They might have pneumonia. Let’s get a chest X-ray! But is that the right decision? How good are chest X-rays at detecting bacterial pneumonia? You might be surprised that the sensitivity is around 80%, depending on the study. Can we figure out whether a patient has pneumonia that is worth treating with antibiotics without it? Can we do this without the patient leaving the assessment room? Here, we discuss a 2014 systematic review and meta-analysis demonstrating that bedside ultrasound by a trained provider can be a very effective diagnostic tool for bacterial pneumonia. Here, we review a systematic review and meta-analysis that answers this very question!
Title:
Lung ultrasound for the diagnosis of pneumonia in adults: a systematic review and meta-analysis 1.
Chavez, M., et al. Respiratory Research 2014.
Population:
Adult (>18yo) ED patients who were screened with lung ultrasound (LUS) against referent CXR/chest CT and clinical criteria for pneumonia.
Intervention:
LUS performed by an experienced clinician is defined as:
- 100 LUS procedures
- Physician with > 10 years experience in LUS
- Trained ED/GP with 3hrs each of didactic/hands-on experience with LUS
Comparison:
CT chest was performed in all studies either as the gold standard or only when discordance between the LUS and CXR existed.
Patients ‘ inclusion criteria were based on radiological evidence of consolidation or alveolar/interstitial infiltrate or clinical criteria, including pneumonia symptoms, chest pain, respiratory failure, or suspected H1N1.
Outcome:
Pooled sensitivity and specificity for diagnosing pneumonia with LUS were 94% and 96%, respectively.
30,000ft view:
As ED physicians we should be skilled with POC ultrasound. Using this as an extension of our clinical examination can help diagnostic accuracy and speed when used in a way that is supported by data.
LUS for pneumonia 2:
- Early pneumonia – B-lines and tiny areas of subpleural consolidation
- Hepatization – solid appearing consolidated lung
- Irregular consolidation / air interface (shred sign)
- Air bronchograms & dynamic air bronchograms (most specific sign)
- Color doppler interrogation
- Associated pleural effusion or empyema
How should this modify your practice:
This SR/MA presents compelling evidence that ED physicians – residents in particular – can achieve an appropriate level of expertise through their training to be deemed experts in LUS to aid diagnosis of pneumonia with a high level of practice.
Take the ultrasound into all cases where pneumonia is on the differential.
Extend yourself:
The paper – https://doi.org/10.1186/1465-9921-15-50
LITF – https://litfl.com/lung-ultrasound-pneumonia/
Author: Dr Adrian Cois MD
Assistant Professor Emergency Medicine
References:
1. Chavez MA, Shams N, Ellington LE, et al. Lung ultrasound for the diagnosis of pneumonia in adults: a systematic review and meta-analysis. Respir Res. 2014;15(1):50. doi:10.1186/1465-9921-15-50
2. Rippey J. Lung Ultrasound: Pneumonia. Life in the Fast Lane • LITFL. Published November 30, 2018. Accessed July 25, 2022. https://litfl.com/lung-ultrasound-pneumonia/
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