Ultrasound detection of the sliding lung sign by prehospital critical care providers

Background: The presence of the sonographic sliding lung sign (SLS) is a sensitive indicator for the absence of a pneumothorax. Objective: The aim of this study was to determine if prehospital critical care providers (PHCPs) can acquire and maintain the necessary skills to determine the presence or absence of the SLS following a brief tutorial. Methods: This was a blinded randomized observational trial using a cadaveric model. The model was randomized to esophageal intubation (negative SLS) or tracheal intubation (positive SLS), and a SonoSite 180 plus (Bothel, WA) machine was used for the examination. After a 9-month period, the PHCPs were reevaluated without additional instruction. Results: There were 8 PHCPs. A total of 6 intubations were performed yielding a total of 48 trials. The presence or absence of the SLS was correctly identified in 46 of the 48 trials, resulting in a sensitivity and specificity of 96.9% (95% confidence interval [CI], 89.6%-99.1%) and 93.8% (95% CI, 93.8%-79.3%), respectively. At the 9-month follow-up, 7 of the original PHCPs were available to participate. A total of 8 intubations were performed yielding a total of 56 trials. The presence or absence of the SLS was correctly identified in all 56 trials, resulting in a sensitivity and specificity of 100% (95% CI, 93.6%-100%). Conclusion: Prehospital critical care providers can accurately determine the presence or absence of the sonographic SLS following a brief tutorial and retain the skill set following a 9-month interval.