Cesarean Delivery and Post-Operative Pain Management With Local Anesthesia

RESEARCH PROTOCOL

Title: Cesarean Delivery and Postoperative Pain Management with Local Anesthesia

Investigators: Aaron Deutsch, MD, Principal Investigator Shelly Holmstrom, MD

Abstract:

Pain control has become a more prominent clinical issue. Typically, a patient undergoing a
Cesarean delivery is administered spinal anesthesia just prior to the surgery.

Postoperative pain is managed with intravenous (IV) narcotics using a patient controlled
anesthesia (PCA) pump device. Once the patient can tolerate oral medications, the PCA pump
is discontinued and the patient uses oral narcotic medications for pain control.

Research has shown that injecting a local anesthetic in the subcutaneous tissue along the
incision can reduce postoperative pain. The objective of this study is randomly assign
patients to receive a local anesthetic or normal saline in the tissues surrounding the
incision and to study the amount of pain experienced postoperatively in these groups of
patients. Our hypothesis is that the patients receiving the local anesthesia along their
incision will have significantly less pain postoperatively and use less narcotic
medications.

Objectives:

Primary: To decrease postoperative pain in women undergoing Cesarean delivery Secondary: To
decrease narcotic use, potentially decrease hospital length of stay, and increase patient
satisfaction

Background, Study Rationale and Significance:

Local anesthesia injected at the incision site fro reduced postoperative pain has been
studied in other abdominal surgeries. The research has demonstrated the effectiveness of
this technique for reduced postoperative pain. One journal article describes a technique
similar to the proposed research project1. However, this article did not show any
significant difference in the postoperative pain following bupivacaine or normal saline
injection of the skin. The authors’ conclusion for this lack of significance was due to
their facility’s high quality analgesia via supplemental subarachnoid morphine.

Numerous other authors have demonstrated the effectiveness of using local anesthesia at
incision sites for reducing pain postoperatively2-4. The proposed research project has the
potential to decrease pain postoperatively, decrease hospital length of stay and increase
patient satisfaction for one of the most common surgeries in the United States of America.

1. Rajakulendran Y, Chan A. “The Effect of Postoperative Skin Infiltration with
Bupivacaine on Postoperative Pain Following Cesarean Section under Spinal Anesthesia.”
International Journal of Obstetric Anesthesia. Oct 1994;Vol 3(4):199-202

2. Einarsson JI, Sun J, Orav J, Young A. “Local Anesthesia in Laparoscopy: A Randomized
Trial.” Obstetrics and Gynecology. Dec 2004; 104:1335-9.

3. Lohsiriwat V, Lert-akyamanee N, Rushatamukayanunt W. “Efficacy of Pre-incisional
Bupivacaine Infiltration on Postoperative Pain relief after Appendectomy: Prospective
Double-Blind Randomized Trial. World Journal of Surgery. 2004 Oct; 28(10):947-50.

4. Khaira HS, Wolf JS Jr. “Intraoperative Local Anesthesia Decreases Postoperative
Parental Opioid Requirements fro Transperitoneal Laparoscopic Renal and Adrenal
Surgery: A Randomized, Double-blind, Placebo Controlled Investigation. Journal of
Urology. 2004 Oct; 172(4 Pt1):1422-6.

Study Population:

Patients currently undergoing a repeat Cesarean delivery with a history of a previous
Cesarean delivery through a Pfannenstiel skin incision will be eligible to enroll in this
study. All ages and races will be eligible. Exclusion criteria include patients with a
primary Cesarean delivery, prior vertical skin incision or an allergy to bupivacaine. The
projected sample size required for this study is 100 (50 patients in each arm).

Study Procedures

Research Plan:

This study is a randomized double blind placebo controlled trial. Patients will be
randomized to either the bupivacaine or placebo (normal saline) group. An opaque envelope
will contain a slip of paper indicating which fluid is to be injected. The anesthesiologist
will open the envelope during the surgery and prepare 30 ml of the study drug. The patients
will have their incision site injected with either the bupivacaine or normal saline at the
completion of the surgery. The patients will be asked to assess their level of pain
following the surgery on postoperative days 0, 1, 2 and 3 using a visual analog scale (VAS).

Expected results:

The hypothesis is that the patients receiving the bupivacaine injection will experience
significantly less postoperative pain and use significantly less IV and oral narcotic
medications.

Human Subject Issues

- there are minimal to no additional risks to the patients in this study. Bupivacaine is
a time proven safe drug (barring patient not allergic) and our dose will be far below
toxicity levels. There are no social risks or risks of confidentiality as patients
will not be personally identified in the study.

- benefits: the benefits to the patient would be a higher satisfaction due to better pain
control. Additionally, patients may require less narcotics post-operatively and a
potentially shorter hospital stay.

- patient information will be kept track of via name and med rec number for chart review
after study completion to assess all data. This info will be limited to only the
primary investigators.

- of note the fetus will be delivered prior to the time of anesthetic administration, so
they will not be exposed.

Informed Consent Informed consent will be obtained at the time of consent for cesarian
delivery. The resident obtaining consent will also obtain the research consent. This will
consist of explaining that the patient may receive either a local anesthetic or placebo to
help assess better post-op pain control. Possible benefits will be explained along with
minimal risks- no more than normal for a cesarian delivery.

The consent process will be available in Spanish and English when applicable.

Statistical Plan

- sample size/power analysis: statistical power for the study to show a statistical
difference was calculated to approx 33 patients in each arm- we will extend to 50.

- statistical analysis:

Data Forms and Questionaire (see attached)