Occurrence and preventability of adverse drug events in surgical patients: a systematic review of literature

Background: Adverse drug events (ADEs) are a considerable cause of inhospital morbidity and mortality. Patient flow differs substantially for surgical and nonsurgical patients: surgical patients are subjected to multiple medication changes related to surgical intervention or postoperative care. The objective of this study is to systematically review the occurrence and nature of ADEs in surgical patients. Also, a comparison with nonsurgical patients was made. Methods: A search was conducted in Embase and Medline identifying studies that reported observational data on the occurrence and nature of ADEs in surgical hospitalised adult patients. If sufficient data were available, the occurrence of (preventable) ADEs was compared between surgical and nonsurgical patients. Results: Six studies fulfilled the inclusion criteria. The occurrence of ADEs in surgical patients ranged from 2.0 to 27.7 per 100 admissions, from 4.7 to 8.9 per 1,000 patient days, or involved 8.9% of the patients. Proportions of preventable ADEs in surgical patients were 18% and 54%, described in two studies. A head-to-head comparison of surgical patients and nonsurgical patients was possible for five of six studies. The occurrence of ADEs in nonsurgical patients was significantly higher than in surgical patients in three studies. Conclusions: ADEs are a relevant problem in surgical patients and nonsurgical patients, with a high proportion of preventable ADEs. The occurrence of ADEs appears to be higher in nonsurgical patients than in surgical patients. However, studies lack details on the differences in nature of ADEs between hospital populations. To improve medication safety this knowledge is essential.