Anesthesia for Cochlear Implantation
General anesthesia with endotracheal intubation is the standard and recommended approach for cochlear implant surgery, particularly in pediatric patients and those requiring complete immobility during the procedure. 1
Standard Anesthetic Approach
Preoperative Preparation
Administer premedication with glycopyrrolate and fentanyl citrate intravenously prior to induction to minimize postoperative nausea, vomiting, and vertigo, particularly after cochleostomy. 1
For pediatric patients under 5 years, oral midazolam premedication is appropriate for anxiolysis, with parental presence highly desirable during induction. 1
Assess for syndromal illnesses that may have specific anesthetic implications, including difficult airway anatomy or prolonged QT interval. 1
Induction and Maintenance
Use thiopentone for induction, suxamethonium for intubation, and maintain with 1.3 MAC halothane in a 1:2 mixture of oxygen and nitrous oxide. 1
Alternative volatile anesthetics or total intravenous anesthesia (TIVA) are acceptable based on institutional preference and patient factors. 1
Critical Intraoperative Considerations
Completely discontinue electrosurgical instruments, especially monopolar diathermy, before the cochlear implant device is placed on the patient to prevent device damage. 1
Allow spontaneous ventilation whenever nerve stimulator is used to locate the facial nerve during surgical dissection. 1
Maintain hemodynamic stability and avoid excessive movement, as the surgery is time-consuming and requires precision. 1
Postoperative Management
Administer ondansetron 0.1 mg/kg IV as prophylactic antiemetic given the high risk of postoperative nausea and vomiting from inner ear manipulation. 1
Provide initial postoperative analgesia with fentanyl 1 μg/kg IV, followed by oral ibuprofen for ongoing pain control. 1
Expect rapid recovery with discharge typically on the first postoperative day. 2
Alternative: Local Anesthesia with Sedation
Local anesthesia with conscious sedation is a viable alternative for adult patients with significant comorbidities (ASA Class III-IV) or those at high risk for general anesthesia, including elderly patients with cardiovascular disease. 3, 4, 5, 2
Patient Selection for Local Anesthesia
Consider this approach for elderly patients (>70 years) with coronary artery disease, diabetes, or other significant medical comorbidities. 5, 2
Patients must be cooperative and able to tolerate the procedure while conscious. 4
Use a modified suprameatal approach or transcanal technique as these require minimal drilling and are better tolerated under local anesthesia. 5, 2
Local Anesthesia Technique
Administer dexmedetomidine for conscious sedation, which provides rapid sedation without respiratory depression and maintains patient cooperation. 4, 5
Combine with remifentanil infusion for analgesia in high-risk cardiac patients. 5
Advantages of Local Anesthesia Approach
Reduced intra- and postoperative complications, particularly cardiovascular events. 4, 2
Faster recovery with minimal postoperative dizziness and vomiting. 3
Lower hospital costs and shorter surgical duration (approximately 60 minutes). 5
Ability to perform intraoperative stapedial reflex measurements with reliable thresholds. 4
Patients can communicate intraoperatively using cue cards, allowing assessment of auditory perception and absence of facial nerve stimulation. 4
Common Pitfalls to Avoid
Never use electrosurgical instruments after the implant device is in place - this is the most critical technical consideration to prevent device damage. 1
Do not proceed with general anesthesia in high-risk elderly patients without considering local anesthesia alternatives, as this unnecessarily increases morbidity. 3, 5, 2
Avoid inadequate antiemetic prophylaxis, as postoperative nausea and vomiting are common due to inner ear manipulation during cochleostomy. 1
Do not overlook syndromal associations in pediatric patients that may complicate airway management or cardiac stability. 1