Evaluation of volume status and lung fluid by lung ultrasound in conventional hemodialysis patients

Aim: Conventional hemodialysis (HD) and ultrafiltration (UF) is one of the most frequently applied treatments in patients with end-stage renal disease (ESRD) and anuria. In this study, it was aimed to determine the relationship of lung ultrasonography (LUS) and inferior vena cava (IVC) measurements with UF in patients undergoing HD and UF, and to determine their usability in the evaluation of fluid status of patients. Materials and Methods: This study included 40 patients with ESRD who underwent anuric ultrafiltration and underwent 4-hour HD 3 times a week for at least 6 months in NEU MTF Hospital, Internal Diseases Department, Department of Nephrology, Dialysis Unit. All study details were explained to the participants and written informed consent was obtained. The ultrasonographic evaluation was performed in the supine position before and after HD for both LUS and IVC measurements. LUS was performed by scanning 12 areas in each patient's anterior, lateral and posterior regions of both hemithorax. B line in each area was scored according to the algorithm. The total number of B lines was calculated by assigning scores to all lung segments from 0 to 3. The change in the number of B lines before and after HD for each patient was recorded as the delta B line. IVC examination was performed with a subxiphoid approach. After expiration (IVC max) and inspiration (IVC min), the image was frozen and their diameters were measured. Collapsibility index was calculated using the formula (IVC-CI) = (IVC max-IVC min)/IVC max x 100. Results: The number of B lines before dialysis was significantly higher than that of B lines after dialysis (p <0.001). There was a significant difference between the number of anterolateral and anterior B lines before and after dialysis (p <0.001). There was a low moderate correlation between the amount of UF and the change in the number of B lines calculated before and after dialysis (r = +0.387, p = 0.014). There was a low-moderate correlation between the change in the number of B lines before and after HD and the weight change of the patients (r = +0.389, p = 0.013). Pre-dialysis IVC min and IVC max mean of patients were significantly higher than post-dialysis IVC min and IVC max mean (p < 0.001). An excellent correlation was found between the IVC max measurement before HD and the number of B lines before HD (r=0.998, p<0.001). There was no significant difference in the mean values of the IVC collapsibility index measured before and after dialysis (p value = 0.421). Conclusion: This study determined that B line numbers and IVC diameter measurements decreased after hemodialysis compared to pre-hemodialysis values. We think these parameters can be useful in determining hemodialysis the patient's excess fluid load and should be used together. Keywords: Lung ultrasonography, B-line number, vena cava collapsibility index, hemodialysis, ultrafiltration.