MS1 Chapter 6

• Purposes of fluids and electrolytes in the body:
• Fluids and electrolytes are essential for cellular metabolism, blood volume, body temperature regulation, and solute transport
• Signs and symptoms of common fluid imbalances:
• Dehydration: thirst, rapid weak pulse, low blood pressure, dry skin, decreased urine output, dark concentrated urine, constipation, increased temperature, weight loss
• Fluid overload: bounding pulse, elevated blood pressure, increased respirations, distended neck veins, pitting dependent edema, increased urine output, weight gain, pulmonary edema, dyspnea
• Patients at highest risk for dehydration and fluid excess: elderly, children, infants, those with fluid loss wounds
• Dehydration: hemorrhage, severe vomiting/diarrhea, draining wounds, profuse diaphoresis, third spacing
• Fluid excess: poorly controlled IV therapy, excessive water ingestion, excessive sodium intake, adrenal gland dysfunction, kidney failure, heart failure, syndrome of inappropriate ADH (SIADH)
• Data to collect in patients with fluid and electrolyte imbalances:
• Dehydration: resolve underlying cause, replace lost sodium, restrict fluids or give IV saline, administer diuretics or steroids
• Fluid overload: treat fluid imbalance first, administer diuretics, dialysis if needed, monitor intake and output, weight, restrict dietary sodium
• Education needs of patients with fluid imbalances:
• Educate on signs and symptoms of imbalances, importance of fluid intake, monitoring weight, and seeking medical attention when needed
• Common causes, signs and symptoms, and treatments for sodium, potassium, calcium, and magnesium imbalances:
• Sodium: hyponatremia (sodium deficit) and hypernatremia (sodium excess)
• Potassium: hypokalemia (potassium deficit) and hyperkalemia (potassium excess)
• Foods with high sodium, potassium, and calcium contents:
• Sodium: pizza, canned vegetables, salty snacks, cheeseburger

  Potassium: sweet potatoes, bananas, yogurt, avocadoes

  Calcium: dairy products, leafy greens, fortified foods
• Common causes of acidosis and alkalosis:
• Acidosis: renal failure, diabetic ketoacidosis, severe diarrhea

  Alkalosis: vomiting, excessive antacid use, hypokalemia
• Arterial blood gases changes for each type of acid-base imbalance:
• Acidosis: decreased pH, decreased bicarbonate

  Alkalosis: increased pH, increased bicarbonate
• Hyperkalemia signs and symptoms:

  • Muscle twitching and cramps
  • Later profound muscle weakness
  • Diarrhea
  • Slow, irregular heartrate with weak pulse
  • Low blood pressure
  • Cardiac arrhythmia, respiratory failure
• Interventions for Hyperkalemia:

  • Limit dietary potassium
  • Hold potassium supplements
  • Administer medications as ordered
  • Potassium-wasting diuretic
  • Kayexalate (sodium polystyrene sulfonate)
  • Insulin with glucose to facilitate the movement of potassium back into the cells
  • Cardiac monitoring
  • Monitor for potentially lethal arrhythmias
• Calcium Imbalances:

  • Normal serum calcium is 8.2-10.2 mg/dL
  • Hypocalcemia: Low calcium level
  • Hypercalcemia: High calcium level
• Food Sources of Calcium:

  • Fortified cereals
  • Cheese
  • Yogurt
  • Milk
  • Almond milk
• Hypocalcemia Signs and Symptoms:

  • Calcium less than 8.2 mg/dL
  • Low Vitamin D prevents calcium absorption
  • Brittle bones
  • Mental status changes
  • Hyperactive deep tendon reflexes (DTR)
  • Positive Trousseau sign
  • Positive Chvostek sign
  • Diarrhea, abdominal cramping
  • Heart rate changes and low blood pressure
  • Tetany
  • Continuous muscle spasms (airway compromise)
• Hypocalcemia Signs and Symptoms (continued):

  • Trousseau Sign: Hand and fingers become spastic and go into palmar flexion in hypocalcemia
  • Chvostek Sign: Facial twitching on tapping the face below and in front of the ear in hypocalcemia
• Interventions for Hypocalcemia:

  • Treat underlying cause
  • Administer medications as ordered
  • IV calcium gluconate
  • Oral calcium supplements
  • Aluminum hydroxide to bind phosphate
  • Increase dietary calcium
  • Teach about foods high in calcium
• Hypercalcemia Signs and Symptoms:

  • Calcium greater than 10.2 mg/dL
  • Mild or slowly progressing calcium increase may have no obvious signs and symptoms
  • Increased heart rate and blood pressure
  • Skeletal muscle weakness
  • Decreased GI motility
  • Urinary calculi (kidney stones)
  • Respiratory and/or heart failure if severe
• Interventions for Hypercalcemia:

  • Cardiac monitoring
  • Administer IV fluids; promote diuresis
  • Administer medications as ordered
  • Diuretics to promote calcium excretion
  • Drugs that slow calcium movement from bones to the blood
  • Pamidronate disodium (Aredia), zoledronic acid (Zometa), or calcitonin
  • Hemodialysis to cleanse the blood of excess calcium
• Magnesium Imbalances:

  • Normal serum magnesium is 1.6-2.2 mEq/L
  • Hypomagnesemia: Low magnesium level
  • Hypermagnesemia: High magnesium level
• Hypomagnesemia Signs and Symptoms:

  • Serum magnesium less than 1.6 mEq/L
  • Alcoholism common cause
  • Positive Trousseau sign
  • Positive Chvostek sign
  • Cardiac arrhythmia and/or cardiac arrest
  • Cardiac arrhythmias such as Torsades may occur
• Interventions for Hypomagnesemia:

  • Treat underlying cause
  • Administer magnesium replacement
  • Cardiac monitoring
• Hypermagnesemia Signs and Symptoms:

  • Serum magnesium greater than 2.2 mEq/L
  • Usually not apparent until the serum level is greater than 4 mEq/L
  • Hypotension
  • Lethargy
  • Skeletal muscle weakness
  • Respiratory failure &/or cardiac failure
• Interventions for Hypermagnesemia:

  • Administer IV fluids
  • Administer medications as ordered
  • Furosemide (Lasix) to increase magnesium secretion
  • Dialysis for kidney failure
• Review Question:

  1. A patient with skin tenting and decreased urine output is most likely experiencing which fluid or electrolyte disorder? Dehydration

  2. Which electrolyte is most critical to healthy cardiac rhythm? Potassium

  3. Which interventions are appropriate to a patient with fluid excess? Monitor weight, Place in Fowler position, Restrict fluid and sodium

  4. What are good food sources of calcium? Milk, Fortified cereals, Yogurt, Cheese
• Acid–Base Balance:

  • Acid: Substance that releases a hydrogen ion
  • Base (Alkali): Substance that binds hydrogen
  • Normal serum pH 7.35 to 7.45
  • pH of a solution can vary from 0-14, with 7 being neutral; 0 to 6.99 being acidic; and 7.01 to 14 being basic (alkaline)
• Acid–Base Control:

  • Cellular buffers, lungs, kidneys help in maintaining serum pH
  • Cellular buffers act as a sponge to soak up or release extra hydrogen ions
  • Lungs regulate carbon dioxide levels in blood
  • Kidneys regulate bicarbonate levels in the body
• Acid–Base Imbalances:

  • Acidosis: Blood is more acidic than normal
  • Alkalosis: Blood is more alkaline than normal
  • Respiratory and Metabolic imbalances can occur suddenly or develop over a long period