The Impact of Blood Flow Rate and Duration of Dialysis Session on Nutritional Status in Hemodialysis Patients

BACKGROUND: Blood flow rate (BFR) and time of dialysis are important determinants of dialysis adequacy. This study aimed to determine the impact of higher BFR and longer dialysis time on nutritional status in chronic hemodialysis (HD) patients.

METHODS: Real-world evidence (RWE) studies of 3 HD units in different hospitals that differ in BFR and/or dialysis time. Group I, HD 5 hr and BFR 200-250 mL/min; group II, HD 4 hr and BFR 270-320 mL/min, and group III, HD 4 hr and BFR 200-250 mL/min. All HD units use the same dialysate flow and dialysis frequency. Nutritional status was assessed using a 3-point scale Subjective Global Assessment.

RESULTS: A total of 233 chronic HD patients were included, mean of age was 52 ± 12.9 years, 46.5% were male. There are 69.5% on SGA class A, 27.5% on SGA class B, and 3% on SGA class C. The proportion of SGA class A in group II was highest compared to group II and III (93.5% vs 79.0% vs 32.1% (p <0.05). There was no SGA class C in group II, whereas 2.4% in group I and 7.4% in group III. In group II there was lower interdialytic weight gain (IDWG) and less use of anti-hypertensive drugs compared to group III (p <0.05).

CONCLUSION: Our study showed that higher BFR and longer dialysis time are associated with better nutritional status in chronic HD patients. A higher BFR seems to have a more substantial impact compared to a longer dialysis time.

Keywords: blood flow rate, dialysis time, subjective global assessment, nutritional status