Smoke inhalation injury occurs from several agents. Thermal injury and chemical injury are the primary initial toxicities. Chemical injury occurs from several materials of combustion and pyrolysis.2  Highly water-soluble irritants such as acrolein, sulfur dioxide, hydrogen chloride and ammonia, and intermediate water soluble irritants such as chlorine and isocyanates are produced. Poorly water-soluble irritants are oxides of nitrogen and phosgene. Simple asphyxiants which displace oxygen include carbon dioxide and methane, and chemical asphyxiants which inhibit mitochondrial activity and reduce hemoglobin carrying capacity include carbon monoxide, cyanide, and hydrogen sulfide. Treatment is generally supportive. Some require antidotes. Most critically ill patients require unique ventilation techniques used for Acute Respiratory Distress Syndrome (ARDS). As toxic pulmonary agents lead to oxidative damage to lung tissues, similar to excessive oxygen supplementation, oxygen supplementation should be provided only as necessary to maintain sufficient oxygenation (pulse oximetry of 90% to 96%).3