Tough Question.† In the 1980s it was assumed that CO bound to the hemoglobin molecule and created a functional anemia.† Once the CO was gone, everything was fine as long as anoxia hadnít occurred during the time the CO was attached to hgb.† However, in
†The memory and concentration deficits, as well as impairment of executive function are diagnosed by formal NP testing done by a neuropsychologist.† Bedside tests are not sensitive enough to delineate these cognitive losses.
†The problem is, we donít know who will develop delayed NP sequelae.† And, we donít know if any treatment will prevent or ameliorate it.
†There has been a great deal of controversy regarding the use of hyperbaric oxygen (HBO) vs. normobaric oxygen in CO exposed patients. Studies are conflicting- one study implies HBO improves NP outcome compared to NBO and another study implies that NBO improved NP outcome compared to HBO, theoretically due to the HBO-induced generation of free radicals.† What a mess.
†Our approach at the TN Poison Center is to put all acute CO exposed patients on face mask (100% O2) for 12 hours. For the asymptomatic or minimally symptomatic patients whose symptoms resolve in 12 hours, no further treatment is recommended. Patients with more severe symptomatology or symptoms that donít resolve, are admitted for 24 hours and 100% O2 normobaric oxygen therapy is continued. HBO is recommended for pregnant women due to the prolonged binding of fetal hgb to CO.†† A physician is called regarding any significant CO exposures.†† A Poison Specialist or Medical Toxicologist would be happy to discuss any patients you see with CO exposure.†
†Question prepared by: Donna L. Seger, M.D.† Medical Toxicologist