Could Deafness Be the Hidden Burden of the Opioid Crisis?

Abstract

The United States’ opioid epidemic has become one of its worst public health crises, but fentanyl abuse is now increasingly being observed outside of the US. 1 Indeed, illicitly manufactured fentanyl is at the heart of the third wave of the opioid epidemic in the US, which began in 2013. 2 Risk of opioid overdose increases among those of male gender aged 20-40 years, in addition to those with a history of psychiatric illness, or chronic, severe medical illness. 3The Patient’s Audiometry Results. Opioid crisis, opioid epidemic, hearing loss, deafness, therapy.While the focus is naturally on fatalities, which the Centers for Disease Control and Prevention cites as the main cause of injury-related death in the US 4, this case demonstrates the additional detriment opioids may have on hearing, which is likely underreported. Patients might present with bizarre behavior, which can reasonably be attributed to comorbid psychiatric illness or drug misuse itself, although could be due to sensory impairment secondary to drug use. While the risk of respiratory depression leading to hypoxia and subsequent brain injury is well understood, the impact on hearing is less so. One proposed mechanism is hypoperfusion of the vestibulocochlear system because of vasopasm, opioid induced vasculitis, or contamination of the drug with other substances, which might be particularly true for illegally procured opiates. A hypoxic independent adverse reaction is also believed to be at play and likely more prevalent among younger patients. This might also have ramifications for those on long-term methadone treatment, in whom long-term hearing loss is rarely reported but subtle sensorineural hearing loss may present. 5 The following case study evidences the sudden sensorineural hearing loss that can occur as an additional, lesser-known adverse event, alongside severe respiratory and generalized central nervous system depression. Case Study: An adolescent male is found at home by a family member, having last been seen a few hours previously. He is unresponsive and cyanosed. On arrival to the emergency department, he is immediately transferred to the intensive care unit for intubation and ventilation to manage type 2 respiratory failure. His family confirms a history of recreational cannabis use, and aside from common childhood (nonauditory) infections, there is no other past medical history and no family history of hearing impairment. He was previously fit and well, working full time at a warehouse. Opioid misuse was confirmed following admission, based on relevant evidence found in his bedroom. Following extubation, behavioral disturbances manifested, marked by agitation, verbal aggression, and sexual disinhibition, which were not in keeping with his premorbid personality. This was managed with input from Liaison Psychiatry and use of medication: olanzapine and clonazepam. Extubation also marked an awareness of deafness, which was confirmed as sensorineural deafness on audiology testing, for which bilateral hearing aids were ultimately required. Audiometry (Figure 1) confirmed severe hearing loss in the left ear and moderate hearing loss in the right ear. By the time of admission to neurorehabilitation at a different hospital group two months after the initial presentation, hearing aids were not yet available. Verbal communication was augmented with writing and gestures. Remarkably, he remained jovial, although his family’s distress was heightened by an inability to communicate with him verbally. He was nonetheless consistent in identifying a “brain problem” as the reason for admission and, of his own volition, spoke of not wanting to resume illicit drug use, recognizing its adverse impact. Clonazepam was ceased, followed by olanzapine, within the first fortnight of admission, given transfer to an environment that offered regular routine and neurorehabilitation therapies. Supply of hearing aids approximately a fortnight into the neurorehabilitation admission marked significant improvement in engagement in therapies and social interaction, much to the delight of his parents. PATIENT OUTCOME On admission to a specialist inpatient neurorehabilitation unit, where a more structured routine could be facilitated, with use of bilateral hearing aids, previous inappropriate behavior ceased. He was increasingly able to manage personal activities of daily living independently. CONSIDERATIONS Clinicians are well-versed in the respiratory adverse events associated with opioid overdose, but lesser known is the risk of hearing loss. Audiologists can help voice the importance of hearing assessment in cases of opioid overdose to help patients achieve optimal recovery outcomes. Consider audiological testing in individuals who present with opioid overdose. Addressing hearing loss can help improve engagement in a structured neurorehabilitation program, which can support functional recovery. Educate family members and caregivers of the implications of hearing loss, so that improved care and communcation can be facilitated.