HYPOTHESIS: Endolymphatic hydrops (EH) associated with cochlear implantation are associated with vestibular dysfunction. BACKGROUND: Vestibular dysfunction is a known risk after cochlear implantation (CI). CI has been shown to cause cochlear hydrops due to fibrosis surrounding the ductus reuniens. However, the association of cochlear hydrops with vestibular hydrops and the relationship to vestibular symptoms remain unknown. METHODS: Histopathological analysis and clinical evaluation of the vestibular end organs of 17 human temporal bones (HTB)s exhibiting cochlear hydrops from 15 CI recipients. RESULTS: Eight of 15 patients with cochlear hydrops due to CI had complaints of dizziness, vertigo, or imbalance following CI. In all 17 HTBs with cochlear hydrops, there was fibrosis, atrophy, or obstruction of the ductus reuniens, and all had straight electrode CI via cochleostomy. In one of the eight reporting postoperative dizziness, labyrinthitis ossificans was deemed causative. Six of the seven remaining patients had EH of both the saccule and utricle. Fifteen of 17 HTBs (88.2%) had saccular EH. In contrast, 8 of 17 HTBs (47.0%) in 7 patients had utricular EH, of which 6 patients had postoperative vertigo spells. It seems that hydrops of the utricle closely corresponds to postoperative vertigo spells and vestibular complaints. CONCLUSION: Implantation of the CI, when complicated by ductus reuniens fibrosis, may cause both cochlear hydrops and vestibular endolymphatic hydrops. Hydrops of the vestibular periphery when involving the utricle seems to be more likely associated with disabling vertigo symptoms. This study supports the round window technique of insertion rather than cochleostomy.

Importance

The novel coronavirus disease 2019 (COVID-19) has proven to be highly infectious, putting health care professionals around the world at increased risk. Furthermore, there are widespread shortages of necessary personal protective equipment (PPE) for these individuals. Filtering facepiece respirators, such as the N95 respirator, intended for single use, can be reused in times of need. We explore the evidence for decontamination or sterilization of N95 respirators for health care systems seeking to conserve PPE while maintaining the health of their workforce.

Observations

The filtration properties and fit of N95 respirators must be preserved to function adequately over multiple uses. Studies have shown that chemical sterilization using soap and water, alcohols, and bleach render the respirator nonfunctional. Decontamination with microwave heat and high dry heat also result in degradation of respirator material. UV light, steam, low-dry heat, and commercial sterilization methods with ethylene oxide or vaporized hydrogen peroxide appear to be viable options for successful decontamination. Furthermore, since the surface viability of the novel coronavirus is presumed to be 72 hours, rotating N95 respirator use and allowing time decontamination of the respirators is also a reasonable option. We describe a protocol and best practice recommendations for redoffing decontaminated N95 and rotating N95 respirator use.

Conclusions and relevance

COVID-19 presents a high risk for health care professionals, particularly otolaryngologists, owing to the nature of viral transmission, including possible airborne transmission and high viral load in the upper respiratory tract. Proper PPE is effective when used correctly, but in times of scarce resources, institutions may turn to alternative methods of preserving and reusing filtering facepiece respirators. Based on studies conducted on the decontamination of N95 respirators after prior outbreaks, there are several options for institutions to consider for both immediate and large-scale implementation.