Factors affecting a persistent increase in the perioperative lactate levels in colorectal cancer surgery and its impact on postoperative outcomes

Aim and objectives: High lactate concentration is a sign of tissue hypoxia in the perioperative period. Therefore, close monitoring of blood lactate is essential in cancer patients undergoing surgery. The first aim of this study is to determine the factors affecting the perioperative consistently high lactate levels in patients undergoing colorectal cancer (CRC) surgery. Our second goal was also to investigate the relationship between persistent perioperative hyperlactatemia and postoperative outcomes. Methodology: Retrospectively enrolled 323 patients who underwent curative resection for colorectal cancer. Lactate values of all patients were examined at the end of the surgery and in ICU-stay at 3rd, 6th, 12th, and 18th hours immediately after surgery. All lactate values above 2 mmol/L were considered elevated. The patients were divided into two groups as those with persistently perioperative increased lactate levels and those without. Results: Thirty-four out of 323 patients experienced persistent hyperlactatemia during the perioperative period. The multivariate analysis presented that lactate levels were affected by BMI >= 30 kg/m(2) (p = 0.005), male sex (p = 0.022), and the TNM stage III (p = 0.045). Major complications were encountered in 45 of 323 patients. Eleven of them were found in the persistent hyperlactatemia group (p = 0.003). Anastomotic leakage was the most common complication among them. The persistent group had a significantly prolonged length of hospital stay (p = 0.050), but there was no survival difference between the two groups (p = 0.797). Conclusion: In this study, which included patients undergoing elective surgery for colorectal cancer, the risk factors for persistent hyperlactatemia during the perioperative period were BMI >= 30 kg/m(2), male gender, and advanced TNM stage. The persistent perioperative hyperlactatemia may predict major complications in the early postoperative period, especially anastomotic leak and also a prolonged hospital stay. On the contrary, it has no prognostic prediction for mortality.