The Effect of Intraperitoneal Instillation of Bupivacaine on Postoperative Pain After Surgical Laparoscopy

Pain after surgical laparoscopy is due to various causes, such as : trocar insertion stimulating somatic pain receptors in the skin ,chemical irritation of peritoneal nerves due to abdominal distension by CO2 which is transformed into carbonic acid in nerves, distention secondary to pneumoperitoneum causes mechanical irritation of visceral and parietal nerves of the peritoneum, furthermore the surgical intervention causing injury and inflammation of the tissues, spillage of blood or serous fluid causing more irritation to the visceral and parietal nerves of the peritoneum which leads to visceral dull aching pain referred mainly to the distribution of the nerve dermatomal area.

Unfortunately, pain is the major complaint of the patients, thus making its evaluation a fundamental requisite in the outcome assessment in our practice. Pain intensity, duration and related disability are the aspects that define pain and its effects. For each of these aspects, different assessment tools exist.

Visual Analogue Scale (VAS) consists of a straight line with the endpoints defining extreme limits such as 'no pain at all' and 'pain as bad as it could be' The patient is asked to mark his pain level on the line between the two endpoints.

There are numerous interventions that are associated with reduction in the incidence, severity or both of pain or a reduction in analgesia requirements for women having surgical laparoscopy for gynecological purposes.

Bupivacaine, is a local anesthetic. In nerve blocks, it is injected around the nerve that supplies a certain area, or into the spinal canal's epidural space, bupivacaine binds to the intracellular portion of voltage-gated sodium channels and blocks sodium influx into nerve cells, which prevents depolarization. Without depolarization, no initiation or conduction of a pain signal can occur.

Hence the idea of our study is to instill bupivacaine in a certain concentration in the peritoneal cavity in an attempt to reduce postoperative pain after surgical laparoscopy for gynecological purposes that will inflect certainly on patient's hospital stay and mobility.

This randomized controlled trial will be conducted for (80) women undergoing laparoscopic procedures at endoscopy unit at El-Shatby Maternity University Hospital, after approval of ethical committee of Alexandria Faculty of Medicine.

Randomization will be through opaque sealed envelopes.

After signing their informed consents, the patients who are included in the study will be divided into two groups each group include (60) patients.

Group A: Patients that will receive intraoperative instillation of bupivacaine. Group B: (Control group) that will not receive the medication.

The patients in both groups will be subjected to:

Pre-operative:

History taking (gynecological, obstetric, medical any drug reaction and surgical), general examination and abdominal examination.

Intra-operative:

premedication : 1.5 microgram/kg fentanyl IV induction of anathesia: 2mg/kg Propofol IV , 0.5 mg/kg Atracurium IV , ventilation via face mask 2-3 minutes , then endotracheal intubation

1gm paracetamol IV as intraoperative analgesia which will not interfere with postoperative pain scoring.

Group (A) only will receive intra-peritoneal 40 ml bupivacaine 0.2%, after laparoscopic procedure before removing trocars.

Eligibility Criteria:
Inclusion Criteria:

1. Patients those are indicated for surgical laparoscopy, whatever the gynecological problem.
2. Age between (18-50) years.
3. Cooperative patient that can express pain and score it.

Exclusion Criteria:

1. Non-cooperative patients that cannot express and score pain.
2. Drug abusers due to altered pain threshold.
3. Surgical laparoscopy indicated for oncological procedures.
4. Any allergy or reaction to any of the derivatives of bupivacaine drug group.
5. Any cardio-pulmonary condition.