Читать книгу 40 Years of Continuous Renal Replacement Therapy - Группа авторов - Страница 29

A well-functioning vascular access is imperative to avoid premature failure of the continuous renal replacement therapy (CRRT) circuit [1–3]. According to Poisseuille’s law, flow through a catheter is related to the fourth power of its radius and inversely related to its length. Thus, the ideal catheter is short and has a large (13–14 Fr) diameter [1–3]. Observational studies showed more malfunctioning and shorter survival for femoral than for jugular dialysis catheters and for left-sided compared to right-sided jugular catheters [3]. A large randomized French multicenter trial did not find a difference in catheter dysfunction between the jugular and femoral approach [4]. However, when right and left jugular catheters were analyzed separately, a trend was observed toward more dysfunction with the femoral than with the right jugular route as well as significantly more dysfunction with the left jugular compared to the femoral access [4]. Based on these observations and additional data from several large studies [4, 5], the Kidney Diseases Improving Global Outcomes (KDIGO) guidelines [6] recommend that the right internal jugular (RIJ) vein should be preferred to obtain vascular access for CRRT. Both femoral veins remain a valuable alternative. Subclavian access is the least advised method because it involves an enhanced risk of kinking and stenosis (Fig. 1). It is self-evident that large-bore catheters will permit better blood flow. In addition, the tip of the catheter should be located in a large vein to assure more adequate blood flow and reduce the risk of recirculation [1–3]. Femoral catheters measuring at least 30 cm are recommended, since catheters of less than 20 cm length cause 3 times more recirculation [1–3]. Insertion of longer soft silicone short-term dialysis catheters in the right atrium proved to be safe and enabled to enhance CRRT life span and to optimize daily delivered CRRT dialysis dose compared with the use of shorter catheters placed in the superior vena cava [5, 7]. Atrial placement of soft-tipped CRRT catheters did not induce more atrial arrhythmia [5, 7]. Accordingly, the KDIGO guidelines recommend placing the tip in the right atrium [6]. RIJ and femoral access are not associated with differences in filter lifespan (FLS) [4, 8]. Concomitantly placed catheters, vein patency, and patient anatomy, posture, and mobility also determine the choice of catheter insertion site. Ultrasound guidance may facilitate catheter placement and reduce insertion-related complications [5–7].

Fig. 1. The right internal jugular (RIJ) vein is the preferred access site because it is the straightest route allowing the highest blood flow (>300 mL/min). Femoral access is a reasonable alternative with no particular preference between right- (RF) or left-sided (LF) insertion. The subclavian (Scl) approach should be avoided.