BACKGROUND: Early diagnosis of complications after abdominal surgery is crucial to improve outcomes. This study aimed to evaluate the use of the peritoneal–serum lactate ratio and of peritoneal lactate levels applied alone for predicting the need for reintervention after abdominal surgery.
METHODS: This prospective observational study included 88 patients who underwent abdominal surgery (48 emergency and 40 elective operations) and presented with fever, leukocytosis, late passage of flatus, and abdominal pain by the fourth postoperative day. The lactate levels were measured in the serum and peritoneal fluid. In total, 31 of 88 patients required reintervention. The receiver operator characteristic analysis was used to determine the best threshold value for the peritoneal-serum lactate ratio and for peritoneal lactate levels applied alone to identify patients who required reintervention.
RESULTS: A peritoneal-serum lactate ratio greater than 4.5 (area under the curve, 0.865; 95% confidence interval, 0.773–0.957; p < 0.001) and a peritoneal lactate value greater than 9.1 mmol/L (area under the curve, 0.834; 95% confidence interval, 0.735–0.934; p < 0.0001) discriminated between patients who required reintervention with a sensitivity of 91.3%, a specificity of 81%, and a negative predictive value of 94.4% and a sensitivity of 81.9%, a specificity of 82%, and a positive predictive value of 89%, respectively.
CONCLUSION: The results of our study support the hypothesis that the peritoneal-serum lactate ratio and the peritoneal lactate level applied alone could be safe, simple, inexpensive, noninvasive, and potentially valuable tools for the early identification of patients who require reintervention after elective or emergency abdominal surgery.
LEVEL OF EVIDENCE: Diagnostic study, level III. Prognostic study, level III.