Cochlear implantation and the older patient

Cochlear implantation (CI) is an acceptable therapeutic option for patients with irreversible hearing loss. Most elderly patients are not being referred due to fear of adverse outcome related to general anaesthesia.

Hearing impairment is one of the most common disabilities in the elderly. For 10% of these patients, the hearing impairment is so profound that conventional amplification devices fail to provide significant benefit. Inability to communicate significantly impacts on the quality of life and overall well-being, leading to cognitive impairment, personality changes, depression and reduced functional status.^1,2

Cochlear implantation is an effective intervention that overcomes the limitation associated with rehabilitation with a hearing aid because it enhances recognition of environmental sounds and restores clarity of self-esteem. Unfortunately, the elderly, who would be appropriate audiologic candidates, are infrequently referred for cochlear implantation due to concerns about risks of general anaesthesia and potentially poorer rehabilitative outcome.

The widely used American Society of Anaesthesia (ASA) physical status classification scale for risk stratification to predict perioperative complication does not include age as an independent risk factor but the American Heart Association (AHA) scale includes it in the lowest risk category.³ The preexisting condition of the elderly patient and not advanced age, in itself, is more likely to be a factor in the morbidity and mortality of a patient undergoing a cochlear implant with general anaesthesia.

The technique of anaesthesia plays a crucial role in the success of cochlear implant surgery as the anaesthesiologist has to produce conditions which facilitate use of nerve stimulators and manage perioperative and postoperative problems such as hypertension, arrhythmias, hypercapnia, acid base imbalance, nausea, vomiting and vertigo.

Cochlear implantation

An 87-year-old male patient was admitted with complaints of bilateral hearing loss for one year after an episode of meningitis. He was recently diagnosed hypertensive on medication. There were no other significant major medical or surgical comorbidities. Standardised general anaesthesia was given for cochlear implantation with optimisation of underlying systems and managed accordingly.

Postoperative course was uneventful and he was discharged on the fourth postoperative day on supportive therapy.

During the follow up after six months, the patient was progressing well with an increased social interaction and was leading a fruitful life.

Discussion

Healthcare professionals and patients have an erroneous perception that age is a significant risk factor for general anaesthesia. Current literature suggests that comorbidities and ASA physical status are more important than age as prognostic factors for an adverse anaesthetic outcome. Coexisting conditions that potentially impact on risk of anaesthesia include cardiopulmonary insufficiency, arthritis, hepatorenal disease, endocrine dysfunction, nutritional status and pharmacokinetic issues. Surgical complications associated with cochlear implantation are not increased in the elderly, as older patients have decreased incidence of flap necrosis, improper electrode placement, dizziness, infection, facial nerve stimulation or injury and cerebrospinal fluid (CSF) leak.⁴

Recent studies have demonstrated the efficacy of cochlear implantation in older patients. In addition, it has been shown to be cost-effective and results in significantly improved quality of life.^5,6 The ability to communicate affords greater independence with many continuing or returning to part or full-time work. The societal contributions of this patient population are immeasurable, especially when compared with the social, health and economic costs of care for their nonhearing counterparts.

Lau et al demonstrated that age itself is not a reliable predictor for unanticipated hospital admission after laparoscopic cholecystectomy.⁷ In comparing age and ASA status, Trus et al and Matin et al independently found no increased risk contribution from age in patients older than 65 years who underwent laparoscopic reflux and urologic surgery respectively.^8,9

Balanced anaesthetic technique has to be implied in elderly patients as myocardial depressant effects of anaesthetic agents, atelectasis associated with mechanical ventilation and volume loading due to intravenous fluid administration – all can contribute to cardiac and pulmonary complications including congestive heart failure, haemodynamic instability and pulmonary insufficiency. The use of bispectral index monitors may aid in the titration of anaesthetic and improve early recovery.

Benefits of cochlear implantation

Cochlear implantation improves communication ability in most adults with deafness and frequently leads to positive psychological and social benefits as well. The greatest benefits seen to date have occurred in postlingually deafened adults. Most individuals demonstrate significantly enhanced speech-reading capabilities, attaining scores of 90-100% correct on everyday sentence materials. Cochlear implantation in prelingually deafened adults provides more limited improvement in speech perception, but offers important environmental sound awareness. Benefit is expressed as a decline in loneliness, depression and social isolation and an increase in self-esteem, independence and social integration.

Conclusion

General anaesthesia is well tolerated by elderly patients undergoing cochlear implantation. The preexisting conditions or comorbidities of the patient are more pronounced risk factors than advanced age alone for morbidity in patients undergoing a cochlear implant with general anaesthesia. Thus, although a marker of comorbidities, age alone should not be a contraindication when determining candidancy for this life-changing technology.

Conflict of interest: none

References

Cacciatore F, Napoli C, Abete P, et al Quality of Life Determinants and Hearing Function in an Elderly Population. Gerontology 1999; 45: 323-28
Mulrow CD, Aguilar C, Endicott JE, et al. Association between hearing impairment and the quality of life of elderly individuals. J Am Geriatr Soc 1990; 38: 45-50
Leung JM, Dzankic S. Relative importance of preoperative health status versus intraoperative factors in predicting postoperative adverse outcomes in geriatric surgical patients. J Am Geriatr Soc 2001; 49: 1080-85
Beliveau MM, Multach M. Perioperative care for the elderly patient. Med Clin North Am 2003; 87: 273-89
Chatelin V, Kim EJ, Driscoll C, et al. Cochlear implant outcomes in the elderly. Otol Neurotol 2004; 25: 298-301
Djalilian HR, King TA, Smith SL, Levine SC. Cochelar implantation in the elderly: results and quality-of-life assessment. Ann Otol Rhinol Laryngol 2002; 111: 890-95
Lau H, Brooks DC. Predictive factors for unanticipated admissions after ambulatory laparoscopic cholecystectomy. Arch Surg 2001; 136: 1150-53
Trus TL, Laycock WS, Wo JM, et al. Laparoscopic antireflux surgery in the elderly. Am J Gastroenterol 1998; 93: 351-53.
Matin SF, Abreu S, Ramani A, et al. Evaluation of age and comorbidity as risk factors after laparoscopic urological surgery. J Urol. 2003; 170: 1115-20

Authors

Naresh Dua, Rachna Bhutani, Prabhat Choudhary, Jayashree Sood