Efficacy of IV Acetaminophen for Pain Management

Overview

The investigators' goal in this planned prospective, randomized, patient blinded study is to compare our standard of care as the control group to an experimental group in which patients receive preemptive IV acetaminophen dosing that is continued every 6 hours for a total of 8 doses in patients who have undergone major gynecologic surgery. The outcomes analyzed will include amount of rescue opioids required, time to return of bowel function, length of hospital stay, and patient satisfaction. The hypothesis is that the addition of IV acetaminophen will decrease the need for opioid rescue and thereby decrease the incidence of associated gastrointestinal side effects including nausea, vomiting, bloating, and constipation. The hope is that it will affect the final outcome of quicker return of bowel function, increased patient satisfaction, shortened hospital stay and prove to be an overall more effective postoperative pain management approach.

This is a patient-blinded prospective study in which patients that undergo major gynecologic surgery via an open abdominal approach will be randomized into two arms: 1. Control Group: Morphine patient-controlled-anesthesia (PCA) for the initial 24 hours post-operation with a low-dose basal rate (0.5mg/hr) and patient administered boluses prn. Oral oxycodone from 24-48 hours post-operation will be used prn for pain and then patients will be transitioned to oral combined oxycodone/acetaminophen for the remainder of their hospital stay. Normal saline 100cc IV will be infused as placebo every 6 hours for a total of eight doses with the first dose being given at time of anesthesia induction. 2. Experimental Group: Morphine PCA for the initial 24 hours post-operation with low-dose basal rate (0.5mg/hr) with patient administered boluses prn. IV acetaminophen 1,000mg will be given every six hours for a total of eight doses with the first dose being given at time of anesthesia induction. Oral oxycodone from 24-48 hours post-operation will be used prn and then patients will be transitioned to oral combined oxycodone/acetaminophen for the remainder of their hospital stay. Outcomes that will be analyzed include the amount of opioids used; time to return of bowel function designated as passage of flatus; time to first bowel movement if it occurs while inpatient; duration of hospital stay; and patient symptoms and satisfaction at the 24 and 48 hour marks as well as at time of discharge.