An Unusual Case of Alarming Lactic Acidosis: Brain Metabolic Cross-Talk.

Abstract

A 39-year-old male with a BMI of 30.8 kg/m ² and a normal medical history underwent excision of a left orbito-cavernal hemangioma (4 × 2 × 2 cm) under general anesthesia. Balanced anesthesia and fluid management guided by pulse pressure variation (kept below 12%) were employed. Despite stable hemodynamics and normal blood sugar levels, arterial blood gas (ABG) analysis revealed a progressive rise in lactate levels, reaching 10.6 mmol/L, accompanied by acidemia. Systemic hypoperfusion was ruled out by maintaining mean arterial pressure between 70-80 mm Hg, ensuring a capillary refill time of less than 3 seconds, and confirming a central venous oxygen saturation of 72%. With a total blood loss of 800 mL, one unit of packed red blood cells was transfused due to concerns about decreased microcirculation and tissue hypoxia. After 10 hours of surgery, sodium bicarbonate (NaHCO3) was administered to mitigate metabolic acidosis and its potential impact on intracranial pressure. Postoperatively, lactate levels remained elevated (8-9 mmol/L), but with continued NaHCO3 infusion, lactate reduced to 6.4 mmol/L, allowing extubation. The patient's lactate normalized by the evening, and recovery was uneventful. This case highlights the significant metabolic disturbances, particularly lactic acidosis, that can arise during brain tumor surgery due to prolonged operative times, large tumor size, higher BMI, and stress-induced metabolic derangements. Awareness and prompt management of these disturbances are crucial for successful patient outcomes.