The objective of this study is to quantify the change in post-operative pain scores and narcotic requirements in women receiving pre and post-operative IV acetaminophen compared to placebo in women undergoing laparoscopic hysterectomy.

Gynecologic surgery has been revolutionized by the incorporation of minimally invasive techniques. Procedures that once resulted in multiple day hospital admissions are now being performed in outpatient surgery centers. Common factors that contribute to delayed discharge are inadequate postoperative pain control and increased nausea and vomiting. A multi-modal pain management approach is considered optimal at controlling postsurgical pain, which includes combining different analgesics that act in varying mechanisms. By using medications that act synergistically, the overall analgesia requirement can oftentimes be decreased.

Opioids have been found to be highly effective in controlling postoperative pain; however, are associated with dose-dependent risks including nausea, vomiting, constipation, urinary retention, sedation, and respiratory depression. Subsequently, non-opioid options are frequently desired in an attempt to minimize narcotic intake. In the United States, intravenous acetaminophen was approved by the US Food and Drug Administration (FDA) in November 2010 for the management of mild to moderate pain and the reduction of fever. Since this time, multiple studies have analyzed the role of intravenous acetaminophen in both acute and postoperative pain; however, none have been specific to laparoscopic hysterectomy. The primary study published evaluating intravenous acetaminophen in laparoscopic hysterectomies also included multiple other laparoscopic procedures from a variety of specialties including general surgery, urology, and urogynecology. In addition, the intravenous acetaminophen was started on average 19 hours after the conclusion of the case once the patient controlled analgesic was discontinued.

Improved postsurgical pain control achieved with intravenous acetaminophen may potentially lead to same day discharge after major laparoscopic gynecologic procedures. Same day discharge after laparoscopic hysterectomy has been shown to be a safe option with proper patient counseling and multi-modal pain medications. In addition, same day discharge is also associated with decreased health care expenditures. With continued efforts to cut hospital costs, the pressure to discharge patients earlier continues to be high.

The investigators propose that intravenous acetaminophen will improve post-operative pain control and decrease narcotic requirements for patients undergoing laparoscopic hysterectomies. Furthermore, The investigators expect to find decreased postsurgical nausea and vomiting and potentially quicker discharge to home. This could have a large impact on the field of gynecologic surgery as major procedures that once required overnight admission may now succeed at same day discharge.

Inclusion Criteria:

• Women aged 18-75
• Ability to read and write in English (our post-operative pain log is only available in English)
• Planning a laparoscopic hysterectomy (includes total laparoscopic hysterectomy, laparoscopic supracervical hysterectomy, laparoscopically assisted vaginal hysterectomy, with or without salpingooophorectomy)

Exclusion Criteria:

• Answering yes to any of the following questions: "Do you have a history of liver disease, kidney disease, hepatitis C, history of liver failure, greater than 3 drinks per day or being have you ever been told by your doctor that they should not take acetaminophen"
• History of cardiac arrhythmia
• History of jaundice
• Acute abdominal inflammatory or infectious process at time of surgery
• Known malignancy at time of surgery
• Known pregnancy at time of surgery
• Plan to perform additional significant surgical procedure at the time of hysterectomy such as extensive excision of endometriosis on bowel or bladder or pelvic reconstructive procedure
• >6cm abdominal incision in order to remove the uterus at time of study-related hysterectomy
• Regular use of narcotic pain medication (defined as use on most days of the week at any point in the past 3 months)
• Allergy to acetaminophen
• Women who weigh less than 50 kilograms on the day of surgery.

18 months

The original protocol involved 154 patients with an expected rate of loss to follow up of 10%. Due to higher than expected loss to follow up the number of patients enrolled was increased to 190.