519 Retrospective Pilot Study to Examine Potential Predictors of a Standardized Scoring System for Smoke Inhalation Injury

Abstract

Introduction Smoke inhalation injury is strongly associated with increased morbidity/mortality. Bronchoscopy is used to diagnosis smoke inhalation injury, but its interpretation is subjective. This study sought to assess diagnostic significance of physical exam, history, location, and adjunct studies characteristically performed on patients suspected of smoke inhalation by comparing these findings to outcomes. The primary goal was to examine variables that could be used to create an accurate smoke inhalation injury scoring system in order to develop an objective method that considers the severity of inhalation injury. Methods This retrospective study evaluated demographics, clinical presentation, carboxyhemoglobin level, intubation on arrival, bronchoscopy, comorbidities, hospital course, and outcomes associated with smoke inhalation. Bronchoscopy findings included: red mucosa, carbon particles at carina, and numerical score (1–4). The primary outcome was resuscitation fluid required in the first 24 hours of treatment compared to that predicted by the modified Brooke formula (2cc*weight in kg* Total Burn Surface Area). If the patient received more fluid than predicted, this was considered positive for smoke inhalation. Differences between predictor/outcome variables were determined using Wilcoxon rank sum test for continuous variables and Chi-squared test for categorical. Results A positive bronchoscopy score was defined on the condition of having positive physical exam finding and/or bronchoscopy score 1–4. Physical exam findings consisted of soot or carbon sputum present on the patient along with hoarseness, wheezing, or a red oropharynx on physical exam. If the patient met one of these conditions, we considered this a positive result. Inclusion criteria: age 18–89, admission from 1/1/2004 and 5/31/18, and diagnosis of smoke inhalation injury/burn injury. There was a significant difference in positive bronchoscopy between those positive for our condition of inhalation injury and no injury (p< 0.001; Table 1). Patients with a positive bronchoscopy score were 9 times more likely (OR=9.91, 95% CI = 2.8–35.01) to be diagnosed with inhalation injury as compared to those without a positive bronchoscopy score. Conclusions These results display the importance of bronchoscopy in suspected smoke inhalation injury and reinforce the need for an objective bronchoscopy assessment. Future studies can build upon these results by creating an objective scoring system to guide providers performing bronchoscopy. Applicability of Research to Practice Due to the 9-fold benefit of performing bronchoscopy, it should be the primary tool used to assess potential smoke inhalation injury; other tests may be secondary in nature.