Monitoring of circulatory dynamics before and after the production of a vascular access point using a non-invasive cardiac output monitor

Abstract

Non-invasive cardiac output monitors are very useful for monitoring circulatory dynamics under numerous clinical settings, including hemodialysis. However, no previous studies have assessed patients’ circulatory dynamics before and after the production of vascular access points using a non-invasive cardiac output monitor. Therefore, herein we evaluated the circulatory dynamics of two patients during the production of vascular access points at the elbow using a non-invasive cardiac output monitor and vascular ultrasound sonography. Case 1 involved an 84-year-old female who underwent surgery to produce a side-to-side anastomosis of the radial artery and cephalic vein. Just after surgery, the patient’s systemic vascular resistance decreased, and her stroke volume increased. Case 2 involved a 91-year-old male who underwent surgery to produce an end-to-side anastomosis of the radial artery and median cubital vein. After surgery, the patient’s circulatory dynamics were not markedly affected; however, he developed steal syndrome and a seroma. The production of vascular access points affects the circulation via a number of mechanisms, e.g., the arteriovenous fistula causes a reduction in vascular resistance, and the shunt flow produces an increase in stroke volume. Furthermore, the circumferential stress-strain relationship between the diameter of and stress within the affected vessels can modify the circulation. In case 2, the inadequate shunt flow volume and the patient’s anatomical factors did not affect his circulation. Non-invasive cardiac output monitors and vascular ultrasound sonography are very useful tools for monitoring circulatory dynamics before and after the production of vascular access points.