Kozomara M, et al. – Researchers tried to find out whether the detrusor contraction during rapid bladder filling is provoked by cold or warm water. The outcomes of this research highlighted that the more frequent occurrence of detrusor overactivity, higher maximum detrusor pressure and lower bladder filling volume in the ice water test (IWT) compared to the warm water test (WWT) are caused by cold water, underlying the theory of a C–fiber mediated bladder cooling reflex in humans.

Methods

• In this randomized controlled double–blind trial, researchers enrolled patients suffering from neurogenic lower urinary tract dysfunction (NLUTD).
• The patients received 2 fillings of the bladder using a 4°C (ice water test, IWT) or 36°C (warm water test, WWT) saline solution with a speed of 100 mL/min at the end of standard urodynamic investigation.
• In this analysis, the order was randomly selected and patients and investigators were blinded for the order sequence.
• The occurrence of detrusor overactivity, maximum detrusor pressure and maximum bladder filling volume during IWT and WWT were considered as a primary outcome.

Results

• They used 40 patients (9 women, 31 men) for data analysis.
• It was noted that NLUTD was caused by spinal cord injury in 33 and by other neurological disorders in 7 patients.
• The data showed that detrusor overactivity occurred significantly (p=0.02) more often during the IWT (30/40, 75%) than during the WWT (25/40, 63%), irrespective of the order of the test.
• Comparing IWT versus WWT, they found that the maximum detrusor pressure was significantly (p<0.001) higher and the maximum bladder filling volume significantly (p<0.001) lower during the IWT.
• In addition, the order of performing the test (IWT first versus WWT first) had no effect on the parameters.