Bloodwork/Tests Flashcards
Template Bleeding Time (TBT)
he TBT is a test that determines the functional ability of platelets to plug a minute wound. A buccal mucosal bleeding test is similar to template bleeding time.
What do APTT and PT test for?
he APTT and PT determine if there are deficiencies in the coagulation factors and do not assess platelet function.
Antithrombin activity
Antithrombin activity is sometimes measured when disseminated intravascular coagulation (DIC) is a concern, but is not used to evaluate platelet function.
What is a major cross match?
recipient serum with donor cells
What is a minor cross match?
donor serum; recipient cells
What is the typical CBC pattern for IMHA? Which breed is genetically predisposed?
This signalment is classic for IMHA, and cocker spaniels are the only known breed to be genetically predisposed to IMHA. The clinical signs are also typical for IMHA but the key to answering this question is the bloodwork. IMHA typically has a normocytic normochromic regenerative anemia and the classic findings seen are autoagglutination and spherocytes. The only abnormal finding commonly seen on a chemistry panel with this disease is a mild to moderate bilirubinemia due to red blood cell hemolysis. The treatment for IMHA is immunosuppressive therapy (prednisone and cyclosporine). A blood transfusion may be indicated if the PCV is very low (usually less than 20%) or if the patient is showing clinical signs for their anemia. Packed red blood cells would be indicated in this case over a whole blood transfusion because it would provide a higher number of red blood cells and maximize the PCV. Vincristine is a drug adminsitered in an emergency situation for immune-mediated thrombocytopenia to increase the function of functional platelets.
What enzyme do you test for to diagnose selenium deficiency?
The correct answer is glutathione peroxidase. Activity of this enzyme is very low in selenium deficient animals resulting in free radical damage.
The best diagnostic test to differentiate pituitary dependent hyperadrenocorticism from adrenal dependent hyperadrenocorticism in dogs is which of the following
The correct answer is high-dose dexamethasone suppression test. HDDST will suppress cortisol secretion in about 75% of PDH patients 3-6 hours post dexamethasone administration. Cortisol secretion does not become suppressed with dexamethasone administration with adrenal dependent hyperadrenocorticism. If cortisol secretion is suppressed with a HDDST, PDH is diagnosed. If cortisol is not suppressed, there is a 50-50 chance that the hyperadrenocorticism is due to PDH or an adrenal tumor.
LDDST will suppress cortisol secretion in approximately 65% of pituitary dependent hyperadrenocorticism patients. The urine cortisol:creatinine ratio measures the significance of urine cortisol concentration and may be increased with both PDH and ADH. Serum cortisol levels may be affected in many different situations such as stress; therefore they are an unreliable indicator of disease. An elevated serum cortisol level will not differentiate between PDH and ADH.
Which of these is considered a hepatic leakage enzyme in the dog?
The correct answer is aspartate aminotransferase (AST). The hepatic leakage enzymes are AST and ALT, meaning that damage to hepatocytes causes leakage of these enzymes and subsequent elevations of serum levels. ALP and GGT are hepatic enzymes induced by cholestasis. Bilirubin is a breakdown product of hemoglobin and is processed by the liver. Bile acids are products of the liver but are not enzymes.
What is the end-point of warfarin therapy in an animal with a pulmonary thromboembolism?
The correct answer is a PT time of 1.5 to 2 times normal. PT is the best of these indexes to monitor warfarin therapy since, at these doses (usually 0.1-0.2 mg/kg), PTT and ACT will be unchanged. An even better method is to use the international normalization ratio (INR), which is a fancy way of taking into account how different PT reactions are run. The goal is to get an INR of 2.0 to 3.0.
What would you expect to find on the bloodwork of a dog that is vomiting due to a gastric outflow obstruction?
The correct answer is hypochloremic metabolic alkalosis. Gastric outflow obstruction leads to emesis of material with a high concentration of gastric hydrochloric acid. As a result, there is loss of chloride and acid from the body. This leaves the animal with hypochloremia and metabolic alkalosis. Vomiting from other causes can sometimes lead to loss of duodenal fluid, which is usually rich in bicarbonate and can lead to acidosis.
This enzyme is the most liver specific in the cow, sheep, goat, and horse.
The correct answer is sorbitol dehydrogenase (SDH). AST can be found in muscle, liver and red blood cells. LDH is found in many places such as muscle, heart and liver. ALP is found in liver, intestine, kidney and bone.
What are the electrolyte abnormalities that should be expected in cases of uroabdomen?
Hyponatremia, hypochloremia, hyperphosphatemiaThere would also be azotemia (elevated urea nitrogen), and possibly hyperkalemia in the blood.
What profile would you expect in a dog with hypervitaminosis D
HIGH PH; HIGH CA
Excessive intake of vitamin D is associated with an increase in 25-hydroxyvitamin D3 levels. At high levels, 25-hydroxyvitamin D3 competes with 1,25-dihydroxyvitamin D3 for its receptors on the intestines and bone causing increased absorption of Ca and P from the intestinal tract and resorption of bone causing increased levels of circulating Ca and P. A common source of confusion is that this is in contrast to PTH which causes high Ca but generally causes unchanged or normal phosphorus because it also enhances renal phosphorus excretion.
What diseases are a high AG associated with?
grain overload, ethylene glycol, renal failure, DKA
