title: Single Versus Multiple Hyperbaric Sessions for Carbon Monoxide Poisoning in a Murine Model.
abstract: Hyperbaric oxygen (HBO) has been advocated for treatment of acute carbon monoxide (CO) poisoning. There exists considerable debate as to whether HBO prevents delayed neurologic sequelae (DNS) due to CO poisoning. Additionally, existing data in the literature supporting HBO efficacy do not identify an optimal number of HBO treatments. We sought to determine in a mouse model whether there is a difference between one versus multiple HBO sessions for the prevention of DNS. Fifty mice were randomized into five groups of ten mice each: (1) control, receiving no CO exposure or treatment; (2) CO poisoned, receiving no treatment (CO group); (3) CO poisoned, receiving normobaric oxygen for 58 min following the end of exposure (CO + NBO group); (4) CO poisoned, followed by one session of HBO(CO + HBO1); and (5) CO poisoned, followed by three HBO treatment sessions, one every 6 h (CO + HBO3). Prior to poisoning, all animals were trained in step-down latency (SDL) and step-up latency (SUL) tasks. One week after exposure and treatment, all five groups were retested to evaluate the retention of this training. There was no difference detected among groups in SDL (p = 0.67 among all groups) when evaluated using a Kruskal-Wallis test. There was a significant difference among groups in SUL (p = 0.027 among all groups) when evaluated using a Kruskal-Wallis test. When individual groups were compared using a Wilcoxon signed-rank test with Bonferroni correction, there were no statistically significant differences in either SDL or SUL. There was no difference between groups treated with either one or three HBO sessions. One possibility to explain this might be that HBO sessions administered some time after a CO exposure may enhance the lipid peroxidation cascade and worsen neurologic outcomes; alternatively, HBO may simply impart no benefit when compared to NBO.
authors.affiliation: Division of Medical Toxicology, Department of Emergency Medicine, University of California, San Diego, CA, USA. shaunc@yahoo.com.|Department of Emergency Medicine, Naval Medical Center, San Diego, CA, USA. shaunc@yahoo.com.
authors.forename: Shaun D
authors.initials: SD
authors.lastname: Carstairs
authors.affiliation: Department of Emergency Medicine, Naval Medical Center, San Diego, CA, USA.
authors.forename: Alexander D
authors.initials: AD
authors.lastname: Miller
authors.affiliation: Division of Medical Toxicology, Department of Emergency Medicine, University of California, San Diego, CA, USA.
authors.forename: Alicia B
authors.initials: AB
authors.lastname: Minns
authors.affiliation: Division of Hyperbaric Medicine, Department of Emergency Medicine, University of California, San Diego, CA, USA.
authors.forename: Jay
authors.initials: J
authors.lastname: Duchnick
authors.affiliation: Clinical Investigation Department, Naval Medical Center, San Diego, CA, USA.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Riffenburgh
authors.affiliation: Division of Medical Toxicology, Department of Emergency Medicine, University of California, San Diego, CA, USA.
authors.forename: Richard F
authors.initials: RF
authors.lastname: Clark
authors.affiliation: Division of Medical Toxicology, Department of Emergency Medicine, University of California, San Diego, CA, USA.|Division of Hyperbaric Medicine, Department of Emergency Medicine, University of California, San Diego, CA, USA.
authors.forename: Christian A
authors.initials: CA
authors.lastname: Tomaszewski
mesh_terms: D000818:Animals; D002249:Carbon Monoxide Poisoning / Q000628:therapy*; D004195:Disease Models, Animal; D006801:Humans; D006931:Hyperbaric Oxygenation / Q000379:methods*; D008297:Male; D000073216:Mental Status and Dementia Tests; D051379:Mice; D017063:Outcome Assessment, Health Care; D010100:Oxygen / Q000627:therapeutic use*; D018709:Statistics, Nonparametric
chemical_list: D010100:Oxygen
keywords: Carbon monoxide; Delayed neurologic sequelae; Hyperbaric oxygen therapy; Rodent