Carbon monoxide poisoning mimicking arterial gas embolism in a commercial diver

A 32-year-old male commercial diver was working at 7,000 feet of altitude in a municipal water tank, at a depth of 27 feet for two hours. While surfacing from a compressed-air surface-supplied dive, he exhibited loss of consciousness and neurological symptoms. He was presumptively diagnosed with arterial gas embolism, flown by pressurized aircraft to a regional medical center and treated with hyperbaric oxygen. During the U.S. Navy Treatment Table 6, new information suggested the patient's air supply had been contaminated by a continuously running engine and compressor. His admission blood was then assayed for carboxyhemoglobin (COHb), which measured 8.8% six hours after surfacing, including four hours of normobaric oxygen inhalation. His estimated COHb based on rough reported half-life calculations at the conclusion of the dive was approximately 45%. The patient's diagnosis was changed to carbon monoxide poisoning from contaminated breathing gas. Upon hospital discharge, he exhibited problems with balance and gait, nystagmus, word-finding limitations and slurred speech. Also, he had cardiac injury treated with carvedilol. When evaluating diving-related casualties, including in commercial divers, clinicians should consider carbon monoxide poisoning as a differential diagnosis.