Three-dimensional bladder ultrasonography with the BladderScan® overestimates post void residual one week after delivery

Abstract

Objective: Postpartum urinary retention is a frequent complication after childbirth. It is usually a temporary condition. However, unrecognised urinary retention can lead to considerable morbidity due to bladder over distention, detrusor atony and long term voiding dysfunction. In our clinic we noticed an overestimation of post void residual measured with the BladderScan® in comparison with catheterization in women one week after delivery. Study design: We included 25 women in this prospective pilot study. These women had a urinary retention over 1000 ml within 4–5 h postpartum. Conform our local protocol, an indwelling catheter was inserted for one week. After removal of the indwelling catheter, a micturition trial was conducted. The post void residual was first measured with BladderScan® (BVI 3000), directly followed by clean intermittent catheterization which is the golden standard at this moment. Results: There was a significant mean difference in post void residual measurements with the BladderScan® and catheterization of 312 ml (95% CI 220–404 ml) (p < 0.001). According to our post void residual definition of 200 ml, the sensitivity and specificity of the BladderScan® was respectively 100% and 17.6%. The positive predictive value was 36%. Conclusion: The BladderScan® (BVI 3000) is a non-reliable instrument to measure post void residual one week postpartum. For now clean intermittent catherization remains the golden standard. Keywords: Postpartum period, Urinary retention, Ultrasonography, Clean intermittent catheterization, Voiding dysfunction