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Updated: Jun 20, 2026

Spinal Sonography for Ultrasound-Guided Lumbar Neuraxial Anesthesia
Published on: January 31, 2025
Unilateral anesthesia does not affect the incidence of urinary retention after low-dose spinal anesthesia for knee
Wolfgang G Voelckel1, Lukas Kirchmair, Peter Rehder
1Department of Anesthesiology and Critical Care Medicine, Medical University, Innsbruck, Austria. wolfgang.voelckel@auvi.at
Abstract:
We evaluated whether unilateral low-dose spinal anesthesia may reduce the likelihood of postoperative urinary retention. Forty patients scheduled for knee arthroscopy randomly received bilateral (n = 20) or unilateral (n = 20) spinal anesthesia with 6-mg hyperbaric bupivacaine 0.5%. The incidence of urinary retention (>500 mL) assessed with an ultrasound device (Bladderscan) and subsequent temporary catherization was 7/20 patients in the bilateral versus 6/20 in the unilateral group (not significant). We concluded that unilateral low-dose spinal anesthesia does not further decrease the likelihood of urinary retention. Our results demonstrate the value and necessity of monitoring bladder volume postoperatively.
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