Pain as a major cause of postoperative nausea.

The incidence of nausea in relation to pain was recorded in 104 patients after abdominal operations. Ten per cent of the patients had episodes of nausea not related to pain. One hundred and fourteen episodes of concomitant pain and nausea were recorded in 61 patients (58.6 per cent). The intravenous injection of morphine or ketobemidone relieved nausea as well as pain in 80 per cent of the episodes. Relief of pain with persistence of nausea was uncommon and if pain relief was inadequate nausea was unabated. Nausea was provoked by 3.4 per cent of the morphine injections, but all patients tolerated similar doses of morphine on other occasions without nausea. Nausea often accompanies pain in the early postoperative period and can be relieved concomitant with the pain by the intravenous use of opiates in adequate doses in a high proportion of cases.