17 Long-Term Pulmonary Sequelae After Inhalation Injury: A Retrospective Cohort Study

Abstract

Abstract Introduction Inhalation injury (INHI) has strong associations with increased rates of in-patient mortality and pneumonia. Data describing long-term health outcomes after inhalation injury are scarce and the true sequelae are largely unknown. The aim of the study is to review long-term pulmonary outcomes in inhalation injury patients. We hypothesize that INHI patients are at greater risk of developing long-term pulmonary sequelae. Methods We present a retrospective case-control of burn patients admitted to an ABA certified facility. We included burn patients with or without medically confirmed INHI who were admitted between 06/2016 to 11/2019 and were part of the regional Department of Health Services (DHS) system. The experimental group was patients with bronchoscopy confirmed INHI. The control groups were ventilated patients with confirmed non-inhalation injury (V) and non-ventilated patients with confirmed non-inhalation injury (NV). These were matched for age, TBSA, sex, previous comorbid pulmonary disease, and smoking status. Primary study outcomes were rates of post-discharge pulmonary sequelae, including ineffective airway clearance, infections, shortness of breath, and malignancy. Secondary outcomes included rates of post-discharge surgeries and readmission, post-discharge non-pulmonary sequelae, and post-discharge days to pulmonary/non-pulmonary sequelae. Results The study population included 33 INHI, 45 V, and 50 NV patients. There were no significant differences in age (P=.98), sex (P=.68), TBSA (P=.18), pulmonary comorbidity (P=.5), or smoking status (P=.92). Outpatient pulmonary sequelae were significantly higher for both INHI and V groups as compared to NV (21% and 17% vs 4%, P=.023, .043). The number of days from discharge to pulmonary sequelae was significantly shorter in the INHI group versus the V group (162±139 days vs 513±314 days, P=.024). Multinomial logistic regression for both INHI and V groups using the variables comorbid pulmonary disease, smoking status, and inpatient course and complications, indicated no effect on post-discharge pulmonary sequelae (all P >.05). All other measures were not significant when comparing INHI to V or NV (all P >.05). Conclusions Both INHI and V groups resulted in higher rates of outpatient pulmonary sequelae independent of inpatient course as compared to NV. While outpatient pulmonary sequelae were not significantly different between INHI and V, the INHI patients presented with complaints earlier. Thus one can conclude that ventilation alone is a significant contributing factor for the long-term pulmonary sequelae reported in this patient population.