Skip to Main Content


  • Image not available.During catheterization of the internal jugular vein the possibility of placement of a vein dilator or central venous catheter into the carotid artery can be decreased by transducing the intravascular pressure waveform or by comparing the blood’s color or Pao2 with an arterial sample.
  • Image not available.The central venous pressure (CVP) catheter’s tip should not be allowed to migrate into the heart chambers.
  • Image not available.Relative contraindications to pulmonary artery catheterization include complete left bundle branch block (because of the risk of complete heart block), Wolff–Parkinson–White syndrome, and Ebstein’s malformation (because of possible tachyarrhythmias).
  • Image not available.Pulmonary artery pressure should be continuously monitored to detect an overwedged position indicative of catheter migration.
  • Image not available.Accurate measurements of cardiac output depend on rapid and smooth injection, precisely known injectant temperature and volume, correct entry of the calibration factors for the specific type of pulmonary artery catheter into the cardiac output computer, and avoidance of measurements during electrocautery.
  • Image not available.Capnography rapidly and reliably indicates esophageal intubation—a common cause of anesthetic catastrophe—but does not detect bronchial intubation.
  • Image not available.The electroencephalographic (EEG) changes that accompany ischemia, such as high-frequency activity, can be mimicked by hypothermia, anesthetic agents, electrolyte disturbances, and marked hypocapnia. Detection of changes in the EEG in an anesthetized patient should lead to an immediate review of possible causes of cerebral ischemia before irreversible brain damage has a chance to occur.
  • Image not available.Because hypothermia reduces metabolic oxygen requirements, it has proved to be protective during times of cerebral or cardiac ischemia.
  • Image not available.Redistribution of heat from warm central compartments (eg, abdomen, thorax) to cooler peripheral tissues (eg, arms, legs) from anesthetic-induced vasodilation explains most of the initial decrease in temperature, with actual heat loss being a minor contributor.
  • Image not available.During general anesthesia, however, the body cannot compensate for hypothermia because anesthetics inhibit central thermoregulation by interfering with hypothalamic function.


One of the primary responsibilities of an anesthesiologist is to act as a guardian of the anesthetized patient during surgery. In fact, “vigilance” is the motto of the American Society of Anesthesiologists (ASA). Because monitoring is helpful in maintaining effective vigilance, standards for intraoperative monitoring have been adopted by the ASA (the box on Standards for Basic Anesthetic Monitoring delineates minimum standards). Optimal vigilance requires an understanding of the technology of sophisticated monitoring equipment—including cost–benefit considerations. This chapter reviews the indications, contraindications, techniques and devices and associated complications, and other clinical considerations for the most important and widely used anesthetic monitors.


(Approved by the ASA House of Delegates on October 21, 1986 and last affirmed on October 15, 2003)


These standards apply to all anesthesia care although, in emergency circumstances, appropriate life support measures take precedence. These standards may be exceeded at any time based on the judgment of the responsible anesthesiologist. They are intended to encourage quality patient care, but observing them cannot guarantee any specific patient outcome. They are subject to revision from time to time, as warranted by the evolution of technology and practice. They apply to all general ...

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.


About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessAnesthesiology Full Site: One-Year Subscription

Connect to the full suite of AccessAnesthesiology content and resources including procedural videos, interactive self-assessment, real-life cases, 20+ textbooks, and more

$995 USD
Buy Now

Pay Per View: Timed Access to all of AccessAnesthesiology

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.