Blood work interpretation Flashcards
Why may haematocrit (HCT) or RBC be increased?
Artifact
Concentration - Dehydration (common), splenic contraction (horses commonly)
Absolute increase in RBC mass - Polycythaemia or inappropriate erythropoietin secretion
Why may haematocrit (HCT) or RBC be decreased?
Artifact
Concentration - IV fluid dilution or splenic relaxation (anaesthetics/tranquilizers)
Anaemia - Haemorrhage, haemolysis, decreased production
Why may haemoglobin be increased?
Artifacts
Iatrogenic - Oxyglobin therapy
Concentration - Dehydration, splenic contraction
Anaemia
Why may haemoglobin be decreased?
Concentration - Iv fluid dilution, splenic relaxation
Anaemia
Why may mean cell volume (MCV) increase?
Artifact
Breed - Greyhounds, Miniature and Toy Poodles
Regenerative anaemia
Folate and Vitamin B12 deficiency
Hyperthyroidism (in some cats)
Why may mean cell volume (MCV) decrease
Artifact - excess EDTA, hyponatremia
Age - young
Breed - Akitas, Shiba Inu, Shar pei, Husky
Iatrogenic - chloramphenicol, lead
Iron deficiency/ excess zinc
Portosystemic shunts
Why may MCHC decrease
Anaemia - regenerative, iron deficiency
Portosystemic shunts
Lead poisoning, vitamin B6 or copper deficiency (uncommon)
RBC swelling
Why may nRBC increase?
Bone marrow injury - sepsis, heat stroke, endotoxemia
Dyserythropoeisis - Neoplasia, macrocytosis
Splenic dysfunction - Hemangiosarcoma, exogenous corticosteroids, post-splenectomy
Heat stroke
Why may reticulocytes be increased?
Regenerative anaemia
Compensated haemolytic anaemia
Absolute polycythaemia
Why may neutrophils be increased
Can increase in stress and inflammation.
When do neutrophil levels decrease
Acute endotoxaemia
Decreased bone marrow production
Increased tissue migration
Increased destruction
Why does left shift occur?
Severe/acute inflammation where bone marrow can’t keep up with production of WBCs to tackle pathology, This causes the release of immature neutrophils and causes ‘left shift’.
What causes variation in lymphocyte numbers?
Most common is physiologic or age-related lymphocytosis. In adults, consider leukaemia and lymphoma. Causes can be iatrogenic e.g corticosteroids
Why may platelet levels increase
Reactive or neoplastic thrombocytosis causes.
What causes a rise in sodium
Artifact
Iatrogenic - hypertonic IVFT
Water deficit
Salt gain - intake or retention
What causes a decrease in sodium
Artifact
Iatrogenic - hypotonic IVFT
Volume overload - CHF, hepatic disease, renal failure
Hypovolaemic hyponatremia
What causes an increase in potassium
Artifacts
Iatrogenic - IVFT or K+ supplementation
Transcellular shift
Decreased renal excretion
What causes a decrease in potassium
Artifact
Decreased intake - anorexia
transcellular shift - metabolic alkalosis etc.
Increased loss - V+, stasis, torsion, renal
What causes an increase in chloride
Artifact
Iatrogenic - Hypertonic IVFT
Metabolic acidosis
Bicarbonate loss - hyperchloremic metabolic acidosis
What causes a decrease in chlorine
Iatrogenic - loop diuretics, sodium-rich fluids
Loss of Cl- rich fluid
What are the causes of hyperglycaemia
Physiologic
Iatrogenic - Drugs inducing insulin resistance
Sustained - Lack of insulin, diabetes, hyperadrenocorticism, acromegaly
What are causes of hypoglycaemia
Artifact
Iatrogenic - insulin administration
Decreased production - Glycogen storage disease, juvenile hypoglycaemia, hepatic insufficiency
Decreased intake
Increased use
Increased insulin secretion
What are causes of increased urea nitrogen?
Increased protein catabolism
Increased protein digestion
Decreased GFR
What are causes of decreased urea nitrogen
Decreased protein intake - diet, young animals
Decreased production - Hepatic disease
Increased excretion - Causes of polyuria
Increased GFR - Portosystemic shunts
What are causes of increased Creatinine?
Artifact
Physiologic
Decreased GFR
What are caused of decreased creatinine?
Physiologic
Decreased production - starvation, decreased muscle mass
Increased GFR - Portosystemic shunts
Causes of increased uric acid
Artifact
Renal disease - decreased GFR, loss of >70% functional renal capacity
Increased deposition - articular gout
What are causes of increased bilirubin?
Physiologic
Increased production
Decreased hepatic uptake
Decreased hepatic conjugation
Inherited
What are the causes of increased ALP?
Physiologic - young, breed
Iatrogenic - liver injury, anticonvulsants, thyroxine
Hepatobiliary - cholestasis
Endocrine - Hyperthyroidism
Bone - Hyperparathyroidism
What causes increased GGT?
Physiologic - neonates
Iatrogenic - Biliary injury or cholestasis, anticonvulsants
Hepatobiliary - hyperplasia, cholestasis
Causes of increased ALT
Artifact
Iatrogenic - liver injury from drugs
Hepatic injury - Many causes
Muscle - Severe muscle injury, aortic thromboembolism, myopathies, trauma
What are the causes of increased AST?
Artifact
Iatrogenic - liver injury, anticonvulsants
Physiologic
Liver - Injury of any cause
Muscle - Myopathies, trauma, WMD, dystrophy
What causes increases of CK?
Artefact
Physiologic - age, post-exercise, anorexia
Iatrogenic - muscle injury, I/M injection, irritant drugs, post-surgery
Muscle injury - nutritional, inherited, toxin
What causes an increase in LDH?
Artifact
Physiologic - exercise
Liver injury
Muscle injury
Neoplasia
What causes an increase in total protein?
Dehydration
Increased albumin
Increased globulins
What causes a decrease in total protein?
Blood loss
Protein-losing enteropathy
Overdilation with fluids
Decreased albumin
Decreased globulins
What causes an increase in albumin?
Artifact
Physiologic - haemoconcentration
Increased production - hepatocellular carcinoma, corticosteroids
What causes a decrease in albumin?
Iatrogenic - excessive fluid administration
Decreased production - malnutrition/starvation, hepatic insufficiency
Increased loss - protein-loss, severe haemorrhage etc.
What causes an decrease in immunoglobulins?
Immunodeficiencies
Failure of passive transfer
Blood loss
Protein-losing enteropathy
What are the most common causes of hyercalcaemia?
Humoral hypercalcaemia of malignancy
Hypoadrenocorticism
What are the most common causes of hypocalcaemia?
Low albumin
Renal disease
Pancreatitis
GI disease
What are causes of increased phosphate?
Artifact
Iatrogenic - phosphate enemas
Physiological - post-prandial, young animals
Increased intake - rodenticides, supplements
Transcellular shift - skeletal muscle injury
Decreased excretion - GFR, hyperthyroidism
What are causes of decreased phosphate?
Artifact
Iatrogenic - diuretics, steroids, antacids
Decreased intestinal absorption
Transcellular shifts
Increased loss
Hepatic lipidosis
What causes an increase in magnesium?
Artifact
Iatrogenic - excessive supplementation
Increased absorption
Decreased excretion - GFR, hypocalcaemia
Release from cells - myopathy, soft tissue necrosis
Increased PTH
What causes a decrease in Magnesium?
Artifact
Physiologic - age
Iatrogenic - administration of Mg-poor fluids
Decreased albumin
Decreased intake - anorexia, high potassium diet
Translocation into cells - insulin, hypothermia
Excess loss
What causes an increase in cholesterol
Increased production
Decreased lipolysis, abnormal processing
Inherited
Decreased excretion - cholestasis
Endocrine disorders - Diabetes mellitus, pancreatitis, hyperadrenocorticism
What are causes of decreased cholesterol
Artifact
Decreased absorption
Decreased production - liver disease
Altered metabolism
Increased lipoprotein uptake
What are common causes of increased triglycerides?
Post-prandial fasting
Diabetes mellitus
Hyperadrenocorticism
Hyperlipidemia
What causes increased amylase?
Acute pancreatitis
Decreased GFR
Intestinal disease or obstruction
What causes increased lipase
Corticosteroids
Acute pancreatitis
Peritonitis, gastritis, obstruction, manipulation
Decreased GFR
What causes an increase in bile acids?
Physiologic
Decreased clearance from the portal circulation
Decreased excretion
What causes a decrease in bile acids
Physiologic - prolonged fasting
Enterohepatic - malabsorption
What parts of the biochemistry panel are used to look at liver health?
Leakage enzymes: ALT, AST, SDH, GLDH
Inducible enzymes: ALP, GGT
Bilirubin, Urea nitrogen, glucose, albumin, cholesterol, bile acids, ammonia
What parts of the biochemistry panel are used to look at kidney health?
Urea
Creatinine
Electrolytes: Sodium, Chloride, Potassium, Calcium, Phosphate, Magnesium
What part of the biochemistry panel are used to look at pancreas health?
Amylase
Lipase
What part of the biochemistry panel is used to look for muscle health?
AST, CK and LDH
What markers look at carbohydrate metabolism?
Glucose and fructosamine
What markers can be used for lipid metabolism?
Triglyceride
Cholesterol
NEFA (non-esterified fatty acids)
B-hydroxybutyrate (BHB)
What is anaemia?
Decreased haemocrit/packed cell volume or haemoglobin
What are the signs of anaemia?
Inadequate perfusion/oxygenation - pale mms, lethargy, exercise intolerance
Tachypnoea/tachycardia
Poor pulse quality, flow heart murmur
Underlying pathology
Where does apparent anaemia occur?
Young animals, anaesthesia, overhydrated
What are some abnormal cell types seen with anaemia?
Nucleated RBCs, reticulocytes, basophilic stippling, Howell-Jolly body, Heinz bodies
In what condition is neutrophilia and spherocytes seen with anaemia?
IMHA
What is the most common form of non-regenerative anaemia?
Inflammation - normocytic normochromic
What type of anaemia is absolute iron deficiency?
Microcytic hypochromic
What is poikilocytosis?
Alteration in cell shape
What conditions are seen with acanthocytes (spur cells)? What do they look like?
Diffuse liver disease, splenic hemangiosarcoma, portosystemic shunts.
Rounded projections of variable diameter and lenghh
What are spherocytes an indicator of? What do they look like?
Immune-mediated haemolytic anaemia
Small, densely staining spherical RBCs
What are schistocytes?
Irregular fragmented erythrocytes through mechanical trauma to circulating erythrocytes
What are Heinz bodies indicative of?
Oxidative damage - paracetamol and onion toxicity
Associated with diabetes mellitus, lymphoma and hyperthyroidism
What is basophilic stippling indicative of?
Signs of regeneration. Associated with lead poisoning.
What are Howell-Jolly Bodies indicative of?
Signs of regeneration. Can be seen with splenectomy or suppressed splenic function
What can babesiosis lead to?
Haemolytic anaemia
Systemic inflammatory response syndrome (SIRS)
Multiple organ dysfunction syndrome (MODS)
What pathologies relate to normocytic normochromic anaemia?
Illness, pre-regenerative or occasionally non-regenerative anaemia.
What pathologies relate to normocytic normochromic anaemia?
Illness, pre-regenerative or occasionally non-regenerative anaemia.
What pathologies link to macrocytic hypochromic anaemia?
Highly regenerative anaemia
What pathologies link to microcytic hypochromic anaemia?
Classic iron deficiency, chronic external blood loss.
What factors can cause a shift of cells from the marginal to the circulating pool?
Epinephrine, glucocorticoids, infection, stress
What are causes of neutrophilia?
Inflammation
Steroid
Physiological
Chronic neutrophil leukaemia
Paraneoplastic
What causes the appearance of foamy cytoplasm?
Dispersed organelles
What causes the appearance of diffuse cytoplasmic basophilia?
Persistent cytoplastic RNA
What causes the appearance of Dohle bodies?
Focal blue-grey cytoplasmic structures
What causes the appearance of asynchronous nuclear maturation?
Finely granular nuclear chromatin in segments
What are causes of neutropenia?
Inflammation
Decreased production
Rare
What are the causes of lymphocytosis?
Physiological
Chronic inflammation
Young animals and recent vaccination
Lymphoproliferative disorders
Hypoadrenocorticism
What are the causes of lymphopenia?
Stress/steroids
Acute inflammation
Loss of lymph
Cytotoxic drugs, radiation
Immunodeficiency syndrome
Lymphoma
What are the causes of monocytosis?
Inflammation
Steroid/stress
Monocytic/myelomonocytic leukemia
What are the causes of eosinophilia?
Hypersensitivity
Parasitism
Hypoadrenocorticism
Paraneoplastic
Idiopathic eosinophilic syndrome
Eosinophilic leukaemia
