High-altitude decompression illness following recreational diving: a case report from Lake Van

Decompression sickness (DCS) is a clinical syndrome caused by inert gas bubble formation following a rapid reduction in ambient pressure, with an increased risk in high-altitude diving due to lower barometric pressure. Although neurological symptoms are well-documented, respiratory involvement is less frequently reported.

A 54-year-old male recreational diver performed his first-ever dive in Lake Van, descending to approximately 30 meters and remaining at depth for several minutes before ascending rapidly to the surface without a decompression stop. Immediately after surfacing, he experienced sudden weakness in both legs and shortness of breath. He aspirated water and recalled calling for help before losing awareness. Located approximately 300 meters from shore, he was towed back by his dive team. Finding no pulse, the team initiated CPR and rescue breathing. Upon arrival, emergency medical services found the patient with spontaneous respiration and a palpable pulse. Within 30 minutes, he was transported approximately 16 kilometers to the nearest hospital. High- flow oxygen treatment via a non-rebreather mask was initiated, and he was transferred to the emergency department. In the emergency department, the patient stated he remembered seeing lights but could not recall the intervening events. Due to neurological deficits and suspected DCS, he was immediately referred to a hyperbaric unit. A single hyperbaric oxygen (HBO₂) treatment session was administered according to the US Navy Table 5 protocol, resulting in marked symptom resolution. The patient was transferred from intensive care to the general ward and discharged at his request after declining further HBO₂ sessions.

This case underscores the risk of high-altitude DCS and highlights the importance of altitude-specific dive planning and timely HBO₂ intervention. Increased awareness among recreational divers is essential to prevent such complications.