The overall goal of anesthesia is survival and optimum recovery from surgery. In order to accomplish this goal, the surgery patient must be continually monitored for changes, especially deterioration in respiration, cardiac function and tissue perfusion regardless of the specific surgery. Cardiovascular (ECG, blood pressure) and respiratory (pulse oximetry, capnography) monitoring are employed to detect patient changes and to direct corrective actions. Technicians who monitor patients during anesthesia are expected to have the mechanical ability to understand and operate these monitoring systems, the creativity to adapt a single piece of equipment to serve both a 3 pound Chihuahua and a 200 pound mastiff, and the knowledge to interpret and respond to results as swiftly as they are collected.

In addition to expensive monitoring equipment, the technician should be well equipped to use his/her senses to detect other indicators of good anesthetic health

     • Mucous membrane color and capillary refill time
     • Urine output
     • Heart rate and pulse equality
     • Respiratory rate and effort

The ECG is an important monitoring tool for the surgery patient, not just for the conduction abnormalities it detects, but for changes in heart rate which can be indicative of serious events [such as the bradycardia (slow heart rate) which often precedes cardiac arrest]. Coupled with other monitoring devices, the changes in heart rate may give vital diagnostic information. For example, when tachycardia (rapid heart rate) occurs concurrently with hypotension (decreased blood pressure) the patient may be suffering from hypovolemia (lack of sufficient circulating fluids) while patients with tachycardia occurring concurrently with hypertension (increased blood pressure) may be experiencing extreme pain. Auscultation of heart rate and simultaneous palpation of peripheral pulses yields more information that either alone. Pulse quality, and synchronicity with heart rate are major indicators of perfusion.

Arterial blood pressure physiology and measurement

Since most post operative complications are directly related to hypotension during or after surgery, blood pressure is considered a vital sign to monitor throughout all surgical procedures. Considering how many factors predispose the patient to hypotension, some premedicants, gas inhalants, presurgical fasting and loss of body fluids, the chances are great that the technician will have to respond appropriately at some point during the anesthetic period