Clinical and predictive value of blood lactate levels during cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC): a comparative analysis.

Postoperative outcome after cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is strongly related to surgical and anesthesiologic expertise. This study aims to evaluate the clinical significance and prognostic value of lactate levels (LL) measured during CRS-HIPEC on postoperative outcome compared to similar major surgical procedures. Patients who were treated between January and September 2019 at our Institute and met the inclusion criteria were selected. Patients were divided into three groups: group 1: patients who underwent major surgical procedures; group 2: patients who underwent CRS without HIPEC; group 3: patients who underwent CRS with HIPEC. Intraoperative LL were analyzed and correlated with surgical procedure and postoperative outcome. We observed a significant increase of LL during surgical/CRS phase (group 1: p = 0.0001; group 2: p = 0.001; group 3: p = 0.057), rather than during the HIPEC phase in group 3 (p = ns). In patients undergoing CRS and peritonectomies, the mean LL were significantly higher compared to group 1 (p = 0.05). Although not statistically significant, the complication rate was higher in patients with end-CRS lactate values > 2 mMol/l, especially in the group undergoing CRS plus HIPEC. Our pilot study shows that higher LL during peritoneal cancer surgery are expected compared to major surgical procedures. Cytoreductive phase, rather than HIPEC, is related to an increase of LL. The role of LL as an early marker of postoperative complications after CRS-HIPEC should be further verified in properly designed studies.