Page 108 - 2020 JSOM Winter

FIGURE 1 The boothless audiometer headset, currently the ulcers, critical illness, or traumatic injury, all of which may be
Wireless Automated Hearing-Test System (WAHTS), allows for present in a service member presenting with AAT. Third, Bar-
comparable detection of hearing loss as using a sound booth. dou et al. in 2015 identified risk factors that, if present, pre-
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Copyright permission obtained for use from the company.
dicted a higher rate of clinically important stress-ulcer bleed,
including male sex (odds ratio [OR] 1.17), maximum serum
creatinine level (OR 1.16), coagulopathy (OR 4.3), and re-
spiratory failure requiring mechanical ventilation (OR 15.6).
For cases with these risk factors, PPIs were deemed the most
clinically effective and cost effective for gastro-protection.

Our experience with the DAT has shown it to be straightfor-
ward to use and robust, requiring minimal training to acquire
high-quality audiometric data and images/video for specialist
otolaryngologist counsel via telemedicine. This has allowed for
the initiation of treatment and/or repatriation, where needed,
with minimum delay.

Treatment Protocol
The DAT treatment protocol (Figure 3) has been developed
as a modification of the protocol outlined for managing adult
hearing loss after blast injury in the 2018 UK national Clinical
Guidelines for Major Incidents and Mass Casualty Events.
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When operational considerations allow, the DAT should
FIGURE 2 The mobile phone–compatible endoscopic imaging be used to rapidly screen all personnel exposed to a signifi-
hardware and software (endoscope-i) allows for live vision of the cant noise or blast. This removes the responsibility for self-
eardrum and transfer of data to a specialist otolaryngolist.
Copyright permission obtained for use from the company. determined initial presentation in those who may not realize
they have sustained an acoustic injury or who wish to report
combat-related hearing loss.

In current operations, the DAT is placed at Role 1. SP work-
ing far forward of Role 1 who have had an acute exposure to
noise or blast are asked a series of screening questions. If any
are positive, the service member should be priority evacuated
to the Role 1 location for DAT assessment. This is imperative
because hearing rescue-treatment efficacy is time limited. If
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operational considerations make evacuation impossible, a sec-
ond screening question assessment is undertaken at 48 hours.
Personnel who remain symptomatic should be offered, after
consent, oral steroids with concurrent gastric cover using a PPI
as a simple “holding” option. Contraindications to systemic
steroid treatment (oral or intravenous) include head trauma
with a Glasgow Coma Scale score <14, systemic infection, ex-
tensive burns, and multisystem trauma. 8

At Role 1, a medical review and DAT assessment are under-
be comparable to (±5dB) occupational audiometry in a mo- taken. If the endoscopic picture of the ear drum and tympa-
bile trailer, across frequencies 500HZ to 8000Hz. Moberly et nometry are normal and the DAT audiogram shows minor
al. released a study in which 210 teleotological images were changes (hearing thresholds no more than 20dB at any fre-
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assessed by 12 different otologists. The congruence rates of quency or hearing thresholds no more than 10dB greater than
seven different types of pathology were 48.6% to 100%. Many the threshold value at a particular frequency on the pre-de-
other studies, however, have suggested much higher congru- ployment audiogram), that service member should be rested
ence, suggesting a comparable result to a face-to-face assess- away from all noise for a further 48 hours and then retested.
ment. 36–38 Notably, remote otoscopy is particularly useful in At that point, if all screening questions are negative, the TM
assessing hearing loss and tympanic membrane perforations. 39 and tympanometry remain normal, and the audiogram is nor-
mal or at predeployment levels, then consideration can be
Similarly, the use of PPIs is justified by a combination of fac- given to the service member’s return to duty if there is an op-
tors. First, soldiers are at a greater risk of gastritis and ulcers erational imperative.
secondary to psychological stress, which carries its own inde-
pendent risk of bleeding. 40–42 Second, a recent meta-analysis by If return to duty is undertaken, the service member must be
Narum et al. consisting of more than 33,000 patients found made aware of the uncertainty relating to long-term hearing
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that hospitalized patients were at greater risk of gastrointesti- outcomes, with or without a further injury. This reflects the
nal bleeding or perforation when taking glucocorticoids; the evolving science relating to the pathophysiology of AAT, par-
authors hypothesized that the reason could be concurrent stress ticularly in relation to discernment of speech in background

106 | JSOM Volume 20, Edition 4 / Winter 2020