Chapter 15 Fluid and Electrolytes Balance and Disturbance

Fluid and Electrolyte Balance • Necessary for life and homeostasis • Nursing role is

Fluid • Approximately 60% of the typical adult is fluid • Varies with age, body size, and sex • Intracellular fluid • Extracellular fluid (ECF) – Intravascular – Interstitial – Transcellular • “Third spacing”: loss of ECF into a space that does not contribute to equilibrium Copyright © 2016 Wolters Kluwer • All Rights Reserved

Electrolytes • Active chemicals that carry positive (cations) and negative (anions) electrical charges • Major cations: • Major anions: – Sodium – Chloride – Potassium – Bicarbonate – Calcium – Phosphate – Magnesium – Sulfate – Hydrogen ions – Proteinate ions • Electrolyte concentrations differ in the fluid compartments Copyright © 2016 Wolters Kluwer • All Rights Reserved

Electrolytes cont’d • Major cation in ECF – Sodium • Major cation in ICF

Regulation of Fluid • Movement of fluid through capillary walls depends on: – Hydrostatic pressure § Pressure exerted on the walls of blood vessels – Osmotic pressure § Pressure exerted by the protein in the plasma • The direction of fluid movement depends on the differences of hydrostatic and osmotic pressures Copyright © 2016 Wolters Kluwer • All Rights Reserved

Regulation of Fluid cont’d • Osmosis • Diffusion • Filtration • Active transport Copyright

Question Which of the following is the major cation in extracellular fluid? a. Calcium

Answer b. Sodium Rationale: Sodium is the most abundant electrolyte in the ECF; its

Fluid Balance • Fluid gain – Dietary intake of fluid and food or enteral feeding – Parenteral fluids • Fluid loss – Kidney: urine output – Skin loss: sensible and insensible losses – Lungs – GI tract • Laboratory tests of fluid balance • Homeostatic mechanisms Copyright © 2016 Wolters Kluwer • All Rights Reserved

Gerontologic Considerations • Reduced homeostatic mechanisms: cardiac, renal, and respiratory function • Decreased body fluid percentage • Medication use • Presence of concomitant conditions Copyright © 2016 Wolters Kluwer • All Rights Reserved

Fluid Volume Imbalances • Fluid volume deficit (FVD): hypovolemia • Fluid volume excess (FVE):

Fluid Volume Deficit • Loss of extracellular fluid exceeds intake ratio of water, and electrolytes are lost in the same proportion as they exist in normal body fluids • Dehydration refers to loss of water alone with increased serum sodium level • May occur in combination with other imbalances • Causes: fluid loss from vomiting, diarrhea, GI suctioning, sweating, decreased intake, and inability to gain access to fluid • Risk factors: diabetes insipidus, adrenal insufficiency, osmotic diuresis, hemorrhage, coma, and third space shifts Copyright © 2016 Wolters Kluwer • All Rights Reserved

Fluid Volume Deficit cont’d • Manifestations: rapid weight loss, decreased skin turgor, oliguria, concentrated urine, postural hypotension, rapid and weak pulse, increased temperature, cool and clammy skin caused by vasoconstriction, lassitude, thirst, nausea, muscle weakness, and cramps • Laboratory data: elevated BUN in relation to serum creatinine, increased hematocrit, and possible serum electrolyte changes • Medical management: provide fluids to meet body needs – Oral fluids – IV solutions: see Table 15 -3 Copyright © 2016 Wolters Kluwer • All Rights Reserved

Fluid Volume Deficit—Nursing Management • Monitor intake and output (I&O) and volumetric solution (VS) • Monitor for symptoms: skin and tongue turgor, mucosa, urinary output (UO), and mental status • Initiate measures to minimize fluid loss • Provide oral care • Administer oral fluids • Administer parenteral fluids Copyright © 2016 Wolters Kluwer • All Rights Reserved

Fluid Volume Excess • Caused by fluid overload or diminished homeostatic mechanisms • Risk factors: heart failure, renal failure, and cirrhosis of the liver • Contributing factors: excessive dietary sodium or sodiumcontaining IV solutions • Manifestations: edema; distended neck veins; abnormal lung sounds (crackles); tachycardia; increased BP, pulse pressure, and CVP; increased weight; increased UO; shortness of breath; and wheezing • Medical management is directed at the cause, restriction of fluids and sodium, and the administration of diuretics Copyright © 2016 Wolters Kluwer • All Rights Reserved

Fluid Volume Excess—Nursing Management • Take I&O and daily weights; assess for lung sounds, edema, and other symptoms; monitor responses to medications such as diuretics • Promote adherence to fluid restrictions and patient teaching related to sodium and fluid restrictions • Monitor and avoid sources of excessive sodium; include medications • Promote rest • Use semi-Fowler’s position for orthopnea • Provide skin care and positioning or turning Copyright © 2016 Wolters Kluwer • All Rights Reserved

Electrolyte Imbalances • Sodium: hyponatremia and hypernatremia • Potassium: hypokalemia and hyperkalemia • Calcium: hypocalcemia and hypercalcemia • Magnesium: hypomagnesemia and hypermagnesemia • Phosphorus: hypophosphatemia and hyperphosphatemia • Chloride: hypochloremia and hyperchloremia Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hyponatremia • Serum sodium less than 135 m. Eq/L • Causes: adrenal insufficiency, water intoxication, SIADH, and losses by vomiting, diarrhea, sweating, and diuretics • Manifestations: poor skin turgor, dry mucosa, headache, decreased salivation, decreased BP, nausea, abdominal cramping, and neurologic changes Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hyponatremia cont’d • Medical management: water restriction and sodium replacement • Nursing management: assessment and prevention, monitoring of dietary sodium and fluid intake, identification and monitoring of atrisk patients and the effects of medications (diuretics and lithium) Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hypernatremia • Serum sodium greater than 145 m. Eq/L • Causes: excess water loss, excess sodium administration, diabetes insipidus, heat stroke, and hypertonic IV solutions • Manifestations: thirst; elevated temperature; dry, swollen tongue; sticky mucosa; neurologic symptoms; restlessness; and weakness – Thirst may be impaired in the elderly or ill Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hypernatremia cont’d • Medical management: hypotonic electrolyte solution or D 5 W • Nursing management: assessment and prevention, assess for over-the-counter (OTC) sources of sodium, offer and encourage fluids to meet patient needs, and provide sufficient water with tube feedings Copyright © 2016 Wolters Kluwer • All Rights Reserved

Question Which of the following is a contributing factor of hyponatremia? a. Heat stroke

Answer c. SIADH Rationale: Potential contributing factors of hyponatremia include disease states associated with SIADH such as head trauma and oat-cell lung tumour, use of diuretics, renal disease, and adrenal insufficiency. Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hypokalemia • Below-normal serum potassium (<3. 5 mmol/L) may occur with normal potassium levels in alkalosis owing to shift of serum potassium into cells • Causes: GI losses, medications, alterations of acid– base balance, hyperaldosteronism, and poor dietary intake • Manifestations: fatigue, anorexia, nausea, vomiting, dysrhythmias, muscle weakness, cramps, paresthesias, glucose intolerance, decreased muscle strength, and deep tendon reflexes (DTRs) Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hypokalemia cont’d • Medical management: increased dietary potassium, potassium replacement, and IV for severe deficit • Nursing management: assessment (severe hypokalemia is life-threatening), monitoring of electrocardiogram (ECG), arterial blood gases (ABGs), and dietary potassium, and providing nursing care related to IV potassium administration Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hyperkalemia • Serum potassium greater than 5. 0 mmol/L • Causes: usually treatment-related, impaired renal function, hypoaldosteronism, tissue trauma, and acidosis • Manifestations: cardiac changes and dysrhythmias, muscle weakness with potential respiratory impairment, paresthesias, anxiety, and GI manifestations Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hyperkalemia cont’d • Medical management: monitor ECG, cation exchange resin (Kayexalate), IV sodium bicarbonate, IV calcium gluconate, regular insulin and hypertonic dextrose IV, and -2 agonists; limit dietary potassium; and perform dialysis • Nursing management: assess serum potassium levels, mix well IVs containing K+, monitor medication effects, and initiate dietary potassium restriction and dietary teaching for patients at risk Copyright © 2016 Wolters Kluwer • All Rights Reserved

Effect of Potassium on ECG Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hyperkalemia • Hemolysis of blood specimen or drawing of blood above IV site may result in false laboratory result • Salt substitutes and medications may contain potassium • Potassium-sparing diuretics may cause elevation of potassium and should not be used in patients with renal dysfunction Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hypocalcemia • Causes: hypoparathyroidism, malabsorption, pancreatitis, alkalosis, massive transfusion of citrated blood, renal failure, medications, other • Manifestations: tetany, circumoral numbness, paresthesias, hyperactive DTRs, Trousseau’s sign, Chovstek's sign, seizures, respiratory symptoms of dyspnea and laryngospasm, abnormal clotting, and anxiety Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hypocalcemia cont’d • Medical management: IV of calcium gluconate, calcium and vitamin D supplements, diet • Nursing management: assessment as severe hypocalcemia is life-threatening, weight-bearing exercises to decrease bone calcium loss, patient teaching related to diet and medications, and nursing care related to IV calcium administration Copyright © 2016 Wolters Kluwer • All Rights Reserved

Trousseau’s Sign Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hypercalcemia • Causes: malignancy and hyperparathyroidism, bone loss related to immobility • Manifestations: muscle weakness, incoordination, anorexia, constipation, nausea and vomiting, abdominal and bone pain, polyuria, thirst, ECG changes, and dysrhythmias Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hypercalcemia cont’d • Medical management: treat underlying cause, administer fluids, furosemide, phosphates, calcitonin, and bisphonates • Nursing management: assessment as hypercalcemic crisis has high mortality, encourage ambulation, fluids of 3 to 4 L/d, provide fluids containing sodium unless contraindicated and fibre for constipation, and ensure safety Copyright © 2016 Wolters Kluwer • All Rights Reserved

Question Of which electrolyte is the following true: 98% of it is found intracellularly?

Answer b. Potassium Rationale: Potassium is the major intracellular electrolyte. 98% of the body’s potassium is inside the cells. Potassium influences both skeletal and cardiac muscle activity. Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hypomagnesemia • Causes: alcoholism, GI losses, enteral or parenteral feeding deficient in magnesium, medications, rapid administration of citrated blood; contributing causes include diabetic ketoacidosis, sepsis, burns, and hypothermia • Manifestations: neuromuscular irritability, muscle weakness, tremors, athetoid movements, ECG changes and dysrhythmias, and alterations in mood and level of consciousness Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hypomagnesemia cont’d • Medical management: diet, oral magnesium, and magnesium sulfate IV • Nursing management: assessment, ensure safety, patient teaching related to diet, medications, alcohol use, and nursing care related to IV magnesium sulfate • Hypomagnesemia is often accompanied by hypocalcemia – Monitor and treat potential hypocalcemia – Dysphagia is common in magnesium-depleted patients; assess ability to swallow with water before administering food or medications Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hypermagnesemia • Causes: renal failure, diabetic ketoacidosis, and excessive administration of magnesium • Manifestations: flushing, lowered BP, nausea, vomiting, hypoactive reflexes, drowsiness, muscle weakness, depressed respirations, ECG changes, and dysrhythmias • Medical management: IV calcium gluconate, loop diuretics, IV NS or RL, hemodialysis • Nursing management: assessment, avoid administering medications containing magnesium, and provide patient teaching regarding magnesium-containing OTC medications Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hypophosphatemia • Causes: alcoholism, refeeding of patients after starvation, pain, heat stroke, respiratory alkalosis, hyperventilation, diabetic ketoacidosis, hepatic encephalopathy, major burns, hyperparathyroidism, low magnesium, low potassium, diarrhea, vitamin D deficiency, and diuretic and antacid use • Manifestations: neurologic symptoms, confusion, muscle weakness, tissue hypoxia, muscle and bone pain, and increased susceptibility to infection • Medical management: oral or IV phosphorus replacement • Nursing management: assessment, encourage foods high in phosphorus, and gradually introduce calories for malnourished patients receiving parenteral nutrition Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hyperphosphatemia • Causes: renal failure, excess phosphorus, excess vitamin D, acidosis, hypoparathyroidism, and chemotherapy • Manifestations: few symptoms, soft-tissue calcifications, symptoms occur owing to associated hypocalcemia • Medical management: treat underlying disorder; use vitamin D preparations, calcium-binding antacids, phosphate-binding gels or antacids, loop diuretics, NS IV, and dialysis • Nursing management: assessment, avoid high-phosphorus foods, and provide patient teaching related to diet, phosphatecontaining substances, and signs of hypocalcemia Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hypochloremia • Causes: Addison’s disease, reduced chloride intake, GI loss, diabetic ketoacidosis, excessive sweating, fever, burns, medications, and metabolic alkalosis • Loss of chloride occurs with loss of other electrolytes, potassium, and sodium • Manifestations: agitation, irritability, weakness, hyperexcitability of muscles, dysrhythmias, seizures, and coma Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hypochloremia cont’d • Medical management: replace chloride—IV NS or 0. 45% NS • Nursing management: assessment, avoid free water, encourage high-chloride foods, and provide patient teaching related to high-chloride foods • Causes: excess sodium chloride infusions with water loss, head injury, hypernatremia, dehydration, severe diarrhea, respiratory alkalosis, metabolic acidosis, hyperparathyroidism, and medications Copyright © 2016 Wolters Kluwer • All Rights Reserved

Hyperchloremia • Manifestations: tachypnea, lethargy, weakness, rapid, deep respirations, hypertension, and cognitive changes • Normal serum anion gap • Medical management: restore electrolyte and fluid balance, LR, sodium bicarbonate, and diuretics • Nursing management: assessment, provide patient teaching related to diet and hydration Copyright © 2016 Wolters Kluwer • All Rights Reserved

Maintaining Acid–Base Balance • Normal plasma p. H is 7. 35 to 7. 45: hydrogen ion concentration • Major extracellular fluid buffer system; bicarbonatecarbonic acid buffer system • Kidneys regulate bicarbonate in ECF • Lungs under the control of the medulla regulate CO 2 and, therefore, carbonic acid in ECF • Other buffer systems – ECF: inorganic phosphates and plasma proteins – ICF: proteins, organic and inorganic phosphates – Hemoglobin Copyright © 2016 Wolters Kluwer • All Rights Reserved

Metabolic Acidosis • Low p. H <7. 35 • Low bicarbonate <22 m. Eq/L • Most commonly caused by renal failure • Manifestations: headache, confusion, drowsiness, increased respiratory rate and depth, decreased blood pressure, decreased cardiac output, dysrhythmias, shock; if decrease is slow, patient may be asymptomatic until bicarbonate is 15 m. Eq/L or less • Correct the underlying problem and correct the imbalance; bicarbonate may be administered Copyright © 2016 Wolters Kluwer • All Rights Reserved

Metabolic Acidosis cont’d • With acidosis, hyperkalemia may occur as potassium shifts out of the cell • As acidosis is corrected, potassium shifts back into the cell and potassium levels decrease • Monitor potassium levels • Serum calcium levels may be low with chronic metabolic acidosis and must be corrected before treating the acidosis Copyright © 2016 Wolters Kluwer • All Rights Reserved

Metabolic Alkalosis • High p. H >7. 45 • High bicarbonate >26 m. Eq/L • Most commonly caused by vomiting or gastric suction; may also be caused by medications, especially long-term diuretic use • Hypokalemia will produce alkalosis • Manifestations: symptoms related to decreased calcium, respiratory depression, tachycardia, and symptoms of hypokalemia • Correct underlying disorder, supply chloride to allow excretion of excess bicarbonate, and restore fluid volume with sodium chloride solutions Copyright © 2016 Wolters Kluwer • All Rights Reserved

Respiratory Acidosis • Low p. H <7. 35 • Pa. CO 2 >42 mm Hg • Always caused by a respiratory problem with inadequate excretion of CO 2 • With chronic respiratory acidosis, the body may compensate and may be asymptomatic; symptoms may include a suddenly increased pulse, respiratory rate, and BP; mental changes; feeling of fullness in the head • Potential increased intracranial pressure • Treatment is aimed at improving ventilation Copyright © 2016 Wolters Kluwer • All Rights Reserved

Respiratory Alkalosis • High p. H >7. 45 • Pa. CO 2 <35 mm Hg • Always caused by hyperventilation • Manifestations: lightheadedness, inability to concentrate, numbness and tingling, and sometimes loss of consciousness • Correct cause of hyperventilation Copyright © 2016 Wolters Kluwer • All Rights Reserved

Arterial Blood Gases • p. H— 7. 35 to 7. 45 • Pa. CO 2— 35 to 45 mm Hg • HCO 3ˉ— 22 to 26 mmol/L • Pa. O 2— 80 to 100 mm Hg • Oxygen saturation >94% • Base excess/deficit ± 2 mmol/L Copyright © 2016 Wolters Kluwer • All Rights Reserved

Question Which of the following clinical manifestations is most characteristic of hypocalcemia and hypomagnesemia? a. Tetany b. Constipation c. Facial flushing d. Diplopia Copyright © 2016 Wolters Kluwer • All Rights Reserved

Answer a. Tetany Rationale: Tetany is the most characteristic manifestation of hypocalcemia and hypomagnesemia. Tetany refers to the entire symptom complex induced by increased neural excitability. Copyright © 2016 Wolters Kluwer • All Rights Reserved

Parenteral Fluid Therapy • Solutions are classified as isotonic, hypotonic, or hypertonic • Nursing management • Venipuncture devices • Performing venipuncture—see Chart 15 -3 Copyright © 2016 Wolters Kluwer • All Rights Reserved

IV Site Selection Copyright © 2016 Wolters Kluwer • All Rights Reserved

Complications of IV Therapy • Fluid overload • Air embolism • Septicemia and other infections • Infiltration and extravasation • Phlebitis • Thrombophlebitis • Hematoma • Clotting and obstruction Copyright © 2016 Wolters Kluwer • All Rights Reserved