Electrolyte Disorders Flashcards
Hyponatremia is a Serum sodium concentration less than what?
135 mEq/L
What is the most common electrolyte abnormality in hospitalized patients? what causes this?
Hyponatremia
often caused by hypotonic fluids
Evaluation for hyponatremia starts with a careful history for what?
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)
Mismanagement of what issue can result in neurologic catastrophes from cerebral osmotic demyelination
Hyponatremia
Mild hyponatremia is what range?
is this symptomatic?
sodium concentrations of 130-135 mEq/L
is usually
asymptomatic
Hyponatremia Mild / Moderate / severe S/S 1) Nausea 2) Malaise
Mild
Hyponatremia Mild / Moderate / severe S/S 1) Respiratory arrest 2) Seizure 3) Coma 4) Permanent brain damage, 5) Brainstem herniation 6) Death
Severe
Hyponatremia Mild / Moderate / severe S/S 1) Headache 2) Lethargy 3) Disorientation
Moderate
Treatment for Hyponatremia
(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.
Tru/False
Iatrogenic cerebral osmotic demyelination from overly rapid sodium correction is minor and reversible with hypotonic saline therapy
False
Generally catastrophic and irreversible
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
Hypernatremia
Intact thirst mechanism and access to water are the primary defense against what issue?
hypernatremia
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
Hypernatremia
Hypernatremia is what value?
Sodium concentration greater than 145 mEq/L
Tx for Hypernatremia
(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)
TX for Hypernatremia
Fluids should be administered over how long?
What is the rate of sodium correction?
- 48-hour period,
- sodium correction of approximately 1 mEq/L/h
Disposition
Patients with symptomatic hypernatremia
hospitalization for evaluation and treatment.
Disposition Hyponatremia
Hospitalization for
1) Monitoring of fluid balance and weights,
2) Treatment
3) Frequent sodium checks
What is a Serum potassium level less than 3.5 mEq/L (3.5 mmol/L).
Hypokalemia
Severe hypokalemia may induce what?
arrhythmias and rhabdomyolysis.
Hypokalemia can result from
1) Insufficient dietary potassium intake,
2) Intracellular shifting of potassium from the extracellular space
The most common cause of hypokalemia is
gastrointestinal loss from infectious diarrhea
S/S of what issue?
(a) Mild to moderate symptoms
- -Muscular weakness
- -Fatigue
- -Muscle cramps
(b) Severe
- -Flaccid paralysis
- -Hyporeflexia
- -Hypercapnia
- -Tetany
- -Rhabdomyolysis
Hypokalemia
Severe Hypokalemia is resulted from what potassium level?
less than 2.5mEq/L
Electrocardiogram of a Hypokalemia pt may show what?
1) Decreased amplitude and broadening of T waves,
2) Premature ventricular contractions,
3) Depressed ST segments
What is the safest and easiest treatment for mild to moderate hypokalemia?
Oral potassium supplementation
–40-100 mEq/day over a period of days to weeks
Complications of hypokalemia
(a) Cardiac arrhythmias
(b) Rhabdomyolysis
Unexplained hypokalemia, refractory hypokalemia, or suggestive alternative diagnoses should be referred for consultation to where?
endocrinology or nephrology
Disposition
Patients with symptomatic or severe hypokalemia, especially with cardiac manifestations,
Hospitalization
What issue
Serum potassium level greater than 5.0 mEq/L (5.0 mmol/L).
Hyperkalemia
Hyperkalemia may develop in patients taking what medications
1) ACE inhibitors,
2) Angiotensin-receptor blockers,
3) Potassium-sparing diuretics
True/False
The ECG may be normal despite life- threatening hyperkalemia
True
Hyperkalemia impairs neuromuscular transmission, causing:
1) Muscle weakness
2) Flaccid paralysis
3) Ileus
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?
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.
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
Hyperkalemia
Ventricular fibrillation and -cardiac arrest are terminal events. of what issue
Hyperkalemia
Emergent treatment for hyperkalemia is indicated when
1) Cardiac toxicity,
2) Muscle paralysis,
3) Severe hyperkalemia (potassium greater than 6.5 mEq/L) even in the absence of ECG changes
Hypernatremia
What may be required to remove potassium in patients with acute or chronic kidney injury
Hemodialysis
