Purpose or Case Report: Volume overload is linked to increased cardiovascular morbidity and mortality in children receiving hemodialysis (HD). Clinician assessment of volume status lacks accuracy and has substantial inter- and intra- observer variability. We investigated the use of ultrasound (US) skin thickness, and muscle elastography in pediatric HD patients.
Methods & Materials: Participants were recruited from our hospital’s outpatient HD unit. The following ultrasound measures were obtained before and 1-hour after HD, for up to 5 separate HD sessions per participant: (1) US elastography of the tibialis anterior muscle (median of 8 shear wave speed measurements; GE Logiq-E9, E10); and (2) US of dermal thickness on the medial surface of the mid tibia (mean of 3 measurements; Vevo 2100 VisualSonics). These measurements were obtained as part of a larger study that includes inferior vena cava and lung US. All images were obtained by sonographers and reviewed by 2 pediatric radiologists.
Results: Six children [median (range) age 13.6 (3.4-17.7) years; 67% male] completed 23 study visits (41 ultrasound scans). The average duration of ultrasound scan (including time to obtain IVC and lung images) was 20.5 minutes (range: 11-35). The average skin thickness was 1.36 mm pre-dialysis and 1.30 mm post-dialysis; while average median velocities for muscle elastography were 2.71 m/sec (IQR: 2.17-3.1) pre-dialysis and 2.67 m/sec (IQR 1.85-3.34) post-dialysis
Conclusions: This pilot study shows that skin thickness and muscle elastography ultrasound measurements were feasible, and differences between pre- and post- dialysis scans exists. Further larger studies that establish the correlation between US, anthropomorphic and laboratory determinants of fluid overload are needed to develop these potential bedside ultrasound applications.