Objective: The purpose of the present study was to assess single-needle dialysis adequacy and other parameters of dialysis efficiency, such as recirculation, hematocrit, calcium and phosphorus level. The complications and adverse events were also evaluated. Time to achieve maximal adequacy of dialysis were compared between 4, 4.5, and 5.0 hours of dialysis session.
Design: Prospective, cross-over trial.
Setting: Renal Unit, Department of Medicine, Bangkok Metropolitan Administration Medical College and Vajira Hospital
Material and Method: Seven stable chronic renal failure patients who regularly used standard hemodialysis (HD) technique with double-needle (DN)were recorded for baseline data including Kt/V, percent recirculation, calcium and phosphorus level, hematocrit, and LDH level. Subsequently, all the patients were placed on single-needle dialysis (SN) for 3 consecutive duration, 4 hours, 4.5 hours and 5.0 hours respectively for 3 weeks in each period. The same parameters were recorded at the end of each period.
Results: Prior to the single-needle phase, the adequacy of dialysis in DN dialysis were within the acceptable range. After switching to SN mode, the Kt/V did not change significantly from the baseline value. However, subgroup analysis in twice weekly dialysis revealed some degree of reduction in Kt/V value albeit not significant. In the thrice weekly group, the Kt/V did not differ from the baseline value and achieved the target level according to the DOQI guideline. The other parameters such as hematocrit, calcium, phosphorus and LDH were not different from the DN group. SN dialysis did not cause more recirculation than the DN group and both were less than 10 percent. There were no other major complications during the SN phase. The outcome of the fistulas were excellent
Conclusion: The SN dialysis has the same efficacy as the conventional DN technique in terms of Kt/V and other parameters such as calcium, phosphorus and LDH values. Both DN and SN caused less than 10% recirculation. There were no reports of adverse events during the treatment period. The double-pump system therefore could be suitable for routine thrice weekly HD in a selected group of patients.

Keywords: Single-needle dialysis, Adequacy of dialysis