Fluid recruitment from shell tissues of the body during haemodialysis.

Patients with kidney failure are prone to accumulate fluids within the superficial tissues, leading to a puffiness of the face, hands, and feet. After dialysis these symptoms disappear. It was the aim of this study to quantify these changes. With the help of A-mode ultrasound in 49 patients (20 females, 29 males) the tissue thickness in the forehead and tibia was measured during dialysis. In the forehead the tissue thickness before dialysis was 4.01 mm (females) and 3.87 mm in the males, decreasing continuously during dialysis by 13.6% and 12.8% respectively (P < 0.001). In the tibia the tissue thickness was 3.87 mm (females) and 3.07 mm (males) and decreased by 12.8% and 23.9% respectively. The sex difference was significant (P < 0.05). From these values it was calculated that 45% of fluid withdrawn came from the superficial shell tissues of the body. It was concluded that these tissues serve as water stores in the interdialytic phase.