Hypothesis: Delayed presentation of secondary airway injury is a significant clinical entity following blast injury.
Design: Retrospective review.
Setting: Combat Support Hospital, Operation Iraqi Freedom.
Patients: Twenty-three blast injury patients with bronchoscopic evidence of secondary airway injury.
Main outcome measures: Symptom development and time frame, bronchoscopic findings, and requirement for mechanical ventilation.
Results: All of the 23 patients presented within 12 hours of injury. Eleven patients (48%) arrived at the hospital after prior endotracheal intubation. The majority (17 patients [74%]) of patients had no carbonaceous sputum, singed nasal hair, or thoracic trauma that would suggest possible airway injury. Bronchoscopy revealed mucosal erythema and edema in 16 (70%) of the patients, 6 (23%) had additional airway carbonaceous deposits, and 5 (21%) had normal findings on initial bronchoscopy. Eight patients (35%) initially breathing spontaneously and demonstrating no thoracic trauma required intubation within 12 hours of admission owing to impending loss of airway patency. Bronchoscopy revealed significant airway edema (>50% patency loss) in 6 (75%) of these 8 patients, with additional carbonaceous deposits in 3 patients (38%). Patients requiring delayed intubation had a significantly greater respiratory rate on initial examination.
Conclusions: Manifestation of secondary airway injury may be delayed up to 12 hours following blast injury. We believe that blast injury patients should be observed for at least 18 hours after injury or until edema has resolved and in a setting amenable to emergent airway support and rapid bronchoscopic evaluation at the earliest indication of possible airway compromise.