Post-Operative Constipation Following Total Knee Arthroplasty
Condition: Constipation
MeSH terms: Constipation
Study type: Interventional
Phase: Phase 2

Summary: 
      Postoperative constipation, defined as no fully satisfying bowel movement within the first
      three postoperative days, is a common occurrence with some researchers estimating that
      between 41 and 85% of postoperative patients experience symptoms. Causes include
      intraoperative medications, postoperative opioid analgesics, decreased mobility, and
      decreased oral intake. Constipation significantly impacts quality of life following surgery.
      Current standard of care for preventing postoperative constipation for patients having a
      single total knee arthroplasty at Cleveland Clinic is discharge on postoperative day one with
      either a prescription to be filled for docusate sodium (brand name Colace®) 100 mg to be
      taken two times a day by mouth for twenty eight days or the filled prescription, plus
      discharge instructions on ways to avoid and treat constipation. Research results show that
      docusate sodium is ineffective for preventing postoperative constipation in orthopedic
      surgery patients, and anecdotal reports confirm this finding. The proposed study uses a
      2-group non-equivalent cohort design to evaluate the effect of one standard dose (17 grams)
      of an over-the-counter osmotic laxative (propylene glycol (PEG 3350), brand name Miralax) by
      mouth prior to discharge to the current standard of care. The primary outcome measure is
      whether patients report of a fully satisfying, normal for them, bowel movement within the
      first three postoperative days. Patient reported data will be collected by phone call four to
      seven days following surgery. Pertinent patient characteristics will be abstracted from the
      electronic medical record. The sample will consist of patients over twenty years old having a
      single total knee arthroplasty by Drs. Stearns, Molloy, or Murray who are admitted to unit 5D
      at Cleveland Clinic Lutheran Hospital postoperatively. Intent to treat analysis will be
      performed using logistic and linear regression models, adjusting for differences between
      groups on patient and surgical characteristics. Based on use of a two-sided Pearson
      chi-square test with 80% power and significance level of 0.05, 49 patients per group are
      required to detect a 25% decrease in constipation rate. To account for attrition we will over
      sample by 50% for a total of 74 per group or 148 total participants.
    


Intervention name(s): Propylene Glycol; Docusate Sodium
Intervention type(s): Drug; Drug
Intervention description(s): Patients in the propylene glycol arm will receive one standard dose of the drug on postoperative day one prior to discharge with the aim of decreasing rates of postoperative constipation for patients following single total knee replacement surgery; Patients in the docusate sodium arm are receiving the current standard of care for prevention of postoperative constipation following single total knee replacement surgery, docusate sodium one pill twice a day by mouth for 28 days
Other intervention name(s): Miralax; PEG 3350; Colace
Intervention MeSH terms: Bismuth subsalicylate
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: constipation; postoperative; total knee arthroplasty