Prevention of Post-operative Urinary Retention
Prevention of Post-operative Urinary Retention
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.
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.
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