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Biomedical subjects

S W Coppinger

Publications and source records attributed to S W Coppinger.

12 recordsLinked to original sources

Use of glyceryl trinitrate patches in patients with ureteral stones: a randomized, double-blind, placebo-controlled study.

OBJECTIVES: To report a randomized, double-blind, placebo-controlled trial of glyceryl trinitrate (GTN) patches. The primary outcome measure was stone passage at 6 weeks. GTN is a potent smooth muscle relaxant that may offer benefit by both reducing pain and facilitating ureteral stone passage. METHODS: Fifty consecutive patients, with a single radiopaque calculus less than 10 mm, were randomized to receive a 6-week course of patches containing either 5 mg GTN or placebo. Patients used a diary to record pain episodes during the 6-week study period and were reviewed weekly with x-ray imaging. Analysis was by intention to treat. RESULTS: Twenty-six patients were randomized to the GTN group and 24 to the placebo group. Seven patients in the GTN group discontinued therapy because of headaches. One patient in the placebo group discontinued because of a skin reaction to the patches. No serious adverse events were recorded. No difference was observed in the stone-free rate at 6 weeks (18 patients in each group), interval to stone passage (median GTN 11.5 days versus placebo 13 days), or interventions performed (5 patients each). Although the GTN group reported fewer pain episodes (median 3.5 versus 6.0), this did not achieve statistical significance. CONCLUSIONS: Our preliminary results did not demonstrate a significant advantage in using GTN compared with placebo, with regard to the stone-free rate at 6 weeks, interval to stone passage, or number of episodes of pain experienced.

Administration, Cutaneous↗

A comparison of 1.5% glycine and 2.7% sorbitol-0.5% mannitol irrigants during transurethral prostate resection.

PURPOSE: We performed a prospective randomized trial comparing glycine 1.5% with 2.7% sorbitol-0.5% mannitol irrigating solution. We evaluated blood loss, fluid absorption, temperature change, cardiac effects and postoperative symptoms. MATERIALS AND METHODS: Between April 1998 and July 1999, 205 treated patients were included in the statistical analysis. Intraoperative irrigating fluid absorption was measured with the patient on the operating table. Serum cardiac troponin I was used as a marker of perioperative myocardial damage. Operative details were recorded, including the type of anesthesia, resection time and the weight of resected tissue. Postoperative symptoms were documented prospectively. RESULTS: Mean patient age was not significantly different in the glycine and sorbitol-mannitol groups. (72.1 versus 73.7 years). American Society of Anesthesiologists grade was also comparable. Median resection time was 27 minutes and resected tissue weighed a mean of 21 gm. The median resection rate was 0.8 gm. per minute. Blood loss and temperature changes during resection were similar in the 2 groups. Overall median blood loss was 216 ml. and irrigant absorption was 140 ml. In the sorbitol-mannitol group significantly less fluid was apparently absorbed during resection (median 88.2 versus 184.4 ml.). Analysis of the incidence of symptoms of the transurethral prostate resection syndrome did not show any differences in the irrigant groups. Cardiac damage measured using troponin I also showed no significant difference in the 2 groups, although there was a high overall incidence of 7.5%. CONCLUSIONS: We noted no significant differences in 1.5% glycine and 2.7% sorbitol-0.5% mannitol as an irrigating solution for transurethral prostate resection.

Aged↗

A case-control study of percutaneous nephrolithotomy versus extracorporeal shock wave lithotripsy.

OBJECTIVES: To assess the relative efficacy of percutaneous nephrolithotomy (PCN) and extracorporeal shock wave lithotripsy (ESWL) in clearing stones and to examine factors which affected the results from each treatment. PATIENTS AND METHODS: The study comprised 390 patients treated with PCN who were compared to 618 patients treated with ESWL. Unconditional logistic regression analysis was used to compare the odds of success and failure in the PCN group with those in the ESWL group, whilst controlling for any potential effects of age, sex, laterality, presence of other stones, previous stone history, pre-operative treatment and centre. RESULTS: PCN was more successful in obtaining satisfactory results than ESWL with an odds ratio of 2.67 (P < 0.001, 95% confidence intervals 1.84-3.87). The odds ratio in favour of PCN was increased after controlling for differences by centre (odds ratio 5.18, 95% confidence intervals 2.89-9.16). No other factors significantly influenced the odds ratio. ESWL was less successful in treating stones > 2 cm in diameter compared to treating stones < 2 cm in diameter (P = 0.001). ESWL results were also affected by re-treatment rates, which were influenced by distance of the local hospital from the lithotripter. The results with PCN improved with experience. The results of ESWL were satisfactory and the treatment cheaper, with a lower morbidity and hospital stay than after PCN for stones < 2 cm in diameter, making it the treatment of choice. However for stones > 2 cm, the results of ESWL were not as good and costs of treatment, morbidity and hospital stay were much closer to those of PCN for similar sized stones. CONCLUSIONS: PCN is more effective than ESWL in clearing stones. However, ESWL is an effective treatment and is usually the treatment of choice for most stones. Nevertheless, PCN remains an important and extremely effective method of treatment. The choice of treatment for stones will be influenced by the distance of a centre from a static lithotripter, and the potential availability of a mobile lithotripter.

Adolescent↗

A method of measuring fluid balance during transurethral resection of the prostate.

OBJECTIVE: To design a practical system for non-invasively monitoring fluid balance during transurethral resection of the prostate (TURP) and other endoscopic procedures. MATERIALS AND METHODS: Load cell transducers are incorporated into a platform placed under the operating table. Output is passed to a digital weighmeter and then to a portable computer. The raw data is filtered using software written by the authors (CAL) and the output displayed both numerically and graphically on the computer screen. The device was tested under laboratory conditions and then assessed in the clinical setting. RESULTS: The device proved stable in both the laboratory and clinical settings. Examples of the common patterns generated during TURP are presented. The prototype has been used routinely in our practice to warn the surgeon and anaesthetist of fluid overload and has been used to monitor fluid balance in several studies. CONCLUSIONS: This instrument provides a practical method of monitoring total fluid balance during TURP. It can be used with either general or regional anaesthesia and provides information not otherwise available. It provides an early warning of significant changes in total fluid balance, particularly irrigant fluid absorption. Use of this device serves to prevent development of the TUR syndrome, a potentially fatal complication of endoscopic surgery. Our ultimate aim is to produce a refined version that is simple, compact and cheap enough to be used routinely in all urological theatres. The cost of a single episode of intensive care for a patient developing iatrogenic complications from irrigant absorption would offset the cost of such a device.

Absorption↗

Cardiovascular performance and core temperature during transurethral prostatectomy.

Hemodynamic performance and core temperature were recorded during transurethral prostatectomy in 52 patients who were stratified according to cardiac symptom score and then randomized to undergo standard (31) or isothermic (21) transurethral prostatectomy. During the standard procedure ambient temperature (21C) irrigant was used, while during isothermic prostatectomy warmed irrigant at 38C was used to prevent heat loss from the bladder, and a warming blanket and humidifying filter were used to decrease cutaneous and respiratory heat loss. Core temperature decreased by a mean of 0.8C (95% confidence interval -0.9 to -0.7) during standard transurethral prostatectomy and by 0.27C (-0.4 to -0.15) during the isothermic procedure. The standard prostatectomy group showed a significant hemodynamic response consisting of increased mean arterial pressure (p < 0.0002), increased index of systemic vascular resistance (p < 0.0001), bradycardia (p < 0.02), and decreased Doppler indexes of stroke volume (p < 0.005) and cardiac output (p < 0.001). The isothermic transurethral prostatectomy group was hemodynamically stable. These differences between the groups suggest that rapid central cooling exerted a significant effect on perioperative hemodynamic performance during transurethral prostatectomy.

Aged↗

Estimation of irrigant absorption during transurethral resection of the prostate. Assessment of fluorescein as a marker.

Absorption of irrigating solution may complicate transurethral resection of the prostate (TURP), and a system which warns of fluid overload reliably would be of benefit in the prevention of these complications. Fluorescein can easily be detected at very low concentrations in blood and can be added to the irrigating solution in amounts invisible to the naked eye, providing a possible means of easily monitoring the absorption of irrigant solution during TURP. To test this hypothesis, the plasma concentration of fluorescein was determined at intervals after intraperitoneal injection in rats. Although the published data on fluorescein suggest that it meets the criteria for a suitable marker substance to be introduced into the irrigant solution, the results show that plasma fluorescein is constant and not dose related. The addition of fluorescein to the irrigant solution would not provide a quantitative means of determining the volume of irrigant absorbed. The use of other substances may provide the answer to this major clinical problem. We have defined a set of criteria which such a substance should fulfil.

Absorption↗

Is urethral pressure profilometry useful in the preoperative assessment of benign prostatic hyperplasia?

The principal aim of this study was to provide an objective assessment of the potential role of urethral pressure profilometry as a technique for assessing prostatic size by direct comparison with endoscopic assessment of prostatic length and computed tomographic measurement of prostatic volume and length. There was a poor correlation between pre-operative prostatic length and amount resected in the operating theatre. The results obtained with urethral pressure profilometry correlated poorly with those obtained using the other techniques, and cannot therefore be relied upon in routine clinical practice. Although there was good correlation between the length of the prostate and prostatic size, assessed by pre-operative computed tomography, this correlated poorly with the amount of tissue resected at operation. Further studies need to be conducted to compare objectively the completeness of prostatic resection with the outcome following prostatectomy.

Aged↗

Haemodynamic evidence for per-operative cardiac stress during transurethral prostatectomy. Preliminary communication.

Haemodynamic changes were measured during routine transurethral prostatectomy (TURP). The heart rate and stroke volume fell progressively over the first 30 min of surgery, resulting in a steady reduction in cardiac output. There was a significant increase in left ventricular afterload from commencement of the procedure. These findings demonstrate that haemodynamic responses, which are not detectable using conventional methods of monitoring, occur during TURP. Increased left ventricular afterload indicates increased myocardial work and oxygen demand which could result in myocardial ischaemia. This may contribute to the increased cardiovascular morbidity and mortality which have been reported to occur after TURP. The possible underlying mechanisms are discussed.

Aged↗

Prazosin in the treatment of prostatic obstruction. A placebo-controlled study.

Eighty patients with prostatic obstruction were entered into a double-blind parallel study of prazosin versus placebo. There were 25 withdrawals or exclusions, leaving 55 patients for analysis. Mean maximum flow rates increased significantly more in patients treated with prazosin than in those treated with placebo (P less than 0.005), but there was no significant reduction in maximum voiding pressure. The mean number of voids, recorded on diary cards, was reduced from an initial 10.0/24 h by 2.1 in the final week, a significantly greater reduction than in the placebo group (P less than 0.01). However, there were no statistically significant changes in the filling cystometrograms. When patients were classified as responders or non-responders in terms of bladder filling, urine flow, bladder emptying, weekly average of voids/24 h and nocturia, the proportion of patients responding to prazosin was significantly greater in all categories except bladder filling and emptying. It was concluded that prazosin at a dose of 2 mg bd is a safe and effective treatment for prostatic obstruction and may be used in patients awaiting surgery and those who are unfit for operation.

Aged↗