Fluid and Electrolytes

Homeostasis

• maintained through consistent fluid and electrolyte adjustments

  • involves renal system, hormones, and neural function

• block reabsorption of NA & Cl in ascending nephron loop

• blocks K+ reabsorption

MOA of loop diuretics

Furosemide

Prototype loop diuretic

• decreased K+ - leads to dysrhythmias

• hypovolemia - leads to HPN, dizziness

• ototoxicity

Adverse effects of furosemide

Increased intracranial pressure, glaucoma

What are osmotic diuretics used for?

Mannitol, glycerin

Examples of osmotic diuretics

Hypovolemia - leads to HPN, dizziness

Adverse effects of thiazide diuretics

Avoid K+ supplements and K+ rich foods

Education to avoid adverse effects of potassium sparing diuretics

Causes tumors in lab animals

Potassium sparing diuretics have a block box warning for which adverse effect?

ACE inhibitors & ARBs

Interacting these drugs with potassium sparing diuretics can increase K+ level and cause dysrhythmias

Daily weights

Nursing management to maintain fluid balance

ECF volume deficits

Intravenous isotonic crystalloids are ideal for what?

• expands intravascular fluid volume

• stays where it is infused, doesn’t alter size of cells

Key characteristics of isotonic crystalloids

Fluid loss, surgical procedures, decreased sodium levels

Uses for isotonic crystalloids

Increased sodium levels and cellular dehydration

Uses for hypotonic crystalloids

To restore plasma volume, maintain cardiac output, and restore blood protein

What is albumin used for?

Ions in water

Electrolytes dissociate into _______

Hydrostatic pressure

Pushes blood out of the capillary

Severe, emergent hyperkalemia

Indications for sodium polystyrene sulfonate (Kayexalate)

• off-label use for hyperkalemia >6.5

• stabilization of myocardial cell membrane

Indications for calcium gluconate

Insulin/dextrose therapy

Calcium gluconate must be used with what type of therapy?

• oral potassium supplements

• IV potassium supplments

Treatment of hypokalemia

Oral sodium replacement

Treatment for mild hyponatremia

IV fluids

Treatment for moderate hyponatremia

Hypertonic fluids

Treatment for severe hyponatremia

• Assess and treat underlying etiology

• Oral/IV NaCl diuretics

Key treatment for hyponatremia

• Stupor/coma

• Alertness changes (confusion)

• Lethargy

• Tendon reflexes decreased

• Limp muscles (weakness)

• Orthostatic hypotension

• Seizures

• Stomach cramping

S&S of hyponatremia (SALT LOSS)

• Flushed & fever

• Restless & irritable

• Increased BP & impaired mental status

• Edema

• So thirsty

S&S of hypernatremia (FRIES)

• hypoparathyroidism

• hypomagnesemia, hyperphosphatemia

• vitamin D deficiency

Causes of hypocalcemia

• CNS and neuromuscular excitability

• Chvostek sign

• Trousseau sign

• ECG abnormalities

Clinical manifestations of hypocalcemia

Chvostek sign

Twitch of facial muscles from tapping facial nerve

Trousseau sign

3 minutes of pressure triggers involuntary hand and wrist spasm

Low albumin levels (due to binding of calcium and albumin)

Causes of hypercalcemia

• decreased excitability of muscles and nerves

• fatigue, weakness, lethargy

Clinical manifestations of hypercalcemia

Same as manifestations of hypercalcemia

Clinical manifestations of hypophosphatemia

Confusion, HPN, decreased reflexes, respiratory depression

Clinical manifestations of hypermagnesemia

Osmotic pressure

Lower concentration to higher concentration

Oncotic pressure

Draws fluid into the capillaries