Laura Scheufele, PT, DPT, WCS
November 9, 2016
Aim: Determine the magnitude of change in intra-abdominal pressure (IAP) during two functional activities: 1) abdominal curl and 2) cough in patients with UI alone and UI and POP.
Design: Exploratory descriptive study.
Inclusion criteria: Consecutive patients diagnosed with UI with or without POP at the Women’s and Newborns teaching hospital Western Australia who were attending for urodynamic studies during a 7 week timeframe
Exclusion criteria: Women < 18 yo, stage 4 POP, women who were physically unable to achieve the testing position, those with a neurological condition, pregnant women, and those unable to understand the instructions.
Data Collection: IAP was recorded trans-vaginally using the standard clinical procedures for multichannel cystometry in centimeters of water using the Delvis UDS 120 equipment. (Considered a valid and reliable measure of IAP.)
1) The pressure-sensing catheter was inserted vaginally and the bladder was filled to 200 ml with subject supine. Resting pressure recorded.
2) Instructed in abdominal curl up with arms across the chest, and instructed to lift the upper body to the point where the inferior angles of the scapulae were off the bed. Performed 3 times with 5 second rest intervals in between. Rest and peak curl pressure measurements were recorded for each repetition.
3) In same position instructed to perform 3 maximal coughs, “as strong a cough as you can”, but with 5 second rests in between. Rest and peak cough pressure measurements recorded.
4) Medical notes reviewed to determine whether patients had previously been diagnosed with POP in additional to UI.
5) Patients asked about their menopausal status.
6) Height and weight measured by nurse and BMI determined.
Statistical analysis: Data analyzed using SPSS statistics software version 20.0.
Mean of the three values for each activity used for all analyses.
Differences in change in IAP between cough and curl up compared using paired t test.
Unpaired t tests used to compare 1) menopausal status (pre- versus post-menopausal), 2) diagnosis (UI vs UI/POP) and 3) BMI (normal to overweight, defined as <30 kb.m="" sup="">-230>
vs. obese, defined as ≥30 kg.m-2) to determine if the pressure generated with cough and curl up differed according to these factors. Statistical significance where p≤0.05.
Descriptive statistics including mean, median, range and standard deviation (SD) calculated. Data shown as mean SD unless specified differently.
Intra-class correlation coefficients (ICC) calculated on the 6 resting and the 3 measurements associated with each activity to determine within-patient variability.
Two-way analysis of variance (ANOVA) of UI vs UI/POP used to determine if there were significant changes in IAP with cough and curl-up and whether the changes differed between the two groups.
Thirty-one women aged 29-80 (mean 56.2) consecutively recruited. One was excluded secondary to a UTI. Sixty percent of the subjects were only diagnosed with UI and forty percent had UI and POP.
BMI’s ranged from 19-39 kg.m-2 (mean 29.93), 14/30 in normal to over-weight category and 16/30 designated in obese category. Sixty-three percent of the participants (19/30) self-reported they were post-menopausal.
Intraclass correlation coefficient (ICC) [95% confidence interval (CI)] for IAP measures were 0.76 (0.64-0.86) for rest, 0.74 (0.57-0.85) for curl and 0.65 (0.46-0.80) for cough.
IAP increased significantly (p<0 .001="" 19.58="" 50.32="" cmh="" curl="" from="" mean="" rest="" sub="" to="">20>O) and rest to cough (mean 19.46 to 78.37 cmH2O). (Table 1)
Cough generated higher changes in pressure than abdominal curl (mean 58.92 vs 30.74 cmH2O ; p<0 .001="" i="" style="mso-bidi-font-style: normal;">)0>, however large variations in change in pressure observed between participants (1.7-159.7 cmH2O for cough and 4-81.7 cmH2O for abdominal curl). (Table 1)
The UI/POP group generated significantly higher overall mean IAP pressures as compared to the UI only group. (p=0.02). (Table 2) UI vs UI/POP: Rest mean: 16.78/16.00 vs 23.78/24.64 cmH2O (p< 0.05); Curl: 43.07 vs. 61.20 cmH2O (p< 0.1); Cough: 66.88 vs. 95.61 cmH2O (p< 0.1).
Menopausal status was not associated with changes in IAP during a curl (p=0.15) or cough (p=0.18).
Obese women had significantly higher IAP at rest compared to non-obese women (22.5 vs 16.2 cmH2O, p < 0.03) and curl (59.4 vs 39.9 cmH2O, p< 0.03); but cough with no significant difference (80.5 vs 75.9 cmH2O).
Cough generated a larger mean increase of IAP than the abdominal curl. Supports education to at risk groups to minimize the effects of increased IAP during cough.
Large variability in the range of IAP between individuals and large peak IAP with abdominal curl and cough only in some women (Table 3).
No clear indication ALL women with UI or UI/POP should be advised to restrict abdominal curls. Speculate that the large variability possibly related to different motor control strategies and co-morbidities.
UI/POP group generated highest pressures with cough and curl and therefore suggest extra caution with this specific population. Also obese subjects with higher IAP at rest and during abdominal curl up suggesting this may be a population that would benefit from more conservative guidelines for abdominal curl up exercises and also education regarding weight loss to assist with reducing negative IAP effects.
In this study vaginal pressure sensor used to record IAP as it is part of standard urodynamic procedure. Some other studies have chosen to measure rectally, and there is disparity between the two methods in sitting and standing in the literature but not supine. Doubtful that movement of the sensor responsible to variability because of the high reliability of resting IAP values between activities.
1) Several urodynamic nurses involved in set-up so possible variability in catheter placement.
2) POP could affect catheter placement.
3) Small sample size.
4) Possibility of inconsistent cough force and potential personal differences in abdominal curl exercise performance.
5) No standardized breathing instructions.
6) Only partial sit up.
7) UI was divided into subgroups or SUI, UUI or mixed because of small sample size.
8) No control group.
9) Did not take into account fatigue on the generation of IAP.
Activity restrictions needs further investigation in PFD population and may require EMG or ultrasound monitoring to determine safe pressure limit for the pelvic floor, however “safe” limit is not known.
Conclusion: Large variability in IAP generated suggests blanket recommendations for activity restrictions in women with pelvic floor dysfunction may be unnecessarily restrictive. Recommend advice be individualized, with obese women and women with POP in particular need of scrutiny.
Weaknesses: Small sample size, large variability in IP generated and results. Possibility of inconsistent cough force, and/or personal differences in abdominal curl exercise performance: no specific instructions to standardize breathing instruction. Several urodynamic nurses involved in testing process, possibly resulting in variable catheter placement within the vagina. POP could also affect catheter placement. No abdominal wall assessment.