Probing the dyspneic patient.

For undifferentiated dyspnea, how would you like to have an accurate diagnosis in 24 minutes?

I love this study.

Basically, for all dyspneic patients (not trauma related, and over age 18), 10 EP’s were given an H&P, vital signs, and an EKG, as well as access to a Chest X-Ray, Chest CT, cardiologist performed echo, and labs including an ABG.

These same 2,683 patients, in tandem, had point of care ultrasound testing (lung, IVC, echo). Here’s the catch – the ultrasonographers were only provided the H&P, vital signs, and EKG then asked to make a diagnosis. The treating provider was blinded to POCUS diagnosis.

These numbers for diagnostic accuracy of POCUS are astounding.

+LR for acute HF? 22 (-LR 0.12)

+LR for ACS? 105 !!!

+LR for pneumonia? 10.5 (-LR 0.13)

+LR for pleural effusion? 95 (-LR 0.23)

+LR for pericardial effusion? 325!!! (-LR 0.14)

+LR for COPD/asthma? 22 (-LR 0.14)

+LR for PE? 345!!!

+LR for pneumothorax? 4635!!! (-LR 0.12)

+LR for ARDS? 90

Yes, for certain things like pneumonia, the difference in p-values between tradition means and POCUS diagnosis was not significantly different, but what about volume status? I cant imagine blindly giving 30 cc/kg would benefit the patient with a plethoric IVC and pleural effusion. There is some elegance a play here.

Additionally, sure, ED diagnosis for ACS had a higher LR, but they also had a cardiologist performing and interpreting echos in the ED (a rather rare siting in a US ED I would imagine) – without much improvement in their -LR (0.53 vs 0.48). For PE, the -LR of POCUS was predictably mediocre if not outright bad (0.6), while the -LR for ED diagnosis of PE, with the benefit of chest CT, was -0.10.

Now look, I get that these EP’s were quite sono-savvy. They all had 2+ years of experience, over 80 hours of ultrasound lessons & training, with at least 150 lung and 150 ED echo’s under their belt. The diagnosis was made in 24 minutes with POCUS in comparison to 186 minutes for traditional means. And while most of us can not do a year+ ultrasound fellowship, and neither can we all be as savvy with the probe as these authors (or Matt, Mike, Jacob, Resa, Laleh, etc) – it does not mean we shouldnt try. You can still greatly increase your yield just by practicing. To boot, the cognitive offload you experience by saving yourself a few hours by (correctly!) knowing which direction you are heading with a patient is an immense boon to both your mental heath & your patients well being.