Clinical importance and characteristics of secondary culture-negative sepsis after surgery for abdominal infection: A retrospective study

Purpose: Herein, we identified whether the clinical outcomes differ according to secondary culture results in postoperative sepsis patients and determined the predictors of culture-negative sepsis after abdominal surgery based on the secondary culture results. Methods: Patients who admitted to the intensive care unit(ICU) after surgery due to abdominal infection and diagnosed with postoperative sepsis were included. Culture tests were obtained from body fluids and drains. Primary culture test was performed immediately after surgery, and secondary culture test was performed within 48 h to 7days after surgery. The participants were divided into the culture-positive sepsis(CPSS) and the culture-negative sepsis group(CNSS) according to culture positivity, and the clinical outcomes were compared. The predisposing factors of secondary CNSS were determined using multiple logistic regression analysis. Results: Among 83 participants, 51 patients (61.4%) showed secondary culture-positivity(2′CPSS) and 32 patients (38.6%) showed secondary culture-negativity(2′CNSS). ICU mortality and in-hospital mortality were not different between two groups, but the length of ICU and hospital stay were significantly longer in 2′CPSS. In multivariate analysis, non-bowel surgery [odds ratio(OR) = 6.934, 95% confidence interval(CI):1.609–29.884, p=0.009], no diabetes (OR = 4.027,95%CI:1.161–13.973, p=0.028), and the prolonged administration of preoperative antibiotics (OR = 1.187,95%CI:1.023–1.377, p=0.024) were revealed as significant predisposing factors of 2′CNSS. Conclusion: Mortality showed no difference according to secondary culture positivity in postoperative sepsis patients after abdominal surgery. If a patient underwent non-bowel surgery or had no diabetes or administered preoperative antibiotics for more than 3 days, the physician should pay more attention to clinical deterioration, even if the seconday culture results are negative.