Can we define the optimal postvoid residual volume at which intermittent catheterization should be recommended, and are there other measures that could guide an intermittent catheterization protocol: ICI-RS 2023.

Abstract

Aims: The postvoid residual (PVR) volume of urine in the bladder is widely used in clinical practice as a guide to initiate treatment, including clean-intermittent self-catheterization (CISC). It is often believed that an elevated PVR causes complications such as recurrent urinary tract infections (UTI) and renal failure. However, evidence for this is limited and identifying alternative measures to guide treatment decisions may optimize patient care. At the International Consultation on Incontinence Research Society (ICI-RS) meeting in 2023 a Think Tank addressed the question of whether we can define the optimal PVR at which CISC should be recommended, and whether there are other measures that could guide a CISC protocol.

Methods: The Think Tank conducted a literature review and expert consensus meeting focusing on current limitations in defining and measuring PVR, and highlighting other measures that may optimize selection for, and persistence with, CISC.

Results: There is no consensus on the threshold value of PVR that is considered "elevated" or "significant." There is a lack of standardization on terminology, and the normal range of PVR in different populations of different ages remains to be well-studied. The measurement of PVR is influenced by several factors, including intraindividual variation, timing and method of measurement. Furthermore, the evidence linking an elevated PVR with complications such as UTI and renal failure is mixed. Other measures, such as bladder voiding efficiency or urodynamic parameters, may be better at predicting such complications, and therefore may be more relevant at guiding a CISC protocol.

Conclusions: There is a lack of high quality evidence to support PVR as a predictor for complications of UTI or renal failure. Threshold values for normal PVR in different populations are unknow, and so threshold values for "elevated" or "significant" PVR cannot be determined. Other factors, such as urodynamic findings, may be better at predicting complications and therefore guiding management decisions, and this remains to be studied. Areas for further research are proposed.