Morbidity Assessment in Surgery: Refinement Proposal Based on a Concept of Perioperative Adverse Events

Table 1

The proposed classification of intraoperative unfavourable incidents.

Grade	Definition of intraoperative incidents
Grade I	Incidents managed without change of operative approach and without further consequences for the patient. This includes minor injury of adherent or adjacent organs and minimal change of intraoperative tactics and cases with blood loss over normal range*.
Grade II	Incidents with further consequences for the patient This includes cases requiring limited resection of intraoperatively injured organs or cases with blood loss which is appreciably over normal range*. For laparoscopic/thoracoscopic/endoscopic surgery it includes intraoperative incidents requiring conversion.
Grade III	Incident leading to significant consequences for patient.

*Amount of blood loss is known parameter influencing on patient postoperative course and recovery [33, 34]. A normal range of blood loss for each particular procedure is subjective in a certain degree, but one can quantify it in regard to different procedures based both on contemporary scientific literature and values typical for own institution. As example in case of liver resection the values of 1000 mL and 2000 mL can be considered to be within normal range and to be appreciably over normal range, respectively, (corresponding to intraoperative incidents Grades I and II). In case of adrenalectomy the corresponding bounds could be considered as 500 mL and 1000 mL, respectively. While reporting intraoperative  unfavourable  incidents, one should indicate this defined bound.