Ultrasonographic Assessment of Extravascular Lung Water in Hospitalized Patients Requiring Hemodialysis: A Prospective Observational Study

Abstract

<b><i>Introduction:</i></b> Sonographic technologies can estimate extravascular lung water (EVLW) in hemodialysis (HD) patients. This study investigated the suitability of a handheld scanner in contrast to a portable scanner for quantifying EVLW in hospitalized patients requiring HD. <b><i>Methods:</i></b> In this prospective study, 54 hospitalized HD patients were enrolled. Bedside lung ultrasound was performed within 30 min before and after dialysis using handheld (phased array transducer, 1.7–3.8 MHz) and portable (curved probe, 5–2 MHz) ultrasound devices. Eight lung zones were scanned for total B-lines number (TBLN). The maximum diameter of inferior vena cava (IVC) was measured. We performed Passing-Bablok regression, Deming regression, Bland-Altman, and logistic regression analysis. <b><i>Results:</i></b> The 2 devices did not differ in measuring TBLN and IVC (<i>p</i> > 0.05), showing a high correlation (<i>r</i> = 0.92 and <i>r</i> = 0.51, respectively). Passing-Bablok regression had a slope of 1.11 and an intercept of 0 for TBLN, and the slope of Deming regression was 1.02 within the CI bands of 0.94 and 1.11 in the full cohort. TBLN was logarithmically transformed for Bland-Altman analysis, showing a bias of 0.06 (TBLN = 1.2) between devices. The slope and intercept of the Deming regression in IVC measurements were 0.77 and 0.46, respectively; Bland-Altman plot showed a bias of −0.07. Compared with predialysis, TBLN significantly (<i>p</i> < 0.001) decreased after dialysis, while IVC was unchanged (<i>p</i> = 0.16). Univariate analysis showed that cardiovascular disease (odds ratio [OR] 8.94 [2.13–61.96], <i>p</i> = 0.002), smoking history (OR 5.75 [1.8–20.46], <i>p</i> = 0.003), and right pleural effusion (OR 5.0 [1.2–25.99], <i>p</i> = 0.03) were strong predictors of EVLW indicated by TBLN ≥ 4. <b><i>Conclusion:</i></b> The lung and IVC findings obtained from handheld and portable ultrasound scanners are comparable and concordant. Cardiovascular disease and smoking history were strong predictors of EVLW. The use of TBLN to assess EVLW in hospitalized HD patients is feasible. Further studies are needed to determine if TBLN can help guide volume removal in HD patients.

Dynamic changes and prognosis of pulmonary congestion by lung ultrasound in hemodialysis patients: a systematic review and meta-analysis

“…The measured values of Area 4, Area 6 and Area 8 are highly consistent with the measured values of dialysis patients diagnosed with pulmonary congestion using Area 28 method [21,22]. Moreover, the consistency of the scores of the B-line between observers was relatively high, and there was no obvious difference in the B-line detection results of different types of ultrasound equipment [7]. LUST' s sub-study aimed at clinicians who can master the B-lines measurement method quickly and effectively after online video training, as well as at nurses who can successfully evaluate B-lines for the differential diagnosis of acute dyspnoea with high accuracy [23].…”

“…Before dialysis, excessive extravascular lung water was correlated with the amount of fluid accumulated before treatment. The nine articles reported that hemodialysis can rapidly reduce the severity of pulmonary congestion, and the number of B-lines changed significantly after dialysis [3][4][5][6][7][8][9][10][11]. The results of eight articles after meta-analysis had statistical significance, which demonstrates that LUS can dynamically monitor the volume status of dialysis patients in real time, as an attempt to more effectively assess the effect of dialysis [4][5][6][7][8][9][10][11].…”

“…The nine articles reported that hemodialysis can rapidly reduce the severity of pulmonary congestion, and the number of B-lines changed significantly after dialysis [3][4][5][6][7][8][9][10][11]. The results of eight articles after meta-analysis had statistical significance, which demonstrates that LUS can dynamically monitor the volume status of dialysis patients in real time, as an attempt to more effectively assess the effect of dialysis [4][5][6][7][8][9][10][11]. Noble et al in a quantitative analysis of a small sample of patients found that for every 500 ml ultrafiltration, the number of B-lines decreased by about 2.7 [18].…”

“…For this analysis, nine studies using B-ultrasound to monitor the real-time dynamic changes of hemodialysis patients before and after dialysis were included [3][4][5][6][7][8][9][10][11] (Table I). The average number of B-lines after the hemodialysis of the nine articles included was lower than that before hemodialysis.…”

Automated lung ultrasound image assessment using artificial intelligence to identify fluid overload in dialysis patients

“…In our study, we pragmatically combined 8-point measurement with HHUSD to enhance the portability of using LUS. HHUSD has been tested for LUS measurement in HD patients (22,23). Miao et al compared the use of HHUSD with a portable US machine, with comparable and concordant measurements of B lines both before and after HD (r 2 = 0.84), though with a signi cant bias of 0.06 (actual B line = 1.2, p = 0.04).…”