Symptoms of smoke inhalation include Local irritant phenomena: Cough, wheezing, stridor Hypoxic manifestations: Confusion, lethargy, coma, tachycardia, tachypnea Carbon monoxide poisoning: Headache, nausea, weakness, confusion, coma Diagnosis of Smoke Inhalation Carboxyhemoglobin (COHb) levels Bronchoscopy Chest x-ray Smoke inhalation is suspected in patients with respiratory symptoms, a history of confinement in a burning environment, or carbonaceous sputum.