BACKGROUND: A number of perioperative risk factors may suppress the immune system and contribute to the development of post-operative complications. The association between surgical site infection (SSI) and other wound-related complications resulting from immunosuppression through either perioperative administration of dexamethasone, pre-operative smoking or alcohol abuse is, however, uncertain.

METHODS: This study was a post hoc analysis of data from the PROXI randomized trial in 1386 patients who underwent emergency or elective laparotomy. We assessed the associations of use of dexamethasone, smoking status and alcohol abuse with the primary outcome, being a composite of SSI, anastomotic leak, wound dehiscence, burst abdomen and 30-day mortality.

RESULTS: The primary outcome occurred in 21% of patients receiving dexamethasone versus 28% of patients not receiving dexamethasone, and this was not statistically significant when adjusting for stratification variables originally used in the PROXI trial [OR 0.90, 95% CI (0.65-1.24)]. In smokers, the primary outcome occurred in 32%, compared with 23% of non-smokers (P = 0.0001). Smokers also had a higher frequency of SSI (25% vs 17%, P < 0.0001) and burst abdomen (3.8% vs 2.4%, P = 0.04). In alcohol abusers, the primary outcome occurred in 48%, compared with 25% in patients who did not abuse alcohol (P = 0.0006). Burst abdomen occurred more commonly in alcohol abusers (15% vs 2.3%, P < 0.0001).

CONCLUSION: Perioperative administration of dexamethasone was not significantly associated with SSI or other wound-related complications. Conversely, smoking and alcohol abuse were both significant predictors of the primary outcome consisting of wound-related complications and mortality.