Anesthesia for awake craniotomy: A retrospective study

Context: Awake craniotomy is increasingly performed the world over. We share our experience of performing craniotomy awake with our anesthetic protocol.
Aims: To evaluate and analyze the anesthesia records of the patients who underwent awake craniotomy at our institution.
Settings and Design: University teaching hospital, Retrospective study.
Materials and Methods: We reviewed records of the 42 consecutive patients who underwent awake craniotomy under conscious sedation using Fentanyl and Propofol infusion until December 2005. The drugs were titrated (Bispectral monitoring was used in 16 patients) to facilitate intermittent intraoperative neurological testing. All patients received scalp blocks with a mixture of bupivacaine and lignocaine with adrenaline. Haloperidol and ondansetron were administered in all patients at induction of anesthesia.
Results: All patients completed the procedure. One patient each needed endotracheal intubation and LMA for airway control during closure, while another required CPAP perioperatively because of desaturation to < 80%. There was significantly decreased use of anesthetics ( P < 0.001) and a trend towards reduction in complications (e.g. respiratory depression and deep sedation) ( P >0.05) with the use of BIS as compared to without BIS. Intraoperative complications were hypertension (19%), tight brain (14.2%), focal seizure (9.5%) respiratory depression (7.1%), deep sedation (7.1%), tachycardia (7.1%) and bradycardia. Two patients desaturated to < 95%. 23.8% patients developed transient neurological deficits. The most frequent postoperative complications were PONV (19%) and seizures (16.6%).
Conclusions: With the use of advanced monitoring and newer anesthetics, awake craniotomy is a relatively safe procedure with an accepted rate of complications.

Keywords
Anesthesia, awake craniotomy, bispectral index, complication, fentanyl, haloperidol, monitoring, propofol, regional anesthesia, scalp block