Background
Dexamethasone has anti-inflammatory properties that can affect postoperative analgesia when added to caudal bupivacaine.
Methods
Seventy-two geriatric patients scheduled for elective total hip replacement under ultrasound guided caudal anesthesia were randomized blindly into two groups: Group BD received caudal isobaric bupivacaine 0.25% (20 ml) and dexamethasone 8 mg (2 ml) and Group BS received caudal isobaric bupivacaine 0.25% (20 ml) and normal saline (2 ml). Postoperative analgesia was assessed by recording time to first rescue analgesia and the analgesic doses (paracetamol and meperidine hydrochloride) required during the first 24 h postoperatively as a primary outcome. Secondary outcomes were the time taken to the onset of sensory analgesia at T10, time to the onset of complete motor block, VAS pain score at rest and on movement at 1, 2, 4, 6, 8, 12 and 24 h, and postoperative adverse events.
Results
Group BD had a significantly longer time to first rescue analgesia [402 (63) vs 213 (53)] min and significantly lower doses of paracetamol [3389 (728) vs 2833 (697)] mg meperidine hydrochloride [78 (30) vs 142 (28)] mg than Group BS. VAS scores were significantly lower in Group BD than Group BS both at rest and on movement respectively at 4, 6, 8, 12 and 24 h.
Conclusion
Adding dexamethasone with isobaric bupivacaine caudal anesthesia prolongs the duration of postoperative analgesia and decreased postoperative analgesic requirement in geriatric patients undergoing total hip replacement surgery in comparison isobaric bupivacaine alone.