Background: Hemodialysis access thrombosis is a significant cause of morbidity for hemodialysis patients and results from decreased access flow caused by venous outflow tract stenosis. Ultrasound dilution (UD) is a practical, noninvasive, and reliable indicator of access flow and is effective in predicting venous stenosis in adult patients receiving hemodialysis.
Methods: The current study is the first to our knowledge to evaluate the accuracy of UD in predicting hemodialysis access stenosis in a pediatric hemodialysis population. Thirteen pediatric patients receiving hemodialysis via permanent access (4 AVF and 9 AVG) received 73 UD measurements over three months.
Results: Mean raw access flow (QA) was 720 +/- 428 mL/min, and mean corrected access flow (QAcorr) was 886 +/- 537 mL/min/1.73 m(2). QAcorr was significantly lower in accesses with stenosis (401 +/- 176 mL/min/1.73 m(2)) versus accesses without stenosis (1158 +/- 330 mL/min/1.73 m(2), P < 0.0001). Unlike flow values reported by raw QA, there was no overlap in flow values reported by QAcorr in accesses with stenosis (174 to 579 mL/min/1.73 m(2)) versus accesses without stenosis (709 to 1711 mL/min/1.73 m(2)). Two patients with an AVG who had QAcorr less than 600 mL/min/1.73 m(2) developed an access thrombosis within one week after UD measurement. No patients with QAcorr greater than 700 mL/min/1.73 m(2) developed access thrombosis in the 30 days following UD measurement.
Conclusions: : The current study supports the use of monthly UD measurement to prevent access thrombosis in children receiving hemodialysis.