Carbon Monoxide and Cyanide Poisoning in the Burned Pregnant Patient

Abstract

Carbon monoxide (CO) is a small molecule poison released as a product of incomplete combustion. Carbon monoxide binds hemoglobin, reducing oxygen delivery. This effect is exacerbated in the burned pregnant patient by fetal hemoglobin that binds CO 2.5- to 3-fold stronger than maternal hemoglobin. With no signature clinical symptom, diagnosis depends on patient injury history, elevated carboxyhemoglobin levels, and alterations in mental status. The standard of care for treatment of CO intoxication is 100% normobaric oxygen, which decreases the half-life of CO in the bloodstream from 5 hours to 1 hour. Hyperbaric oxygen (HBO2) is a useful adjunct to rapidly reduce the half-life of CO to 20 minutes and the incidence of delayed neurologic sequelae. Because of the slow disassociation of CO from hemoglobin in the fetus, there is a far stronger indication for HBO2 in the burned pregnant patient than in other burn patient populations.Cyanide intoxication is often a comorbid disease with CO in inhalation injury from an enclosed fire, but may be the predominant toxin. It acts synergistically with CO to effectively lower the lethal doses of both cyanide and CO. Diagnosis is best made in the presence of high lactate levels, carboxyhemoglobin concentrations greater than 10%, injury history of smoke inhalation from an enclosed fire, and alterations in consciousness. While treatment with hydroxocobalamin is the standard of care and has the effect of reducing concomitant CO toxicity, data indicate cyanide may also be displaced by HBO2.Carbon monoxide and cyanide poisoning presents potential complications impacting care. This review addresses the mechanism of action, presentation, diagnosis, and treatment of CO and cyanide poisonings in the burned pregnant patient and the use of HBO2 therapy.

Carbon monoxide releasing molecule-2 attenuates Pseudomonas aeruginosa-induced ROS-dependent ICAM-1 expression in human pulmonary alveolar epithelial cells

“…Long-term exposure to low concentrations of CO can cause dizziness, vomiting, difficulty breathing, and muscle weakness. Even though CO is toxic to humans at high concentrations, many studies have documented that low-doses exogenous CO (approximately 250–500 ppm) have protective function against various human diseases [7] , [8] . In this study, we suggest that CO derived from CORM-2 can possibly be used as a therapeutic for lung inflammation.…”

“…Carbon monoxide (CO) is currently known to be generated in cells or tissues as a byproduct of heme oxygenase (HO) after heme catalytic activity [6] . Even though CO is toxic to humans at high concentrations, many studies have documented that low-doses exogenous CO (approximately 250–500 ppm) have protective function against various human diseases [7] , [8] . Previous studies have confirmed that low concentrations of CO or CO-releasing molecules (CORMs) can eliminate microorganisms [9] , regulate cell death [10] , and resist inflammation [10] .…”

To substantiation of the list of hazardous highly toxic chemicals that are subject to special control regarding handling, storage, use and disposal. Part II (arsenic compounds and cyanide)

“…They are often used as a means of chemical terrorism [45,48]. In addition, during World War II, the Nazis used cyanide as a means of genocide in gas chambers [21,22,40,54,55]. Certain anticancer drugs contain cyanide groups.…”

“…The first signs are bitterness in the mouth, sore throat, laryngospasm, dizziness, excessive salivation, nausea, vomiting, shortness of breath and confusion. But the severity of these mani-festations decreases a few hours after the removal of the victim from the contaminated area and the use of antidote therapy [38][39][40][41][42][43][44][49][50][51][52][53][54][55]. The action of cyanide in low concentration in the atmospheric air causes the development of minor symptoms, in particular the appearance of a feeling of fear, headache, vomiting, shortness of breath, sometimes with the smell of bitter almonds and dizziness.…”

The Diagnosis and Treatment of Carbon Monoxide Poisoning

“…A case report showed a COHb measurement of 61% at fetal autopsy, although the mother had a measurement of 7% after just an hour's O 2 treatment. For this reason, some authors regard pregnancy as a strict indication for HBOT (23), especially in the presence of neurological symptoms, signs of fetal stress, occurrence of syncope, or high COHb levels (4).…”