Efficacy of Adding Dexmedetomidine Versus Ibuprofen as an Adjuvant to Intraperitoneal Bupivacaine for Pain Control After Laparoscopic Gynecological Procedures

The patients will be randomly allocated by simple randomization using a computer program into two equal groups by closed envelope technique:

Group 1: Bupivacaine/Ibuprofen group (BI): Patients will receive 50ml bupivacaine 0.25% (125 mg) + 400 mg Ibuprofen diluted in 100 ml normal saline.

Group 2: Bupivacaine/Dexmedetomidine group (BD): Patients will receive 20 ml bupivacaine 0.25% (125 mg) + 1 µq/kg dexmedetomidine diluted in 100 ml normal saline.

Group 3: Control group/Bupivacaine group (B): Patients will receive 50 ml Bupivacaine 0.25% (125mg) diluted in 100 ml normal saline.

All the previous drugs will be injected intraperitoneally through trocars at the end of the surgery.

All patients will be assessed preoperatively by careful history taking, full physical examination, laboratory evaluation, and other appropriate investigations.

At the preoperative visit, all patients will be instructed on how to evaluate their pain by using the visual analog scale (VAS) (range from 0-10., 0 =no pain, 10 = worst pain).

• Intraoperative settings:

All patients will receive a standardized general anesthetic. Intravenous induction will be achieved with propofol, fentanyl (up to 2 µg/kg), rocuronium 0.6 mg/kg, and ondansetron 4 mg. All patients will be intubated with an endotracheal tube and mechanically ventilated to maintain normocarbia. Anesthesia will be maintained with 50% oxygen/ air mixture and isoflurane, intravenous fentanyl boluses (up to 3 µg/kg), rocuronium to maintain muscle relaxation and intravenous fluids administered as Ringer's lactate (minimum of 20 mL/kg) at the discretion of the attending anesthesiologist. All incision sites were infiltrated with 0.25% bupivacaine, and CO2 insufflation pressure was limited to a maximum of 15 mmHg.

At the end of the procedure injections will be given by the surgeon through trocars intraperitoneally, then isoflurane will be discontinued and, the neuromuscular blockade will be antagonized by using neostigmine 0.05mg/kg plus atropine 0.01 mg/kg after assessment by nerve stimulator according to the train of four and will be administered to reverse the effect of rocuronium. then the trachea will be extubated, all patients will be transferred to the post-anesthesia unit (PACU). After completion of the surgical procedure, patients will be transferred to the post-anesthetic care unit (PACU), and the Modified Aldrete Score will be assessed and discharged after fulfilling an Aldrete score of ≥9.

To achieve blinding, the study drugs will be prepared in a ready-to-inject form by a separate anesthesiologist who is not involved in the study. This way, neither the patient nor the anesthesiologist administering the drug will be aware of the type of medication being used. The physician who will gather patient data is also unaware of the medications administered. During the first 24 hours After surgery, all patients will receive post-operative pain protocol (1 gm paracetamol IV every 8 hr.).

Pethidine 0.5 mg/kg diluted in 5 ml, titrated IV as rescue analgesia if VAS is greater than 3, or at any time the patient demands additional analgesia.

In the presence of nausea, with or without vomiting, granisetron 1 mg will be given intravenously and repeated if nausea persists (maximum dose of 3 mg per day).

Complications including postoperative nausea, vomiting, and other complications related to the drug used (e.g., toxicity,) will be recorded up to 24 hours after surgery.

The intensity of postoperative abdominal and shoulder pain will be measured on arrival in the recovery room and subsequently at time intervals of 2, 4, 6, 12, and 24 h using a 10-cm linear visual analog scale (VAS). The scale consisted of a horizontal line marked ''no pain' at one end and ''worst pain' at the other. Abdominal pain scores were measured at rest (supine), with activity (sitting up from supine), and with coughing. The time interval from extubation to the first administration of nalbuphine will be registered. The consumption of postoperative analgesics was recorded. Side effects (nausea, vomiting, sweating, dizziness, tinnitus, muscular twitches, and circumoral numbness), and recovery variables (return of bowel function, time interval to ambulation, resumption of liquid intake, and hospital discharge) will be assessed by the ward nurses at 2-h intervals. Patients were immediately given 1 mg intravenous granisetron and repeated if nausea persisted (maximum dose of 3 mg per day).

if they experience nausea or vomiting. Patients will be deemed ready for discharge from the hospital when they are afebrile, vital signs are stable, oral nutrition (liquid) was tolerated without discomfort, and bowel function has returned. Bowel recovery time was defined as the time from the end of anesthesia until the presence of good intestinal sound (estimated by the same surgeon) or the first passage of flatus.

Outcome measures:

• Primary outcome: > Post-operative pain severity by VAS (at 0 (the point of full recovery state at PACU), 6 hr., 12 hr., 18 hr., and 24 hr.) will be assessed.
• Secondary outcomes:
• Cumulative postoperative opioid consumption (total amount of opioid consumption) in the first 24 hours postoperatively.
• The onset of the first analgesic request. (Time of rescue analgesia).
• Patient satisfaction after 1st postoperative day (four-point scale (1 =excellent, 2= good, 3= fair,4= poor)).
• Incidence of postoperative nausea and vomiting.
• Incidence of complications (LA toxicity,).
• The hemodynamics of the patients (mean ABP, HR) will be measured at 0 hr., 6 hr., 12 hr., 18 hr., and 24 hr. after surgery.