Abstract:
Background : Complication associated with hemodialysis vascular access is one of the most important morbidity among ESRD patients receiving chronic hemodialysis. Several recommendations for routine monitoring of vascular access for incipient failure have been proposed. Vascular access blood flow (Qac) is a screening method to identify vascular access stenosis before its failure. Heretofore, there are no available data regarding the cut-off point values of Qac on native arteriovenous fistula (AVF). Ultrasound dilution technique (Transonic Systems Inc.) is the gold standard for measuring Qac. Herein, we reported the first prospective study report in Thailand using this technique for vascular access monitoring. Objective : To monitor Qac and to define the minimum Qac that can predict vascular access thrombosis. Patients and Methods : From December 1998 to December 1999, Qac was evaluated and measured every 3 months by using ultrasound dilution technique (Transonic RHD 01System) in 64 HD patients (51 AVF, 13 PTFE graft). Vascular access survival and vascular access failure were recorded and analyzed. Results : For AVF : The values of Qac were 737.90+-66.66 (mean+-SE) ml/min. Nine patients with vascular access thrombosis within 5 months had less Qac than patients without thrombosis (317+-55.42 VS.805.46+-76.42 ml/min, p=0.001). The cut-off point of Qac for prediction of thrombosis within 5 months is 445 ml/min (p=0.05). Correlating factors which could alter the values of Qac included age, height, body surface area and ischemic heart disease. The presence of diabetes mellitus, however, had no effect on Qac. Conclusions : 1. Ultrasound dilution technique is a simple and accurate method in determining Qac. 2. Patients with thrombosis had less Qac than patients without thrombosis. The cut off point value for prediction of thrombosis within 5 months is 445 ml/min. 3. High flux hemodialysis with Qac>400 ml/min could be operated in Thai dialysis patients. 4. Native AVF could be performed and effectively used in diabetes patients without increased risk of thrombosis