The Beirut ammonium nitrate blast: A multicenter study to assess injury characteristics and outcomes

Background: Blasts incidents impose catastrophic aftermaths on populations regarding casualties, sustained injuries, and devastated infrastructure. Lebanon witnessed one of the largest nonnuclear chemical explosions in modern history-the August 2020 Beirut Port blast. This study assesses the mechanisms and characteristics of blast morbidity and mortality and examines severe injury predictors through the Injury Severity Score.

Methods: A retrospective, multicenter cross-sectional study was conducted. Data of trauma patients presenting to five major acute-care hospitals in metropolitan Beirut up to 4 days following the blast were collected in a two-stage process from patient hospital chart review and follow-up phone calls.

Results: A total of 791 patients with a mean age of 42 years were included. The mean distance from the blast was 2.4 km (SD, 1.9 km); 3.1% of victims were in the Beirut Port itself. The predominant mechanism of injury was being struck by an object (falling/projectile) (293 [37.0%]), and the most frequent site of injury was the head/face (209 [26.4%]). Injury severity was low for 548 patients (71.2%), moderate for 62 (8.1%), and severe/critical for 27 (3.5%). Twenty-one deaths (2.7%) were recorded. Significant serious injury predictors (Injury Severity Score, >15) were sustaining multiple injuries (odds ratio [OR], 2.62; p = 0.005); a fracture (OR, 5.78; p < 0.001); primary blast injuries, specifically a blast lung (OR, 18.82; p = 0.001), concussion (OR, 7.17; p < 0.001), and eye injury (OR, 8.51; p < 0.001); and secondary blast injuries, particularly penetrating injuries (OR, 9.93; p < 0.001) and traumatic amputations (OR, 13.49; p = 0.01). Twenty-five percent were admitted to the hospital, with 4.6% requiring the intensive care unit. At discharge, 25 patients (3.4%) had recorded neurologic disability.

Conclusion: Most injuries sustained by the blast victims were minor. Serious injuries were mostly linked to blast overpressure and projectile fragments. Understanding blast injuries characteristics, their severity, and management is vital to informing emergency services, disaster management strategies, hospital preparedness, and, consequently, improving patient outcomes.

Level of evidence: Prognostic and Epidemiologic; Level III.