Transversus abdominis plane block or subcutaneous wound infiltration after open radical prostatectomy: a randomized study.

BACKGROUND: Open radical retropubic prostatectomy (ORRP) is associated with moderate pain. We hypothesized that a transversus abdominis plane (TAP) block would reduce post-operative pain, morphine consumption and opioid-related side effects compared with wound infiltration and placebo in this population. METHODS: This was a randomized, double-blind and placebo-controlled study. The operations were performed with patients in general anaesthesia. Patients were allocated to receive either bilateral TAP block (n = 23), wound infiltration (n = 25) or placebo (n = 25). Treatment was 40 ml ropivacaine 0.75% and placebo was 40 ml saline 0.9%. Pre-operatively, all patients received oral gabapentin, ibuprofen and paracetamol, followed by oral paracetamol and ibuprofen at regular doses and intervals, and patient-controlled analgesia with IV morphine from 0 h to 24 h post-operatively. RESULTS: Visual analogue scale pain score during mobilization 4 h post-operatively (primary outcome) did not differ significantly between the TAP block and placebo group (TAP 28 ± 22 mm vs. placebo 33 ± 18 mm, P = 0.64). Pain scores (as area under the curve) during the first 24 h were not significantly different among any of the three groups, neither at rest nor during mobilization. Morphine consumption (0-24 h) did not differ significantly between groups {TAP block = 15 [8-23] mg, infiltration 15 [8-36] mg, placebo 15 [3-30] mg, [median (interquartile range)]}. Levels of nausea, sedation and number of vomits were not different among the groups. CONCLUSION: Neither TAP block nor wound infiltration with ropivacaine improved a basic multimodal analgesic regimen with paracetamol, ibuprofen and gabapentin after ORRP.

Urinary bladder volume measurements: comparison of three ultrasound calculation methods.

OBJECTIVE: To assess the precision of three different automatic calculation methods in real-time bladder volume measurement. MATERIAL AND METHODS: Bladders from 34 medical staff volunteers were examined. Two examinations of each subject were performed independently by 2 examiners using 2 identical ultrasound scanners with no delay between the examinations. Three different automatic calculation algorithms, available as software in the ultrasound scanner, were applied on the frozen ultrasound pictures. After registration of the voided volume with an uroflowmeter, the subjects were scanned again in order to assure complete emptying. RESULTS: Voided volumes ranged from 45 ml to 508 ml. The precision of each method was equal but the LWH method measured significantly lower values than the ELLIPSOID and AREA method. Errors in the range of -56.1% to +58.8% for all volumes and methods were found. Data for voided volumes greater than 150 ml (n = 29) were investigated separately, but no significant improvement in accuracy for any of the methods was found. CONCLUSIONS: Ultrasound bladder volume calculation is an easy method for estimation of bladder volume. The prolate ellipsoid method (LWH) is recommended as the standard calculation method because it is fast and easy. Unacceptable large measure errors are found and too rigid conclusions based on ultrasound measurements of bladder volume should be avoided.

Effect of a full bladder on urine production in humans.

OBJECTIVE: To demonstrate the reduction in urine production in healthy humans upon bladder distension and to identify the factors responsible for this reduction. MATERIALS AND METHODS: Twelve healthy females were investigated twice in a cross-over designed experiment: once with the urinary bladder empty at the start and once pre-filled to 60% of the maximum bladder capacity. Glomerular filtration rate, effective renal plasma flow, urine content of catecholamines, blood pressure, pulse rate, plasma arginine vasopressin (AVP) and plasma concentration of renine and electrolytes were analysed together with serum osmolality. RESULTS: Three subjects failed to reach maximum bladder capacity during the "full bladder" test and were excluded. The urine production in the "full-bladder" test was significantly lower than the "empty-bladder" test (p = 0.024). In the "full-bladder" test a significant increase in mean blood pressure was found (p=0.01). No further significant changes were demonstrated. CONCLUSIONS: Acute bladder distension causes a reduction in urine production or a "pooling of urine" in the upper urinary tract in healthy humans. The mechanism is unknown.