The Clinical Outcome of Elevated Peri-Operative Lactate Levels in Patients Undergoing Craniotomy

Elevated perioperative serum lactate is a common finding during craniotomy, but its clinical significance and origin—whether reflecting systemic hypo perfusion or localized cerebral metabolic shifts—remain unclear. This study aimed to prospectively evaluate the association between intraoperative hyperlactatemia and postoperative outcomes in elective craniotomy patients. In this prospective study, 50 adult patients undergoing elective craniotomy for brain tumors or lesions were enrolled. Arterial blood gas analyses, including serum lactate measurements, were performed preoperatively, immediately postoperatively, and at 24 hours. Patients were stratified into High-Lactate (HL, ≥2 mmol/L) and Normal-Lactate (NL,