PubMed Health⌕ Search

Biomedical subjects

S C Radley

Publications and source records attributed to S C Radley.

23 records · Page 2Linked to original sources

A comparison of ambulatory and conventional urodynamic studies in men with borderline outlet obstruction.

OBJECTIVE: To compare detrusor function and outlet behaviour on ambulatory urodynamic monitoring (AUM) with conventional cystometrography in symptomatic men with borderline evidence of bladder outlet obstruction (BOO), as determined by conventional cystometrography, and to assess the usefulness of AUM in reclassifying this population of patients into obstructed and unobstructed groups. PATIENTS AND METHODS: Sixty-nine consecutive men (mean age 59.6 years) with lower urinary tract symptoms (mean International Prostate Symptom Score 19.1) and borderline BOO on a medium-fill conventional urodynamic study (CUS) were examined prospectively with AUM. Detrusor contractility, obstruction grade, maximal voiding detrusor pressure (pdet(max)), detrusor pressure at peak flow (pdet Qmax) and peak flow rate (Qmax) determined by both methods were compared. The incidence of detrusor instability (DI) detected by both modalities was also evaluated. RESULTS: There was considerable disagreement between the investigations during the voiding phase. Detrusor contractility was higher on AUM than on CUS (P= 0.003) and obstruction grade was significantly lower on AUM (P=0.018). There was no difference in pdet(max) nor pdet Qmax. The mean (95% confidence interval) Qmax was higher on AUM, at 12.9 (1.3) mL/s, than on CUS, at 8.9 (0.8) mL/s. On the Abrams-Griffiths nomogram the most significant changes were six men (10%) from equivocal to obstructed, seven (11%) from equivocal to unobstructed and two (3%) from obstructed to unobstructed on CUS and on AUM, respectively. Thus, in 24% of patients there was a potentially clinically significant change resulting from the information generated by AUM. DI was identified on CUS in 26 (41%) men and on AUM in 25 (40%); 35 men (56%) had evidence of DI on either AUM or CUS. CONCLUSION: The significant disagreement between the findings on CUS and AUM suggests that the conditions under which pressure-flow investigations are carried out significantly affect findings in borderline cases. The reclassification of patients by AUM into obstructed and unobstructed groups occurs in 24% and may be clinically relevant. AUM appears to be complementary to CUS in the assessment of men who are borderline for obstruction on conventional testing, but the clinical implications of this have yet to be determined.

Constriction, Pathologic↗

Relaxant effects of potassium-channel openers on normal and hyper-reflexic detrusor muscle.

OBJECTIVE: To compare the effects of the potassium-channel openers, levcromakalim and YM934, in isolated human detrusor muscle from normal and hyper-reflexic bladders. MATERIALS AND METHODS: Strips of human detrusor muscle from normal and hyper-reflexic bladder were pre-contracted with carbachol and the potassium-channel openers (0.1-0.3 mumol/L) were added cumulatively to the organ baths. Other strips were field-stimulated at frequencies producing 25% and 75% of the maximum response to field stimulation. Contractions could be abolished by atropine (10 mumol/L) and tetrodotoxin (1 mumol/L). RESULTS: The hyper-reflexic bladder was significantly more sensitive to carbachol than the normal bladder but the maximum response was significantly lower in the hyper-reflexic tissue. There was no significant difference between the potency of the potassium-channel openers in normal and hyper-reflexic detrusor muscle. Hyper-reflexic bladder was significantly more sensitive to electrical field stimulation than was normal bladder: maximum responses to field stimulation were not significantly different. Concentration-response curves for the potassium-channel openers were displaced to the left in hyper-reflexic bladder at both 25% and 75% maximum frequencies: however, only with levcromakalim at 75% of the maximum frequency was the shift significant. CONCLUSION: The greater sensitivity of hyper-reflexic bladder to carbachol and field stimulation supports existing evidence for post-junctional supersensitivity in detrusor instability. The results of this study also suggest that there are no appreciable changes in KATP channel function in the unstable bladder.

Benzopyrans↗