Monitoring instruments for anesthesia

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Monitoring instruments for anesthesia

People receiving anesthesia must be carefully monitored because the medications used for anesthesia affect the central nervous system, cardiovascular system, and respiratory system (airway and lungs). Anesthesia suppresses many of the body’s normal automatic functions and may significantly affect your breathing, heartbeat, blood pressure, and other body functions.

Instruments commonly used for monitoring during anesthesia include:

• An inflatable blood pressure cuff. This is usually strapped around your upper arm.
• A pulse oximeter, a small instrument that is attached to your finger, toe, or earlobe to measure the level of oxygen in your bloodstream.
• An electrocardiogram (EKG, ECG) to monitor your heart activity, which uses a set of small wires (leads) placed on the skin of your chest and held in place by small adhesive patches.
• A temperature probe. A monitor connected to your skin by a lead held in place by a small round adhesive patch may be used to measure skin temperature. A thermometer that is attached to a small tube inserted through the mouth into the esophagus after you are asleep may be used to measure internal body temperature.
• An oxygen analyzer and carbon dioxide analyzer on the anesthesia machine. These instruments measure the amount of oxygen and carbon dioxide gases inhaled and exhaled in your breath.

Other monitoring instruments may also be used, depending on your condition, the type of surgical procedure you are having, and the type of anesthesia used. These may be invasive monitors that need to be placed inside the body, including:

• A urinary catheter, a small, flexible tube inserted into the bladder to collect urine.
• Catheters that are inserted into certain arteries or veins to accurately measure blood pressure or to measure heart or lung function. These larger catheters also are sometimes needed to deliver medications or blood transfusions.
• A transesophageal echocardiograph, an instrument that is inserted through the mouth and down the throat into the esophagus to monitor the heart.

Some of these monitors may be put in place only after you have been brought to the surgery room or after you have been given general anesthesia.

Credits

Last updated:	February 04, 2008
Author:	Caroline Rea, RN, BS, MS
Reviewed By:	E. Gregory Thompson, MD - Internal Medicine, John M. Freedman, MD - Anesthesiology
Editors:	Maria G. Essig, MS, ELS, Pat Truman, MATC