NEPHROLOGY - ORIGINAL PAPER Lung ultrasound during hemodialysis: the role in the assessment of volume status Nicola Vitturi • Mauro Dugo • Marta Soattin • Francesco Simoni • Luisa Maresca • Riccardo Zagatti • Maria Cristina Maresca Received: 8 February 2013 / Accepted: 19 June 2013 Ó Springer Science+Business Media Dordrecht 2013 Abstract Objective Fluid balance is important in patients undergoing hemodialysis. ‘‘Dry’’ weight is usually estimated clinically, and also, bioimpedance is con- sidered reliable. Ultrasonography of inferior vena cava (IVC) estimates central venous pressure, and lung ultrasound evaluates extravascular (counting B-lines artifact) lung water. Our study was aimed to clarify their usefulness in the assessment of volume status during hemodialysis. Methods A total of 71 consecutive patients under- going hemodialysis underwent lung and IVC ultra- sound and bioimpedance spectroscopy immediately before and after dialysis. Results There was a significant reduction in the number of B-lines (3.13 vs 1.41) and in IVC diameters (end-expiratory diameter 1.71 vs 1.37; end-inspiratory diameter 1.19 vs 0.95) during dialysis. The reduction in B-lines correlated with weight reduction during dialysis (p 0.007); none of the parameters concerning the IVC correlated with fluid removal. At the end of the dialysis session, the total number of B-lines correlated with bioimpedance residual weight (p 0.002). Discussion The reduction in B-lines correlated with fluid loss due to hemodialysis, despite the small pre- dialysis number, confirming that lung ultrasound can identify even modest variations in extravascular lung water. IVC ultrasound, which reflects the intravascular filling grade, might not be sensitive enough to detect rapid volume decrease. Clinically estimated dry weight had a poor correlation with both bioimpedance and ultrasound techniques. Post-dialysis B-lines num- ber correlates with residual weight assessed with bioimpedance, suggesting a role for ultrasound in managing hemodialysis patients. Keywords Dialysis Á Bioimpedance Á Vena cava inferior Á Ultrasound Á Extravascular lung water Introduction Determination of fluid balance to prevent both under- or overhydration is an important issue in patients undergoing hemodialysis (HD) for end-stage renal disease (ESRD); during hemodialysis, fluids are removed by ultrafiltration to achieve an ideal status of body fluid volumes reflected by the correct ‘‘dry’’ weight. Dry weight (DW) estimate is performed clinically combining the patient’s symptoms, blood pressure and physical signs: such an estimate is achieved by means of trial and error and therefore intrinsically prone to imprecision. N. Vitturi (&) Á M. Soattin Á F. Simoni Á L. Maresca Department of Medicine, University of Padova, Via Giustiniani 2, 35128 Padova, Italy e-mail: nvitturi@gmail.com M. Dugo Á R. Zagatti Á M. C. Maresca Renal Unit, Ca’ Foncello Hospital, Treviso, Italy 123 Int Urol Nephrol DOI 10.1007/s11255-013-0500-5