electrolytes - Sheet1 Flashcards
What is the major extracellular fluid electrolyte?
Sodium.
What is hypernatremia?
Serum sodium > 145 mEq/L, caused by kidney pathology or excessive intake.
What is hyponatremia?
Serum sodium < 135 mEq/L, caused by plasma dilution or sodium loss; common in hospitalized patients.
What is the classification of sodium chloride (NaCl)?
Therapeutic: Agent for hyponatremia; Pharmacologic: Electrolyte, sodium supplement.
What are adverse effects of sodium chloride?
Hypernatremia, lethargy, confusion, muscle tremors/rigidity, hypotension, restlessness, pulmonary edema.
What are contraindications for sodium chloride?
Hypernatremia, CHF, impaired renal function.
What is the most abundant intracellular cation?
Potassium (K⁺).
What is the normal extracellular potassium level?
3.5–5 mEq/L.
What is hypokalemia?
Serum potassium < 3.5 mEq/L, caused by loop/thiazide diuretics, ↓ intake, alkalosis, ↑ insulin, vomiting, diarrhea, or laxative abuse.
What are symptoms of hypokalemia?
Weakness, paralysis, risk for fatal dysrhythmias, intestinal dilation, and ileus.
What is potassium chloride (KCl) used for?
Treating or preventing hypokalemia.
What are adverse effects of oral KCl?
GI irritation (abdominal pain, nausea, vomiting, diarrhea), intestinal injury, hyperkalemia.
What are the nursing considerations for oral KCl?
Take with meals or a full glass of water, remain upright during administration.
What are the nursing considerations for IV KCl?
Must be diluted, infused slowly (≤ 10 mEq/h), never given as IV push, monitor serum K⁺, renal function, ECG, and I&O.
What is hyperkalemia?
Serum potassium > 5 mEq/L, caused by severe tissue trauma, Addison’s disease, acute acidosis, misuse of K⁺-sparing diuretics, or K⁺ overdose.
What are symptoms of mild hyperkalemia (5–7 mEq/L)?
T-wave heightening and PR interval prolongation.
What are symptoms of severe hyperkalemia (8–9 mEq/L)?
Risk of cardiac arrest, confusion, anxiety, dyspnea, muscle weakness, numbness, and tingling.
How is hyperkalemia treated?
Withhold K⁺-rich foods/meds, calcium salts (e.g., calcium gluconate) for cardiotoxicity, glucose + insulin infusion, sodium bicarbonate for acidosis, sodium polystyrene sulfonate (Kayexalate), or dialysis.
What is magnesium’s role in the body?
It is the 2nd most abundant intracellular cation (~40 mEq/L), required for enzyme activity, binding of mRNA to ribosomes, and regulating neurochemical transmission and muscle excitability.
What is the normal serum magnesium level?
1.8–3 mEq/L.
What causes hypomagnesemia?
Diarrhea, hemodialysis, renal disease, prolonged IV feeding, chronic alcohol abuse, diabetes, and pancreatitis.
What are the effects of hypomagnesemia on muscles and the CNS?
Increases acetylcholine release, leading to muscle excitability; also causes increased CNS neuron excitability, disorientation, psychoses, and seizures.
What causes hypermagnesemia?
Renal insufficiency, especially with Mg-containing antacids or cathartics.
What are the symptoms of mild hypermagnesemia?
Muscle weakness, hypotension, sedation, and ECG changes.
What are the severe symptoms of hypermagnesemia?
Respiratory paralysis at 12–15 mEq/L and cardiac arrest at >25 mEq/L.
What is magnesium sulfate (MgSO4) used for?
Oral prophylaxis of magnesium deficiency and IV/IM treatment of hypomagnesemia.
What are the adverse effects of oral MgSO4?
Diarrhea.
What are the administration guidelines for MgSO4 IM?
0.5–1 gm four times a day.
What are the administration guidelines for MgSO4 IV?
10% solution at a rate of 1.5 mL/min or less.
Why is injectable calcium important when administering MgSO4?
To counteract potential magnesium toxicity.
What are nursing considerations for MgSO4 administration?
Assess vital signs every 10–15 minutes when giving IV, monitor serum magnesium levels, test patellar reflex before parenteral doses, assess for early signs of toxicity, and notify if respiratory rate falls below 12 breaths/min.
When should MgSO4 administration be discontinued?
If urine output is less than 100 mL in the preceding 4 hours.
