SIADH Flashcards
1
Q
Where is the antidiuretic hormone produced?
A
- The hypothalamus and secreted by the posterior pituitary gland
2
Q
What is another name for antidiuretic hormone?
A
- Vasopressin
3
Q
What does ADH do?
A
- Stimulates water reabsorption from the collecting ducts in the kidneys.
4
Q
A condition where where is inappropriately large amounts of ADH.
A
- SIADH
5
Q
What causes blood sodium to be low with SIADH?
A
- Excessive ADH, results in excessive water reabsorption in the collecting ducts, the water dilutes the sodium in the blood.
6
Q
Where does euvolemic hyponatremia come from?
A
- Excessive water reabsorption from the collecting ducts is not significant enough to cause fluid overload, therefore patients end up with euvolemic hyponatremia.
7
Q
Due to excessive water reabsorption, patients with SIADH will have high what?
A
- High urine osmolality
2. high urine sodium
8
Q
What are symptoms of SIADH?
A
- H/A
- Fatigue
- Muscle aches and cramps
- confusion
- severe hyponatremia can cause seizures and reduced consciousness
9
Q
What are causes of SIADH?
A
- post op major surgery
- infection, atypical pna and lung abscess
- head injury
- medications (thiazides, diuretics, carbamazepine, vincristine, cyclophosphamide, antipsychotics, SSRI’s, NSAIDs)
- Malignancy, small cell lung cancer
- Meningitis
10
Q
Why is sodium correction in patients with SIADH done slowly?
A
- Prevention of Pontine myelinolysis
11
Q
What should clinicians aim for in sodium changes when correcting sodium levels in patients with SIADH?
A
- 10 mmol/24 hours sodium change
12
Q
What two medications are effective at treating SIADH?
A
- Tolvaptan- They are very powerful and can cause a rapid increase in sodium. Therefore they are usually initiated by a specialist endocrinologist and require close monitoring, for example 6 hourly sodium levels.
- Demeclocycline tetracycline ABT that inhibits ADH
