Variables of patient-controlled analgesia. 1. Bolus size

Anaesthesia. 1989 Jan;44(1):7-10. doi: 10.1111/j.1365-2044.1989.tb11087.x.


The efficacy of a range of demand doses of morphine for patient-controlled analgesia was studied. Patients who self-administered the smallest dose (0.5 mg) were frequently unable to achieve good pain control; patients who received the largest dose (2 mg) had a high incidence of ventilatory depression. A dose of 1 mg was the best increment under the conditions of this study but the relationship between increment and lockout interval requires consideration.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abdomen / surgery
  • Adult
  • Aged
  • Evaluation Studies as Topic
  • Female
  • Humans
  • Male
  • Middle Aged
  • Morphine / administration & dosage*
  • Morphine / adverse effects
  • Morphine / therapeutic use
  • Pain, Postoperative / drug therapy*
  • Random Allocation
  • Self Administration


  • Morphine