The Pre-Anesthetic Blood Tests involve a group of tests that give us a broad view of what is going on in the pet at the time the blood is taken. In combination with the physical examination, we can assess the patient's anesthetic risk and make modifications in the anesthetic plan if needed. In other cases, potentially life threatening conditions can be detected that must be addressed before anesthesia can be safely induced.
Complete Blood Count
Called the "CBC" this allows for an evaluation of the three cell populations in the blood--- the red blood cells (RBCs), the white blood cells (WBCs), and the platelets. The RBCs are responsible for getting oxygen to the tissues of the body. Deficiencies or "anemia" can slow the healing process. The WBCs play a major role in the body's defense system, fighting off infections. Abnormalities can indicate an infection or an increased susceptibility to infection post-operatively. Lower than normal platelet counts generally mean a slower than normal clot time. In surgeries, this is simply critical.
Alanine Aninotransferase (ALT)
The "ALT" is an enzyme found in liver cells. Elevations indicate liver cell damage. Many of the anesthetics used in veterinary medicine must leave the body after being broken down by the liver cells. If enough of the liver cells are damaged, anesthetic risk increases.
Blood Urea Nitrogen (BUN) and Creatinine
"BUN" is produced in the liver and is removed from the body by the kidneys. Lower than normal levels are seen in some liver diseases while high levels are features of dehydration or kidney disease. Chemicals that are produced by the breakdown of the anesthetics may also require this pathway to get out of the body. Creatinine also is a kidney test. Elevations can increase anesthetic and surgery risk for the patient.
High blood glucose values are seen in diabetes or, especially in cats coming to the veterinary clinic, stress. As the primary energy substance in the blood, low levels effect healing and anesthetic recovery.