Preoperative Cesarean Section Intravenous Acetaminophen and Postoperative Pain Control: A Blinded Randomized Placebo-Controlled Trial

Research Protocol

Preoperative Cesarean Section Intravenous Acetaminophen and Postoperative Pain Control: A Blinded Randomized Placebo-Controlled Trial

Background: To date, there has been no study that has analyzed the use of intravenous acetaminophen given preoperatively in scheduled cesarean deliveries. There have been studies in non-obstetrical surgical procedures that have demonstrated better pain scores and less use of opiates post surgery when administered preoperatively. If these study findings were found to be equally effective post-cesarean delivery, then fewer opiates would be used by the mother. This would benefit better ambulation and less bowel dysfunction by the mother and less effect on the newborn if the mother is breast-feeding. Acetaminophen is one the drugs of choice for analgesia in obstetrics, because it has no known effects on the mother or fetus/newborn. The drug has been found to be safe when given intravenously. Likewise, more patients are found to have therapeutic levels when the drug is given intravenously versus oral administration. Lastly, since patients are NPO prior to scheduled surgery, giving a medication orally is not recommended. Of the prospective blinded studies performed to date, small numbers have been used ranging from 20 to 28 in each arm. Intravenous acetaminophen is already being used preoperatively for scheduled cesarean sections at UT Medical Center Labor & Delivery and the presumption by the nursing staff is that the patients who receive this "do better" post-delivery (with less pain and less need for oral opiates), but without a blinded placebo-controlled trial, this finding cannot be proven or reported.

Specific Aims: The primary aim of this study is to see if maternal opiate use is decreased in the postoperative period for the study group which receives 1 gram of acetaminophen prior to scheduled cesarean section. The secondary aim of this study is to evaluate the length of stay of the mother post-delivery in both the study and placebo groups to see if there are any differences. If found to be significant, this can be analyzed for cost effectiveness. Lastly, pain scores will be evaluated to determine if they improved with preoperative acetaminophen. To date no one has ever studied the cord blood levels of acetaminophen following administration close to delivery, and as such no information on normal acetaminophen levels in the newborn is available.

Enrollment: Enrollment will involve all pregnant patients that enter labor and delivery for a scheduled cesarean delivery once the study is started until a total of 150 are obtained. Enrollment will be determined by the Primary physicians involved in the study, or nurse practitioners/research coordinators or any of the anesthesia or obstetrical residents.