Prevention of Post-operative Urinary Retention

Study Overview
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Brief Summary
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The purpose of this study is to determine if tamsulosin (FLOMAX) is effective in preventing post-operative urinary retention following abdominal surgery. Post-operative urinary retention is a common post-operative complication, occurring in up to 30% of patients undergoing abdominal surgery. It can be described as the inability to initiate urination or properly empty one's bladder following surgery. It is usually self-limited, but it requires the use of catheterization to empty the bladder in order to prevent further injury to the bladder or kidneys and to relief the discomfort of a full bladder. Tamsulosin is a medication that is commonly used in men with urinary symptoms related to an enlarged prostate. There is some evidence to suggest that it may also potentially be beneficial for preventing post-operative urinary retention. Therefore, in this research study, subjects scheduled for abdominal surgery will be randomly assigned to take either tamsulosin once-daily or placebo once-daily for one week leading up to surgery, and up to several days after surgery. Urinary function will be assessed and compared between these two treatments. The hypothesis is that tamsulosin will reduce the rate of postoperative urinary retention compared to placebo.

Detailed Description
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Postoperative urinary retention (POUR) complicates up to 30% of general abdominal operations. It results in patient discomfort, embarrassment, interference with therapies, and significant nursing burden. More importantly, urinary retention necessitates use of intermittent catheterization or placement of an indwelling urinary catheter, which exposes the patient to an increased risk of urinary tract infection (UTI), urethral injury, and potentially increased hospital length of stay and cost. For these reasons, a safe and effective intervention for preventing POUR would be highly valuable. Despite such a need, no contemporary studies exist evaluating medications that can be used to prevent POUR in broad general surgery populations. To address this gap, the investigators have designed a prospective, randomized, double-blind, placebo-controlled trial to test the hypothesis that preoperative loading with tamsulosin will prevent POUR in patients undergoing elective, inpatient complex intra-abdominal surgery and thereby lead to improved short-term outcomes. Tamsulosin is a safe and widely-used selective alpha-1-A adrenergic blocker commonly used for the treatment of lower urinary tract symptoms in men with benign prostatic hypertrophy. It has also been shown to have some benefit in reducing POUR and need for catheterization in men undergoing inguinal hernia repair and other outpatient urologic procedures. This study is a randomized, double-blind, placebo-controlled trial in which patients scheduled for inpatient complex intra-abdominal surgery will be randomized to receive either tamsulosin or placebo for 7 days pre-operatively, and up to several days post-operatively, and then rates of POUR will be compared between the two groups (Aim 1). A retrospective analysis of the data will be used to identify risk factors for POUR and subgroups of patients that would derive the greatest benefit from preoperative tamsulosin (Aim 2). Furthermore, short-term outcomes, including rate of urinary tract infection (UTI) and hospital length of stay, will be compared between the tamsulosin and placebo groups (Aim 3). Enrolled subjects will be randomized using a blocked, stratified randomization process to either tamsulosin or placebo. Stratification variables include gender, pelvic vs non-pelvic surgery, and International Prostate Symptom Score (IPSS) survey results (which is a measure of baseline lower urinary tract symptoms). After a 7-day treatment period, subjects will undergo surgery as scheduled, and then the assigned treatment will be continued for up to a total of 14 days until the subject either has return of normal voiding function, has required replacement of an indwelling urinary catheter, or is discharged from the hospital.

Official Title
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Pre-operative Tamsulosin for the Prevention of Post-operative Urinary Retention: a Randomized, Double-blind, Placebo-controlled Trial

Conditions
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Urinary Retention, Urinary Tract Infections

Intervention / Treatment
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* Drug: Tamsulosin
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: English-speaking Able to provide informed consent Scheduled to undergo an elective, complex intra-abdominal operation with a planned postoperative inpatient stay of at least 1 night Exclusion Criteria: Less than age 18 Allergy or contraindication to tamsulosin Serious sulfa allergy Current use of alpha blocker (alfuzosin, doxazosin, prazosin, silodosin, terazosin, verapamil, tamsulosin) or oral alpha agonist (midodrine), or initiation of one of these medications during the intervention phase of the study will result in subject withdrawal from the study Current warfarin use Pre-existing indwelling urinary catheter, suprapubic catheter, or urostomy End stage renal disease or dialysis-dependence Sitting systolic blood pressure in the upper extremity of less than 100mm Hg at time of eligibility screening Presence of orthostatic hypotension at the time of eligibility screening (orthostatic hypotension is defined as a drop in systolic blood pressure of 20mm Hg from sitting to standing, or drop in diastolic BP of 10 mm Hg from sitting to standing after 2-3 minutes of standing after being in a sitting position) Anticipated inability to take oral medications on post-operative day #0 Anticipated requirement for indwelling urinary catheter beyond post-operative day #2 Non-English speaking Pregnant or breast-feeding Unwillingness to answer all 7 questions on the IPSS (International Prostate Symptom Score) survey Lacking capacity to provide informed consent

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Tamsulosin<br> | Drug: Tamsulosin<br>* Tamsulosin 0.4mg capsule orally once daily, dosed 30 minutes after dinner or before bed, starting 7 days before surgery and continuing for 0-5 days postoperatively. Outline of schedule: Day 1-7: tamsulosin 0.4mg in the evening Day 8: surgery; tamsulosin 0.4mg in the evening if the subject has not yet completed the bladder management protocol Day 9-14: tamsulosin 0.4mg in the evening until the subject either 1) completes the bladder management protocol (defined by two consecutive voids with post-void residual <200mL), or 2) has an indwelling urinary catheter replaced, or 3) is discharged from the hospital, whichever occurs first. The minimum number of total doses is 7; the maximum number of total doses is 14. The 14th dose will be the final dose regardless of bladder function.<br>* Other names: Flomax;|
| Placebo Comparator: Placebo<br> | Drug: Placebo<br>* Placebo capsule orally once daily, dosed 30 minutes after dinner or before bed, starting 7 days before surgery and continuing for 0-5 days postoperatively. Outline of schedule: Day 1-7: placebo in the evening Day 8: surgery; placebo in the evening if the subject has not yet completed the bladder management protocol Day 9-14: placebo in the evening until the subject either 1) completes the bladder management protocol (defined by two consecutive voids with post-void residual <200mL), or 2) has an indwelling urinary catheter replaced, or 3) is discharged from the hospital, whichever occurs first. The minimum number of total doses is 7; the maximum number of total doses is 14. The 14th dose will be the final dose regardless of bladder function.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Need for Any Intermittent Catheterization Postoperatively as a Binary Outcome | need for any intermittent catheterization after leaving the operating room or after initial indwelling urinary catheter (IUC) removal; subjects will be straight catheterized if the subject either 1) reports bladder discomfort, or 2) has a bladder scan for >500milliliters; or 3) has a post-void residual volume >500milliliters | within 0-7 days after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Need for Replacement of Indwelling Urinary Catheter as a Binary Outcome | Need for replacement of an IUC after surgery or after initial removal of an IUC that was placed at the time of surgery; replacement of IUC is dictated by the institutional bladder management protocol after requiring the use of straight catheterization for 24 hours | within 0-7 days after surgery | 
| Time Until First Spontaneous Void | time from IUC removal, last intermittent catheterization (if performed in the operating room or post-anesthesia care unit), or departure from the operating room (if no IUC placed intraoperatively) until first spontaneous void | within 0-7 days after surgery | 
| Total Number of Intermittent Catheterizations Required Per Subject | total number of intermittent catheterizations required, as dictated by the institutional bladder management protocol | within 0-7 days after surgery | 
| First Post-void Residual Urine Volume | The post-void residual (PVR) urine volume as measured by bedside hand-held bladder scanning immediately following the first spontaneous void | within 0-7 days after surgery | 
| Discharge From Hospital With Indwelling Urinary Catheter | Does the subject have a urinary catheter in place at the time of discharge from the hospital? This is a binary outcome measure of whether or not the subject is discharged from the hospital with an indwelling urinary catheter in place due to inadequate voiding function. | up to 30 days after surgery | 
| Urinary Tract Infection (UTI) | Either a culture-positive UTI prior to discharge from the hospital or subject self-reported clinician-diagnosed UTI occurring within 30 days of surgery | up to 30 days after surgery | 
| Hospital Length of Stay in Days | Collected after the participant is discharged from the hospital, total number of consecutive days (including day of surgery) until the participant is discharged from the hospital | up to 30 days after surgery | 
| Number of Participants Who Experienced Adverse Events | Adverse events, systematically collected. Summary results reported here, please refer to Adverse Events section of the results record for detailed reporting. | treatment day 1 (7 days before surgery) until 30 days after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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double-blind method, tamsulosin, randomized controlled trials as topic, random allocation, placebos, Adrenergic alpha-Antagonists, urinary retention, urinary tract infections, urinary catheters, catheter-related infections, postoperative complications