Pre-op Patient - Lab Tests

What determines which preanesthetic diagnostic tests are performed?

The patient’s history and PE findings

What diagnostic tests may be performed before anesthesia?

CBC, chemistry, electrolytes, TT4, and clotting panels

What values are included in the minimum database?

PCV, plasma color, TS, glucose, BUN, and ALT

What should be done if preanesthetic lab results are abnormal or invalid?

Notify the vet before proceeding with anesthesia

What does PCV measure?

The percentage of whole blood occupied by RBCs

What is another name for PCV?

Hematocrit (HCT)

What is the normal canine PCV range?

37-54%

What is the normal feline PCV range?

27-48%

What can a decreased PCV indicate?

Chronic renal failure, autoimmune disease, clotting disorders, or trauma

What can an increased PCV indicate?

Dehydration or rarely absolutely polycythemia

What does total solids (TS) evaluate?

Plasma protein levels

What are the three major plasma proteins?

Albumin, globulin, and fibrinogen

What is oncotic pressure?

The pulling force exerted by plasma proteins, especially albumin

What happens when total protein decreases?

Oncotic pressure decreases, potentially causing edema

Why is low total protein concerning during anesthesia?

More unbound anesthetic may be available in the bloodstream, increasing drug effects

What is the normal canine total protein range?

5.4-7.5 g/dL

What is the normal feline total protein range?

5.7-7.6 g/dL

What can increased total protein indicate?

Dehydration, cancer, or infection

What does blood glucose evaluate?

Carbohydrate metabolism and endocrine function

What is the normal canine blood glucose range?

76-120 mg/dL

What is the normal feline blood glucose range?

58-120 mg/dL

What blood glucose level indicates severe hypoglycemia?

Below 40 mg/dL

What does BUN stand for?

Blood urea nitrogen

What does BUN evaluate?

The kidneys’ ability to remove urea from the blood

What produces the urea measured by BUN?

Amino acid breakdown

Why is BUN important before anesthesia?

Kidney function can affect the elimination of certain anesthetic drugs

Why should BUN never be evlauated alone?

It must be interpreted with creatinine and urine specific gravity (USG)

What is the normal canine BUN range?

9-27 mg/dL

What is the normal feline BUN range?

18-34 mg/dL

What does ALT stand for?

Alanine aminotransferase

What does elevated ALT indicate?

Damage to hepatocytes (liver cells)

What medications can increase ALT?

Anticonvulsants and corticosteroids

What is the normal canine ALT range?

8.2-109 U/L

What is the normal feline ALT range?

25-97 U/L

A preoperative patient has an elevated PCV. What condition should you suspect?

Dehydration

A patient has decreased total protein and develops edema. What is the likely cause?

Decreased oncotic pressure

A patient has low total protein before anesthesia. What drug-related concern should you recognize?

Increased effects of highly protein-bound anesthetics

A patient has a glucose of 35 mg/dL. What abnormality is present?

Severe hypoglycemia

A patient has elevated BUN. What additional values should be evaluated?

Creatinine and urine specific gravity

A patient has elevated ALT. Which organ may have cellular damage?

Liver

A patient has elevated total protein. What are three possible causes?

Dehydration, infection, or cancer