May 17th Conference Review Questions

Mike Quinn: Electrolyte Abnormalities, Part I from April 12^th and Part II

1.        A patient presents with a Na of 131.  In which of the following clinical scenarios would one have hyponatremia despite having a normal amount of total body sodium?

a)      Congestive heart failure

b)      SIADH

c)       Renal tubular acidosis

d)      Ascites

e)      It is not possible to have hyponatremia with a normal total body Na

2.        You are called to the bedside of a 4 month old previously healthy infant who presented with vomiting and diarrhea, and is now having generalized seizures.  His seizure persists despite two doses of Ativan.  An istat reveals a Na of 119.   All of the following are true statements regarding hyponatremic seizures EXCEPT:

a)      1 cc/kg of 3%NaCl will raise the plasma sodium by approximately 1 mEq/L

b)      The patient should be treated with 3-5 cc/kg 3%NS until the seizure stops

c)       Rapid normalization of the sodium is indicated as the patient is symptomatic  with seizures

d)      Overly rapid correction of hyponatremia may result in osmotic demyelination syndrome

3.       A 12 yo F with ESRD presents to the ED with a chief complaint of “I feel like I need to be dialysed”- she left town for a few days and missed two rounds of hemodialysis.   Which of the following symptoms would you most likely expect that she is experiencing?

a)      Muscle weakness

b)      Muscle cramps

c)       Constipation

d)      Tetany

4.        You place her on a cardiac monitor as you order labs and an istat.  You note peaked t-waves on the monitor as the nurse calls out that the istat K+ is 7.5.   Your patient is still well appearing.  You order a formal EKG, labs, and a dose of calcium gluconate.  Your med student asks why Calcium is helpful and you respond that it:

a)      Raises the resting membrane potential

b)      Lowers the resting membrane potential

c)       Raises the threshold membrane potential

d)      Lowers the threshold membrane potential

5.       You discuss the case with nephrologist and as they plan to admit her for dialysis, they recommend that you use other agents to treat her hyperkalemia.  All of the following treatments for hyperkalemia will drive K+ into cells EXCEPT:

a)      Calcium

b)      Insulin and glucose

c)       Sodium bicarbonate

d)      Albuterol

Answers Here