A narrative systematic review of randomised controlled trials that compare cannulation techniques for haemodialysis.

BACKGROUND: Cannulation of arteriovenous access for haemodialysis affects longevity of the access, associates with complications and affects patients' experiences of haemodialysis. Buttonhole and rope ladder techniques were developed to reduce complications. However, studies that compare these two techniques report disparate results. This systematic review performs an in-depth exploration of RCTs, with a specific focus on cannulation as a complex intervention. METHODS: A PICO question and protocol was developed as per PRISMA-P guidance and registered on PROSPERO (CRD42018094656 https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=112895). The systematic review included any RCT performed on adult patients with end-stage kidney disease undergoing cannulation of arteriovenous fistulae or grafts for in-centre haemodialysis, as performed by healthcare staff. Assessment of quality of RCTs and data extraction were performed by two co-authors independently. Data were extracted on the study design, intervention and comparator and outcomes, including patency, infection and patients' experiences. RESULTS: The literature search identified 241 records. Ten records met inclusion criteria, which described five different RCTs that compared buttonhole to either rope ladder or usual practice. Results were disparate, with patency and infection results varying. Pain Visual Analogue scores were the only measure used to capture patients' experiences and results were inconclusive. All RCTs had differences and limitations in study design that could explain the disparity in results. CONCLUSION: Current evidence does not allow definitive conclusions as to whether buttonhole or rope ladder needling technique is superior. Future RCTs should describe interventions and comparators with adequate detail, embed process evaluation, use standardised outcome measures and build on feasibility studies to produce definitive results.

Continuous online monitoring of ionic dialysance allows modification of delivered hemodialysis treatment time.

Considerable intrinsic intrapatient variability influences the actual delivery of Kt/V. The aim of this study is to examine the feasibility of using continuous online assessment of ionic dialysance measurements (Kt/V(ID)) to allow dialysis sessions to be altered on an individual basis. Ten well-established chronic hemodialysis (HD) patients without significant residual renal function were studied (mean age 65+/-4.3 [38-81] years, mean length of time on dialysis 66+/-18 [14-189] months). These patients had all been receiving thrice-weekly 4-hr dialysis using Integra dialysis monitors. Dialysis monitors were equipped with Diascan modules permitting measurement of Kt/V(ID). Predicted treatment time required to achieve a Kt/V(ID) > or = 1.1 (equivalent to a urea-based method of 1.2) was calculated from the delivered Kt/V(ID) at 60 and 120 min. Treatment time was reprogrammed at 2 hr (ensuring all planned ultrafiltration would be accommodated into the new modified session duration). Owing to practical issues, and to avoid excessively short dialysis times, these changes were censored at no more than+/-10% of the usual 240-min treatment time (210-265 min). Data were collected from a total of 50 dialysis sessions. Almost all sessions (47/50) required modification of the standard treatment time: 13/50 sessions were lengthened and 34/50 shortened (mean length of session 232.2+/-2.5 [210-265] min). A Kt/V(ID) of > or = 1.1 was achieved in 39/50 sessions. The difference in mean urea-based Kt/V poststudy (1.3+/-0.05 [1.1-1.6]) and mean achieved Kt/V(ID) (1.16+/-0.02 [0.7-1.37]) was significant (p = 0.002). The use of individualized variable dialysis treatment time using online ionic dialysance measurements of Kt/V(ID) appears both practicable and effective at ensuring consistently delivered adequate dialysis.