Severe carbon monoxide poisoning treated by hyperbaric oxygen therapy--a case report

Carbon monoxide (CO) poisoning is an important cause of mortality and late neurological sequelae such as memory loss, personality changes, psychosis, dementia, and so on. The benefits of hyperbaric oxygen (HBO) therapy are still discussed, but the majority of trials recommend it in severe cases with coma and/or hemodynamic instability, irrespective of carboxyhemoglobin (COHb) level, to prevent permanent neurological deficits. We present a 35-yr-old woman who underwent accidental CO poisoning. Although breathing 100% oxygen by mask during transfer to the hospital, she was in deep coma, hypotensive, cyanotic, and hypoxic (arterial pO(2) 7,41 kPa, HbO(2) 87.8%), with serum COHb 26.7% on hospital admission. Orotracheal intubation, mechanical ventilation, iv fluids, dobutamin, and norepinephrine were administered. COHb level decreased to 17.2% within 1 h. To prevent severe neurological sequelae, the patient was transferred as soon as possible to an HBO center 60 km distant to perform HBO therapy twice at 3.0 and once at 2.2 atm within 24 h. After the second HBO session, the patient regained consciousness, and respiratory failure and shock resolved. She was transferred to our hospital and discharged few weeks later with discrete paresis of peripheral nerves, discrete ischemic brain lesions on computed tomography (CT) scan, and moderately abnormal electroencephalogram (EEG) without cognitive disturbances. She was able to resume her daily activities. We conclude that in severe CO poisoning, normobaric oxygen therapy and resuscitation by fluids, inotropic agents, and catecholamines is essential for survival, but additional HBO therapy seems to prevent major neurological sequelae.