THE EFFECT OF PREOPERATIVE MEDICATION WITH MORPHINE ON POSTOPERATIVE ANALGESIA WITH MORPHINE

¹ Anesthesia Laboratory, Harvard Medical School, Massachusetts General Hospital, Boston

Morphine, 10 mgm. per 70 kgm. body weight, given twice before surgery and normal saline given in the same way do not affect the analgesic potency of 10 mgm. morphine per 70 kgm. of body weight given postoperatively every 2 hours when necessary for moderate or severe wound pain.

The premedication does affect the time of onset of pain sufficient to require a narcotic after the operation. After the preoperative morphine medication patients request medication for postoperative pain significantly later after the end of operation than patients medicated with placebo preoperatively. (Reasons why heavy preoperative medication is objectionable are presented in the text.)

Morphine, 10 mgm. per 70 kgm. of body weight, is a more effective and longer lasting analgesic when given against moderate than against severe pain. Its duration of action in severe pain is approximately 4.6 hours, in moderate pain it is 5.4 hours. The incidence of severe pain is greater early than late postoperatively. Differentiation between severe and moderate pain has been shown to be possible by a given patient. This differentiation is useful for the appraisal of analgesic agents, and is of particular importance in the evaluation of analgesics when the subject material has pain of changing intensity.

This article has been cited by other articles:

				S. G. MACRIS, J. S. GRAVENSTEIN, C. W. REICHLE, and H. K. BEECHER Drug Synergism (Potentiation) in Pain Relief in Man: Papaverine and Morphine Science, July 11, 1958; 128(3315): 84 - 85. [PDF]