Clinical Chemistry Flashcards
(92 cards)
1
Q
What are the causes of HYPERthyroidism?
A
- Autoimmune- Grave’s disease
- Thyroid nodules
- Chemical toxicity eg. Amiodarone
2
Q
What are the clinical signs of HYPERthyroidism?
A
Increased metabolic rate: Diarrhoea, weight loss anxiety
Increased sympathetic drive: Sweating, tachycardia, tremor
Goitre
Thyroid acropachy
Exophthalmos
Lid retraction
Pretibial myxoedema
3
Q
What is thyroid acropatchy?
A
Extreme mannifestation of hyperthyroidism
Clubbing
Painful finger and toe swelling
Periosteal bone reaction
4
Q
What is pretibial myxoedema?
A
Oedematous swelling above the lateral malleoli
Due to hyaluronic acid deposition
Discoloured skin
5
Q
What is exophthalmos
A
Anterior bulging of the eye out of the orbit
6
Q
What are the treatments for HYPERTHYROIDISM?
A
- Thionamides eg. Carbimazole which inhibit thyroid peroxidase
- Radioactive iodine
- Thyroidectomy
7
Q
What are the causes of HYPOTHYROIDISM?
A
- Autoimmune- Hashimoto’s
- Iodine deficiency
- Pituitary disease
8
Q
What are the clinical signs of HYPOthyroidism?
A
Weight gain Dry skin and hair Hoarse voice Bradycardia Constipation Tiredness Round puffy face Depression
9
Q
What are the treatments for HYPOthyroidism?
A
- Levothyroxine - aim for normal TSH, check after 4 weeks
10
Q
Which hormones are produced by the anterior pituitary?
A
Growth Hormone Thyroid Stimulating Hormone Prolactin FSH and LH ACTH
11
Q
Which hormones are released by the posterior pituitary?
A
Oxytocin
ADH
12
Q
What are the clinical features of a prolactinoma?
A
Galactorrhoea (spontaneous milk production)
Amenorrhoea
Loss of axillary/pubic hair
13
Q
What causes a prolactinoma?
A
Pituitary adenoma
14
Q
What is the treatment for a prolactinoma?
A
Dopamine agonists eg. Bromocriptine, Cabergoline
as dopamine inhibits prolactin synthesis
Rare side effects = manic symptoms
15
Q
What are the clinical features of acromegaly?
A
Large hands/ feet
Wide nose
Sweating and headache
Cardiomyopathy, hypertension, diabetes
16
Q
What are the treatments for acromegaly?
A
- Trans-sphenoidal surgery 1st line
- Somatostatin analogues eg. Lanreotide, Ocreotide which are growth hormone inhibiting hormone
- Pegvisomant if resistant
17
Q
What is the role of ADH?
A
Acts on renal collecting ducts, reabsorption of water via aquaporins
Makes urine more concentrated
18
Q
What happens in diabetes insipidus?
A
Too LITTLE ADH produced due to posterior pituitary damage
Large volume urine
Blood more concentrated
Causes hypernatraemia, thirst, polyuria
19
Q
What is the treatment for diabetes insipidus?
A
Desmopressin (ADH analogue)
20
Q
What happens in SIADH?
A
Too much ADH produced, causes low urine output and increased blood volume so hyponatraemia
21
Q
What are the causes of SIADH?
A
Head injury
Malignancy- lung small cell, pancreas, prostate
Infection - Pneumonia, meningitis
Medication- Diuretics, AEDs, SSRIs
22
Q
What are the treatments for SIADH?
A
- Volume restriction
- Vasopressin antagonists (Vaptans)
- Demeclocycline
23
Q
What is Addison’s disease?
A
Primary adrenal insufficiency
Leads to decreased adrenalin, cortisol and aldosterone
24
Q
What are the causes of HYPERnatraemia?
A
Volume loss- diarrhoea, vomit, burns Diabetes insipidus Primary hyperaldosteronism (Conn's) Iatrogenic- incorrect fluid replacement Osmotic diuresis
25
How is hypernatraemia managed?
1. Oral fluid
2. Glucose 5% IV 1:6
3. Saline 0.9% if volume depleted
26
What are the causes of hyponatraemia?
IF DEHYRDRATED:
1. Loss via kidneys: Addison's excess diuretics, renal failure, osmotic diuresis
2. Loss elsewhere: diarrhoea, vomit, burns, fistulae, bowel obstruction, CF, trauma
IF NOT DEHYDRATED:
3. Cardiac failure, renal failure, liver cirrhosis, nephrotic syndrome
4. SIADH, volume overload, severe hypothyroidism
27
What is the treatment for hyponatraemia?
Correct sodium/ water loss:
1. Fluid restrict if asymptomatic
2. Saline 0.9% slowly
3. Vaptans- vasopressor receptor antagonists- promote water loss without sodium loss
28
What is the risk if saline is given too quickly to correct Hyponatraemia?
Central Pontine Myelinolysis
Irreversible and often fatal pontine demyelination seen in rapid correction of low sodium.
29
What is normal plasma osmolality?
275-295mOsm/Kg
30
Which foods are high in potassium?
```
Banana
Prune juice
Papaya
Raisins
Mango
Orange
Pear
```
31
After a potassium load, which hormones are released?
```
Insulin
Aldosterone
Catecholamines (adrenalin, noradrenalin, dopamine)
```
32
How do insulin and catecholamines impact on potassium levels?
IF potassium INCREASES, insulin and catecholamines cause INCREASED uptake of potassium to cells (skeletal muscle, liver and adipose)
33
How does aldosterone impact on potassium levels?
It INCREASES the amount of potassium excreted renally
34
What are the potassium levels in metabolic ACIDOSIS?
HYPERkalaemic
35
What are the potassium levels in metabolic ALKALOSIS?
HYPOKalaemic
36
What ECG changes are seen in HYPERKalaemia?
1. Tall tented T waves
2. Wide QRS complex
3. Flattened P wave
37
What are the concerning signs/ symptoms in HYPERkalaemia?
Fast irregular pulse
Palpitations
Chest pain
Light headedness
38
What are the causes of HYPERkalaemia?
INCREASED POTASSIUM INTAKE: oral or IV therapy
REDUCED POTASSIUM EXCRETION: CKD, Addison's, Tubular defects
ALTERED DISTRIBUTION: Metabolic acidosis
Rhabdomyolysis, crush injury, diabetes
DRUGS: ACEIS, ARBS, Spironalactone
39
Which blood bottle should be collected first; yellow or purple?
Yellow
| Then Purple
40
How should HYPERkalaemia be treated?
1. Cardioprotection: ECG monitor, Calcium gluconate
2. Potassium removal: Furosemide, Ion exchange resins, dialysis
3. Potassium redistribution: Insulin, glucose, salbutamol nebuliser, bicarbonate
41
What are the consequences of Hyperkalaemia?
```
Weakness
Paralysis
Nausea and vomit
Ileus
Arrhythmias
```
42
What are the causes of HYPOKalaemia?
1. GI LOSSES: Diarrhoea, Fistula, Pyloric stenosis
2. RENAL LOSSES: Loop diuretics, Mineral corticoid excess eg. Cushings, Conn's
3. REDISTRIBUTION: Salbutamol, Metabolic Alkalosis
43
What are the ECG changes in HYPOKalaemia?
Flat T wave/ T wave inversion
Prominent P waves and U waves
ST depression
Prolonger PR interval
44
How is HYPOKalaemia treated?
1. Oral potassium eg. Sando k
| 2. IV potassium
45
What is the role of parathyroid hormone?
Increases serum calcium and Decreases serum phosphate
Increases osteoclast activity
Increases renal production of Vit D3
46
What is the role of calcitonin?
Decreases serum calcium
47
How does magnesium impact PTH?
Magnesium REDUCES the release of PTH
48
Which protein does calcium bind in blood?
Albumin (40% of calcium is bound, rest is free)
49
What are the signs/ symptoms of hypocalcaemia?
```
SPASMODIC:
S- Spasms
P- Perioral paraesthesia
A- Anxious and irritable
S- Seizures
M- Muscle tone increased -> wheeze and colic
O- Orientation impaired
D- Dermatitis
I- Impetigo
C- Corner of mouth twitches Chvostek sign
```
50
What are the causes of LOW calcium with HIGH phosphate?
1. Hypoparathyroidism
2. CKD
3. Magnesium deficiency
4. Pseudohypoparathyroidism
51
What are the causes of LOW calcium with NORMAL/ LOW phosphate?
1. Vitamin D deficiency
2. Osteomalacia (adult version of rickets)
3. Acute pancreatitis
4. Respiratory alkalosis
5. Over hydration
52
What are the signs of Hypercalcaemia?
Bones, stones, moans, groans
```
Abdominal pain
Vomiting
Depression
Hypertension
Kidney stones
Weight loss
Ectopic calcification
```
53
What are the commonest causes of hypercalcaemia?
Malignancy- bone mets, myeloma
| Hyperparathyroidism
54
What suggests that malignancy has caused a Hypercalcaemia?
Raised ALP
Low albumin, chloride and potassium
Raised phosphate
Alkalosis
55
What suggests that hyperparathyroidism has caused a hypercalcaemia?
Raised PTH
56
What are the less common causes of Hypercalcaemia?
Sarcoidosis
Vitamin D excess
Lithuim
Tertiary hyperparathyroidism
57
How is HYPERCalcaemia treated?
1. Correct dehydration 0.9% saline
2. Bisphosphonates- inhibit osteoclasts eg. Zoledronate
3. Calcitonin
58
What is the triad that makes up nephrotic syndrome?
1. Proteinuria
2. Oedema
3. Hypoalbuminaemia
59
What is an insulinoma?
Benign tumour of pancreatic islet cells; presents with hypoglycaemia when fasting.
60
What will the blood results be of a patient with an insulinoma?
Raised insulin levels when fasting
Glucose below 2.5
Raised C-Peptide
61
What is a Phaeochromocytoma?
Adrenal medulla tumour, producing catcholamines
| 10% malignant, 10% familial, 10% bilateral
62
How does a Phaeochromocytoma present?
```
Sweating
Episodic headaches
Tachycardia
Pallor
Anxiety
Hypertension
```
63
What is normal serum phosphate?
0.8- 1.5
64
What are the causes of hypophosphataemia?
Vitamin D deficiency
Alcohol withdrawal
Refeeding syndrome
Primary hyperparathyroidism
65
What is the most common cause of hyperphosphataemia?
CKD
66
When should Conn's (Primary Hyperaldosteronism) be expected?
1. Hypertension WITH hypokalaemia
2. Hypertension despite 3 ant hypertensives
3. Hypetension in <40yrs female
67
What is the most common cause of Cushing's?
Excess steroid use (Cushing's syndrome)
68
What is the second most common cause of Cushing's?
Pituitary adenoma (Cushing's disease)
69
How does Addison's affect Na, K, glucose levels?
Low sodium
High potassium
Low glucose
70
What are the causes of hypoyglycaemia in diabetics?
1. Insulin use
2. Sulfonylureas (Glicazide)
3. Missed meal, excess insulin dose, increased activity
71
What are the causes of hypoyglycaemia in non diabetics?
```
EXPLAIN:
Ex- Exogenous drugs: ACEIs, B Blockers, Alcohol, Aspirin overdose
P- Pituitary insufficiency
L- Liver failure
A- Addisons
I- Insulinoma
N- Neoplasms
```
72
What is Whipple's Triad (Hypoglycaemia)?
1. Low blood glucose
2. Symptoms and signs of hypogylcaemia
3. Symptoms relieved when blood glucose rises
73
Which CAUSES of hypoglycaemia will have low insulin, and raised ketones?
Alcohol
Addison's
Pituitary insufficiency
74
Which CAUSE of hypoglycaemia will have raised insulin and C peptide on fasting?
Insulinoma
75
What is the treatment for hypogylcaemia?
If conscious- orange juice
If conscious but uncooperative- glucogel on gums
If unconscious- IV glucose, IM glucagon
Long acting carbohydrate once recovered
76
What are the 2 main types of hyperglycaemia and which patients do they affect?
1. Diabetic ketoacidosis- Mainly type 1
| 2. Hyperglycaemic hyperosmolar state- Type 2
77
What 3 criteria are present to diagnose DKA?
1. Hyperglycaemia
2. High ketones (blood/urine)
3. Acidosis
78
What are the symptoms of DKA?
Drowsiness
Vomitting
Dehydration
79
What is the treatment for DKA?
1. Fluids
2. Insulin
Keep checking VBG (pH, Bicarbonate, potassium)
80
How does Hyperglycaemic Hyperosmolar state differ to DKA?
HHS:
1. Glucose >30
2. no acidosis
3. no excess ketones
4. Type 2 diabetics
5. less sudden onset
81
What is the WHO criteria for diagnosing diabetes with regards to HbA1c?
>48mmol.L
| 6.5%
82
How does type 1 diabetes usually present?
Polyuria
Polydispia
Weight loss
Ketosis
83
How does Type 2 diabetes usually present?
Often asymptomatic
| Complications such as MI
84
What is metabolic syndrome?
Obesity plus 2 of:
1. Hypertension
2. Raised triglycerides
3. Reduced HDL cholesterol
4. Diabetes/ high glucose
85
Which diabetic drug is a Biguanide?
Metformin
86
What are the side effects of Metformin?
Nausea
Diarrhoea
Abdominal pain
NOT HYPOGLYCAEMIA
87
Which diabetic drug is associated with weight gain?
Glicazide (sulfonylurea)
88
Which diabetic drugs are associated with hypoglycaemia?
Glicazide (sulfonylurea)
| Glitazone
89
Which diabetic drug is associated with raised LFTs?
Glitazone
90
What are the most common causes of hyperkalaemia?
CKD
| Metabolic acidosis
91
What blood results are needed to diagnose Diabetes mellitus?
1. HbA1c >48mmol/l
2. Fasting glucose >7mmol/L
3. Random blood glucose >11mmol/l
92
What can trigger diabetic ketoacidosis?
Infection
Stress
Pancreatitis
Non compliance with insulin
