Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Timby/Smith: Introductory Medical-Surgical Nursing, 11/e Chapter 16: Caring for Clients With Fluid, Electrolyte, and Acid–Base Imbalances

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Fluid and Electrolyte Balance Body fluids –Components Water and chemicals Electrolytes: substances that carry electrical charge when dissolved in fluid Acids: release hydrogen into fluid Bases: substances bind with hydrogen –Purpose: regulate fluid volume, buffer blood to keep its pH neutral

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Fluid and Electrolyte Balance—(cont.) Body fluid compartments –60% of body is water –Intracellular fluid: fluid located within cells –Extracellular fluid: fluid outside of the cells Interstitial fluid Intravascular fluid; plasma

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Intake and Output Average fluid intake –Adult: 2500 mL/day (Range: 1800 to 3600 mL/day) –Sources: food and liquids Fluid elimination –Sources Urination, bowel elimination, perspiration, breathing Insensible losses: sweat, exhaled air

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Distribution of Fluids and Electrolytes Physiologic process: translocation of fluid and exchange of chemicals (electrolytes, acids, bases) is continuous –Five processes Osmosis: movement of water through a semipermeable membrane; tonicity Filtration: promotes movement of fluid according to pressure differences; kidneys Passive and facilitated diffusion; example: insulin facilitates distribution of glucose inside cells Active transport: sodium–potassium pump; requires ATP

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Mechanisms of Fluid and Electrolyte Regulation Mechanisms to maintain normal fluid volume and electrolyte concentrations –Types Osmoreceptors: neurons that sense blood concentration; simulates release of ADH; baroreceptors Renin-angiotensin-aldosterone system: chemicals released to increase BP and blood volume Natriuretic peptides: ANP and BNP released; increases urine production

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Fluid Imbalances Hypovolemia: low volume of extracellular fluid –Causes: vomiting, diarrhea, wounds, profuse urination; hemoconcentration Dehydration: extracellular and intracellular fluids are reduced –Assessment Findings: thirst Diagnostic Findings: elevated Hct and blood cell counts, elevated urine specific gravity –Medical Management: restore fluid deficit; oral or IV Nursing Management: 8 to 10 glasses water/day; avoid caffeine beverages; restrict sodium

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Fluid Imbalances—(cont.) Hypervolemia: high volume of water in intravascular fluid compartment –Causes: excessive oral intake, IV fluids, heart failure, kidney disease, adrenal gland dysfunction; circulatory overload –Assessment Findings: weight gain, elevated BP, pitting or nonpitting edema, dependent edema, moist lung sounds Diagnostic Findings: low Hct and blood cell count, low specific gravity; hemodilution –Medical Management: restrict oral or parenteral fluid; diuretics; limit sodium

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Nursing Care Plan: Hypervolemia Nursing diagnosis: Excess Fluid Volume related to intake that exceeds fluid loss –Baseline and daily weights (weight gain 2 lb/24 hours) –Accurate intake and output –Auscultate lung sounds –Measure BP, heart rate, respiratory rate –Inspect skin for edema, cracks, and breakdown

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Question A client is at risk for impaired skin integrity due to compromised circulation related to heart failure. Interventions to maintain intact skin includes: A) Changing the client’s position every 4 hours B) Restricting ambulation C) Applying elastic stockings D) Keeping client’s legs lower than the heart

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer C) Applying elastic stockings Rationale: Elastic stockings support valves in the veins and prevent fluid from pooling in dependent areas such as the feet and ankles.

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Third-Spacing Third-spacing—translocation of fluid from intravascular to tissue compartments –Causes: hypoalbuminemia, burns, severe allergic reactions –Assessment Findings: ascites, generalized edema Diagnostic Findings: hemoconcentration, CVP normal, blood counts borderline –Medical Management: albumin infusion, IV diuretic

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Electrolyte Imbalances Electrolyte imbalances occur as deficits and/or excess; accompanied by fluid changes –Causes Deficits: administration of IV fluids, vomiting, diarrhea, diuretics Excess: orally consumed, parenteral administration of electrolytes, kidney failure, endocrine dysfunction, crushing injuries, burns Priority electrolytes imbalances: sodium, potassium, calcium, magnesium

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Sodium Imbalances Functions: maintaining normal nerve and muscle activity, regulating osmotic pressure, preserving acid–base balance Hyponatremia –Causes: profuse diaphoresis, diuresis, loss of GI secretions (suctioning, drains), Addison’s disease –Assessment Findings: mental confusion, muscular weakness, anorexia, elevated body temperature, tachycardia –Medical Management: foods high in sodium, IV sodium chloride

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Sodium Imbalances—(cont.) Hypernatremia –Causes: diarrhea, excessive salt intake, high fever, excessive water loss, decreased water intake –Assessment Findings: thirst; dry, sticky mucous membranes; decreased urine output; fever Diagnostic Finding: >145 mEq/L –Medical Management: water intake, hypotonic IV solution (0.45% NaCl or 5% Dextrose) Nursing Management: I&O; assess vital signs; dietary restrictions or supplements

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Potassium Imbalances Function: maintaining normal nerve and muscle activity Hypokalemia –Causes: potassium-wasting diuretics (Lasix, HydroDIURIL), GI tract fluid loss (suctioning, drains, vomiting), corticosteroids, IV insulin and glucose –Assessment Findings: fatigue, weakness, nausea, cardiac dysrhythmias, paresthesias Diagnostic Finding: <3.5 mEq/L –Medical Management: potassium-sparing diuretics (Aldactone), K + foods, oral supplements (K-Lor), IV

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Potassium Imbalances—(cont.) Hyperkalemia –Causes: renal failure, potassium-sparing diuretics, supplements, diet sodas, crushing injuries, Addison’s disease, parenteral potassium salts –Assessment Findings: diarrhea, nausea, muscle weakness, cardiac dysrhythmias Diagnostic Finding: >5.5 mEq/L –Medical management: decreasing K + intake, administration of insulin and glucose, Kayexalate, peritoneal dialysis or hemodialysis Nursing Management: medications, diet teaching

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Calcium Imbalances Hypocalcemia Function: blood clotting, transmission of nerve impulses, regulated by parathyroid gland –Causes: vitamin D deficiency, hypoparathyroidism, burns, pancreatitis, corticosteroids, blood administration, intestinal malabsorption –Assessment Findings: tingling, circumoral paresthesia, muscle cramps, positive Chvostek’s sign, Trousseau’s sign, bleeding, tetany Diagnostic Finding: serum calcium <8.8 mg/dL –Medical Management: oral calcium and vitamin D, IV calcium

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Calcium Imbalances—(cont.) Hypercalcemia –Causes: parathyroid tumors, multiple fractures, Paget’s disease, prolonged immobilization, chemotherapy agents, multiple myeloma –Assessment Findings: deep bone pain, constipation, anorexia, polyuria, pathologic fractures, kidney stones Diagnostic Finding: serum calcium >10 mg/dL –Medical Management: cause, IV sodium chloride, Lasix, corticosteroids or plicamycin –Nursing Management: diet teaching, fluids, fall safety

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Magnesium Imbalances Function: transmission of nerve impulses, activation of enzyme systems including functioning of B vitamins Hypomagnesemia –Causes: alcoholism, diabetic ketoacidosis, renal disease, burns, malnutrition, intestinal malabsorption, diuresis, prolonged gastric suction –Assessment Findings: tachycardia, paresthesias, neuromuscular irritability, HTN, mental changes –Diagnostic Finding: serum magnesium <1.3 mEq/L –Medical Management: oral or IV magnesium, diet supplements

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Magnesium Imbalances—(cont.) Hypermagnesemia –Causes: renal failure, Addison’s disease, excessive antacid or laxative use, hyperparathyroidism –Assessment Findings: flushing, hypotension, lethargy, bradycardia, muscle weakness, coma –Diagnostic Finding: serum magnesium >2.1 mEq/L –Medical Management: decreasing oral magnesium or parenteral replacement, mechanical ventilation Nursing Management: BP and respiratory monitoring

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Question Which of the following interventions would be appropriate when caring for a client with hypercalcemia? A) Encourage fluids. B) Promote bed rest. C) Administer calcium supplement tablets. D) Administer antibiotics.

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer A) Encourage fluids. Rationale: Hypercalcemia is a condition in which serum calcium is elevated. By providing increased amounts of fluid, calcium excretion is promoted and the amount of circulating calcium decreases.

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Acid–Base Balance Regulation of normal plasma pH (7.35 to 7.45= normal) Carbonic acid (H 2 CO 3 ) and bicarbonate (HCO 3 ) –Chemical: adding or removing hydrogen ions –Organ: lungs regulate carbonic acid levels and kidneys regulate bicarbonate levels; decompensation Imbalance types –Acidosis: excessive accumulation of acids or excessive loss of bicarbonate in body fluids –Alkalosis: excessive accumulation of bases or loss of acid in body fluids

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Acid–Base Imbalances Metabolic Acidosis (pH <7.35 to 7.45) –Causes: shock, cardiac arrest, starvation, diabetic ketoacidosis, renal failure, ASA overdose, loss of intestinal fluid, wound drainage –Assessment Findings: deep and rapid breathing, Kussmaul’s breathing, nausea, headache, flushing, abdominal pain, weakness Anion gap –Medical Management: cause, replacing fluids and electrolytes, IV bicarbonate

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Acid–Base Imbalances—(cont.) Metabolic Alkalosis (pH >7.45) –Causes: excessive bicarbonate-containing drugs, diuretic therapy, vomiting, gastric suctioning –Assessment Findings: anorexia, nausea, paresthesias, confusion, hypertonic reflexes, decreased respirations –Medical Management: cause, potassium administration, sodium chloride administration Nursing Management: ABG findings; reports assessment findings

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Acid–Base Imbalances—(cont.) Respiratory Acidosis (pH <7.35) –Causes: pneumothorax, pulmonary edema, asthma, pneumonia, drug overdose, head injuries CF –Assessment Findings: cyanosis, tremors, respiratory insufficiency –Medical Management: mechanical ventilation, airway suctioning, bronchodilators, and antibiotics Arterial blood gas (ABC): values to determine acid–base balances: pH, HCO 3, PaCO 2

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Acid–Base Imbalances—(cont.) Respiratory Alkalosis (pH 7.45) –Causes: anxiety, fever, overactive thyroid, ASA poisoning, mechanical ventilation –Assessment Findings: increased respiratory rate, light-headedness, numbness and tingling of fingers and toes, paresthesias, sweating, panic –Medical Management: rebreathe expired air (brown bag breathing), sedation Nursing management: report assessment findings, monitor laboratory values

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Question Which acid–base disturbance would be most characteristic of a narcotic overdose? A) Metabolic Acidosis B) Respiratory Acidosis C) Metabolic Alkalosis D) Respiratory Alkalosis

Copyright © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer B) Respiratory acidosis Rationale: A narcotic overdose slows the rate and depth of breathing. This leads to retention of carbon dioxide (acid). Hypoventilation problems produce respiratory acidosis.