Effect of total intravenous anaesthesia on intraoperative monitoring of cochlear implant function in paediatric patients.

UNLABELLED: There is increasing evidence in medical literature which proves that post-operative outcomes in children implanted early are better. Initial setting of these children's stimulation parameters is challenging because of their limited communication abilities. Intraoperative electrical impedance measurements, electrically evoked stapedial reflex threshold (ESRT) and evoked compound action potential (ECAP) are used for implant settings in some centres as no cooperation is required from the child. Aim Evaluate the effects of intravenous anaesthesia on intraoperative monitoring of cochlear implant function in paediatric cochlear implantees at our centre. Method Prospective study from January 2011 to December 2011. COHORT: 29 children. Age - 18 months to 11 yrs. All children had bilateral severe to profound sensorineural hearing loss. Children with compromised neural/cochlear anatomy were excluded. Patients were maintained on an infusion of Fentanyl @ 0.3-0.6 ugm/kg/hr and Propofol @ 4-8 mg/kg/hr intraoperatively. Intraoperative measurements were done after performing the train of four test on the adductor pollicis muscle Results It was observed that ESRT was unaffected by intravenous anaesthesia. Electrical impedance and ECAP were not affected by any technique of anaesthesia. Conclusion Intravenous anaesthesia has little or no effect on the intraoperative auditory thresholds and is therefore recommended for determining these thresholds during cochlear implant surgery.