Pulsatile Flushing Technique in Reducing Blockage of T-CVAD for Haemodialysis Patients

Official title

Exploring the Effectiveness of Pulsatile Flushing Technique in Reducing Blockage of the Tunnelled Central Venous Access Device Among Haemodialysis Patients in Multiple Renal Centres in Hong Kong: A Cluster Non-Randomised Controlled Trial Study

Overview

This study investigates the effectiveness of pulsatile flushing techniques in reducing blockage in Tunnelled Central Venous Access Device (T-CVAD) among patients undergoing haemodialysis (HD) treatment at multiple renal centres within the Hospital Authority (HA) in Hong Kong. With limitation in single service protocol for each cluster of renal units, it is designed as a prospective, parallel, cluster non-randomised controlled trial involving 591 patients from 14 renal units. In order to identify the most effective flushing technique for T-CVAD maintenance, survival analysis on clinical effectiveness, in terms time-to-event blockage of the T-CVAD, among three trial arms: 1) Intervention Group A (IG-A) using pulsatile flushing technique with 0.4 second pause time interval; 2) Intervention Group B (IG-B) using pulsatile flushing technique with 1 second pause time interval; 3) Control Group (Con) using standard bolus flushing technique. The findings facilitate development of best practice for T-CVAD maintenance, optimise T-CVAD maintenance protocols, and ultimately improve patient outcomes. This groundbreaking study is expected to signify substantial progression in the nursing management of HD and T-CVAD.

Interventions

• Device Pulsatile Flushing Technique (0.4s pause interval)
  Pulsatile flushing technique consists of multiple small boluses injected intermittently with 0.4-second pauses between each bolus resulting in unsteady turbulent flow, performed by a renal nurse who passed a formal train-the-trainer program on "pulsatile flushing technique" taught and assessed by designated nurse consultant (renal care).
• Other Pulsatile Flushing Technique (1s pause interval)
  Pulsatile flushing technique consists of multiple small boluses injected intermittently with 1-second pauses between each bolus resulting in unsteady turbulent flow, performed by a renal nurse who passed a formal train-the-trainer program on "pulsatile flushing technique" taught and assessed by designated nurse consultant (renal care).
• Device Bolus Flushing Technique
  Bolus flushing technique involves the continuous administration of a single, concentrated volume of flush solution resulting in consistent laminar flow

Primary outcome measures

• Time-to-event T-CVAD Blockage [Time frame: From the date of recruitment until the end of the study (at least 1-year follow-up) or date of termination (e.g., blockage, death, refusal to participate in the study… etc) whichever comes earlier, assessed up to 24 months.]

Eligibility criteria

Inclusion criteria

• Patients undergoing HD treatment with Tunnelled Central Venous Access Device (T-CVAD) in the above collaborators under the Hospital Authority
• Able to understand spoken and written Chinese or English

Exclusion criteria

• Patients with Non-Tunnelled Central Venous Access Device (NT-CVAD)
• Temporary dysfunction (e.g., kicking of the catheter) resolved with repositioning
• Confirmed case of fibrin sheath occlusion which can only be resolved through surgical intervention
• Non-thrombotic occlusion due to mechanical causes (e.g., catheter malposition)
• Patient declined or incompetent to provide written informed consent.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Non-randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Supportive care

Study locations

Hong Kong · 1 center

• Queen Elizabeth Hospital — Kowloon

Publications

• Chan, P. S., Lee, M., & Au WN et al. (2024). Evidence-based Practice Review of Haemodialysis Catheter Flushing Technique in NTWC Renal Units. Retrieved from the Poster Presentation, HA Convention, HKSAR.
• Guiffant G, Durussel JJ, Merckx J, Flaud P, Vigier JP, Mousset P. Flushing of intravascular access devices (IVADs) - efficacy of pulsed and continuous infusions. J Vasc Access. 2012 Jan-Mar;13(1):75-8. doi: 10.5301/JVA.2011.8487. PMID 21748725
• J. Mehta, H. (2021). Hemodialysis Vascular Access with Central Venous Disease. IntechOpen. doi: 10.5772/intechopen.9303
• Boord C. Pulsatile Flushing: A Review of the Literature. J Infus Nurs. 2019 Jan/Feb;42(1):37-43. doi: 10.1097/NAN.0000000000000311. PMID 30589719
• Giraudeau B, Weijer C, Eldridge SM, Hemming K, Taljaard M. Why and when should we cluster randomize? J Epidemiol Popul Health. 2024 Feb;72(1):202197. doi: 10.1016/j.jeph.2024.202197. Epub 2024 Feb 9. PMID 38477478
• World Health Organization. (n.d.). Cluster Randomized Trials 4.3. In WHO Guidance on Research Methods for Health-EDRM (pp. 266-270).
• Geller SA, Nichols WS, Rojter SE, Chan RC, Petrovic LM, Vierling JM, Makowka L. Hepatitis C virus is not recoverable from liver tissue in cryptogenic cirrhosis: failure to identify hepatitis C virus-RNA using reverse transcription-mediated polymerase chain reaction. Hum Pathol. 1996 Nov;27(11):1161-5. doi: 10.1016/s0046-8177(96)90309-3. PMID 8912825
• Wolf J, Tang L, Rubnitz JE, Brennan RC, Shook DR, Stokes DC, Monagle P, Curtis N, Worth LJ, Allison K, Sun Y, Flynn PM. Monitoring Central Venous Catheter Resistance to Predict Imminent Occlusion: A Prospective Pilot Study. PLoS One. 2015 Aug 31;10(8):e0135904. doi: 10.1371/journal.pone.0135904. eCollection 2015. PMID 26322512

Identifiers

NCT: NCT07567456 · CIRB-2025-277-1

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗