Obstetric pain relief using epidural narcotic agents

perhaps it has not been sufficiently emphasised that this treatment should probably be reserved for short-lasting pain, due to the rapid exhaustion of its efficacy after repeated doses. We have experimented with this method since 1977 just after Wang’s Communication in Paris5, and we have applied it intrathecally, in the treatment of myocardial infarction pain, because of its characteristics of brief duration and often high intensity of the pain. The absence of circulatory and respfratory effects of intrathecal morphine at the low doses used ‘(0.5 mg in our patientstalready demonstrated in animals6-seemed to us to be another favourable factor this type of patient. Our initial study was conducted on 19 subjects divided into two groups (A, intrathecal morphine, and B, control (morphine and/or pentazocine either intramuscular or intravenous). The results demonstrated the greater efficacy, in 24 hours, of a singleintrathecal dose of 0.5 mg ofmorphine with respect to a repeated analgesic dose 40 times greater of the same drug and/or pentazocine administered either intramuscularly or intravenously. There were no circulatory or respiratory side-effects. Statistical evaluation was carried out, and the difference between the degree of average analgesia obtained in the two groupes was significant. The only side-effect we observed was a tendency toward urine retention. This study was reported at the International Symposium on Pain, held in Sorrento (June 11-15, 1979) and, in addition to being published in the Abstracts of that Symposium, it has recently been cited in Mineria Anesta.’ Serrizio di Anestesia e Rianimazione, V. PASQUALUCCJ Ospedale Regionale, Perugia,