Clinical Pathology Flashcards
Principles
Reference laboratories vs in clinic laboratories (including pros and cons of each)
Reference: Used to assess non-life threatening conditions. Pros (3) - 1. More reliable results 2. More analytes tested 3. Interpretation provided. Cons - Longer turnaround for results
In clinic: Used to assess life threatening conditions, eg. electrolyte abnormalities (K+, Ca2+, Na+), Hypoglycaemia (collapse, seizures), Marked anaemia, Thrombocytopaenia. Pros (2) - 1. Rapid diagnosis 2. More profitable for practice. Cons (3) - 1. Relies on self-interpretation 2. Less variability 3. More expensive for client
Principles
Variability
a) Random inherent variability
b) Inter-animal biological variability (young animals, older animals, greyhounds)
a) Less variability - analytes under homeostatic control (glucose, K+, Ca2+), Increased variability - liver enzymes, proteins
Principles
a) What does it mean if a patient’s values are outside the reference interval
b) What can result in a healthy animal having results outside the reference interval
a) Results are abnormal
b) Biological variability (age, breed, analytes)
Principles
For each of the following, what type of test tube are samples taken in
a) Haematology
b) Coagulation
c) Biochemistry/Endocrinology
d) Ionised Ca2+/ Urgent Biochemistry
e) Glucose
f) Cardiac troponins/Phenobarbitone
Biochemistry
Describe the following biochemical analyses, icluding samples that cannot be used
a) Photometric/Colorimetric
b) Electrochemistry
c) Turbidimetric
d) Electrophoresis
Biochemistry
Sample Quality pre-analytical errors (serum colour, cause, assay interference)
a) Haemolysis
b) Lipaemia
c) Icterus
Biochemistry
Sample handling pre-analytical errors (effects on biochemistry profile)
a) Delayed sample separation
b) EDTA contamination
c) Young patient
d) Stress/excitement
e) Steroids
f) Potassium Bromide (drug)
g) Phenobarbitone (drug)
Biochemistry
Biochemical markers of damage and function ( damage markers and dysfunction markers for each body system)
a) Renal
b) Hepatic (hepatocellular)
c) Hepatic (biliary)
d) Pancreas
e) Heart
f) Muscle
g) Small intestine
Biochemistry
Renal function markers
- Kidneys are responsible for the excretion of nitrogenous waste
- Renal disease will lead to reduced renal function and glomerular filtration rate
- Accumulation of nitrogenous waste (urea and creatinine) indicates decreased excretory function of the kidney
- But remember that dehydration can cause increased urea and creatinine
- Azotaemia only occurs when over 3/4 of renal function is lost
Biochemistry
Muscle damage markers
a) Creatinine kinase (CK)
b) AST
a) Most specific marker of myocyte damage. Peak serum CK at 4-6 hours post damage. Normal serum CK after 24-48 hours post damage
b) Monocyte and hepatocyte damage. Long half life (12 hours)
Biochemistry
Causes of hyperglycaemia (4) and examples
Biochemistry
Causes of Hypoglycaemia (5) with examples (and state concentration indicating hypoglycaemia)
< 3mmol/L
Biochemistry
Causes of hyperlipidaemia (4) with examples
Biochemistry
Urinalysis
a) Why useful
b) Urine specific gravity
c) Dipstick test
d) Sediment exam
a) Important measure of renal function
Plasma proteins and calcium
a) What are most serum proteins produced by (what are the exceptions)
b) Two types of serum protein
c) Methods of measuring plasma proteins (3) + advantages and causes of error for each
a) Hepatocytes (except for immunoglobulins)
b) Albumin (half life in dogs - 8 days, half life in cattle - 2-3 weeks) and globulins (all proteins except albumin)
Plasma proteins
Disorders of serum proteins - Selective hypoalbuminaemia
4 main causes and examples of what leads to these
Plasma proteins
Disorders of serum proteins - Non-selective hypoalbuminaemia
Main causes (3) and examples
Plasma proteins
Systemic infalmmation - acute phase proteins seen in
a) Dogs
b) Cats
c) Cattle
d) How long for them to increase
e) What can use of steroids lead to
f) What can dehydration lead to
a) CRP
b) SAA, AGP
c) SAA
d) 24 hours
e) Hyperalbuminaemia
f) Hyperproteinaemia
Plasma proteins
Disorders of serum proteins - Selective hypoglobulinaemia
a) Cause
b) How to diagnose (4)
a) Failure of passive transfer (suckling)
b) 1. Zinc sulphate turbidity test
2. Serum GGT
3. Plasma [total protein]
4. Radial immunodiffusion assay
Calcium
Describe calcium homeostasis
Calcium
Causes and related pathologies of
a) Pseudo-hypercalcaemia (2)
b) Hypercalcaemia (5)
Calcium
Causes and related pathologies of
a) Pseudo-hypocalcaemia (3)
b) Hypocalcaemia (5)
Calcium
a) Correction of hypercalcaemia (4)
b) Correction of hypocalcaemia (2)
a) 1. IV fluid therapy 2. Bisphosphonate or Calcitonin treatment 3. Loop diuretics 4. Identify root cause
b) 1. Calcium gluconate (IV) 2. Identify root cause
Electrolytes
Describe sodium homeostasis
Electrolytes
Sodium imbalances - Hyponatraemia
- causes
- related pathologies leading to the causes
Electrolytes
Sodium imbalances - Hypernatraemia
- Causes
- Related pathologies leading to the causes
- treatment
Treatment: IV fluid therapy, but do not correct faster than 0.5 mmol/L/hr due to risk of cerebral oedema
Electrolytes
Hypoadrenocorticism (Hyponatraemia)
a) Signalments (1)
b) Clinical signs (4)
c) Pathology (3)
Ketonuria (Hyponatraemia)
d) Causes of ketonuria (2)
Sodium abnormalities
e) Associated clinical signs
a) Females predisposed
b) 1. Intermittent vomiting and diarrhoea 2. Lethargy 3. Abdominal pain 4. Weight loss / anorexia
c) 1. Immune mediated destruction of adrenal glands 2. Reduced cortisol production 3. Reduced aldosterone production -> low serum [Na+], high serum [K+]
d) 1. Negative energy balances causing a shift in energy production from carbohydrates to lipids 2. Diabetes mellitus
e) Associated with neurological signs (weakness, depression, seizures)
Electrolytes
Chlorine renal reabsorption
Complete the table
Electrolytes
What happens to Cl- when
a) HCO3- increases
b) Na+ increases
c) Acidosis
d) Alkalosis
a) Cl- decreases
b) Cl- increases
c) Cl- excreted with H+ in distal tubule
d) Cl- reabsorbed and HCO3- excreted in distal tube
Electrolytes
Chloride imbalances
Complete the table
Electrolytes
a) Potassium functions (4)
b) Clinical signs of hyperkalaemia (2)
a)
- Regulation of intracellular osmolarity
- Concentration gradient across the cell membrane establishes resting membrane potential
- Essential for excitable cell function (e.g. nerves, myocardium)
- Cardiac pacemaker potential – sinoatrial node pace maker function
b) 1. Bradycardia 2. Weakness
Electrolytes
a) Emergency treatment of hyperkalaemia (4)
b) Most commum cause of hyperkalaemia result, and reasons for this (3)
a) 1. Calcium gluconate to reduce bradycardia and stabilise cardiac membrane 2. Frusemide
3. IV fluid therapy (dilution) 4. Remove urinary obstruction (catheterise)
b) Most common cause is pseudo-hyperkalaemia
1. Thrombocytosis (clotting) in blood sample
2. Delayed serum separation +/- haemolysis
3. EDTA contamination (expect low Ca2+)