Fluids and Electrolytes

Water

  1. Adults: 60% - 20% EFC, 40% ICF
  2. Children: 70% - 18% ECF, 52% ICF

Electrolytes

  1. Cations: Positively charged ions
  2. Anions: Negatively charged ions

Fluid Compartments

  1. Intracellular Fluid Compartment (ICF) within the cell
  1. major cation: potassium
  2. major anion: phosphate
  1. Extracellular Fluid Compartment (ECF) outside the cell
  1. major cation: sodium
  2. major anion: chloride

Movement of Electrolytes

  1. Diffusion: movement of substances from higher concentration to lower concentration

    Example: Peritoneal dialysis and gas exchange

  2. Active Transport: cell membrane actively transports electrolyte to the direction needed, regardless of concentration on either side.
  • Example: sodium – potassium pump
    •

    Movement of Water pg. 1249

    1. Filtration: pressure in arteries creates pressure into arterioles, which force fluid through arteriole wall. The movement between capillaries to interstitial fluid. AKA Hydrostatic Pressure, ex: kidneys.
    2. Osmosis: water moves from more water (fewer particles) to less water (more particles). Low concentration to high concentration.

    Osmolality Table 45-1

    1. Osmotic Pressure: drawing power of water depends on number of particles in solution.
    2. Osmolality:
    1. isotonic: solution with the same osmolality as plasma, ex: NS, LR
    2. hypotonic: solution with lesser solute concentration than plasma, ex: 0.45% saline, 0.33% saline, 2.5% dextrose. (cell swells)
    3. hypertonic: solution with greater solute concentration than plasma, ex: 5% dextrose in 0.45 saline, 5% dextrose in NS, 5% LR, 3% saline.

    Fluid and Electrolyte Control pg. 1250

    1. Blood Pressure: all filtration depends on BP
    2. Blood Proteins: colloid osmotic pressure – plasma proteins. Without colloid pressure you will notice edema and decrease in BP
    3. Fluid Intake: decreased blood volume and increased blood volume concentration. Water is the end product in the breakdown of food.
    4. Fluid Output:
    1. Kidneys: Table 45.2
    1. Skin:
    1. Lungs:
    1. GI tract:
    1. Hormones:

    Measuring Electrolytes

    Milliequivalents per Liter: mEq/L

    Common Fluid and Electrolyte Imbalances

    1. Sodium: norm adult: 135-145mEq/L, responsible for H2O movement (less common for imbalance)
  • Hyponatremia <130
    1. Causes: Kidney disease, Adrenal Insufficiency, GI losses, Increased sweating, diuretics, metabolic acidosis, interruption of Na – K pump with decreased cell K and decreased serum Na
    2. S/S: weak – rapid pulse, hypotension, dizziness, apprehension – anxiety, abdominal cramps, nausea, vomiting, diarrhea, coma and convulsions, fingerprints remaining on sternum after palpation, cold/clammy skin, personality change
    3. Labs: serum Na <135mEq/L, serum osmolality <280mOsm/Kg, and urine specific gravity <1.010
    4. Tx: eat salty foods and take salt tablets
    •
  • Hypernatremia >145 rare
    1. Causes: Ingestion of large amounts of salt solution (near drowning, IV), too many salt tablets, increased aldosterone secretion.
    2. S/S: severe nausea/vomiting, decreased UO, thirst, dry, flush, CNS changes – agitation, hyperactivity
    3. Labs: serum Na >145mEq/L, serum osmolality >295mOsm/Kg, and urine specific gravity <1.030
    4. Tx: increase large amounts of water, IV fluid
    •
    1. Potassium (note: if IV greater than 20mEq, must be on pump) norm:3.5 – 5.0
  • Hypokalemia <3.5 K
    1. Causes: use of diuretics (Lasix), diarrhea and vomiting
    2. S/S: fatigue, weakness, decrease appetite, heart arrhythmia (flat T wave and depressed ST segments)
    3. Tx: oral supplements, IV K replacement
    •
  • Hyperkalemia >5.6 K
    1. Causes: IV running too fast with K, taking K without Lasix (Dr may DC Lasix and forget to DC K supplement), kidney failure
    2. S/S: irritability, nausea, diarrhea, cardiac arrhythmias/standstill, muscle paralysis
    3. Tx: restriction of K intake (renal failure restrict), oral meds to excrete K in intestines (lactulose), enema solution that exchanges Na for K, severe – kidney dialysis
    •
    1. Calcium norm adult: 4.5 - 5.6 mg/dl
  • Hypocalcemia
    1. Causes: rapid administration of blood containing citrate, hypoalbuminemia, hypoparathyroidism, Vit D deficiency, neoplastic diseases, and pancreatitis.
    2. S/S: numbness and tingling of fingers and circumoral region, hyperactive reflexes, positive Trousseau’s sign (carpopedal spasm with hypoxia), positive Chvostek’s sign (contraction of facial muscles when facial nerve tapped), tetany, muscle cramps, pathological fractures with chronic hypocalcemia
    3. Lab: serum Ca <4.3mEq/L and ECG changes
    •
  • Hypercalcemia
    1. Causes: Hyperthyroidism, metastatic bone tumors, Paget’s disease, osteoporosis, prolonged immobilization
    2. S/S: decreased muscle tone, anorexia, nausea, vomiting, weakness, lethargy, low back pain from kidney stones, decrease LOC, cardiac arrest
    3. Lab: serum Ca levels >5mEq/L, x-ray showing generalized osteoporosis, widespread bone cavitation, and radioplaque urinary stones, elevated BUN >25mg/ml, elevated creatinine >1.5mg/100ml caused by FVD or renal damage due to urolithiasis.
    •
    1. Magnesium: norm adult: 1.2-2mEq/L
    2. Hypomagnesemia
      3.
      1. Causes: Inadequate intake: malnutrition and alcoholism, inadequate absorption: diarrhea, vomiting, nasogastric drainage, fistulas, excessive dietary calcium (competes magnesium for transport sites) small intestine diseases hypothyroidism, Excessive loss resulting from thiazide diuretics, aldosterone excess, polyuria
      2. S/S: Muscular tremors, hyperactive deep tendon reflexes, confusion, disorientation, tachycardia, positive Chvostek's and Trousseau's signs
      3. Lab: serum magnesium > 1.5 mEq/L (also associated with hypocalcemia and hypokalemia)
  • Hypermagnesemia
    1. Causes: Renal failure, excessive parenteral administration of magnesium
    2. S/S: in acute hypermagnesemia: hypoactive deep tendon reflexes, shallow and slow respirations and heart rate, hypotension, flushing
    3. Lab: serum magnesium > 2.5 mEq/L
    •

    • Fluid Imbalances pg 1253

    1. Isotonic Imbalances: Loosing fluids and electrolytes in equal amounts.
    1. Fluid Volume Excess (FVE): hypervolemia
  • Causes:
    •
  • S/S:
    •
  • Labs:
    •
  • Tx:
    •
    1. Fluid Volume Deficit (FVD): hypovolemia
  • Causes:
    •
  • S/S:
    •
  • Labs:
    •
  • Tx: increase fluid intake
    •
    1. Third-Space Syndrome:
  • Causes:
    •
  • S/S:
    •
  • Labs:
    •
  • Tx:
    •

    • Hypovolemic Shock:

    1. Symptoms:
    1. Treatment:

    Nursing Assessment For Fluid Imbalances

    At Risk: - Very young/old, chronic diseases, trauma, burns, therapies, and GI losses

    1. History:
    1. Physical Exam:
    1. Lab Data:

    Correcting Fluid Imbalances

    1. Nursing Implementation
    1. Replacement of Fluids

    IV Solutions

    1. Hydrating Solutions

    ex:

    a. NS .9%

    b. 1/2 NS .45%NaCl

    c. 1/4 NS .22%

      1. Dextrose in water (D5W) 5% Dextrose
      2. e. Dextrose in saline' D5NS, D51/2, D51/4
    1. Maintenance Solutions

    ex:

    a. LR

  • Na, K, Ca, Cl, and lactate in roughly same concentration as plasma

    b. D5LR

    •
    1. Replacement Solutions

    ex:

    1. IV fluid and electrolytes
    2. TPN
    3. blood

    Monitoring IV Fluid Therapy

    1. Assessment
    1. Complications of IV therapy

    Infection Control of IV Therapy

    1. Patient
    1. IV bags
    1. Tubing
    1. Dressing changes
    1. Site

    Blood and Blood Products

    1. Products
    1. Potential complications Table 45-8

    Other notes:

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