Electrolytes and renal

Question 1

EKG changes with hypermagnesemia

Answer 1

Wide QRS

Long PR

Question 2

Electrolyte abnormalities associated with refeeding syndrome

Answer 2

Hypophosphatemia
Hypomagnesemia
Hypokalemia

Question 3

What effect does placement of an NGT beyond the pylorus have on aspiration risk? Pneumonia risk?

Answer 3

No change in aspiration risk

Decreased risk of pneumonia

Question 4

Where does the majority of sodium resorption occur in the kidneys?

Answer 4

Proximal tubules account for 65-70% of sodium resorption

Question 5

Electrolyte effects of acetazolamide

Answer 5

Causes hyperchloremic metabolic acidosis

Wasting of sodium and bicarbonate from the proximal tubules causes urine alkalization

Question 6

Uosm:Posm ratio suggestive of prerenal oliguria due to hypovolemia

Answer 6

> 1.5

Question 7

Hypermagnesemia symptoms correspond with serum levels. What are the symptoms in order of increasing serum level? At what Mg level do respiratory and cardiac arrest occur?

Answer 7

Reduced reflexes, cardiac depression with EKG changes (long PR, wide QRS)’ weakness, hypotension and bradycardia, respiratory and cardiac arrest.

Respiratory and cardiac arrest occur at Mg levels of 15-20.