Time of Day Impacts Surgical Site Infection in Emergency Gastrointestinal Surgery in Kenya

Surgical site infections (SSIs) are a leading cause of postoperative morbidity, particularly in low- and middle-income countries (LMICs). The influence of operative timing on SSI risk remains unclear in these settings. This study aimed to assess the association between case timing and SSIs following emergency gastrointestinal surgery at a tertiary hospital in Kenya.

We performed a retrospective cohort study of adult patients undergoing emergency gastrointestinal operations between January 2016 and December 2019. Procedures were categorized by timing: weekday daytime (08:00-16:59) versus off-peak (weeknights, weekends, and holidays). The primary outcome was SSI. Multivariable logistic regression adjusted for wound classification, procedure type, and the Africa Surgical Outcomes Study (ASOS) risk score. Sensitivity analyses evaluated duration of illness, prior care, operative duration, presence of perforation, year of admission, admission to the intensive care unit, and number of surgeons.

Of 400 patients included, 58 (14.5%) developed an SSI. SSI occurred in 19.9% of weekday cases versus 11.7% of off-peak cases (p = 0.029). In adjusted analysis, weekday operations were associated with increased odds of SSI (OR 2.0, 95% CI 1.1-3.6, and p = 0.024). Dirty wound classification and small intestine and colorectal cases were also associated with increased SSI rates in the model. The observed SSI rate was significantly lower than the 28.6% rate predicted by GlobalSurg data for middle-HDI countries (p < 0.001).

Contrary to findings from high-income settings, emergency operations performed during off-peak hours were associated with fewer SSIs than weekday cases. This may reflect workflow differences or lower operating room traffic. The findings support ongoing efforts to optimize perioperative systems and challenge assumptions about off-hour surgical care in LMICs.