Hemodialysis vascular assessment by an ultrasound dilution method (transonic) in patients older than 65 years

Abstract

Malfunction of vascular access is one of the most frequent causes of morbidity and mortality in hemodialysis patients (HD). Early diagnosis makes possible the most frequent vascular access (VA) used in HD patients. The arteriovenous fistula (AVF), both autologous or heterologous, is the appropriate correction by an interventional radiologist or by surgery, before thrombosis appears. For this purpose, a follow-up of VA is mandatory. New technologies offer non-invasive methods for this purpose. In HD sessions ultrasound ‘on line’ and ultrasound-dilution techniques permit us to monitor vascular access in HD patients. Also transonic technology has been validated for this purpose, although the limitations of its use among elderly patients is unknown. Using the Transonic HD 01 monitor, we studied vascular access in 45 patients in HD older than 65 years, and compared them with 47 patients who were younger than 65 years. The parameters analyzed were: effective flow Qt, recirculation, venous pressure and access flow. We found no significant differences between these parameters but in both groups found that the effective flow measure by Transonic was lower than that measured by a blood pump. Both groups contained patients who had no recirculation but had an access flow that was lower than expected. To rule out stenosis of VA in those patients, we performed an Eco Doppler confirming that all patients had stenosis. With this method, one can determines the access flow and thus predicts the possibility of future thrombosis. Conclusion: Our data confirm that one can evaluate VA in patients older than 65 years with Transonic HD01 monitor, and also in patients younger than 65 years. Due to the special characteristics of the vessels in elderly patients, Transonic HD01 monitor is a good method by which to monitor VA in them.