Intro to diuretics and renal disease Flashcards Preview

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Flashcards in Intro to diuretics and renal disease Deck (72)
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1

What are the 3 common uses of diuretics?

- control ECF volume
- increase urine volume output
- lower ECF volume

2

What conditions would result in needing to control ECF volume?

- hypertension: non-renal failure induced elevations in ECF
- edema: trauma, congestive heart failure

3

What do most diuretics target?

Na excretion/resorption
- since Na stays in the lumen, so does water

4

Why does decreased resorption of other electrolytes occur with diuretic use?

Since water remains in the tubules, there is an increased flow rate through the tubules which leads to diminished resorption of electrolytes (Ca, Mg, etc) that rely on a concentration gradient for passive reabsorption
- do not see an increase in the concentration of other electrolytes that would normally occur with reabsorption of Na and water (so, no increase in concentration = no concentration gradient established)

5

Diuretics are considered to be potassium ______

Wasting
- increased Na, water, and flow rate prevents an increase in K concentration at the level of the distal tubule and collecting duct, promoting more rapid excretion of K+

6

What diuretics are not K+ wasting?

Those that target Na resorption by the principle cells of the distal tubules and collecting ducts

7

Osmotic diuretics

Increase tubular osmolarity
- use with excess glucose or urea
- ex: mannitol

8

Loop blocker diuretics

Inhibit Na-K-Cl cotransport
- blocks concentrating and diluting ability
- increase urine output of Na, Cl, K, etc
- increase quantities of solutes delivered to distal parts of nephrons, which act as osmotic agents
- disrupt countercurrent multiplier system by decreasing absorption of ions from Henle into the medullary interstitium
- ex: furosemide

9

Thiazide diuretics

Inhibit Na Cl cotransport by targeting the Na-Cl co transporter on the apical membrane of early distal tubules
- ex: hydrochlorothiazide

10

Carbonic anhydrase inhibitors

Inhibit H secretion and HCO3 reabsorption = blocking Na reabsorption
- disadvantage: can cause acidosis due to loss of bicarb
- used to manage HYPP
- ex: acetazolamide

11

Aldosterone antagonist

Blocks aldosterone receptor in the cortical collecting tubule principle cells = decreased reabsorption of Na and secretion of K (leading to a decrease in excretion of K)
- ex: spironolactone

12

Na channel blocker

Blocks Na entry into the Na channels of the apical membrane of the collecting tubule cells that were inserted under the influence of aldosterone
- leads to decreased activity of Na K ATPase pump, reducing secretion of K
- ex: amiloride

13

Kidney is the primary organ responsible for long term maintenance of ___

pH

14

What are the 6 main functions of the kidney?

- excretion of metabolic waste products
- regulation of acid-base balance
- control of arterial pressure
- regulation of water and electrolyte excretion
- secretion, metabolism, and excretion of hormones
- excretion of foreign chemicals

15

Uremia

Accumulation of nitrogenous waste products
- urea, creatinine, ammonia

16

Hyperkalemia causes ______

Arrhythmias, neuromuscular dysfunction

17

Acidosis

Affects CNS function and all cell processes
- retention of H and organic acids, loss of bicarb

18

Hypertension or hypotension

Failure to excrete or conserve sodium and water
- failure to produce renin = no angiotensin
- edema or dehydration

19

What 2 hormones are produced by the kidney?

- renal erythropoietic factor: absence leads to anemia
- 1,25 dihydroxycholecaliferol (Vit D): absence leads to osteomalacia

20

Does renal disease have subclinical signs?

NO
- kidney can be deteriorating for a while without clinical signs appearing

21

Renal disease clinical signs

Often vague
- general malaise
- inappetence
- polyuria/polydipsia
- weight loss
- weak/lethargy
- hypertension
- edema

22

Prerenal disease will typically result in _______

Diminished renal blood flow

23

What are the 3 main causes for diminished RBF?

- volume loss: diminished renal perfusion (diarrhea, hemorrhage, etc)
- volume redistribution: endotoxemia, septicemia, 3rd space sequestration
- cardiovascular failure: diminished renal perfusion (myocardia, valve disease, etc)

24

Dehydration is typically a ______ issue

Prerenal

25

SpGr should be ____ in dehydration

High

26

How does the macula densa react during states of mild dehydration?

Induces afferent arteriolar dilation and release of renin from juxtaglomerular cells results in efferent arteriolar constriction
- both work to preserve GFR and glomerular hydrostatic pressure, ensuring filtration/elimination of Cr

27

Why does BUN increase during dehydration?

Low flow states cause increased time for reabsorption of urea
- ADH induced carrier proteins facilitate urea reabsorption from medullary collecting tubules

28

High urine SpGr with a high BUN and Cr indicates ____

Pre-renal azotemia

29

High BUN and Cr with a lower urine SpGr indicates _____

Renal failure

30

Glomerulonephritis, vasculitis, and chronic hypertension are all forms of _____

Renal disease