Introduction: Postoperative urinary retention can cause serious complications. An ultrasound bladderscanner has been shown to be useful in distinguishing between patients who need catheterisation and patients who do not. We wished to investigate if clinical assessment including inspection, percussion and palpation of the bladder is of any use in this perspective. In this study we compare clinical findings with ultrasound examinations.
Material and methods: Two trained doctors each investigated 25 postoperative patients clinically immediately after ultrasound examination in the recovery room. Ultrasound examination was carried out by trained nurses using BladderScan BVI 3000. Assessed and measured volumes as well as patient height, weight, asa-class and sex were registered.
Results: We found a high negative predictive value of 92% for a cut-off limit of 500 ml. The corresponding positive predictive value was a modest 38%. This tendency was seen for cut-off-limits exceeding 300 ml.
Conclusion: Clinical assessment of bladder size might be useful in terms of ruling out a big volume postoperatively. Because of the low positive predictive value, we recommend verifying urinary retention judged by clinical assessment with ultrasound examination before catheterisation. Also, one has to remember that urinary retention occurs with different volumes in different patients.