Presented by: Sufyan Shaikh BSc, MSc (c)
Institute of Medical Science, University of Toronto, ON, Canada; 2. Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada; St. Michael’s Hospital, Division of Urology, Department of Surgery, University of Toronto, Toronto, ON, Canada

Introduction

Maintaining an appropriate flow rate (FR) during continuous bladder irrigation (CBI) is important to mitigate blood stasis and urinary clot retention. However, guidelines for controlling FR are absent and consensus amongst healthcare providers is lacking. Furthermore, intrinsic differences in equipment confound FR control. For these reasons, we compared FR through 3 commonly used brands of CBI tubing and discussed their implications.

Materials

3L saline bags were hung from weight sensors that were retrofitted to an IV pole. Weight change over time was used to determine FR. The roller clamp affixed to the CBI tubing was divided into 5 equal setpoints (SP), and the roller wheel (RW) was cycled between SPs and the closed position in 30-second intervals. We conducted 3 trials with 2 sets of tubing from each brand, both with and without a 22 Fr catheter attached.

Results

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Figure 1 shows the average FR at the 5 SPs with and without a catheter attached. The gray bars represent experiments without a catheter and report the potential FR achievable without any restrictions. Significant inter-brand differences exist at each SP; for example, Brand A had no flow until SP3, whereas Brand B reaches 50% of max FR at SP1. The colored bars represent experiments with a catheter and report the FR achieved in clinical practice. With a catheter attached, all 3 brands have limited adjustability and the same maximum FR.

Conclusion

Our data show that the RW is an unreliable predictor of FR and does not scale linearly, which can be problematic as clinicians intended changes may not be occurring as expected. Furthermore, with a catheter attached, the RW seems to act like an “on-off” switch and provides extremely limited FR control, suggesting that the catheter is the FR-determining step. This may be concerning since, presently, the RW is the only way to regulate CBI and may infer that standardized guidelines cannot be generalized for different brands if titrating based on the RW.

Funding

None.

Co-Authors

Kai-Ho Fok, BASc, MASc, MD, FRCSC
Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada; St. Michael’s Hospital, Division of Urology, Department of Surgery, University of Toronto, Toronto, ON, Canada

Jonguk Lee, BEng, MASc (c)
Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada; KITE – Toronto Rehabilitation Institute, University Health Network, Toronto, ON, Canada

Karim Habib, BSc, MSc, MD (c)
The University of Limerick, School of Medicine, Limerick, Ireland; St. Michael’s Hospital, Division of Urology, Department of Surgery, University of Toronto, Toronto, ON, Canada

Egor Parkhomenko, B.Sc, MD
St. Michael’s Hospital, Division of Urology, Department of Surgery, University of Toronto, Toronto, ON, Canada

Brian Carrillo, BEng, MEng, PhD
WellSpring Research, Toronto, ON, Canada

Monica Farcas, BEng, MEng, MD, FRCSC
Institute of Medical Science, University of Toronto, ON, Canada; Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada; St. Michael’s Hospital, Division of Urology, Department of Surgery, University of Toronto, Toronto, ON, Canada