Association of Postoperative Hypoglycemia With Mortality After Elective Craniotomy

BACKGROUND AND OBJECTIVES: Hypoglycemia is a known risk of intensive postoperative glucose control in neurosurgical patients. However, the impact of postoperative hypoglycemia after craniotomy remains unexplored. This study aimed to determine the association between postoperative hypoglycemia and mortality in patients undergoing elective craniotomy. METHODS: This study involved adult patients who underwent elective craniotomy at the West China Hospital, Sichuan University, between January 2011 and March 2021. We defined moderate hypoglycemia as blood glucose levels below 3.9 mmol/L (70 mg/dL) and severe hypoglycemia as blood glucose levels below 2.2 mmol/L (40 mg/dL). The primary outcome was postoperative 90-day mortality. RESULTS: This study involved 15 040 patients undergoing an elective craniotomy. Overall, 504 (3.4%) patients experienced moderate hypoglycemia, whereas 125 (0.8%) patients experienced severe hypoglycemia. Multivariable analysis revealed that both moderate hypoglycemia (adjusted odds ratio [aOR] 1.86, 95% CI 1.24-2.78) and severe (aOR 2.94, 95% CI 1.46-5.92) hypoglycemia were associated with increased 90-day mortality compared with patients without hypoglycemia. Moreover, patients with moderate (aOR 2.78, 95% CI 2.28-3.39) or severe (aOR 16.70, 95% CI 10.63-26.23) hypoglycemia demonstrated a significantly higher OR for major morbidity after adjustment, compared with those without hypoglycemia. Patients experiencing moderate (aOR 3.20, 95% CI 2.65-3.88) or severe (aOR 14.03, 95% CI 8.78-22.43) hypoglycemia had significantly longer hospital stays than those without hypoglycemia. The risk of mortality and morbidity showed a tendency to increase with the number of hypoglycemia episodes in patients undergoing elective craniotomy (P for trend = .01, <.001). CONCLUSION: Among patients undergoing an elective craniotomy, moderate hypoglycemia and severe hypoglycemia are associated with increased mortality, major morbidity, and prolonged hospital stays. In addition, the risk of mortality and major morbidity increases with the number of hypoglycemia episodes.