Risk factors for surgical site infection following laparotomy: Effect of season and perioperative variables and reporting of bacterial isolates in 287 horses.
Authors: Isgren C M, Salem S E, Archer D C, Worsman F C F, Townsend N B
Journal: Equine veterinary journal
Summary
# Editorial Summary: Surgical Site Infection Following Equine Laparotomy A retrospective analysis of 287 horses undergoing exploratory laparotomy over three years identified surgical site infection (SSI) in just over a quarter of cases (73 horses, 25.4%), with multivariable logistic regression revealing several significant risk factors for this costly post-operative complication. Greater bodyweight, elevated packed cell volume (≥48%) on admission, small intestinal resection procedures, and post-operative colic all substantially increased SSI likelihood, whilst three-layer incision closure proved markedly protective compared to two-layer technique (odds ratio 0.31). Notably, seasonal variation emerged as a strong independent risk factor, with winter and summer months carrying 3.8- and 5.6-fold increased odds respectively, though surgery performed outside standard working hours showed no significant association with infection rates. Bacterial culture revealed predictable enteric flora (E. coli in 59.5% of isolates, Enterococcus and Staphylococcus species also common), though antimicrobial resistance patterns were concerning, with 92% of isolates resistant to penicillin and 18% to gentamicin. For practitioners, these findings emphasise the importance of three-layer closure protocols, heightened vigilance during seasonal peaks, and careful perioperative management in higher-risk patients—particularly those presenting with elevated haematocrit or requiring intestinal resection—whilst suggesting that emergency surgical timing need not be a primary infection control concern.
Read the full abstract on PubMed
Practical Takeaways
- •Implement three-layer closure technique for laparotomy incisions to reduce SSI risk by approximately 70%
- •Heightened infection surveillance and preventive protocols should be considered for surgeries performed during winter and summer months
- •High-risk patients (heavy bodyweight, elevated PCV on admission, small intestinal resection cases, those developing post-operative colic) warrant intensified post-operative monitoring and infection prevention strategies
Key Findings
- •SSI developed in 73/287 horses (25.4%) during hospitalization following laparotomy
- •Winter and summer surgery significantly increased SSI risk (OR 3.84 and 5.63 respectively) compared to other seasons
- •Three-layer incision closure was protective against SSI (OR 0.31) compared to two-layer closure
- •Greater bodyweight, elevated packed cell volume (≥48%), small intestinal resection, and post-operative colic were independent risk factors for SSI
- •E. coli (59.5%), Enterococcus spp. (42.4%), and Staphylococcus spp. (25.4%) were the most common isolates, with 92% penicillin resistance