge if patient stays longer in the hospital.

^aMinor complications: Grade I–III; major complications: Grade IV–VI.

^bDuration of median hospital stay for that disease and procedure which is present in the particular institution is to be applied as a reference value.

^cNeed for artificially pulmonary ventilation during patient anaesthesia is a boundary to define general anaesthesia.

^dCases when an intervention was done due to suspicion of complication (without its confirmation) are not to be regarded as a basis for severity grading. However such cases should be reported (see examples in the text).