HBOT for Carbon Monoxide Poisoning

Patients manifesting signs and symptoms of serious carbon monoxide poisoning (e.g., transient or prolonged unconsciousness, neurologic signs, cardiovascular dysfunction or severe acidosis) should be referred for HBO therapy regardless of COHb level, as COHb levels do not correlate with signs and symptoms. However, referral of patients with COHb ≥ 25% is reasonable or when neuropsychological testing is abnormal. Treatment should begin at the time of diagnosis.  Optimal dosing (pressure, duration, frequency) is not known but optimal benefit from HBOT occurs in those treated with the least delay after exposure. The majority of facilities offer single session HBOT to CO-poisoned patients; however, in selected patients repeated treatments may yield better outcome. Several protocols have been developed; however, most offer 2.8-3.0 ATA initial compression, then 2 ATA for 120-140 minutes, occasionally followed by additional 2 sessions for 90 minutes in six to twelve hour intervals, without further HBOT. Even with appropriate HBOT some patients will develop cognitive or other neurologic sequella which does not appear to be altered by continued HBOT. Children may be treated safely but may still have long-term problems. Pregnant women may be treated safely. Evidence of fetal distress is indication of need for HBOT despite normal carboxyhemoglobin levels and the absences of symptoms in the mother.