Last Updated: 2008-03-07 12:02:01 -0400 (Reuters Health)

NEW YORK (Reuters Health) – Nitrous oxide-oxygen mixture is superior to morphine for pain relief during the care of bedsores and painful ulcers in the elderly, results of a new study suggest.

"Care procedures for bedsores and ulcers often can be painful," Dr. Pierre Basset of Chambery Hospital Center, France, and colleagues write in the February issue of the Journal of Pain and Symptom Management. "The drugs currently used for analgesia often provide insufficient relief, and there is no standardized analgesic method for use during the care of adults and the elderly."

In an open-label study, the researchers compared the efficacy of nitrous oxide-oxygen mixture versus morphine during painful bedsore and ulcer care procedures in 34 inpatients between the ages of 53 and 96 years (median 84 years). Each patient received morphine (M), nitrous oxide-oxygen mixture (E), or morphine + nitrous oxide-oxygen mixture (ME) during lesion care in a crossover protocol. The treatments were changed every 2 days, for a study duration of 6 days.

The main endpoint was the level of pain, assessed with a behavioral scale to evaluate pain in non-communicating adults (ECPA). A significant overall difference was observed among the three groups (p < 0.01).

The average differences in the ECPA score after and before care were +5.2, -0.3, and -0.6 in the M, E, and ME groups, respectively. A significant difference was found between M and E (p < 0.01), and M and ME (p < 0.01).

"This pilot study demonstrates the superiority of nitrous oxide-oxygen mixture over morphine for analgesia," the team concludes.

Adverse event rates were similar with each treatment, and the events were mild and transient.

"It is important to note that the administration of nitrous oxide-oxygen mixture is not totally without danger," Dr. Basset’s team points out. "It must be done in an airy room … and in the presence of staff trained in emergency procedures."

Nonetheless, they say the procedure was easy to use and was well accepted by patients and nursing staff.

J Pain Symptom Manage 2008;35:171-176.

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