April 1997

Evaluation of morphine versus fentanyl for postoperative analgesia after ambulatory surgical procedures.

Claxton AR, McGuire G, Chung F, Cruise C;

Anesth Analg 1997; 84:509-514.

[ see abstract below ]

Claxton et al examined the postoperative side effects and adequacy of pain management in adult patients undergoing outpatient surgical procedures. Fifty-eight adults were randomly assigned to receive either morphine or fentanyl in equipotent doses in a double-blind, randomized fashion. Opioid doses were titrated in the postanesthesia care unit (PACU) to visual analog scores of < 40mm and patient satisfaction.

In the ambulatory surgical unit, oral pain medication was available. Pain scores, amount of analgesia used, the incidence of side effects (nausea and vomiting, sedation, and dizziness), the times to achieve recovery milestones, and fitness for discharge were studied. Equal amounts of morphine and fentanyl were used in the PACU, however, pain scores were higher in the group which received fentanyl. This group also required more analgesic treatment when compared to the morphine treated patients (59% vs. 17% - p < 0.0002). The morphine treated patients did have a higher in cidence of nausea and vomiting (59% vs. 24% - p < 0.016).

There was no difference between treatment groups regarding duration of surgery, types of surgical procedures, duration of stay in the PACU, or time to meet discharge criteria. The authors conclude that: "Morphine produced a better quality of analgesia but was associated with an increased incidence of nausea and vomiting, the majority of which occurred after discharge."

Although this paper concerns adult patients, it confirms my bias in the treatment of children. I have often witnessed the use of fentanyl to treat pain in the PACU which may result in rapid treatment of the pain but that treatment is short lived. The patient may soon meet discharge criteria, but shortly thereafter the child is in pain and usually at this point they are on their way home or have been transferred back to the floor where pain treatment is likely to be less than timely.

I have never understood the logic of using a short acting opioid to treat long acting pain! I am astonished when residents tell me that they have no experience in using morphine! This paper confirms for me the importance of using long acting opioids and, if needed, add to that the use of an antiemetic. Unfortunately once again this touches the topic mentioned above: the cost of the long acting but effective antiemetics. At some point society will have to help us decide what they wish and where we should be investing our health care dollars.

I would hope that we vote to treat pain, prevent nausea and vomiting, and in so doing improve the quality of our care and find other ways of saving money.

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ABSTRACT