Incidence and predicting factors of perioperative complications during monitored anesthesia care for awake craniotomy

Study objective: To assess incidence and predicting factors of awake craniotomy complications.

Design: Retrospective cohort study.

Setting: Operating room and Post Anesthesia Care unit.

Patients: 162 patients who underwent 188 awake craniotomy procedures for brain tumor, ASA I to III, with monitored anesthesia care.

Measurements: We classified procedures in 3 groups: major event group, minor event group, and no event group. Major events were defined as respiratory failure requiring face mask or invasive ventilation; hemodynamic instability treated by vasoactive drugs, or bradycardia treated by atropine, bleeding >500 ml, transfusion, gaseous embolism, cardiac arrest; seizure, cerebral edema, or any events leading to stopping of the cerebral mapping. Minor event was defined as any complication not classified as major. Multivariate logistic regression was used to determine predicting factors of major complication, adjusted for age and ASA score.

Main results: 45 procedures (24%) were classified in major event group, 126 (67%) in minor event group, and 17 (9%) in no event group. Seizure was the main complication (n = 13). Asthma (odds ratio: 10.85 [1.34; 235.6]), Remifentanil infusion (odds ratio: 2.97 [1.08; 9.85]) and length of the operation after the brain mapping (odds ratio per supplementary minute: 1.01 [1.01; 1.03]) were associated with major events.

Conclusions: Previous medical history of asthma, remifentanil infusion and a long duration of neurosurgery after cortical mapping appear to be risk factors for major complications during AC.