Serial lung and IVC ultrasound in the assessment of congestive heart failure.

Abstract

Background: Management of congestive heart failure (CHF) is dependent on clinical assessments of volume status, which are subjective and imprecise. Point-of-care ultrasound (POCUS) is useful in the diagnosis of CHF, but how POCUS findings correlate with therapy remains unknown. This study aimed to determine whether the changes in clinical evaluation of CHF with treatment are mirrored with changes in the number of B lines on lung ultrasound (LUS) and inferior vena cava (IVC) size. In this prospective observational study, investigators performed serial clinical and ultrasound assessments within 24 h of admission (T1), day 1 in hospital (T2) and within 24 h of discharge (T3). Clinical assessments included an evaluation of the jugular venous distension (JVD), hepatojugular reflux (HJR), pulmonary rales and a clinical congestion score was calculated. Ultrasound assessment included the IVC size and collapsibility, and the number of B lines in an 8-point scan.

Results: Fifty consecutive patients were recruited with a mean age of 71.2 years (SD 12.7). Mean clinical congestion score on admission was 5.6 (SD 1.4) and declined significantly over time to 1.3 (0.91), as did the JVP, HJR and pulmonary rales. No significant changes were found in the IVC size between T1 [1.9 (0.65)] and T3 [2.0 (0.50)] or in the IVC collapsibility index [T1 0.3 (0.19) versus T3 0.25 (0.16)]. The mean number of B lines decreased from 11 (6.1) at T1 to 8.3 (5.5) at T3, although this decrease did not reach statistical significance. Spearman correlation between JVP and HJR versus IVC collapsibility and total B lines did not yield significant results.

Conclusions: Clinical exam findings correlate over time during the management of CHF, whereas LUS and IVC results did not. The number of B lines did decrease with therapy, but did not reach statistical significance likely because the sampled population was small and had only mild heart failure. Further studies are warranted to further explore the use of lung ultrasound in this patient population.