Vascular access, membranes and circuit for CRRT

Abstract

The goal of continuous renal replacement therapy (CRRT) is to mimic native kidney clearance as closely as possible by modulating solute and volume by balancing waters in a slow continuous manner. To obtain maximal efficacy, CRRT should run uninterrupted for 24 h a day and/or deliver the prescribed amount of clearance. However, delivery of CRRT is frequently lower than prescribed; three separate reports found that it was 20%-30% lower than that prescribed. [1][2][3] This is often due to decreased circuit life, which not only causes patients to be off therapy for varying amounts of time but also has consequences beyond that of decreased dose delivery (Table 1).Consequently, CRRT circuit life has been identified by the Acute Dialysis Quality Initiative group (ADQI) as a key quality metric to monitor. 4,5 CRRT circuit life depends on several factors including circuit characteristics, anticoagulation, and implementation of an appropriate prescription. This review will focus on the circuit-related factors that are critical in determining circuit life; access, membrane, and the CRRT machine circuit (Figure 1). | VA SCUL AR ACCE SSThe first link in the circuit to consider is the vascular access so that blood is delivered to the membrane at an adequate flow rate for waste(s) removal but without clotting and circuit dysfunction. The most commonly used access for CRRT is a short-term hemodialysis catheter (STDC) inserted into one of the central veins. Tunneled dialysis catheters (TDCs) can also be utilized, and have been suggested to be the first choice in select and longer care patients, as they may have improved delivery metrics and fewer complications. 6 However, these results have not yet been validated in a randomized controlled

Meta-analysis of haematocrit and activated partial thromboplastin time as risk factors for unplanned interruptions in patients undergoing continuous renal replacement therapy

“…30 Many factors influence unplanned interruptions, including the patency of temporary catheter access, filter membrane material, treatment modality, pre- and post-dilution ratios, filtration fraction and PLT, HCT and coagulation parameters, such as APTT, PTA and INR. 31,32 Identifying the influencing factors is critical to avoiding unplanned interruptions and ensuring smooth treatment.…”

Programs and processes for advancing pediatric acute kidney support therapy in hospitalized and critically ill children: a report from the 26th Acute Disease Quality Initiative (ADQI) consensus conference

“…Despite careful selection and placement, malfunctioning of vascular access—kinking/bending, leakage, thrombosis, infection, or high turbulence in inadequately sized catheters—contributes significantly to circuit failure necessitating a circuit/filter change [ 59 ]. Although pediatric recommendations for catheter size are available [ 60 ], optimal catheter sizing based on patient weight or height has not been established in pediatrics.…”