The effect of posture on cerebral oxygenation during abdominal surgery

Anaesthesia. 2001 Dec;56(12):1181-4. doi: 10.1046/j.1365-2044.2001.02084.x.


Performing surgery with a patient in the head-down position for several hours may cause marked facial and conjunctival oedema. It is not known whether oedema might also be occurring within the cranial cavity. This study, using near-infrared regional cerebral oximetry, was performed to see if there was any evidence of cerebral anoxia during operations performed with patients in the head-down position compared with those performed on patients who were flat. Patients managed in the head-down position did not demonstrate any reduction in regional cerebral oxygenation, but those who were managed flat did. An explanation of these paradoxical findings is elusive.

MeSH terms

  • Abdominal Neoplasms / surgery*
  • Adult
  • Aged
  • Aged, 80 and over
  • Cerebrovascular Circulation / physiology*
  • Female
  • Head-Down Tilt / physiology
  • Humans
  • Intraoperative Care / methods
  • Male
  • Middle Aged
  • Oximetry / methods
  • Oxygen / blood
  • Oxygen Consumption / physiology*
  • Posture / physiology*
  • Spectroscopy, Near-Infrared


  • Oxygen