Electrolyte Disorders

Question 1

Hyponatremia is a Serum sodium concentration less than what?

Answer 1

135 mEq/L

Question 2

What is the most common electrolyte abnormality in hospitalized patients? what causes this?

Answer 2

Hyponatremia

often caused by hypotonic fluids

Question 3

Evaluation for hyponatremia starts with a careful history for what?

Answer 3

1) New medications,
2) Changes in fluid intake (polydipsia, anorexia, intravenous fluid rates and composition),
3) Fluid output (nausea and vomiting, diarrhea, ostomy output, polyuria, oliguria, insensible losses)

Question 4

Mismanagement of what issue can result in neurologic catastrophes from cerebral osmotic demyelination

Answer 4

Hyponatremia

Question 5

Mild hyponatremia is what range?

is this symptomatic?

Answer 5

sodium concentrations of 130-135 mEq/L
is usually
asymptomatic

Question 6

Hyponatremia
Mild / Moderate / severe 
S/S
1) Nausea
2) Malaise

Answer 6

Mild

Question 7

Hyponatremia
Mild / Moderate / severe 
S/S
1) Respiratory arrest
2) Seizure
3) Coma
4) Permanent brain damage,
5) Brainstem herniation
6) Death

Answer 7

Severe

Question 8

Hyponatremia
Mild / Moderate / severe 
S/S
1) Headache
2) Lethargy
3) Disorientation

Answer 8

Moderate

Question 9

Treatment for Hyponatremia

Answer 9

(a) Restriction of free water and hypotonic fluid intake is the initial step in hyponatremia management.
(b) Free water intake should generally be less than 1-1.5 L/day,
- —More severe free water restriction may be necessary in patients with minimal free water clearance
- —Hypertonic saline may be necessary in patients with negative free water clearance.

Question 10

Tru/False
Iatrogenic cerebral osmotic demyelination from overly rapid sodium correction is minor and reversible with hypotonic saline therapy

Answer 10

False

Generally catastrophic and irreversible

Question 11

Definition of what issue?

(a) Sodium concentration greater than 145 mEq/L.
(b) Typically, hypovolemic due to free water losses
(c) Rarely, excessive sodium intake may cause hypernatremia

Answer 11

Hypernatremia

Question 12

Intact thirst mechanism and access to water are the primary defense against what issue?

Answer 12

hypernatremia

Question 13

Signs and symptoms of what issue?

(a) Dehydration patient
- -Orthostatic hypotension
- - Oliguria
(b) Early signs
- - Lethargy
- - Irritability
- -Weakness
(c) Severe signs (usually Na > 158mEq/L)
- -Hyperthermia
- -Delirium
- -Seizures
- -Coma

Answer 13

Hypernatremia

Question 14

Hypernatremia is what value?

Answer 14

Sodium concentration greater than 145 mEq/L

Question 15

Tx for Hypernatremia

Answer 15

(a) Correcting the cause of the fluid loss
(b) Replacing water
(c) Replacing electrolytes (as needed)
(d) Fluids should be administered over a 48-hour period,
- –Aiming for serum sodium correction of approximately 1 mEq/L/h (1 mmol/L/h)

Question 16

TX for Hypernatremia
Fluids should be administered over how long?
What is the rate of sodium correction?

Answer 16

• 48-hour period,

- sodium correction of approximately 1 mEq/L/h

Question 17

Disposition

Patients with symptomatic hypernatremia

Answer 17

hospitalization for evaluation and treatment.

Question 18

Disposition Hyponatremia

Answer 18

Hospitalization for

1) Monitoring of fluid balance and weights,
2) Treatment
3) Frequent sodium checks

Question 19

What is a Serum potassium level less than 3.5 mEq/L (3.5 mmol/L).

Answer 19

Hypokalemia

Question 20

Severe hypokalemia may induce what?

Answer 20

arrhythmias and rhabdomyolysis.

Question 21

Hypokalemia can result from

Answer 21

1) Insufficient dietary potassium intake,

2) Intracellular shifting of potassium from the extracellular space

Question 22

The most common cause of hypokalemia is

Answer 22

gastrointestinal loss from infectious diarrhea

Question 23

S/S of what issue?

(a) Mild to moderate symptoms
- -Muscular weakness
- -Fatigue
- -Muscle cramps
(b) Severe
- -Flaccid paralysis
- -Hyporeflexia
- -Hypercapnia
- -Tetany
- -Rhabdomyolysis

Answer 23

Hypokalemia

Question 24

Severe Hypokalemia is resulted from what potassium level?

Answer 24

less than 2.5mEq/L

Question 25

Electrocardiogram of a Hypokalemia pt may show what?

Answer 25

1) Decreased amplitude and broadening of T waves,
2) Premature ventricular contractions,
3) Depressed ST segments

Question 26

What is the safest and easiest treatment for mild to moderate hypokalemia?

Answer 26

Oral potassium supplementation

–40-100 mEq/day over a period of days to weeks

Question 27

Complications of hypokalemia

Answer 27

(a) Cardiac arrhythmias

(b) Rhabdomyolysis

Question 28

Unexplained hypokalemia, refractory hypokalemia, or suggestive alternative diagnoses should be referred for consultation to where?

Answer 28

endocrinology or nephrology

Question 29

Disposition

Patients with symptomatic or severe hypokalemia, especially with cardiac manifestations,

Answer 29

Hospitalization

Question 30

What issue

Serum potassium level greater than 5.0 mEq/L (5.0 mmol/L).

Answer 30

Hyperkalemia

Question 31

Hyperkalemia may develop in patients taking what medications

Answer 31

1) ACE inhibitors,
2) Angiotensin-receptor blockers,
3) Potassium-sparing diuretics

Question 32

True/False

The ECG may be normal despite life- threatening hyperkalemia

Answer 32

True

Question 33

Hyperkalemia impairs neuromuscular transmission, causing:

Answer 33

1) Muscle weakness
2) Flaccid paralysis
3) Ileus

Question 34

Your patient was clenching her fist during venipuncture from being scared of needles
-serum potassium resulted in a level higher that 5.0 mEq/L

What is your next course of action and why?

Answer 34

Repeat laboratory testing to rule out false hyperkalemia
-Fist clenching during venipuncture may raise the potassium concentration by 1-2 mEq/L by causing acidosis and potassium shift from cells.

Question 35

ECG results may indicate what?

1) Bradycardia,
2) PR interval prolongation,
3) Peaked T waves,
4) QRS widening,
5) Conduction disturbances
- -Bundle branch block
- –Atrioventricular block

Answer 35

Hyperkalemia

Question 36

Ventricular fibrillation and -cardiac arrest are terminal events. of what issue

Answer 36

Hyperkalemia

Question 37

Emergent treatment for hyperkalemia is indicated when

Answer 37

1) Cardiac toxicity,
2) Muscle paralysis,
3) Severe hyperkalemia (potassium greater than 6.5 mEq/L) even in the absence of ECG changes

Question 38

Hypernatremia

What may be required to remove potassium in patients with acute or chronic kidney injury

Answer 38

Hemodialysis