Electrolyte imbalances and DI

Question 1

where are ADH an oxytocin made

Answer 1

posterior pituitary gland and supraoptic nucleus

Question 2

adh receptors?

Answer 2

v1a- vasculature
v2- renal collecting tubes- reabsorption of water
v1b- pituitary

Question 3

ADH release is controlled by

Answer 3

osmoreceptors in hypothalamus - day to day
baroreceptors in brainstem and great vessels

Question 4

what is osmolality

Answer 4

mOsmol/kg

Question 5

what factors can affect osmolality

Answer 5

number of particles
concentration of ions
presence of solutes

Question 6

disease associated with the posterior pituitary

Answer 6

1-lack of vasopressin = AVP deficiency
2-resistance to action of vasopressin= avp resistance
3-inappropiate ADH release

Question 7

what happens with high adh levels

Answer 7

conc urine
high urine osmolality

Question 8

what does avp resistance and deficiency cause

Answer 8

polyuria
polydipsia
no glycosuria

Question 9

how to diagnose diabetes insipidus

Answer 9

measure urine volume
check renal function and serum calcium

Question 10

Difference between cranial and nephrogenic DI

Answer 10

Cranial- decrease in production of ADH
Nephrogenic- impaired response to adh

Question 11

causes of AVP deficiency

Answer 11

acquired- idiopathic, tumours , trauma
primary- autosomal dominant

Question 12

common cause of AVP resistance

Answer 12

lithium

Question 13

management of avp deficiency

Answer 13

treat underlying condition
desmopressin- high activity at V2 receptor

Question 14

define hyponatraemia

Answer 14

serum sodium < 135 mmol/l
severe <125 mmol/l

Question 15

normal serum sodium levels

Answer 15

135- 144mmol

Question 16

moderate symptoms of hyponatraemia

Answer 16

Headache
* Irritability
* Nausea / vomiting
* Mental slowing
* Unstable gait / falls
* Confusion / delirium
* Disorientation

Question 17

severe symptoms of hyponatraemis

Answer 17

stupor/coma
convulsions
resp arrest

Question 18

what is hypocalcaemia

Answer 18

low calcium levels in blood serum

Question 19

Common causes of hypocalcaemia

Answer 19

Hypoparathyroidism
Vit d deficiency
Kidney failure

Question 20

corrected calcium equation?

Answer 20

total serum ca + 0.02 x (40-serum albumin)

Question 21

presentation of hypocalcaemia

Answer 21

Spasm
Parasthesia
Anxious
Seizures
Muscle tone increase
Orientation impaired
Dermatitis
Impetigo
Cardiomyopathy

Question 22

investigation of hypocalcaemia

Answer 22

levels of PTH, VIT D
serum calcium levels
ecg- prolonged QT interval

Question 23

treatment of hypocalcaemia

Answer 23

Acute- IV calcium gluconate

Question 24

complications of hypocalcaemia

Answer 24

seizure
cardiac arrest

Question 25

what is hypercalcaemia

Answer 25

decrease PTH increase ca2+

Question 26

Causes of hypercalcaemia

Answer 26

Primary hyperparathyroidism Malignancy Sarcoidosis

Question 27

Symptoms of hypercalcaemia

Answer 27

abormal bone remodelling kidney stones abdo pain lethargy,depression

Question 28

investigations for hypercalcaemia

Answer 28

-fasting serum and phosphate samples serum pth and ca2+ ultrasiund if investigations point to primary hyperparathyroidism

Question 29

treatment for hypercalcaemia

Answer 29

- rehydration with saline -rehydration with bisphosphonates -furosemide

Question 30

define hyperkalaemia

Answer 30

serum potassium <3.5mmol/l

Question 31

cause of hypokalaemia

Answer 31

decrease K intake increase of K into cells increase in K excretion

Question 32

presentation of hypokalaemia

Answer 32

muscle weakness hyporeflexia cramps

Question 33

what would an ecg show for hypokalaemia

Answer 33

Small or inverted t waves prominent U waves long PR interval depressed ST segments

Question 34

investigations for hypokalemia

Answer 34

metabolic panel ecg urine electrolytes

Question 35

treatment for hypokalaemia

Answer 35

mild- ORAL replacement - SEVERE- IV replacement 40mml

Question 36

complications of CVD

Answer 36

chronic heart failure , Acute MI long QT syndrome

Question 37

define hyperkalaemia

Answer 37

serum potassium >5.5

Question 38

causes of hyperkalaemia

Answer 38

increase intake increased production shift from intracellular to extracellular

Question 39

clinical presentation of hyperkalaemia

Answer 39

neuromuscular transmission muscle weakness and paralysis chest pain Hyperreflexia

Question 40

what would an ecg show for a patient with hyperkalaemia

Answer 40

Tall tented t waves small P waves Wide QRS complex Ventricular fibrilations

Question 41

treatment of hyperkalemia

Answer 41

If ECG changes- stabilise cardiac membrane by IV calcium gluconate if no changes in ecg- comined insulin/ dextrose with nebulised salbutamol

Question 42

what is carcinoid syndrome

Answer 42

occurs due to the release of serotonin from a carcinoid tumour

Question 43

most common cause of carcinoid syndrome

Answer 43

small intestine malignancy

Question 44

presentation of carcinoid syndrome

Answer 44

flushing, diarrohoea, abdo cramos , bronchospasm, fibrosis

Question 45

1st line test for carcinoid syndrome

Answer 45

urinary 5-hydroxyindoleacetic acid test

Question 46

what electrolyte disturbance would make you consider SIADH

Answer 46

hyponatraemis

Question 47

Three types of cancers that cause SIADH

Answer 47

small cell carcinoma Prostate cancer Cancer of thymus

Question 48

Role of pth

Answer 48

Increase bone remodelling and turnover Pth increases the amount of calcium absorbed in the kidney which means less excreted in kidney Increases absorption of ca in thr gut