Air embolism in the sitting position*

Effects of the Sitting Position on Blood Flow in the Internal Carotid Artery of Man During General Anesthesia

“…There was a transient rise in mean arterial pressure and internal carotid flow associated with painful stimuli (pinching) applied to the patient while in the sitting position. 5. The results of the study indicate that, prior to placing an anesthetized patient in a sitting position, there has already been a significant reduction in cerebral blood flow if hyperventilation anesthetic techniques are being employed.…”

Advantages of the Prone Position for Neurosurgical Procedures on the Upper Cervical Spine and Posterior Cranial Fossa in Children

“…It also facilitates venous return to the heart, reliev ing intracranial venous stagnation and thereby controlling venous pres sure and ooze brain swelling. But, many experienced surgeons and anes thetists are fully aware of the drawbacks of this sitting position [4,7,8,11,15,18,21,23,24]. Such pitfalls include the risks of venous air em bolism systemic hypotension and diminished cerebral blood flow, tem perature drift and the possibility for the patient to slide down the table during surgery.…”

Automatic Measurement of Blood Pressure without Arterial Puncture

“…Nevertheless, under reasonably favourable conditions, instruments such as the H1matonograph can give days or even weeks of regular measurements, with a degree of reproducibility which would be difficult and very laborious to attain using manual methods. The incidence of venous air embolism in patients having suboccipital craniectomies in the sitting position is variously quoted as 1-15% (Hunter 1962, Michenfelder et al 1966, Tisovec & Hamilton 1967. The diagnosis depends on the detection of changes in the cardiopulmonary system or of the murmur and alterations in heart sounds produced by the air bubbles.…”