Hyperlactatemia and Elective Tumor Craniotomy: Prospective Observational Study of Prevalence, Risk Factors, and Association With Short-Term Outcomes

BACKGROUND: Hyperlactatemia is common during brain tumor craniotomy, although the pathophysiology and association to outcome are unclear. We prospectively investigated prevalence and risk factors for perioperative hyperlactatemia (S-lactate ≥2.2 mM) as well as its association with short-term outcomes in patients undergoing elective brain tumor craniotomy. METHODS: In 450 patients, arterial lactate was measured hourly from the first surgical incision until 6 hours postoperatively. The primary outcome was a change in the level of neurological disability, measured by the modified Rankin Scale preoperatively and at 30 days after surgery. Secondary outcomes were length of hospital stay, new neurological deficits at discharge, days alive and out of hospital at 30 days, and 30-day mortality. Hyperlactatemia was analyzed both as a dichotomous (≥1 measurement of S-lactate ≥2.2 mM) and as a continuous variable (lactate load). We used both a multivariable regression and a backward stepwise regression analysis to identify risk factors for hyperlactatemia and factors associated with postoperative outcomes. RESULTS: Hyperlactatemia was seen in 66% of the study participants. No association was found between hyperlactatemia and modified Rankin Scale change from baseline to 30 days or any other clinical outcome. Independent factors associated with hyperlactatemia were mean perioperative glucose (0.14; 95% CI: 0.09-0.18; P<0.001), preoperative glucocorticoid dose (0.09; 95% CI: 0.06-0.12, P<0.001), malignant CNS-derived tumor type (0.25; 95% CI: 0.08-0.42; P=0.004), and inverse noradrenaline dose (-0.02; 95% CI: -0.04 to -0.006, P=0.006). CONCLUSIONS: We did not find an association between perioperative hyperlactatemia and short-term outcomes in patients undergoing brain tumor craniotomy. Preoperative glucocorticoids, perioperative glucose, malignant CNS tumor, and noradrenaline dose were independently associated with hyperlactatemia.