Variations in the effect of epidural morphine in gynecological and obstetric patients

A prospective study was performed on the effect of epidural morphine (2 mg in 10 ml of saline) in three groups of patients: (1) following gynecological operations, 60; (2) following cesarean section, 120; (3) patients in active labor, 30. Pain relief in the first group was uniformly and almost invariably complete for up to 24 hours. In the second group spasmodic visceral pain was felt after about 10 hours, relieved by light analgesics. The wound was not painful. In the third group only hypoalgesia was obtained during labor, but if an episiotomy was done, the pain in the perineum was relieved. Few side effects were observed: urinary retention, vomiting, and non-segmental itching. Neither motor nor sympathetic block were noted. The somatic effect of epidural morphine was reliable and uniform, whereas visceral pain was poorly affected. The side effects cause relatively little disturbance at the dose used.