Clinical factors associated with pulmonary complications after blunt chest trauma: a retrospective cohort study

Blunt chest wall trauma is a major contributor to global trauma burden and is associated with a high rate of delayed pulmonary complications, including pneumonia and respiratory failure. Several risk factors, such as advanced age, injury severity, and the number of rib fractures, have been identified, and multiple scoring systems have been developed to predict outcomes. However, the applicability of some existing scoring systems may be limited in settings where detailed radiographic assessment is not routinely available. This study aimed to identify readily available clinical factors associated with pulmonary complications following blunt chest trauma. This retrospective cohort study included adult patients (≥ 18 years) with blunt chest trauma admitted to Maharaj Nakhon Chiang Mai Hospital between January 1, 2022, and December 31, 2024. Patients with unsurvivable injuries (AIS = 6), delayed presentation with pre-existing complications, or died in the emergency department were excluded. The primary outcome was the occurrence of pulmonary complications within 30 days. Secondary outcomes included hospital length of stay, ICU length of stay, duration of mechanical ventilation, and mortality. Increasing age (adjusted OR 1.07 per year, 95% CI 1.03–1.11; p < 0.001) and lower systolic blood pressure (adjusted OR 0.97 per mmHg, 95% CI 0.94–0.99; p = 0.014) were independently associated with complications. Patients with complications had significantly longer hospital stay (14 vs. 8.5 days), ICU stay (5 vs. 2 days), and duration of mechanical ventilation (5 vs. 3 days) (all p < 0.01). Pulmonary complications are common after blunt chest trauma and are associated with worse clinical outcomes. Increasing age and lower initial systolic blood pressure were independently associated with pulmonary complications. These readily available clinical factors may help identify patients who warrant closer monitoring.