Sudden Vertigo and Hearing Loss After a Three-Dive Day
A 31-year-old surface-supplied commercial diver makes three dives from a barge in 33 msw: 42 minutes, 55 minutes and 38 minutes, each with an 8-minute in-water stop at 6 m. He reports difficulty clearing his right ear on the second dive and forces it. Twenty minutes after the final surfacing he develops sudden rotary vertigo, vomiting, right-sided hearing loss and loud tinnitus. In the medic's shack he is pale and sweating, holds his head still, and has horizontal nystagmus with the fast component to the left. The right tympanic membrane is dull and injected with a small hemorrhage over the pars tensa; the left is normal. There is no limb weakness, sensory loss, rash or joint pain. Glucose 6.1 mmol/L, BP 138/84, pulse 52 and regular, SpO2 98% on air. The supervisor must choose transport: the nearest 24-hour recompression chamber is 2 hours by road; a helicopter could reach a different chamber in 90 minutes including transfer time but flies at 900 m cabin altitude. Seas are calm and road traffic is light.
1. Build the differential for this vertigo and hearing loss, then argue which diagnosis is most likely using the specific findings that support and oppose it.
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Differential to consider
- Inner ear barotrauma (round or oval window rupture/fistula) after a forced Valsalva
- Inner ear decompression sickness (vestibular and/or cochlear)
- Alternobaric vertigo
- Middle ear barotrauma with serous labyrinthitis
- Labyrinthitis or vestibular neuronitis (coincidental)
- Vertebrobasilar ischaemia (unlikely at this age with no other deficits)
Why the distinction is hard here
- The forced clearance and the haemorrhage on the pars tensa point at barotrauma of the middle ear with possible inner ear involvement.
- The 20-minute delay after surfacing, the depth and duration of the dives and the in-water stops are all compatible with decompression sickness; vertigo and hearing loss are the classic inner ear presentation.
- The left-beating nystagmus with right-sided deafness indicates a destructive right labyrinthine lesion - this fits both a fistula and inner ear DCS and does not discriminate between them.
- Barotrauma vertigo usually starts at the moment of the strain, but a fistula can present hours later, especially after further pressure change or straining.
- Absence of rash, joint pain or other neurological signs does not exclude DCS: isolated inner ear DCS is well described.
Conclusion
The honest answer is that the two cannot be separated reliably at the dive site. Treat the case as presumed inner ear DCS requiring urgent recompression while taking precautions for a possible fistula (no further forceful Valsalva, no straining, head-up positioning), and involve ENT early. Delaying recompression to look for a fistula risks permanent hearing loss from untreated DCS.
2. State your immediate management on site, including the things that must not be done, and justify each element.
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Do
- 100% oxygen by a well-sealed mask with reservoir, continuously, including during transport. It speeds inert gas elimination and is the single most useful pre-chamber measure.
- Position supine with the head raised about 30 degrees; this reduces raised labyrinthine pressure if a fistula is present and does not harm DCS management.
- Control vomiting with an antiemetic (for example ondansetron 4 mg IV). Vomiting raises intralabyrinthine and intrathoracic pressure and risks aspiration in a patient who cannot move his head.
- Keep him still, warm and nil by mouth; carry out serial neurological and cranial nerve checks and document them with times.
- Give IV fluid only if there is clinical hypovolaemia; hypotension is not present here.
Do not
- Do not allow nose-blowing, forceful Valsalva, auto-inflation, lifting or straining - all can enlarge a perilymph fistula.
- Do not give sedatives or nitrous oxide; they obscure the neurological examination and nitrous oxide expands gas spaces.
- Do not give drugs that alter the vestibular picture before the baseline examination is recorded.
- Do not delay transfer for an ENT opinion if the chamber is the more distant destination; ENT can review at the receiving facility.
- Do not let him travel alone or drive himself; he is vomiting and cannot tolerate head movement.
3. Choose the transport method and defend the choice, stating what must be arranged with the receiving chamber and what could change your decision.
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Recommendation: road, with 100% oxygen and a paramedic escort.
Reasoning:
- The time penalty is small. Road takes about 2 hours; the helicopter takes 90 minutes including transfer, so the real saving is around 30 minutes - the time spent loading, flying and unloading usually erodes much of that.
- The helicopter flies at a cabin altitude of 900 m, roughly 0.91 ATA, which is a further 0.9 msw-equivalent ascent and can expand existing bubbles and worsen DCS. Ground transport keeps him at sea level.
- He cannot tolerate head movement and is vomiting; a road ambulance allows continuous positioning, suction, monitoring and oxygen, and the crew can stop if he deteriorates.
- Definitive treatment is recompression, and the road route delivers him to a 24-hour chamber capable of a US Navy Treatment Table 6.
Arrange in advance: notify the chamber of a suspected inner ear DCS with possible barotrauma so that a physician and an ENT are available and the table is prepared; request a bed and a neuro-examination on arrival; tell them about the antiemetic and the last dose.
What would change the plan: airway compromise or a falling level of consciousness, uncontrollable vomiting, or a road route blocked by weather or traffic. In those cases use the helicopter, but ask for the lowest possible cabin altitude and keep him on 100% oxygen throughout.