Transient Vertigo and Hand Numbness After Two Air Dives
A 41-year-old recreational diver completed two air dives: 32 msw for 25 minutes, a 90-minute surface interval, then 18 msw for 40 minutes. Within 10 minutes of surfacing he had vertigo, nausea, and tingling of the left hand. By the time the boat docked 45 minutes later, the vertigo had resolved and only mild left-hand numbness remained. He is alert, gait normal, no focal weakness, tympanic membranes clear. The nearest hyperbaric chamber is 3 hours by road; the local hospital has CT but no hyperbaric ambulance. He asks to drive home and 'watch it.' The dive computer shows no missed stops but the second dive pushed the no-decompression limit.
1. What is your leading diagnosis, and how should the resolution of vertigo influence urgency?
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The leading concern is type II decompression sickness with inner-ear (vestibular) involvement, though arterial gas embolism and combined injury are possible. Vertigo, nausea, and hand paresthesia after a provocative dive profile fit inner-ear DCS; the hand numbness suggests spinal or peripheral involvement. Resolution of vertigo does not lower urgency. Transient neurologic symptoms after diving are treated as DCS until proven otherwise, and deterioration can be delayed. The profile-two dives, the second near the no-decompression limit-supports a significant nitrogen load. Do not attribute this to seasickness or dehydration without a careful neurologic exam. Start 100% oxygen, arrange urgent evacuation, and contact a diving medicine consultant or chamber. The key judgment is that improvement is not reassurance-it is a reason to move quickly while the patient is stable.
2. How should he be transported, and what is the role of CT before chamber treatment?
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Transport should be by the fastest available route to a hyperbaric facility, with the patient lying flat (not Trendelenburg), on 100% oxygen by tight-fitting mask, with IV access and continuous observation. If air transport is used, keep altitude as low as possible; a pressurized aircraft or a low-altitude helicopter is preferable to a commercial flight at cabin altitude. Do not let him drive himself. CT is not a gatekeeper: it is poor at detecting AGE and does not exclude DCS. If CT is immediately available and will not delay chamber treatment, it may help exclude hemorrhage or stroke mimics, but a normal CT should not change the decision to recompress. The judgment is to treat the clinical syndrome, not the image.
3. If symptoms fully resolve before arrival, should he still undergo recompression? Justify your answer.
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Yes, unless a diving physician with chamber backup documents an alternative plan. Complete resolution is common in DCS, but untreated type II DCS can recur or leave subtle deficits; recompression with oxygen is low-risk compared with missed inner-ear or spinal injury. Use a standard type II treatment table, with a physician extending it if symptoms recur. If the chamber is unavailable, keep him on 100% oxygen and evacuate. The counterargument-'he is better, so observe'-is weak because the exam cannot reliably exclude ongoing bubble injury, and transport takes 3 hours. Document serial neurologic exams and a shared decision.