To administer a general anesthetic is to render a patient completely unconscious in order to perform surgery or examinations which require the patient to be totally immobilized.
Significant advances in medicine and technology have reduced the risk for your pet receiving a general anesthetic. While there is always a risk involved, screening for underlying blood and organ disorders, improved monitoring equipment, and shorter-acting induction and maintenance drugs have all improved the safety of anesthesia.
The first way the veterinarian minimizes the potential for injury to the patient is by determining whether there are any health problems that may complicate anesthesia. Abnormal findings on a general physical exam, temperature, and heart rate can reveal illness. Blood is drawn, and a chemistry panel is performed to check for anemia, liver and kidney dysfunction, and electrolyte imbalance. Blood pressure and electrocardiogram (ECG) are assessed before induction of anesthesia to detect abnormalities.
Anesthetic agents cause a drop in blood pressure which can reduce tissue-oxygen perfusion. Intravenous fluids are administered through a catheter to maintain blood pressure and prevent damage to the kidneys and other organs. In the case of an emergency, life saving drugs can be administered through the IV catheter.
An endotracheal tube is passed through the mouth into the wind pipe to provide an airway and connect the patient to a gas anesthetic machine. In general, gas anesthetics like Isoflurane and Sevoflurane are safer than injectable anesthetics. Only a small percentage of the gas is metabolized by the liver, making recovery time very rapid. Injectable drugs take the body longer to eliminate, except in the case of reversible anesthetics like medetomidine.
Monitoring devices have greatly improved the safety of anesthesia as well. Pulse oximetry and end tidal CO2monitors verify adequate ventilation of the patient. ECG detects heart arrhythmias that can signal serious trouble during surgery. Blood pressure measurements ensure adequate tissue perfusion. And, trained technicians constantly monitor vital signs and report to the surgeon any unexpected changes.
The specific anesthetic protocol is at the discretion of the veterinarian. They are very well equipped to keep your pet healthy and safe during anesthesia. While anesthetic complications do occur, they are becoming rarer since the health of the patient is first assessed, safer drugs are available, and careful monitoring of vital signs using better technology is possible.