Page 54 - JSOM Summer 2025

Undersea and Hyperbaric Medicine

Case Studies and Review

Michael J. Day, MPAS, PA-C, MS *;
1
Joshua K. Radi, PhD, PA-C 2

ABSTRACT
There is a dearth of studies in undersea and hyperbaric med- chamber by the unit’s DMT. Upon reaching the chamber, the
icine (UHM), likely due to the limited number of clinicians area of numbness had spread, and he was recompressed to a
currently specializing in UHM. Due to the high-consequence treatment depth of 60FSW. A Navy Undersea Medical Officer
nature of diving and the effects of pressure on the human (UMO) was consulted, and the patient completed a Treatment
body, medical clearance is of the utmost importance. Despite Table Six (described below) with no extensions, and symptoms
all efforts to mitigate the possibilities of dive maladies, divers were completely relieved. The patient was diagnosed with an
occasionally succumb to the effects of prolonged submersion. arterial gas embolism (AGE) caused, in part, by a rapid accent.
This article provides an in-depth look at three individuals who The diver has since fully recovered and returned to diving duty
suffered from separate dive-related medical events. In each ex- after being cleared by an Army Diving Medical Officer (DMO)
ample, UHM was applied and successfully mitigated short and and Navy UMO.
long-term medical consequences. The manuscript then reviews
common and life-threatening dive maladies, with an in-depth Case 2
examination of decompression strategies and diving clearance. An Army engineer diver was conducting a dive off the coast
of Hawaii with a maximum depth of 85 feet and a bottom
Keywords: undersea and hyperbaric medicine; hyperbaric time of 20 minutes. She experienced some facial pain during
medicine; diving medicine; dive; recompression chamber; the descent but continued the dive. Upon surfacing, she had
emergency evacuation hyperbaric stretchers; pulmonary severe light sensitivity and diffuse subconjunctival hemor-
overinflation syndrome; decompression sickness; rhage. The patient was seen in the emergency department and
decompression illness; barotrauma released with the direction to apply cold compresses. Twelve
days later she was seen by her DMO, who diagnosed her with
facial barotrauma due to mask squeeze. This was caused by
the failure to equalize the mask properly during descent. Her
Introduction
symptoms had continued to improve, but she still had light
This article provides an in-depth look at three individuals who sensitivity and conjunctival erythema at this point. She denied
suffered from separate dive-related medical events. In each ex- blurry vision or hyphema at any time. The patient was referred
ample, undersea and hyperbaric medicine (UHM) was applied to ophthalmology, who conducted an assessment 5 days later.
and successfully mitigated short and long-term medical conse- The ophthalmologist confirmed the diagnosis of subconjuncti-
quences. Following these case studies, the manuscript reviews val hemorrhage and cleared her to return to dive duty.
common and life-threatening dive maladies, with an in-depth
examination of decompression strategies and diving clearance. Case 3
In May 2023, the National Oceanic Atmospheric Admin-
Case 1 istration (NOAA) Ship Rainier conducted scientific diving
In September 2023, an Army engineer diver conducted a dive in operations in the South Pacific Ocean. On board were approx-
Kauai, Hawaii. There was a diving medical technician (DMT) imately 35 crew, including eight scientific divers, two DMTs,
and hyperbaric chamber at the job site, and definitive care was and an Army DMO. Throughout the first 2 weeks of this leg
located on the island of Oahu, approximately 120 miles away. of the journey, the divers sustained no major medical issues
The dive in question had a maximum depth of 72 feet of sea- other than motion sickness and a mild case of middle ear baro-
water (FSW) and a bottom time of 37 minutes. The diver was trauma, colloquially referred to as “the squeeze.” At this time,
operating solo, per operational requirements, with a standby the Rainier was still days away from definitive medical care,
diver ready. The diver’s ascent took 1:07min, more than dou- operating solely under the supervision of the DMO, DMTs,
bling the allowable travel rate. The diver reported issues with and dive supervisor with a hyperbaric chamber on board.
his buoyancy compensator not deflating properly. Upon sur-
facing, the diver had no complaints, was examined, and placed The divers were conducting their fourth consecutive day of
under direct supervision; 13 minutes after surfacing, he re- diving operations off the coast of Howland Island when one
ported a numb region on his chest. The diver was immedi- of the divers fell ill. They conducted approximately five to
ately placed on 100% O and transported to the hyperbaric six dives daily, ranging between 20 and 45 feet in depth for
2
Correspondence to mjday7@gmail.com
2
1 CPT Michael J. Day is affiliated with the 130th Engineer Brigade, Schofield Barracks, HI. MAJ Joshua K. Radi is affiliated with the 93rd Weap-
ons of Mass-Destruction-Civil Support Team, Hawaii Army National Guard, Kapolei, HI.
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