In a patient with burns

(A) Carbon monoxide is highly toxic to the pulmonary tract # Inhalation injury> These occur in those trapped in enclosed spaces. They are particularly common in association with bums of the head and neck. Various parts of the respiratory tract may be injured.> The inhalation of hot gases causes a thermal burn to the upper airway. This is manifest early on by stridor, hoarseness, cough and respiratory obstruction. Inhalation of the products of combustion causes a chemical burn to the bronchial tree and lungs.> This is manifest by hypoxia, acute respiratory distress syndrome and respiratory failure; it may be of delayed onset. Systemic absorption of, in particular, carbon monoxide (but also hydrogen cyanide from burning plastics) causes poisoning.> Carbon monoxide displaces oxygen from haemoglobin to form carboxyhaemoglobin, reducing the oxygen-carrying capacity of the blood. It also has intracellular effects.> Patients who survive the original incident may arrive confused or unconscious. Inhalation injury has an additive effect on mortality in all burns.