Neurocognitive sequelae after carbon monoxide poisoning and hyperbaric oxygen therapy

Abstract

Carbon monoxide (CO) has been the leading cause of poisoning mortality in many countries and hyperbaric oxygen (HBO) is a widely accepted treatment for CO poisoning. However, some patients with CO poisoning will still develop neurocognitive sequelae regardless of HBO therapy, which can persist since CO poisoning or be present days to weeks after a recovery from CO poisoning. HBO has been used in the prevention and treatment of neurocognitive sequelae after CO poisoning, and some mechanisms are also proposed for the potential neuroprotective effects of HBO on the neurocognitive impairment after CO poisoning, but there is still controversy on the effectiveness of HBO on neurocognitive sequelae after CO poisoning. In this paper, we briefly introduce the neurocognitive sequelae after CO poisoning, summarize the potential predictive factors of neurocognitive sequelae, and discuss the use of HBO in the treatment and prevention of neurocognitive sequelae after CO poisoning.

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

“…Further classifications of the long-term neurological effects of CO poisoning have been recently proposed. In DNS, there is a marked decline of at least one standard deviation on a specific psychological test score from a prior score, while in Persistent Neurological Sequelae (PNS), the cognitive impairment persists over six weeks after the event, as summarized by Ning et al [15]. Marchinkowska et al, in their systematic review about the efficacy of HBO treatment in various neurological conditions with cognitive disturbances, combine PNS and DNS into DEACMP or "Delayed Encephalopathy after Acute CO Poisoning" [16].…”

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

“…[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. [15] Prior studies have shown that using HBO therapy in the acute phase of CO poisoning reduces immune-mediated neuropathology and can reduce the incidence of DNS. [15,16] It has been reported that a historical cohort study in which all patients with a diagnosis of CO poisoning managed in a regional hospital in Hong Kong from February 12, 2003 to November 8, 2013, was conducted.…”

“…[15] Prior studies have shown that using HBO therapy in the acute phase of CO poisoning reduces immune-mediated neuropathology and can reduce the incidence of DNS. [15,16] It has been reported that a historical cohort study in which all patients with a diagnosis of CO poisoning managed in a regional hospital in Hong Kong from February 12, 2003 to November 8, 2013, was conducted. Of the clinical profiles of 93 patients analyzed, 24 patients who received HBO therapy at an earlier time did not develop the following DNS, which showed a 100% protective effect of HBO therapy against DNS in patients with severe CO poisoning.…”

“…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 [15] …”

“…Prior studies have shown that using HBO therapy in the acute phase of CO poisoning reduces immune-mediated neuropathology and can reduce the incidence of DNS [15,16] . It has been reported that a historical cohort study in which all patients with a diagnosis of CO poisoning managed in a regional hospital in Hong Kong from February 12, 2003 to November 8, 2013, was conducted.…”