Fluid And Electrolyte Disturbances

Question 1

Dopamine

Answer 1

Natriuretic effect

Question 2

Aldosterone

Answer 2

Activates Na Cl reabsorption within aldosterone-sensitive distal nephron

Question 3

Mannitol

Answer 3

Filtered by glomeruli

Not reabsorbed in proximal tubule

Causes osmotic diuresis

Question 4

Acetazolamide

Answer 4

Inhibit proximal tubular Na Cl absorption via inhibition of carbonic anhydrase

Question 5

Trimethoprim and pentamidine

Answer 5

Inhibit distal tubular Na reabsorption through amiloride sensitive ENaC channel

Question 6

Daily fecal fluid loss

Answer 6

100-200 ml/day

Question 7

Insensible losses

Answer 7

500-650 ml/day

Question 8

Hypovolemia and
Hypochlormeic alkalosis due to vomitting diarrhea or diuretics

What is the expected urine na?

Answer 8

> 20

Question 9

Renal causes of hyponat

Expected Urine Na?

Answer 9

> 20

Question 10

Inhibits renal concentrating activity, thiazides or loop diuretics?

Answer 10

Loop (blunts countercurrent mechanism)

Question 11

Cerebral salt wasting

Answer 11

Hypovolemic hyponat
UNa > 20 (inappropriate natriuresis)

Assoc w: 
SAH 
TBI 
Craniotomy 
Encephalitis 
Meningitis

Question 12

Hypervolemic hyponat with Urine Na > 20

Answer 12

Acute or chronic renal failure

Question 13

Primary vs secondary AI in terms of volume status and Na levels?

Answer 13

Primary- hypovolemic hyponat

Secondary- euvolemic hyponat

Question 14

Most common cause of euvolemic hyponat?

Answer 14

SIADH

Question 15

Other causes euvolemic hyponat?

Answer 15

Glucocorticoid deficiency 
Hypothyroidism
Stress
Drugs 
SIADH

Question 16

Class of drugs which most commonly cause SIADH

Answer 16

SSRIs

Question 17

Most common malignancy assoc w SIADH

Answer 17

Small cell lung Ca

Question 18

Symptomatic hyponat at levels..

Answer 18

<125

Question 19

Overly rapid Na correction

Answer 19

> 8-10 in 24 hrs

> 18 in 48 hrs

Question 20

ODS presentation

Answer 20

Paraparesis / quadriparesis
Dysphagia 
Dysarthria
Diplopia 
Locked in syndrome 
LOC

Question 21

AVP agonist

Answer 21

Desmopressin

Question 22

Most common manifestation of hypernatremia

Answer 22

Altered mental status

Question 23

Correction of acute hypernat

Answer 23

Rate of 1mM/hr

Question 24

Nephrogenic vs central DI in response to DDAVP

Answer 24

Nephrogenic - less than 50% increase in Urine osmolality pr <150 mOsm/kg from baseline

Question 25

Nephrogenic DI causes

Answer 25

Genetic mutations Hypercalcemia Hypokalemia Drugs (lithiumn ifosfamide, antiviral agents)

Question 26

Major K channels that mediate its secretion

Answer 26

ROMK - mediate bulk of K secretion | Flow sensitive big Potassium (BK) channel

Question 27

Increase in distal delivery of Na and distal flow rate: effect on K?

Answer 27

Enhance K secretion —> hypokalemia

Question 28

Decrease distal delivery of Na, effect on K?

Answer 28

Blunts ability to excrete K —> hyperkalemia

Question 29

Aldosterone effects on K

Answer 29

Increases activity of ENaC—> K secretion —> hypoK

Question 30

Possible treatment for TTP

Answer 30

Propanolol 3mg/kg

Question 31

Urine calcium in hiazide diuretics vs loop diuretics

Answer 31

HYPERcalciuria in LOOP diuretics | HYPOcalciuria in THIAZIDE diuretics

Question 32

Liddle syndrome

Answer 32

``` Autosomal dominant Gain in function mutation in ENaC Severe hypertension + hypokalemia Unresponsive to spironolactone Sensitive to amiloride ```

Question 33

Hypokalemic alkalosis | Loss of function of TALH

Answer 33

Bartter’s

Question 34

``` Hypokalemic alkalosis Loss of function of DCT segments Chondro calcinosis (abnormal deposition of CPPD in joints) Hypomagnesemia Marked hypocalciuria ```

Answer 34

Gittleman’s syndrome

Question 35

ECG changes with K <2.7 mmol/L

Answer 35

Broad flat T waves ST depression QT prolongation

Question 36

Same clinical manif with Liddle’s syndrome but | Responds to spironolactone

Answer 36

SAME (syndrome of apparent mineralocorticoid excess)

Question 37

Reduction of serum K by 2.0 mM results in loss of ____ mmol of total K stores

Answer 37

400-800 mmol

Question 38

ECG changes in hyperkalemia

Answer 38

Tall peaked T waves - 5.5-6.5 Loss of p waves 6.5-7.5 Widened qrs 7.0-8.0 Sine wave pattern > 8.0

Question 39

Effect of hypercalcemia in px taking digoxin

Answer 39

Potentiates cardiac toxicity of digoxin

Question 40

Effect of Calcium gluc

Answer 40

Effect starts in 1-3 mins, Lasts 30-60 mins May repeat if no ECGchanges (hyperkalemia)

Question 41

Glucose insulin solution

Answer 41

Effect begins 10-20 mins Peaks 30-60 mins Lasts 4-6 hrs If cbg > 200-250 , hold D5W

Question 42

Beta blockers for hyperkalemia

Answer 42

``` Albuterol 10-20 mg Inhaled over 10 mins Effect starts at 30 mins Peak at 90 mins Lasts for 2-6 hrs ```