Randomized comparison of vaginal and rectal measurement of intra-abdominal pressure during subtracted dual-channel cystometry

Submaximal pelvic floor muscle contractions: similar bladder-neck elevation, longer duration, less intra-abdominal pressure

INTRODUCTION AND HYPOTHESIS

An adequate pelvic floor muscle contraction (PFMC) elevates the bladder neck (BN) and stabilizes it during increased intra-abdominal pressure (IAP). A maximal PFMC may increase the IAP and thereby prevent BN elevation. The aim of this study was to assess BN elevation during submaximal and maximal PFMC and their achievable duration.

METHODS

We recruited 68 women with stress urinary incontinence and 14 vaginally nulliparous continent controls who were able to perform a PFMC on vaginal palpation. Women were upright and performed a maximal PFMC as long as possible, followed by a submaximal PFMC, controlled by vaginal electromyogram (EMG). BN position was measured with perineal ultrasound, IAP and urethral pressure with a microtip catheter, and breathing with a circular thorax sensor.

RESULTS

A submaximal PFMC elevated the bladder neck 4 mm in continent and incontinent women (p = 0.655) and 4.5 vs. 5 mm during maximal PFMC (0.528). Submaximal PFMC was maintained significantly longer than a maximal PFMC (33 vs 12 s) with no difference between groups. A maximal PFMC resulted in BN descent in 29% of continent and 28% of incontinent women, which was not observed during submaximal PFMC. Breathing was normal in 70% of continent and 71% of incontinent women during submaximal PFMC but stopped completely in 21 and 50%, respectively, during maximal PFMC (p = 0.011). IAP increase was significantly greater with maximal PFMC in both groups (24 vs. 9.6 cmH₂O and 17 vs. 9 cmH₂O, respectively).

CONCLUSION

Submaximal PFMC are sufficient to elevate the bladder neck, can be maintained longer, and breathing was not influenced.

Intra-abdominal pressure during Pilates: unlikely to cause pelvic floor harm

INTRODUCTION AND HYPOTHESIS

The objective was to describe the intra-abdominal pressures (IAP) generated during Pilates Mat and Reformer activities, and determine whether these activities generate IAP above a sit-to-stand threshold.

METHODS

Twenty healthy women with no symptomatic vaginal bulge, median age 43 (range 22-59 years), completed Pilates Mat and Reformer exercise routines each consisting of 11 exercises. IAP was collected by an intra-vaginal pressure transducer, transmitted wirelessly to a base station, and analyzed for maximal and area under the curve (AUC) IAP.

RESULTS

There were no statistically significant differences in the mean maximal IAP between sit-to-stand and any of the Mat or Reformer exercises in the study population. Six to twenty-five percent of participants exceeded their individual mean maximal IAP sit-to-stand thresholds for 10 of the 22 exercises. When measuring AUC from 0 cm H2O, half the exercises exceeded the mean AUC of sit-to-stand, but only Pilates Reformer and Mat roll-ups exceeded the mean AUC of sit-to-stand when calculated from a threshold of 40 cm H2O (consistent with, for example, walking).

CONCLUSION

Our results support recommending this series of introductory Pilates exercises, including five Mat exercises and six Reformer exercises to women desiring a low IAP exercise routine. More research is needed to determine the long-term effects of Pilates exercise on post-surgical exercise rehabilitation and pelvic floor health.

Effects of walking speeds and carrying techniques on intra-abdominal pressure in women

INTRODUCTION AND HYPOTHESIS

Walking speed and carrying technique affect intra-abdominal pressure (IAP) in women. In this study, we tested the feasibility of monitoring IAP outside the laboratory environment and compared IAP while study participants were (1) carrying 13.6 kg (similar to a 3-month old in car seat) in six different ways while walking 100 m; and (2) while walking 400 m at self-selected slow, normal, and fast paces.

METHODS

Forty-six healthy women between 19 and 54 years completed the walking and lifting activities; the order for each was randomized. IAP was monitored with an intravaginal pressure transducer that wirelessly transmitted pressure data to a portable base station. We analyzed maximal peak IAP and area under the curve (AUC) IAP.

RESULTS

Monitoring IAP outside of the laboratory was feasible. Mean maximal IAP during walking increased as pace increased: 42.5 [standard deviation (SD) 10.2], 50.5 (10.9), and 62.0 (12.1) cmH2O for slow, medium, and fast speeds, respectively: p < 0.0001 by mixed-model analysis of variance (ANOVA). The corresponding AUC of IAP for walking decreased as pace increased. The awkward carry, side carry, and front carry activities each resulted in higher mean maximal IAP [65.8 (10.6), 67.7 (12.8), and 77.3 (13.1) cmH2O, respectively] than the carry-in-backpack activity [55.5 (11.4) cmH2O; p < 0.0001].

CONCLUSION

Subtle variations in walking speed or method of carrying a toddler-size load can produce significant changes in IAP. Whether these changes increase the risk of pelvic floor disorders is not yet clear. However, these data suggest that further inquiry into optimal methods and appliances to assist women in carrying may create a lower IAP profile.

Urodynamic studies for management of urinary incontinence in children and adults

BACKGROUND

Urodynamic tests are used to investigate people who have urinary incontinence or other urinary symptoms in order to make a definitive, objective diagnosis. The aim is to help select the treatment most likely to be successful. The investigations are invasive and time consuming.

OBJECTIVES

The objective of this review was to determine if treatment according to a urodynamic-based diagnosis, compared to treatment based on history and examination, led to more effective clinical care of people with urinary incontinence and better clinical outcomes.The intention was to test the following hypotheses in predefined subgroups of people with incontinence:(i) urodynamic investigations improve the clinical outcomes;(ii) urodynamic investigations alter clinical decision making;(iii) one type of urodynamic test is better than another in improving the outcomes of management of incontinence or influencing clinical decisions, or both.

SEARCH METHODS

We searched the Cochrane Incontinence Group Specialised Register, which contains trials identified from the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and MEDLINE In-Process, handsearching of journals and conference proceedings (searched 19 February 2013), and the reference lists of relevant articles.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing clinical outcomes in groups of people who were and were not investigated using urodynamics, or comparing one type of urodynamic test against another were included. Trials were excluded if they did not report clinical outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data.

MAIN RESULTS

Eight trials involving around 1100 people were included but data were only available for 1036 women in seven trials, of whom 526 received urodynamics. There was some evidence of risk of bias. The four deaths and 12 dropouts in the control arm of one trial were unexplained.There was significant evidence that the tests did change clinical decision making. Women in the urodynamic arms of three trials were more likely to have their management changed (proportion with change in management compared with the control arm 17% versus 3%, risk ratio (RR) 5.07, 95% CI 1.87 to 13.74), although there was statistical heterogeneity. There was evidence from two trials that women treated after urodynamic investigations were more likely to receive drugs (RR 2.09, 95% CI 1.32 to 3.31). On the other hand, in five trials women undergoing treatment following urodynamic investigation were not more likely to undergo surgery (RR 0.99, 95% CI 0.88 to 1.12).There was no statistically significant difference however in the number of women with urinary incontinence if they received treatment guided by urodynamics (37%) compared with those whose treatment was based on history and clinical findings alone (36%) (for example, RR for the number with incontinence after the first year 1.02, 95% CI 0.86 to 1.21). It was calculated that the number of women needed to treat was 100 women (95% CI 86 to 114 women) undergoing urodynamics to prevent one extra individual being incontinent at one year.One trial reported adverse effects and no significant difference was found (RR 1.10, 95% CI 0.81 to 1.50).

AUTHORS' CONCLUSIONS

While urodynamic tests did change clinical decision making, there was some evidence that this did not result in better outcomes in terms of a difference in urinary incontinence rates after treatment. There was no evidence about their use in men, children, or people with neurological diseases. Larger definitive trials are needed in which people are randomly allocated to management according to urodynamic findings or to management based on history and clinical examination to determine if performance of urodynamics results in higher continence rates after treatment.

Clinical evaluation of a wireless intra-vaginal pressure transducer

OBJECTIVE

To describe the development, feasibility and validity of a wireless intra-vaginal pressure transducer (IVT) which can be used to measure intra-abdominal pressure in real-world settings.

STUDY DESIGN

A feasibility study was conducted in sixteen physically active women to determine retention and comfort of various IVT prototype designs during activity. A criterion validity study was conducted among women undergoing urodynamic testing to determine the accuracy of the IVT prototypes when compared to accepted clinical standards.

RESULTS

A final prototype wireless IVT was developed after four design revisions of the second generation model. The feasibility study found that women reported the final prototype comfortable to wear and easily retained during physical activity. Intra-abdominal pressure measurements from the final prototype IVT compared favorably to standard urodynamic transducers, thus confirming evidence of its utility.

CONCLUSION

We have successfully advanced the design of a wireless, intra-vaginal pressure transducer which provides accurate measures of intra-abdominal pressure. The final wireless IVT is better tolerated by patients and overcomes limitations of traditional urodynamic testing while laying the foundations for intra-abdominal pressure monitoring outside of the clinic environment.

Development and testing of a vaginal pressure sensor to measure intra-abdominal pressure in women

AIMS

Elevated intra-abdominal pressure (IAP) may be a potentially modifiable risk factor for pelvic floor disorders. However, limited evidence exists due to the lack of instruments suitable to measure abdominal pressures in real world settings. The aim of this study was to develop and test a vaginal sensor prototype to measure intra-abdominal pressure in women.

METHODS

We developed a non-directional vaginal sensor by housing pressure-sensing circuit boards in 1.2 x 3 cm radially symmetric silicon capsules. We characterized the response in a standardized pressure chamber. Eight women wore a sensor intra-vaginally while undergoing filling cystometry. We compared peak pressures during coughing, valsalva, squatting, and jumping to those obtained using a #10 French rectal balloon urodynamics catheter. We calculated Pearson's correlation coefficients between rectal and vaginal sensors for each event.

RESULTS

The vaginal sensors exhibited linear responses during initial bench testing. Each transducer correlated well with the rectal balloon catheter during coughing, valsalva, and squatting (r = 0.97, 0.94, and 0.97, respectively). However, the rectal balloon catheter recorded higher peak and lower, often negative, trough pressures during jumping. The vaginal sensor showed no such artifact.

CONCLUSIONS

This vaginal pressure sensor can be used as a surrogate for measuring intra-abdominal pressure in women without advanced prolapse. By measuring pressure at the physiological source, the vaginal sensor is less prone to extraneous noise and error than current transducers. Using this prototype, we will next develop a remote wireless version to capture a range of abdominal pressures experienced outside of the laboratory setting.