Peroperative and immediate postoperative adverse events in patients undergoing elective general and orthopaedic surgery. The Gothenburg study of perioperative risk (PROPER). Part II.

All anaesthetic and surgical procedures impose a certain risk of complications. However, reliable estimates of this risk from prospective studies are rare. This study is a prospective clinical epidemiological study of 1361 consecutive patients subjected to elective general and orthopaedic surgery. These patients were followed from an extensive preoperative assessment to three months after the operation. In this report the peroperative and early postoperative period in the postoperative care unit or intensive care unit is described. General anaesthesia was given to 59% and regional/local anaesthesia to 41%. Adverse peroperative events occurred in 19%. The most common were circulatory events (11%), respiratory (4%), and allergic events (1%). Most events were of minor severity. However, with the official registration system, only 1 out of 8 events was detected. In the postoperative unit one or more adverse event was noted in 47% of the cases. These were dominated by circulatory (18.4%) and respiratory events (5.0%). CNS depression was noted in 6.8% of the cases. Most per- and postoperative event variables were highly correlated to the degree of surgical stress. In conclusion, a new concept for preoperative assessment and the registration of events during and after surgery was used. In this way, a large number of events of importance, not least for quality assurance, were found that would be missed with the official coding system. In a previous report we could show that even minor events affected the cost of care substantially.