The supine stress test: A simple method to detect intrinsic urethral sphincter dysfunction

Purpose: A new clinical test for intrinsic urethral sphincter dysfunction i s proposed and compared to abdominal leak point pressure determination by v ideo urodynamics. Materials and Methods: Patients were prospectively included in the study if they had stress urinary incontinence symptoms and were to undergo video ur odynamic testing, Patients with urinary tract infection, cystocele, rectoce le and vaginal vault prolapse were excluded from study. A supine stress tes t using cough and Valsalva's maneuvers was performed after bladder filling to 200 mi. with sterile normal saline solution by gravity. Efflux of the bl adder solution from the meatus coinciding with the cough or Valsalva maneuv er indicated a positive clinical test. A video urodynamic study, including abdominal leak point pressure, was performed. Intrinsic urethral sphincter dysfunction was diagnosed if abdominal leak point pressure was less than 10 0 cm. water. Test indexes were calculated based on the results of the supin e stress test and the abdominal leak point pressure measurements. Results: Results were positive in 30 of 41 consecutive patients and negativ e in 11. Using abdominal leak point pressure measurement, the supine stress test had 93.5% sensitivity, 90.0% specificity, 96.7% positive predictive v alue and 81.8% negative predictive value for detecting intrinsic urethral s phincter dysfunction. Conclusions: The supine stress test is easy, quick and inexpensive, and a p ositive test is a reliable predictor of intrinsic urethral sphincter dysfun ction. A negative test is highly correlated with the absence of intrinsic u rethral sphincter dysfunction during video urodynamic testing. This test is more reliable in diagnosing intrinsic urethral sphincter dysfunction than other nonurodynamic tests reported in the literature. The supine stress tes t can be a useful supplement to cotton swab testing for urethral hypermobil ity in determining the appropriate management for stress urinary incontinen ce.