ANOTHER SIMPLER BYPASSING DIALYSATE TECHNIQUE FOR MEASURING POST-HEMODIALYSIS BUN

Background. The most popular method for estimating post-haemodialysis BUN is the low blood flow technique. The low blood flow technique with a blood flow of 50 ml/min for 3 min may encompass the first two phase s of post-haemodialysis urea rebound by access and cardiopulmonary rec irculations. Some patients may have risk of clotting in extracorporeal circuit while slowing blood flow. Therefore we proposed another simpl er sampling technique for measuring post-haemodialysis BUN(C-2). Metho ds. In the present study, 28 long-term haemodialysis patients were div ided into two groups. In group 1 (n = 15), C-2 sample (C2-50) was coll ected immediately after blood how was slowed down to 50 ml/min for ano ther 3 min. Then blood flow was reset to 300 ml/min. Finally, C-2 samp le (C-2B) was obtained from arterial port at the end of bypassing dial ysate for another 3 min. In group 2 (n = 13), C-2 sample (C-2B) was ob tained from arterial port at the end of bypassing dialysate for 3 min with a blood flow of 250 ml/min. Then dialysate was reset to original flow rate and C-2 sample (C2-50) was collected soon after blood flow w as slowed down to 50 ml/min for another 3 min. In the meantime, recirc ulation rate was also checked. Results. The above two groups have simi lar results and there are no significant differences of post-haemodial ysis BUN and calculated Kt/V between low blood how technique and bypas sing dialysate technique. Conclusion. The bypassing dialysate techniqu e is another simpler and practical technique for the routine estimatio n of post-haemodialysis BUN.