Perioperative Epidural Versus Intravenous Local Anesthetic Infusion in Open Upper Abdominal Surgery

The study evaluates the efficacy of intravenous lidocaine as an analgesic modality in patients undergoing open upper abdominal surgery; when compared with thoracic epidural analgesia. Half of participants will receive intravenous lidocaine infusion, while the other half will receive thoracic epidural bupivacaine infusion.

Postoperative pain is one of the commonest problems encountered by anaesthesiologists, especially after open abdominal surgeries, in which post-operative pain would cause a restrictive respiratory dysfunction, which is associated with poor postoperative outcomes. Despite the fact that epidural blocks provide superior analgesia; it is not often an ideal option as it frequently causes hypotension that may require excessive intravenous fluid administration, which is particularly deleterious after bowel surgery. Other complications include epidural hematoma and higher failure rate. Furthermore epidural analgesia may be contraindicated in some patients e.g. patients on certain anti-platelet therapy and patients refusing the technique. Other modalities to control postoperative pain are used e.g. intravenous analgesics and continuous wound infiltration, but none of which was proven to be as effective as epidural block. Whether perioperative lidocaine infusion is as effective as epidural block in reducing post-operative pain, is this study's concern. Some researches studied the efficacy of lidocaine infusion in controlling neuropathic as well as acute postoperative pain with encouraging results. Lidocaine infusion was found to reduce postoperative pain, opioid consumption and the length of hospital stay. Although risks of neurological and cardiac toxicity exist, these were not substantiated in the trials. Lidocaine has been described to have both analgesic, and anti-hyperalgesic effects6, as well as anti-inflammatory properties. It also accelerates the return of post-operative gastrointestinal function, which is of particular importance after major abdominal surgery. Opposite to opioids, which increase the incidence of nausea and vomiting, lidocaine decreases their incidence.

Epidural catheters will be placed in the 9th or 10th thoracic intervertebral space prior to induction of anesthesia.Through the thoracic epidural catheter 0.125% bupivacaine at a rate of 5 mL/h will be infused. The infusion continues for 24h

Intravenous lidocaine infusion will typically start in the operating room prior to induction of anesthesia at a rate of 2 to 3 mg/min. Postoperatively, the rate will be decreased to 0.5 to 1 mg/min. The infusion continues for 24h

Verbal Numeric Rating Score is an 11-point scoring system used to assesses the postoperative pain level of the participants

Inclusion Criteria: Patients undergoing open upper abdominal surgery Exclusion Criteria: Bleeding diathesis History of allergy to local anesthetics Pregnancy/ lactation Cardiovascular disease Respiratory disease