injuries poisoning
Pulmonary Chemical Warfare Agents
Diagnosis of Pulmonary Chemical Warfare Injuries
Clinical evaluation Frequent re-evaluation for deterioration Sometimes bronchoscopy, chest x-ray Clinical diagnosis is used to recognize exposure and distinguish type of damage (not necessarily the precise agent). Patients with an initially noisy chest and prominent symptoms are presumed to have type 1 involvement (large airways). Delayed onset of shortness of breath with a relatively quiet chest suggests type 2 damage. Although a high dose of type 2 agent may initially cause coughing, sneezing, and wheezing, these signs typically decrease over time; the patient then appears well until developing progressive shortness of breath. Chest x-ray may be normal initially. Scattered opacities due to chemical or secondary pneumonitis may develop with type 1 damage. Eventually, as Pulmonary Edema becomes radiographically evident, Kerley B lines and fluffy interstitial infiltrates due to type 2 damage will become visible. Bronchoscopy can confirm type 1 damage but may miss early type 2 damage. Laboratory testing is not helpful in initial diagnosis, but pulse oximetry and/or arterial blood gas (ABG) measurements can help monitor for clinical deterioration. Severe signs of type 1 damage (eg, severe wheezing, inspiratory stridor, soot around the nose or mouth due to smoke inhalation) should lower the threshold for early intubation. With a type 2 agent, it is important to re-triage patients frequently. Initially asymptomatic patients also require monitoring for deterioration; even mild symptoms are grounds for prompt transport to a medical facility because such patients often deteriorate further. Most patients with shortness of breath due to early pulmonary edema can be triaged as delayed for medical treatment; they can usually tolerate a short delay if more immediate casualties require treatment. However, such patients should have highest priority (urgent) for evacuation because they may require definitive, life-saving treatment in a pulmonary intensive care unit. 