Hyperbaric oxygen for late sequelae of carbon monoxide poisoning enhances neurological recovery: case report

Abstract

Neuropsychiatric sequelae have been reported in 15%-45% of survivors of carbon monoxide (CO) poisoning. Hyperbaric oxygen (HBO2) therapy reduces the incidence of cognitive and neurological a dysfunction. The efficacy of providing HBO2 beyond the first one to two days after initial insult is unknown. However, some evidence exists for the benefit of this treatment. We report on treating a patient 14 months after CO injury, who responded with markedly improved neurologic status. A 27-year-old scholar was found comatose due to CO poison- ing (carboxyhemoglobin = 31.7%). He received five acute HBO2 treatments. After discharge, he developed chorea, Parkinsonism, dystonia, memory loss, slowed processing speed and verbal fluency, leaving him disabled. After the patient reached a clinical plateau, HBO2 was tried again at 90 minutes at 2.4 ATA plus air breaks. Neuropsychological testing was performed at baseline and after each 20 HBO2 cycles, five of which were per- formed during the period from 14-22 months after CO exposure. After the first 20 treatments, Parkinsonism and dystonia improved. After 40 sessions, further improvements were seen on mental speed, verbal fluency, and fine motor movements. The outcome following 100 treatments was that the patient regained independence, including the ability to drive and to become gainfully employed. Our case calls into question the concept that HBO2 therapy has no role during the chronic phase of CO brain injury. Randomized clinical trials should be considered to evaluate the therapeutic efficacy of HBO2 in patients with neurological sequelae following CO injury.

Delayed Neurological Sequelae Successfully Treated with Adjuvant, Prolonged Hyperbaric Oxygen Therapy: Review and Case Report

“…Xiang compared three groups of patients suffering from DEACMP and undergoing HBO therapy, treated without vs. two different regimes of IV dexamethasone, and reported a significantly higher improvement in the experimental group at 4 weeks, especially in the 10 mg/day vs. the 5 mg/day arm [29]. On the other hand, the use of a prolonged HBO treatment (100 sessions) without adjuvant drugs has been reported to be beneficial even 14 months after CO intoxication [30]; differently from the abovementioned cases, since prolonged HBO was administered months after the intoxication, the inflammatory damage was already established, and the use of corticosteroids would not have been beneficial. Therefore, more studies are still needed to solve the issue of adjuvant drugs in treating DNS.…”

Acute carbon monoxide poisoning in Shandong, China: an observational study

“…The most severe complication of acute CO poisoning is delayed neurological sequelae (DNS). DNS has long been a worldwide clinical concern because it leads to serious deterioration in a patient's quality of life, jeopardizes their independence, and eventually leads to an unavoidable disability, or even death [10–13] . Although most patients with mild CO poisoning could recover fully from the acute phase, more than half of the patients with severe CO poisoning would develop a tragic DNS within 3 days to 6 weeks after CO poisoning onset [14] .…”

“…DNS has long been a worldwide clinical concern because it leads to serious deterioration in a patient's quality of life, jeopardizes their independence, and eventually leads to an unavoidable disability, or even death. [10][11][12][13] Although most patients with mild CO poisoning could recover fully from the acute phase, more than half of the patients with severe CO poisoning would develop a tragic DNS within 3 days to 6 weeks after CO poisoning onset. [14] Therefore, it is necessary for patients to go to the HBO department as early as possible, ideally within 24 h after CO exposure, for early emergency treatment and DNS prevention.…”