Abstract | OBJECTIVES: Sonographic thoracic B-lines and N-terminal pro-brain-type natriuretic peptide ( NT-ProBNP) have been shown to help differentiate between congestive heart failure (CHF) and chronic obstructive pulmonary disease ( COPD). The authors hypothesized that ultrasound (US) could be used to predict CHF and that it would provide additional predictive information when combined with NT-ProBNP. They also sought to determine optimal two- and eight-zone scanning protocols when different thresholds for a positive scan were used. METHODS: This was a prospective, observational study of a convenience sample of adult patients presenting to the emergency department (ED) with shortness of breath. Each patient had an eight-zone thoracic US performed by one of five sonographers, and serum NT-ProBNP levels were measured. Chart review by two physicians blinded to the US results served as the criterion standard. The operating characteristics of two- and eight-zone thoracic US alone, compared to, and combined with NT-ProBNP test results for predicting CHF were calculated using both dichotomous and interval likelihood ratios (LRs). RESULTS: One-hundred patients were enrolled. Six were excluded because of incomplete data. Results of 94 patients were analyzed. A positive eight-zone US, defined as at least two positive zones on each side, had a positive likelihood ratio (LR+) of 3.88 (99% confidence interval [CI] = 1.55 to 9.73) and a negative likelihood ratio (LR-) of 0.5 (95% CI = 0.30 to 0.82), while the NT-ProBNP demonstrated a LR+ of 2.3 (95% CI = 1.41 to 3.76) and LR- of 0.24 (95% CI = 0.09 to 0.66). Using interval LRs for the eight-zone US test alone, the LR for a totally positive test (all eight zones positive) was infinite and for a totally negative test (no zones positive) was 0.22 (95% CI = 0.06 to 0.80). For two-zone US, interval LRs were 4.73 (95% CI = 2.10 to 10.63) when inferior lateral zones were positive bilaterally and 0.3 (95% CI = 0.13 to 0.71) when these were negative. These changed to 8.04 (95% CI = 1.76 to 37.33) and 0.11 (95% CI = 0.02 to 0.69), respectively, when congruent with NT-ProBNP. CONCLUSIONS: Bedside thoracic US for B-lines can be a useful test for diagnosing CHF. Predictive accuracy is greatly improved when studies are totally positive or totally negative. A two-zone protocol performs similarly to an eight-zone protocol. Thoracic US can be used alone or can provide additional predictive power to NT-ProBNP in the immediate evaluation of dyspneic patients presenting to the ED.
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Authors | Andrew S Liteplo, Keith A Marill, Tomas Villen, Robert M Miller, Alice F Murray, Peter E Croft, Roberta Capp, Vicki E Noble |
Journal | Academic emergency medicine : official journal of the Society for Academic Emergency Medicine
(Acad Emerg Med)
Vol. 16
Issue 3
Pg. 201-10
(Mar 2009)
ISSN: 1553-2712 [Electronic] United States |
PMID | 19183402
(Publication Type: Journal Article)
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Chemical References |
- Biomarkers
- Peptide Fragments
- pro-brain natriuretic peptide (1-76)
- Natriuretic Peptide, Brain
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Topics |
- Adolescent
- Adult
- Aged
- Biomarkers
(blood)
- Diagnosis, Differential
- Dyspnea
(blood, diagnostic imaging, physiopathology)
- Emergency Service, Hospital
- Female
- Heart Failure
(blood, diagnostic imaging, physiopathology)
- Humans
- Likelihood Functions
- Male
- Middle Aged
- Natriuretic Peptide, Brain
(blood)
- Peptide Fragments
(blood)
- Predictive Value of Tests
- Prospective Studies
- Pulmonary Disease, Chronic Obstructive
(blood, diagnostic imaging, physiopathology)
- Sensitivity and Specificity
- Ultrasonography
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