Oxyhaemoglobin saturation following elective abdominal surgery in patients receiving continuous intravenous infusion or intramuscular morphine analgesia

Anaesthesia. 1992 Mar;47(3):256-60. doi: 10.1111/j.1365-2044.1992.tb02131.x.


Oxygen saturation was continuously measured using computerised pulse oximetry for 8 h overnight pre-operatively and for the first 24 h postoperatively in 40 patients receiving intermittent intramuscular morphine or continuous infusion of morphine following elective upper abdominal surgery. The proportion of time with an oxygen saturation less than 94% was used as an index of desaturation. Patients receiving continuous infusion analgesia received a larger morphine dose and achieved better analgesia than the intramuscular group. Postoperatively, the duration of desaturation increased 10-fold over pre-operative values, 'intramuscular' patients spending 39.0% (SD, 37.0%) and 'continuous infusion' patients 40.0% (SD, 37.5%) of the time below 94% saturation. Although newer therapies (e.g. epidural analgesia and patient-controlled analgesia) are currently receiving greater attention, the sequelae of these more traditional analgesic techniques warrant further study.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abdomen / surgery*
  • Adolescent
  • Adult
  • Aged
  • Humans
  • Infusions, Intravenous
  • Injections, Intramuscular
  • Middle Aged
  • Monitoring, Physiologic
  • Morphine / therapeutic use*
  • Oximetry
  • Oxyhemoglobins / analysis*
  • Pain Measurement
  • Pain, Postoperative / blood
  • Pain, Postoperative / drug therapy*
  • Time Factors


  • Oxyhemoglobins
  • Morphine