Electrolytes, Parenteral Management (IV's) and TPN Flashcards
What is the difference between a cation and an anion?
Provide examples of electrolyte cations and anions.
A cation is an ion with a positive electrical charge and an anion is an ion with a negative electrical charge.
Examples of Cations:
Sodium (Na+); Potassium (K+); Calciun (Ca++); Magnesium (Mg++)
Examples of Anions:
Chloride (Cl-); Bicarbonate (HCO3-); Sulfate (SO4-); Hydrogen phosphate (HPO4-)
Which electrolyte cation is the most abundant electrolyte in the body?
Sodium (Na+)
What are the functions of sodium in the body?
- Regulates water balance
- Controls the extracellular fluid volume through osmotic pressure.
- Increases cell membrane permeability
- Stimulates conduction of nerve impulses and helps maintain neuromuscular irritability.
- Controls contractility of muscles (esp heart)
What is the normal level of sodium concentration in the blood?
134 - 142 mEq/L
What is the term for less than normal concentration of sodium in the blood?
What is considered less than normal concentration?
What happens in the body during this condition?
Hyponatremia
<134 mEq/L
-Caused by water excess or loss of sodium
-The body decreases water excretion
-As sodium levels decrease in the extracellular fluid, water is pulled into the cells causing them to become edmatous
-As fluid moves into the cells, potassium is shifted out, causing potassium imbalance.
What are the most common signs & symptoms of hyponatremia?
Confusion, headache, fatigue, postural hypotension, N/V, abd cramps. **severe or prolonged deficit can cause seizures
What electrolyte pairs off AGAINST sodium? When sodium is conserved by the kidneys, this electrolyte is excreted?
Potassium
What is the sodium blood concentration level for hypernatremia?
What can cause hypernatremia?
> 145 mEq/L
Causes:
-Water loss, excess sodium
-Decreased Na excretion: renal failure; corticosteroids
-Increased Na intake: Oversalting; processed, frozen, canned, smoked foods; antacids containing sodium
-Increased water loss: sweating, fever, diarrhea
What happens in the body during hypernatremia?
-The body attempts to correct the imbalance by conserving water though renal reabsorption.
-Fluid Shifts from the cells to the interstitial spaces resulting in cellular dehydration.
.
What is the dominant intracellular cation?
Potassium
What are the functions of potassium in the body?
- Regulation of water and electrolyte content within the cell.
- Promotes transmission of nerve impulses and skeletal muscle function.
- Assists in the cellular metabolism of carbohydrates and proteins
- Controls the hydrogen ion concentration
How much potassium intake is required each day?
What is the normal extracellular level of potassium?
65 mEq
3.5 - 5 mEq/L
What is the main organ affected by potassium imbalances?
The heart
What is the main organ affected by sodium imbalances?
The brain
What are the main causes of hyperkalemia?
- Renal Failure
- Metabolic Acidosis
- Use of salt or potassium supplements
- Tissue trauma/damage (including from chemotherapy)
- Infusion of blood nearing expiration
What medications can cause hyperkalemia?
Beta blockers (-lols), potassium-sparing diuretics, angiotensin-converting enzyme inhibitors (-prils), nonsteriodal antiinflammatory drugs, aminoglycosides (ie. gentamicin, streptomycin)
What are the main signs and symptoms of hyperkalemia?
N/V/D, Cardiac dysrhythmias, ECG changes (high T wave), Cardiac arrest
What is the potassium level that indicates hypokalemia?
What are the main causes?
< 3.5 mEq/L
- NPO
- Conditions causing very large urine output
- Metabolic alkalosis
- GI losses (vomiting, diarrhea, GI suctioning, Cushing’s syndrome)
- Potassium-losing diuretics (thiazides, furosemide (lasix)); digitalis, corticosteroids
- Excessive diaphoresis
What are the main signs and symptoms of hypokalemia?
- Skeletal muscle weakness (leg cramps)
- Cardiac dysrhythmias (weak, irregular pulse)
- ECG Changes (flat T wave)
If potassium and sodium levels are both depleted, which one will the kidneys conserve by re-absorption and which one will be excreted?
Sodium will be reabsorbed and potassium will be excreted.
What 4 hormones help to balance sodium (Na+) and chloride (Cl-)?
Aldosterone, Angiotensin II, ANP (Atrial natriuetic peptide), ADH (Antidiuretic hormone)
What is the main anion in interstitial and intravascular fluid?
Chloride
What is the normal range for Chloride?
96-105 mEq/L
Which 2 electrolytes does Chloride commonly combine with?
Which electrolyte is Chloride frequently paired with? (When this electrolyte is low, Chloride is also low)
Sodium (Sodium Chloride) and Potassium (Potassium Chloride)
Sodium.
Although rare, hyperchloremia is possible when levels of which electrolyte fall?
Bicarbonate (HCO3-)
What is the normal level of Calcium?
4.5 mEq/L -5.3 mEq/L
In addition to Vitamin D, what 2 hormones are necessary for the absorption and utilization of calcium?
Calcitonin and parathyroid hormone
What is the ratio of carbinic acid to bicarbonate for homeostasis?
1:20