Effectiveness of Flow Volume Measurement Training Using a Custom-Made Doppler Flow Simulator

Abstract

Introduction: This study was conducted to analyze the effectiveness of a custom-made Doppler ultrasound (DUS) flow simulator, vascular phantom, and Doppler test fluid in the training of dialysis staff in flow volume (FV) measurements for arteriovenous (AV) access in hemodialysis (HD) patients.

Methods: A DUS flow simulator was constructed using a continuous renal replacement therapy machine. Vascular phantoms were constructed using a rubber enema tube and keyboard cleaning gel. The Doppler test fluid consisted of freeze-dried instant coffee granules and 0.9% saline. This easy and affordable simulator was used to train 12 dialysis staff members, with no previous experience in DUS FV measurement. After a 3-day lecture course, the staff members performed DUS analyses on the AV access of HD patients. Thereafter, they underwent a 3-day training course using the simulator and then performed the DUS analyses of the AV access again. Each staff member assessed the FV 3 times, and the mean values of the measurements pretraining and posttraining were analyzed using paired t tests.

Results: The difference in the mean value of FV measurements and the reference value decreased from 131.6 mL/min to 62.5 mL/min (95% confidence interval = 30.0-108.0, P = 0.002), and the standard deviation of the FV measurements decreased from 96.9 mL/min to 47.0 mL/min (95% confidence interval = 7.9-91.8, P = 0.023) after DUS training with the simulator.

Conclusions: The accuracy and reproducibility of FV measurements markedly improved after training with the simulator; it may be helpful for medical practitioners involved in AV access for HD treatment.