The LUSBI ultrasound protocol effectively distinguished cardiac from non-cardiac causes of shortness of breath, validated by the peptide biomarker NT-proBNP in 80 ER patients.
p = 0.004NT-proBNP levels — the gold-standard peptide biomarker for heart failure — differed significantly across the LUSBI protocol's diagnostic profiles, validating the ultrasound-based approach.
What the researchers found
Researchers created the LUSBI protocol — combining lung ultrasound, BREST heart failure risk scores, and inferior vena cava measurements — to distinguish cardiac from non-cardiac causes of shortness of breath in the emergency department. The protocol was validated against NT-proBNP, a peptide biomarker for heart failure.
NT-proBNP values differed significantly across LUSBI protocol profiles (p=0.004), confirming that the protocol's ultrasound-based classifications align with biochemical evidence of heart failure. There was also a significant difference (p=0.001) in LUSBI profiles between patients categorized by central venous pressure.
The protocol proved effective for quickly confirming or ruling out a cardiac cause of breathing difficulty in 80 emergency department patients.
Why it matters
Shortness of breath is one of the most common emergency department complaints, and quickly determining whether it's caused by heart failure or lung disease changes treatment entirely. The LUSBI protocol offers a rapid bedside approach using ultrasound that was validated against the gold-standard peptide biomarker NT-proBNP. This is relevant to peptide science because NT-proBNP — a fragment of brain natriuretic peptide — serves as the laboratory benchmark against which new diagnostic approaches are measured.
The numbers in context
n=80 · p=0.004 for NT-proBNP across LUSBI profiles · p=0.001 for CVP category differences · 2 groups: experimental (dyspneic) and control
How the study worked
Cross-sectional study in an emergency department. 80 patients divided into experimental (dyspnea as main complaint) and control groups. Each patient received lung ultrasound, inferior vena cava measurements, and BREST scoring to create LUSBI protocol profiles. NT-proBNP blood levels served as the biochemical reference standard for cardiac origin.
Who was studied
80 emergency department patients with and without dyspnea as their primary complaint
What this study cannot tell us
Small sample size (80 patients) from a single emergency department. Cross-sectional design cannot establish the protocol's predictive accuracy over time. No comparison with established diagnostic algorithms like the Framingham criteria. The study was conducted at one center, limiting generalizability.
How to read the evidence
Small single-center cross-sectional study with 80 patients. While statistically significant results were achieved, the small sample and lack of comparison with established diagnostic algorithms limit the evidence strength.
When this study was published
Published in 2024, this study reflects current point-of-care ultrasound capabilities and NT-proBNP testing standards. Relevant to ongoing efforts to integrate bedside tools with biomarker diagnostics.
The bigger picture
NT-proBNP has become the go-to peptide biomarker for heart failure diagnosis, but blood tests take time. Point-of-care ultrasound protocols like LUSBI aim to provide immediate answers at the bedside. This study validates ultrasound findings against the peptide biomarker, showing how peptide-based laboratory tests serve as the benchmark for evaluating new diagnostic approaches in emergency medicine.
Questions still open
- How does the LUSBI protocol's diagnostic accuracy compare to NT-proBNP testing alone?
- Would combining LUSBI with rapid NT-proBNP point-of-care testing improve outcomes beyond either alone?
- Can this protocol reduce time-to-treatment in busy emergency departments?
Common questions
What is NT-proBNP and why is it used?
Why not just use the blood test instead of ultrasound?
Read the original research
The LUSBI Protocol (Lung Ultrasound/BREST Score/Inferior Vena Cava)-Its Role in a Differential Diagnostic Approach to Dyspnea of Cardiogenic and Non-Cardiogenic Origin.
Medicina (Kaunas, Lithuania), 60(9)
Citation
Dojcinovic, Boris; Banjac, Nada; Vukmirovic, Sasa; Dojcinovic, Tamara; Vasovic, Lucija V; Mihajlovic, Dalibor; Vasovic, Velibor. (2024). The LUSBI Protocol (Lung Ultrasound/BREST Score/Inferior Vena Cava)-Its Role in a Differential Diagnostic Approach to Dyspnea of Cardiogenic and Non-Cardiogenic Origin.. Medicina (Kaunas, Lithuania), 60(9). https://doi.org/10.3390/medicina60091521