Elevated Intraoperative Serum Lactate During Craniotomy Is Associated With New Neurological Deficit and Longer Length of Stay

Background: Hundreds of thousands of craniotomies are performed annually in the United States. During craniotomy, elevated serum lactate is a concerning and not infrequent occurrence. Elevated intraoperative serum lactate may occur as a result of global hypoperfusion or localized intracerebral ischemia from surgical retraction or inadequate blood supply. The distinction between systemic and hypoperfusion confined to the brain is important because the treatment differs. For example, fluid resuscitation may be indicated in the former but not the latter. Methods: To address whether elevated intraoperative serum lactate is associated with hypoperfusion confined to the brain or systemic hypoperfusion, we performed a retrospective cohort study of elective adult (age above 18) craniotomy cases. These included 436 surgeries which were performed at our institution under general anesthesia between May 2011 and August 2013. Results: Elevated intraoperative serum lactate in craniotomy patients is associated with new neurological deficits (odds ratio, 2.11) and longer length of stay (20% less likely to be discharged on a given day). Elevated lactate was not associated with systemic complications such as myocardial infarction or mortality. Conclusions: Our findings highlight the importance of conducting a definitive prospective study analyzing the clinical impact and mechanism behind hyperlactatemia in the craniotomy population. Knowledge of the serum lactate level may be of value in guiding intraoperative anesthetic and surgical decisionmaking.