Using Ultrasound and Enuresis Alarms to Assess Bladder Emptying in Non-Verbal Children

Bladder emptying can be particularly challenging to assess in non-verbal children with medical complexities, as these patients often lack clear indications of voiding. This study aimed to evaluate the feasibility and effectiveness of using an enuresis alarm to guide post-void residual (PVR) measurement in such patients. A total of 15 non-verbal, diaper-voiding patients under the age of 21 were prospectively enrolled during a hospital stay from July to September 2023. Exclusion criteria included urinary tract infections and indwelling catheters. The study protocol involved alternating between a 4-hour period with the enuresis alarm and a routine care period where PVR was assessed based on nurse observations of wet diapers. PVR measurements were taken using an ultrasound bladder scanner. The primary endpoint focused on PVR volumes, while the secondary endpoint examined the number of detected voids. The median age of participants was 10 years, with the most common diagnoses being cerebral palsy, spastic quadriplegia, and epilepsy. After excluding voids less than 10% of estimated bladder capacity and alarms triggered by stool, linear regression analysis showed that the use of the alarm was associated with a mean decrease of 21.09 mL in PVR volume. Furthermore, a 1 kg increase in patient weight correlated with a mean increase of 1.36 mL in PVR volumes. Notably, the median number of detected voids during the alarm period was significantly higher than during routine care (3 vs. 1). No adverse events were reported throughout the study. These findings suggest that enuresis alarms can effectively enhance void detection and reduce PVR in complex non-verbal, diaper-voiding children, offering a promising tool for more accurate bladder assessments.