Evaluating the Impact That a Lung Ultrasound Training Program to Detect Acute Heart Failure Has on Paramedic Behavior

Objective

Previous studies have revealed that paramedics can learn how to perform lung ultrasound (LUS) to identify pulmonary edema and acute heart failure, but studies evaluating subsequent clinical application are lacking. We set out to evaluate how the implementation of a LUS training program affected paramedic behavior (Kirkpatrick’s methodology level 3).

Methods

This was a prospective observational cohort study on paramedics from a single agency. Paramedics completed 1 hour of training including a pre- and post-intervention survey and test, 30 minutes of didactics, 30 minutes of hands-on scanning, and an independent objective structured clinical evaluation. They, then, completed a ride-along with a physician trained in LUS. For the next 15 months, paramedics independently performed and interpreted clinically indicated LUS examinations on patients being transported for shortness of breath. The number of LUS performed, accuracy of interpretation, image quality, and change in management based on LUS findings were analyzed.

Results

Of 26 paramedics, 22 (85%) completed 109 LUS in 15 months, with a median of 2 LUS performed per paramedic (range 1-18). Sensitivity and specificity of paramedic-performed LUS for pulmonary edema were 73.8% (confidence interval 0.58-0.85) and 91.0% (confidence interval 0.81-0.96), respectively. Of the 31 true positives, 20 patients (64.5%) were treated with nitroglycerin, furosemide, or positive pressure ventilation, whereas 11 patients were not treated despite a positive LUS result. Median image quality was 4 (range 1-5) on a 5-point scale.

Conclusion

Implementation of a LUS training program led to most paramedics using LUS in the clinical setting and obtaining high-quality images. Specificity of paramedic-performed LUS was high when compared with hospital diagnosis. Prehospital heart failure treatment based on LUS findings was moderate.