Monitoring During Anesthesia

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

Instruments commonly used for monitoring during anesthesia include:

• An inflatable Reference blood pressure cuff Opens New Window Reference Opens New Window. This is usually strapped around your upper arm.
• A Reference pulse oximeter Opens New Window, a small instrument that is attached to your finger, toe, or earlobe to measure the level of oxygen in your blood.
• An Reference electrocardiogram Opens New Window (EKG, ECG) to monitor your heart activity. Small wires (leads) are 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 Reference esophagus Opens New Window 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 Reference urinary catheter Opens New Window. This is a small, flexible tube inserted into the bladder to collect urine.
• Catheters that are inserted into certain arteries or veins. These can accurately measure blood pressure or measure heart or lung function. These larger catheters also are sometimes needed to deliver medicines or blood transfusions.
• A Reference transesophageal echocardiograph Opens New Window. This instrument 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.

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