Dexamethasone & Ketamine as Adjuvants to Bupivacaine for Incisional Infiltration in Pediatric Abdominal Operations

Wound infiltration with local anaesthetics is a simple, effective and inexpensive means of providing good analgesia for a variety of surgical procedures without any major side-effects.

Patients and Methods Type of Study:Randomized, controlled, double-blind study.

Study Setting: Ain Shams university hospitals.

Study Period: 3months after approval of the ethical committee.

Study Population:

Inclusion Criteria:

Children of both sexes aged 1-8 years, ASA I-II, undergoing moderate to major abdominal operations.

Exclusion Criteria:

History of diabetes, cardiac or neurological disease Hypersensitivity to any of the drugs used in the study Risk of wound complications ( as infected wound, history of wound dehiscence, hypo-albuminaemia) Multiple incision sites Operations scheduled as day-case

Sample size: using PASS program version 15, setting alpha error at 5%and power at 80%. Based on previous studies the needed sample is 50 cases per group (total 150 patients).

Sampling Method: simple random sampling Children will be randomized into three groups 50 patients each.

• Group I: Bupivacaine 0.25% 1ml/kg will be injected subcutaneously by the surgeon before wound closure.
• Group II: In addition to bupivacaine, ketamine 1mg/kg diluted in 10 ml normal saline will be injected subcutaneously by the surgeon before wound closure. Bupivacaine and ketamine will be administered using two separate syringes.
• Group III: In addition to bupivacaine, dexamethasone 0.2mg/kg diluted in 10 ml normal saline will be injected subcutaneously by the surgeon before wound closure. Bupivacaine and dexamethsone will be administered using two separate syringes.

Study Tools and Study Procedures:

In all groups, drugs will be prepared by the attending anesthesiologist and injected by the surgeon (both will be blinded to the procedure) Anesthetic technique In all children, anesthesia will be induced by sevoflurane or propofol 2mg/kg IV, fentanyl 2ug/kg, atracurium 0.5 mg/kg followed by endotracheal intubation and mechanical ventilation with pressure controlled mode. Anesthesia will be maintained with sevoflurane in oxygen. All children will be monitored using ECG, non invasive blood pressure cuff, pulse oximeter and temperature probe. Ringer acetate will be used as the replacement fluid. At conclusion of surgery, the trachea will be extubated after reversal of the muscle relaxant with neostigmine 0.05 mg/kg + atropine 0.02 mg/kg and the child transferred to the postanesthesia care unit.

Comparisons will be done between both groups as regards: time needed for first analgesic dose (primary outcome), The FLACC pain scale will be assesed over a 24hour period as follows: (table 1) in PACU, then 2 hourly for 12 hours then 4 hourly.),Total number of administrations of rescue analgesia in the first 24 hours postoperatively, incidence of wound complications over a 7 d period (secondary outcomes)

First analgesic dose:

If the FLACC scale was more than 3 either during intervals of FLACC recording or in between, intravenous paracetamol was provided at a dose of 15mg/kg then fixed around the clock every 6 hours.

Rescue analgesia If pain persisted or recurred rectal diclophenac 1mg/kg or ibuprophen in children in whom oral intake has been allowed.