Workshop - Laboratory Medicine Flashcards
How do we classify Anaemia by cell size?
Macrocytic - MCV above normal;
- Vitamin B12 Deficiency
- Folate deficiency
- Alcohol excess
Normocytic - MCV in normal range
Microcytic - MCV below normal;
- Iron deficiency
- Thalassaemia
What is MCH and how would you calculate it ?
Mean corpuscle haemoglobin
- Quantifies the amount of haemoglobin in a individual red cell
Haemoglobin/RBC count
What is MCHC and how would you calculate it ?
Mean corpuscle haemoglobin concentration;
- Average concentration of haemoglobin in a cell
- i.e correlates Hb content with the volume of the cell
Haemoglobin/Packed cell volume
Also gives a rough guide to shade of erythrocytes - more pale the lower MCHC
What is MCV and how would you calculate it ?
Mean cell volume
- Size of RBC
Packed cell volume/RBC count
What do Neutrophils indicate and what percentage of white blood cells do they make up ?
Bacterial infection - 62%
What do Monocyte indicate and what percentage of white blood cells do they make up ?
Viral illness, chronic infectious disorder (mononucleosis or an autoimmune disease like lupus), some malignant cancers - 5.3%
What do Eosinophils indicate and what percentage of white blood cells do they make up ?
Parasitic infection, an hypersensitivity reaction or cancer - 2.4%
What do Basophil indicate and what percentage of white blood cells do they make up ?
Rare, found in some cancers - 0.4%
What do Lymphocytes indicate and what percentage of white blood cells do they make up ?
Viral infection, some bacterial, some cancer - 30%
What are the functions of Platelets ?
- Wound repair
- Cytokine signalling
- Aggregation
- Adhesion
- Blood clotting
- Activation
What is a releasing or inhibiting hormone?
A releasing or inhibiting hormone is released from he hypothalamus and acts upon the pituitary gland
What is a tropic hormone?
A tropic hormone is released from the anterior pituitary gland and acts upon a target tissue
What is a hormone?
A hormone is released by the target tissue and acts on target cells as well as having a negative or positive feedback action on the hypothalamus and pituitary gland
What are the thyroid hormones and their order of release?
The hypothalamus secretes Thyrotropin Releasing Hormone (THR) causing the pituitary to release Thyroid Stimulating Hormone (TSH) which causes the thyroid gland to produce Triiodothyronine (T3) and Thyroxine (T4)
T3 and T4 suppress the release of TRH and TSH as well as acting on target cells
What is the problem in Cushing’s Syndrome?
Too much Cortisol
What is the problem in Conn’s Syndrome?
Too much Aldosterone
What is the problem in Addison’s?
Not enough Cortisol and Aldosterone
What are the 2 key hormones that the homeostasis of calcium relies on ?
1). Parathyroid hormone - In Hypoglycaemia
2). Calcitonin - In Hyperglycaemia
Diabetic Ketoacidosis;
1) how you would identify them in clinical practice.
2) How do we treat these conditions in secondary care?
3) Which type of diabetes are they most commonly seen in?
- Absolute (or near) insulin deficiency resulting in;
- Severe hypoglycaemia
- Ketone body production
- Systemic acidosis
- Develops over hours to 1-2 days
- Most common in type 1 diabetes but can be seen in type 2
Symptoms;
- Polydipsia—thirst
- Polyuria—urination
- Polyphagia—appetite
- Feeling tired and sleepy
- Blurred vision
- Confusion and passing out
- Stomach pain, feeling or being sick
- High blood sugar levels
Treatments for DKA include: insulin, usually given into a vein (intravenously) fluids given into a vein to rehydrate your body. nutrients given into a vein to replace any you’ve lost.
HHS (Hyperosmolar Hyperglycaemic State);
1) how you would identify them in clinical practice.
2) How do we treat these conditions in secondary care?
3) Which type of diabetes are they most commonly seen in?
- Severe relative insulin deficiency
- Profound hyperglycaemia and hyperosmolarity (from urinary free water losses)
- No significant ketone body production or acidosis
- Develops over days to weeks
- Typically present in Type 2 or previously unrecognised diabetes
- Higher mortality
Symptoms;
- Polydipsia
- Polyuria / oliguria / anuria
- Headache
- Nausea, vomting, abdo pain
- Confusion
- Seizures
- Low GCS
Treatment;
1. Fluids to hydrate you.
2. Electrolytes (such as potassium) to balance the minerals in your body.
Insulin to control your blood sugar levels.
HHS is more often seen in people with type 2 diabetes who don’t have their diabetes under control
