Nonsteroidal antiinflammatory drugs (NSAIDs) are commonly combined with intravenous morphine patient-controlled analgesia to relieve postoperative pain. NSAIDs have a documented 30-50% sparing effect on morphine consumption. However, most of the studies have not demonstrated a decrease in morphine adverse effects. A meta-analysis of randomized controlled trials was performed to evaluate the risk of morphine adverse effects in patients treated with NSAIDs. Twenty-two prospective, randomized, double-blind studies including 2,307 patients were selected. NSAIDs decreased significantly postoperative nausea and vomiting by 30%, nausea alone by 12%, vomiting alone by 32% and sedation by 29%. A regression analysis yielded findings indicating that morphine consumption was positively correlated with the incidence of nausea and vomiting. Pruritus, urinary retention, and respiratory depression were not significantly decreased by NSAIDs.

Performing an ultrasound-guided perineural circumferential hydrodissection with D5W into which LA is injected leaves nerve block outcome unchanged. The assumption that this procedure may reduce the risk of intravascular injection and systemic toxicity remains to be demonstrated.

No abstract