title: Combined carbon monoxide and cyanide poisoning: a place for treatment.
abstract: During fires, victims can inhale significant carbon monoxide (CO) and cyanide (CN) gases, which may cause synergistic toxicity in humans. Oxygen therapy is the specific treatment for CO poisoning, but the treatment of CN toxicity is controversial. To examine the indication for treatment of CN toxicity, we have established a canine model to delineate the natural history of combined CO and CN poisoning. In seven dogs (24 +/- 3 kg), CO gas (201 +/- 43 mL) was administered by closed-circuit inhalation. Then, potassium CN was intravenously (i.v.) infused (0.072 mg.kg-1.min-1) for 17.5 +/- 3.0 min. Cardiorespiratory measurements were conducted before and after these toxic challenges. Despite significant CO poisoning (peak carboxyhemoglobin fractions [COHb] = 46% of total hemoglobin [Hb]; elimination t1/2 = 114 +/- 42 min) with attendant decrease in blood O2 content, CO had essentially little effect on any hemodynamic or metabolic variable. On the other hand, CN severely depressed most hemodynamic and metabolic functions. Compared to baseline values, CN caused significant (P < 0.01) decreases in cardiac output (6.4 +/- 2.0 to 3.1 +/- 0.5 L/min) and heart rate (169 +/- 44 to 115 +/- 29 bpm) and decreases in oxygen consumption (VO2) (133 +/- 19 to 69 +/- 21 mL/min) and carbon dioxide production (VCO2) (128 +/- 27 to 103 +/- 22 mL/min). However, these critical hemodynamic and metabolic variables recovered to baseline values by 15 min after stopping the CN infusion, except lactic acidosis which persisted for at least 25 min after the CN infusion.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Anesthesiology, University of California at Irvine, Orange 92613-1491.
authors.forename: P H
authors.initials: PH
authors.lastname: Breen
authors.forename: S A
authors.initials: SA
authors.lastname: Isserles
authors.forename: J
authors.initials: J
authors.lastname: Westley
authors.forename: M F
authors.initials: MF
authors.lastname: Roizen
authors.forename: U Z
authors.initials: UZ
authors.lastname: Taitelman
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000097:blood; D002248:Carbon Monoxide / Q000493:pharmacokinetics; D002249:Carbon Monoxide Poisoning / Q000097:blood / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D002263:Carboxyhemoglobin / Q000032:analysis; D003486:Cyanides / Q000493:pharmacokinetics; D004195:Disease Models, Animal; D004285:Dogs; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D006856:Hydrogen Cyanide / Q000506:poisoning*; D006863:Hydrogen-Ion Concentration; D007262:Infusions, Intravenous; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption; D011041:Poisoning / Q000503:physiopathology / Q000628:therapy; D011190:Potassium Cyanide / Q000008:administration & dosage / Q000506:poisoning
chemical_list: D003486:Cyanides; D002245:Carbon Dioxide; D006856:Hydrogen Cyanide; D002248:Carbon Monoxide; D002263:Carboxyhemoglobin; D011190:Potassium Cyanide; D010100:Oxygen