Postoperative pain relief

Experimental work has shown that pre-emptive analgesia, i.e. administering opioids or performing neural blocks before injury, may prevent the development of central sensitization and secondary hyperalgesia after tissue damage. Several studies have examined this clinically attractive hypothesis. Although preoperative administration of morphine has been reported to reduce postoperative morphine requirements in many of the studies conducted so far’, wider evidence that pre-emptive analgesia significantly reduces analgesic requirements after surgery is unconvincing2. Nevertheless, for practical reasons the sight of a surgeon wielding a syringe of local anaesthetic, particularly at the beginning of surgery, is a welcome one to most anaesthetists.