Risk factors of post-operative severe hyperlactatemia and lactic acidosis following laparoscopic resection for pheochromocytoma.

Severe hyperlactatemia (SH)/lactic acidosis (LA) after laparoscopic resection of pheochromocytoma is an infrequently reported complication. The study aims to investigate the incidence of this complication and to determine the clinical risk factors. Patients who underwent laparoscopic resection for pheochromocytoma between 2011 and 2014 at Peking Union Medical College Hospital were enrolled. LA was defined as pH < 7.35, bicarbonate <20 mmol/L, and serum lactate ≥5 mmol/L; SH as lactate ≥5 mmol/L; and moderate hyperlactatemia (MH) as lactate 2.5-5.0 mmol/L without evidence of acidosis (pH > 7.35 and/or bicarbonate >20 mmol/L). Data concerning patient demographics, clinical history, and laboratory results were collected and statistical analyses were performed. Out of 145 patients, 59 (40.7%) developed post-operative hyperlactatemia. The incidences of MH and SH/LA were 25.5% and 15.2%, respectively. Multivariate analysis demonstrated that body mass index (BMI) (odds ratio [OR], 1.204; 95% confidence interval [CI], 1.016-1.426), 24-hour urine epinephrine concentration (OR, 1.012; 95% CI, 1.002-1.022), and tumor size (OR, 1.571; 95% CI, 1.102-2.240) were independent predictors of post-operative SH/LA. The data show that post-operative SH/LA is not a rare complication after pheochromocytoma resection and may be closely associated with higher BMI, larger tumor size, and higher levels of urine epinephrine.