Effect of total intravenous vs volatile anesthetics on intraoperatively acquired electrically evoked compound action...

The purpose of the present study was to compare the effects of inhalational anesthesia to those of total intravenous anesthesia on intraoperative electrically evoked compound action potential (e-ECAP) thresholds in children undergoing cochlear implantation.

Randomized prospective study.

Tertiary referral teaching hospital.

Forty children aged 6 months to 17years with bilateral severe-to-profound sensorineural hearing loss and undergoing cochlear implantation were enrolled in the study.

Patients were randomly assigned (1:1 ratio) into 2 groups to receive inhalational or total intravenous anesthesia.

The e-ECAP measurements were obtained with neural response telemetry software.

All electrodes showed lower e-ECAP thresholds under propofol, and results were statistically significant for the apical electrodes (P<.05). There was no statistical difference in the impedances between the 2 groups. Propofol minimally affected the e-ECAP. In contrast, the impedance was not affected by anesthesia.

Volatile anesthetics result in higher e-ECAP thresholds in children, suggesting that e-ECAP thresholds acquired during inhalational anesthesia overestimate auditory nerve stimulation levels, which may cause discomfort postoperatively and adversely affect the child's adaptation to the implant. We recommend the use of total intravenous anesthesia for the measurement of the e-ECAP thresholds during cochlear implant surgery.