Lactate Levels and Their Relation to Surgical Site Infections in Patients Undergoing Cytoreductive Surgery with Hyperthermic Intraperitoneal Chemotherapy

<b><i>Introduction:</i></b> Peritoneal carcinomatosis (PC) patients undergoing cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) face a high risk of morbidity. Surgical site infections (SSIs) are among the main contributors to this issue. This relation is influenced not only by the effects of major surgical resections but also by the hemodynamic changes induced by HIPEC. Although elevated lactate levels (LL) have been associated with greater complication rates in CRS-HIPEC patients, their direct association with the development of SSIs has not been thoroughly investigated. <b><i>Methods:</i></b> Patients who underwent CRS + HIPEC were retrospectively reviewed. Pre-operative demographic data, hemodynamic parameters and records, transfusion records, and all post-operative follow-up and treatment records were analyzed. Patients were categorized into SSI+ and SSI-. Factors contributing to SSI development were examined using regression analysis. <b><i>Results:</i></b> A total of 110 patients who underwent CRS + HIPEC between January 2018 and December 2021 were included in the study. LL obtained at intensive care unit (ICU) admission were greater in patients who developed SSIs (p = 0.020). Cutoff point for ICU admission LL in diagnosing SSI was ≥6 mmol/L (area under the curve: 0.640 [0.526-0.753], p = 0.020). SSI development (23% vs. 50%, p = 0.003) was more prevalent in patients with lactate values ≥6 mmol/L. In multi-variable analysis, LL ≥6 mmol/L (odds ratio [OR]: 4.614, p = 0.005) and clean-contaminated wounds (OR: 27.677, p = 0.002) were related with increased SSI development. <b><i>Conclusion:</i></b> In patients with PC, LL of 6 mmol/L or greater during the ICU stay have been associated with SSI development. For this high-risk patient subgroup, a readily available peri-operative parameter such as lactate may guide prophylactic antibiotic selection. However, despite its high specificity, the low sensitivity of our findings should be carefully considered before clinical decision-making. Further studies analyzing larger, more homogeneous cohorts are needed to better clarify the relation between LL, SSI development, and prophylactic antibiotic use.