We conducted a study to determine the type, incidence, and timing of complications that occur in patients who have a carbon monoxide (CO) exposure serious enough to require hyperbaric oxygen therapy (HBOT). Complication data were retrospectively collected from a ten-year period for 297 consecutive CO-poisoned emergency department patients who received HBOT. HBOT was indicated for 41% of the patients because of an elevated carboxyhemoglobin (COHb) level alone. Central nervous system dysfunction, including loss of consciousness, and/or cardiovascular dysfunction, was the criteria for HBOT in 59% of patients, regardless of their COHb level. The mean peak COHb level was 38 mg%, with 88% of patients having a peak COHb level greater than 25 mg%. The mortality rate was 6% in this case series. Cardiac arrest occurred in 8% of patients; all experienced their first arrest prior to HBOT. The 3% of patients who sustained an isolated respiratory arrest and those who had a myocardial infarction did so prior to HBOT. Several complications, however, occurred for the first time or as a recurrent event during HBOT. These included emesis (6%), seizures (5%), agitation requiring restraints or sedation (2%), cardiac dysrhythmias or arrests (2%), and arterial hypotension (2%). No patient’s level of consciousness deteriorated subsequent to the initial resuscitation except for those who later had a generalized seizure. The most significant complication attributable to HBOT was tension pneumothorax, noted in three patients (1%).(ABSTRACT TRUNCATED AT 250 WORDS)

Sloan, Murphy, Hart, Cooper, Turnbull, Barreca, Ellerson, , (1989). Complications and protocol considerations in carbon monoxide-poisoned patients who require hyperbaric oxygen therapy: report from a ten-year experience. Annals of emergency medicine, 1989 Jun;18(6):629-34. https://www.ncbi.nlm.nih.gov/pubmed/2729687