SEATTLE -- Medisystems Corporation today announced the results of another clinical study demonstrating its ReadySet High Performance Blood Tubing delivered a more reliable blood flow rate and a higher urea reduction ratio (URR) and dialysis dose (Kt/V), compared to Fresenius Medical Care, Inc. CombiSet blood tubing.
This study by Anatole Besarab, MD, director of clinical research, Nephrology and Hypertension Division at Greenfield Health System, part of Henry Ford Health System in Detroit, has been accepted for presentation at the ASAIO-ISAO Joint Conference 2003 in Washington, D.C. this June. Medisystems is a leading supplier of hemodialysis tubing disposables in the U.S.
The prospective clinical study compared dialysis results using Medisystems ReadySet Blood Tubing vs. CombiSet blood tubing (Ahmed J, Besarab A, Lubkowski T, Frinak S; Not All Manufactured Blood Tubing Sets are Equal: Effects on Qb and Kt/V; ASAIO-ISAO Joint Conference, 2003, Abstract).
Twenty-three patients were dialyzed for one week using CombiSet blood tubing followed by 1 week using ReadySet blood tubing. Access blood flow, machine-indicated blood flow, blood flow actually delivered to the dialyzer, and pre-pump pressures were measured at the start of each treatment, after 1 hour, 2 hours, and at the end of treatment. A new dialyzer was used for the mid-week treatment, and urea clearance, URR, and Kt/V measurements were made. While the time averaged set blood flows were equivalent for the two different blood tubing sets, the difference between the machine-indicated flow and actual dialyzer blood flow were smaller for ReadySet Blood Tubing than for CombiSet tubing, indicating that Medisystems ReadySet tubing maintains a more consistent, reliable blood flow to the dialyzer throughout the four-hour treatment than CombiSet. This more reliable blood flow with ReadySet tubing corresponded with a significantly greater URR (+3.5 percent, p=0.039) and Kt/V (+0.14, p=0.04), compared to CombiSet tubing.
Results from an earlier retrospective study  presented at the American Society of Nephrology 2002 conference, showed that higher Kt/V and URR on dialyses using ReadySet tubing correlated with higher pumped blood flows, measured both volumetrically in vitro and in vivo. In this earlier study, initial blood pump speed settings and flows were similar, however ReadySet blood flows decreased only 1.8 percent during the four-hour procedures while CombiSet blood flows fell 9.2 percent.
In summary, prior studies have shown that hemodialysis patients have fewer complications and survive longer with higher doses of dialysis. [2-5] The aforementioned studies show that differences between delivered flow and prescribed flow exist but are significantly smaller with ReadySet than with CombiSet blood tubing, which results in higher doses of dialysis being delivered with ReadySet. This difference is especially important for patients who run high blood flows or have marginal Kt/V.
Besarab is recognized internationally as an expert in the field of nephrology and is also vice chair of the National Kidney Foundation's K/DOQI Vascular Access Work Group.
Medisystems Corporation, founded in 1981, is a market leader for hemodialysis blood tubing sets, A.V. fistula needles, hemodialysis access management products, apheresis needles and other ancillary products in the United States.
Besarab A, Zasuwa G, Frinak S; Blood Tubing Type Affects Delivered Kt/V; J AM Soc Neprol, Vol.12, Sept. 2002, pp 412A, Abstract SA-P0728.
Hakim RM, Breyer J, Ismail N, Schulman G: Effects of dose of dialysis on morbidity and mortality. Am J Kidney Dis 23: 661-669, 1994.
Lowrie EG: Chronic dialysis treatment: Clinical outcome and related processes of care. Am J Kidney Dis 24: 255-266, 1994.
Held PJ, Port FK, Wolfe RA, Stannard DC, Carroll CE, Daugirdas JT, Bloembergen WE, Greer JW, Hakim RM: The dose of hemodialysis and patient mortality. Kidney Int 50: 550-556, 1996.
Parker TF, Husni L, Huang W, Lew N, Lowrie EG, Dallas Nephrology Associates: Survival of hemodialysis patients in the US is improved with greater quantity of dialysis. Am J Kidney Dis 23: 670-680, 1994.