Nephrology Flashcards
___
affects the Efferent arteriole causing increase in GFR but with compensatory Na reabsorption
Angiotensin = responds due to decrease BP
____ facilitate dilation of Afferent arteriole causing increase in GFR but no Na reabsorption
ANP = responds due to increase atrial pressure
Na loss and volume loss
Parathyroid hormone is secreted in response to a decrease in [Ca], increase [PO4], or decrease 1,25OH D3. in response, ___
- Increase Ca reabsorption in DCT
- Decrease PO4 reabsorption in PCT
- Increase 1,25-OHD3 production
- Increase Ca and PO4 absorption from the gut
Most frequent cause of hyperkalemia
decrease in renal K excretion
- RAAS system
- Hyporeninemic, hypoaldosteronism
- Addison disease
What is the most urgent step if hyperkalemia is suspected?
ECG
since hyperkalemia can lead to life threatening arrythmia
[Hyperkalemia ECG changes]
Tall, peaked T waves
5.5 - 6.5
[Hyperkalemia ECG changes]
Loss of P waves
6.5 - 7.5
[Hyperkalemia ECG changes]
widened QRS
7-8
[Hyperkalemia]
Used for immediate antagonism of the cardiac effects
- IV calcium gluconate
[Transcellular Potassium Shift]
K enters the cell due to
- Insulin
- Beta agonist
- Alkalosis
[Transcellular Potassium Shift]
K exits the cell due to
- Hyperosmolarity
- Exercise
- Cell lysis
- Acidosis
[Bartter vs Gitelman]
Mimics loop diuretic
Bartter
[Bartter vs Gitelman]
(+) Polyuria (+) polydipsia (-) HPN Hypokalemia normal Mg Increased urinary Ca excreation
Bartter Syndrome
[Bartter vs Gitelman]
(-) polyuria
(-) polydipsia
(+) tetany
(-) growth retardation
Low urinary CA
Low serum Mg
Gitelmann
Low MG due to TPMR 6 defect
[Bartter vs Gitelman]
mimic Na-Cl co transporter
Gitelman
What is the first step in diagnostic evaluation of hypercalcemia?
Check albumin
Corrected Ca = 40 - albumin x 0.02 + measure Ca
What is the main hormone that regulates Ca levels in the body
Parathyroid hormone
What are the effects of parathyroid hormone in the body?
- Bone resorption to increase serum Ca and P
- Increase Vit D synthesis
- Increase Ca reuptake but increase P excretion in the kidneys
Hypercalcemia in malignancy is usually due to overproduction of what hormone?
PTHrp
Most common PTHrp secreting tumor
- Squamous cell tumors
Vitamin D secreting tumor
Lymphoma
Granulomatous diseases like TB, Fungal infections and sarcoidosis increase Ca absorption in the gut by ___
ectopic production of alpha-1 hydroxylase that converts calcidiol to 1,25OHD3
Paget Disease causes hypercalcemia by ___
abnormal production of RANKL by osteoblast
High RANKL increases osteoclast activity
What is the defect in Familial Hypocalciuric Hypercalcemia which is a cause of hyperparathyroidism leading to hypercalcemia?
Calcium sensing receptor dysfunction