fluid and electrolytes notes

Overview

  • Normal balance between the body’s fluids, electrolytes, and acids/bases is crucial for health.

  • Homeostasis can be disrupted by abnormalities in fluid levels and electrolyte content.

  • Feedback mechanisms maintain fluid and electrolyte balance.

  • Major systems involved:

    • Nervous and endocrine systems.

    • Integumentary, respiratory, digestive, and urinary systems play significant roles.

Impact of Disorders on Homeostasis

  • Any disorder, disease, or injury can disrupt homeostasis.

  • Increased risk of fluid-electrolyte imbalance or acid-base imbalance occurs in:

    • Individuals at the extreme ends of the age spectrum (old and young).

    • Clients with burn injuries.

    • Clients with preexisting conditions or chronic illnesses.

  • Nurses are responsible for monitoring clients for actual or potential threats to homeostasis.

  • Nursing care focuses on:

    • Monitoring.

    • Maintaining fluid and electrolyte balance.

Diagnostic Tests

Chemistry Panels

  • Study of electrolytes, minimum includes:

    • Sodium (Na), Potassium (K), Chloride (Cl), and Glucose.

  • Can be ordered for single electrolytes or combinations:

    • "Chem 7" or BMP (Basic Metabolic Profile).

    • CMP (Comprehensive Metabolic Profile).

CBC

  • Complete blood count includes WBCs, RBCs, Hgb, and Hct.

LFTs

  • Liver function tests to assess liver health.

ABGs

  • Arterial blood gases providing insight into respiratory and metabolic status.

Key Concepts

  • Fluid and electrolyte disturbances can affect anyone but are particularly common in:

    • Ill and hospitalized patients, including those undergoing surgical and diagnostic procedures.

    • Young children and older adults.

Common Medical Treatments

Fluid Volume Excess

  • Conditions of excess body water in ECF or electrolyte excess may require:

    • Medications to remove excess from the body (oral or rectal).

    • Oral or IV medications to draw out fluids/electrolytes for elimination.

Fluid Volume Deficit

  • May occur with ECF electrolyte deficits. Treatment involves:

    • Administering fluids, electrolytes, and other substances to restore balance.

    • Potassium and other electrolytes administered orally or via IV.

    • IV preferred if oral absorption is inadequate for serious problems.

Example of Treatment

  • Large volume infusion (e.g., 1000cc of potassium) can be added to IV fluids (e.g., 1/2 NS with 20 KCl).

  • Administer smaller volume via intermittent infusion.

  • Monitor blood levels and adjust dosages accordingly.

  • Following correction of critical deficits, oral restrictions may be lifted, and oral fluid or electrolyte replacement can commence.

Nursing Process

Data Collection

  • Observe and monitor all patients for potential disorders in fluid or electrolyte balances.

  • Obtain lab results and report abnormalities to physicians.

  • Baseline levels are crucial for comparisons and identification of abnormalities.

Data Collection Methods

  • Collect and document data on fluid/electrolyte balance by observing:

    • Skin appearance and turgor (elasticity or tonus).

    • Urine volume and specific gravity.

    • Balance between intake and output.

    • Daily weight comparisons.

Indicators of Fluid and Electrolyte Imbalances

  • Presence or absence of edema (swelling).

  • Poor skin turgor; changes in skin color and moisture level.

  • Sudden weight gain or loss; hypertension or hypotension.

  • Significant discrepancies in intake vs. output.

  • Symptoms such as dyspnea, orthopnea, crackles upon auscultation.

  • Abnormal electrolyte levels in lab reports; elevated temperature; changes in urine specific gravity; psychological or sensorium abnormalities.

Nursing Diagnoses for Fluid and Electrolyte Disorders

  • Diagnoses are based on data collection including:

    • Impaired Oral Mucous Membranes related to dehydration, evidenced by:

    • Dry tongue, oral lesions, poor skin turgor, and low urine output.

    • Impaired Urinary Elimination related to changes in urinary output.

    • Excess Fluid Volume related to electrolyte imbalance, evidenced by:

    • Edema in extremities, pulmonary edema, hypertension, ascites, or sodium retention.

    • Deficit Fluid Volume related to fluid or electrolyte imbalance, evidenced by:

    • Hypotension, rapid weight loss, dry skin, concentrated urine, poor skin turgor.

    • Impaired Tissue Integrity resulting from edema or dehydration.

    • Impaired Physical Mobility due to fluid retention or electrolyte disturbances.

Planning and Implementation

  • Care plans aim at:

    • Assisting patients in meeting daily needs.

    • Maintaining balance between intake and output.

    • Educating patients and families about the disorder, prognosis, and treatment regimen.

Teaching the Client and Family

  • Involve patients and families by:

    • Planning diet according to fluid and electrolyte needs.

    • Monitoring dietary restrictions (e.g., Na+ or K+).

    • Following a specified schedule and amounts for food and fluids (such as a 2gm Na diet).

    • Ensuring comprehension of restrictions enhances compliance.

Evaluation

  • Assess whether short-term and long-term goals have been met.

  • Determine ongoing realism of long-term goals.

  • Future nursing care plans should consider:

    • Client’s prognosis.

    • Complications arising.

    • Client’s response to treatment.

Maintenance of Fluid Balance

  • Homeostatic balance of water must be maintained across body fluid compartments.

  • Fluid circulation:

    • Blood-plasma circulates to all body areas.

    • Tissue and lymph fluids move between compartments.

    • Intracellular fluid (ICF) remains relatively stable; disturbances jeopardize patient stability.

  • Imbalances lead to problems such as fluid volume excess or deficit.

Fluid Volume Excess (FVE)

  • Definition: Excessive retention of water and sodium in ECF. Overhydration refers to excess water specifically in extracellular spaces.

Possible Causes of FVE

  • Increased Fluid Intake:

    • Rapid IV fluids containing sodium.

    • Enteral tube feedings (e.g., NG tube).

  • Decreased Urine Output:

    • Related to kidney or liver disorders, physical disorders affecting heart effectiveness (e.g., heart failure).

  • Excess Ingestion of Sodium:

    • Sources like table salt and sodium-rich medications.

  • Physiological Factors:

    • Stress from surgery or trauma causing aldosterone and ADH production, leading to retention of sodium and water.

Nursing Care for FVE

  • Daily observations and data collection.

  • Documentation of effects from treatments (e.g. diuretics).

  • Possible prescriptions for sodium restrictions.

Edema

  • Definition: Excessive interstitial fluid accumulation; can be local (in one area) or generalized (throughout the body).

  • Common conditions: FVE, congestive heart failure (CHF), thrombophlebitis, liver cirrhosis.

  • Increased venous pressure may lead to reabsorption of fluids.

Causes of Edema

  • Low Protein Levels:

    • Malnutrition or liver disease draws fluid out of blood vessels into tissues.

  • Poor Lymphatic Drainage:

    • Lowers osmotic pressure, retaining more fluid.

  • Sodium Restriction due to disorders hindering sodium excretion causes water allocation to tissues.

  • Inflammation:

    • Increased arterial dilation and capillary permeability.

  • Physical Stress:

    • Surgery can increase interstitial fluid due to trauma.

Types of Edema

  • Dependent Edema:

    • Swelling in lower extremities of ambulatory or sedentary individuals.

  • Pitting Edema:

    • Observable dent forms upon slight pressure; graded on scale of +1 to +4 based on duration dent persists.

  • Anasarca:

    • Generalized edema throughout the body; associated conditions include heart problems, kidney failure, and liver failure.

Monitoring for Edema

  • Handle edematous areas with care to prevent breakdown and ulceration.

  • Reposition frequently.

  • Elevate swollen body parts above heart level to relieve edema.

Fluid Volume Deficit (FVD)

  • Definition: Deficiency of fluid and electrolytes in the ECF; dehydration indicates decreased water volume with simultaneous electrolyte changes.

Possible Causes of FVD

  • Inadequate fluid intake (e.g., starvation).

  • Loss of body fluids through:

    • Excessive sweating.

    • Diarrhea or vomiting.

    • Excessive urine output.

    • Drainage from wounds or burns.

    • Prolonged fever.

    • Inability to conserve water; primarily linked to renal failure or endocrine disorders.

Nursing Measures for FVD

  • Monitor skin turgor and urine output to assess hydration status.

  • Evaluate skin for tenting (indicates dehydration).

  • Encourage oral fluid intake unless contraindicated (e.g. risk of aspiration).

  • Consider IV fluid therapy or Total Parenteral Nutrition (TPN) as necessary.

Maintenance of Electrolyte Balance

  • Electrolytes must be balanced for proper bodily function; imbalances can lead to severe consequences.

  • Electrolytes measured in milliequivalents per liter (mEq/L).

  • SI units and milligrams per deciliter (mg/dL) can also be used for measurement.

Key Electrolytes:

  • Sodium (Na+): (135-145 mEq/L) - Main electrolyte in ECF, influences the distribution of water in ICF and ECF.

    • Severity of symptoms from Na+ imbalance depends on cause, speed of change, and degree of change.

    • Hypernatremia: - Na+ ≥ 145 mEq/L; treated with water replenishment.

    • Hyponatremia: …

Maintenance of Acid-Base Balance

  • Acid-base balance is crucial for effective cellular activity; normal ECF pH is approximately 7.4. Slight alterations in pH can significantly affect bodily functions.

Types of Acidosis and Alkalosis

  • Acidosis:

    • Metabolic acidosis: decreased bicarbonate ions (HCO₃⁻) or excess hydrogen ions (H⁺).

    • Respiratory acidosis: increased carbon dioxide levels.

    • Treatment focuses on correcting underlying causes.

  • Alkalosis:

    • Metabolic alkalosis: excess bicarbonate or loss of acids (e.g., from vomiting).

    • Respiratory alkalosis: marked by hyperventilation and reduced CO₂ levels.

Arterial Blood Gases (ABGs)

  • Normal ranges:

    • pH: 7.35-7.45

    • PaCO₂: 35-45 mmHg

    • HCO₃⁻: 22-26 mEq/L

  • ABG interpretation helps determine acidosis or alkalosis type.

Diagnostic Methods using ABGs

  • Use a tic-tac-toe method to categorize acid, normal, or alkaline conditions based on pH, PaCO₂, and HCO₃⁻ values.

  • Analyze patient conditions and diagnose effectively between respiratory vs. metabolic issues.

Example Practice Case

  • Patient scenario demonstrates how to use the ABG interpretation for diagnosis, concluding with respiratory acidosis based on observed lab values.

Key Electrolytes:

  • Sodium (Na+): (135-145 mEq/L) - Main electrolyte in ECF, influences the distribution of water in ICF and ECF.

    • Severity of symptoms from Na+ imbalance depends on cause, speed of change, and degree of change.

    • Hypernatremia: - Na+ ≥ 145 mEq/L; causes include:

    • Dehydration: due to inadequate water intake or excessive loss (sweating, diarrhea).

    • Excess sodium intake: from dietary sources or medications (e.g., saline IV fluids).

    • Diabetes Insipidus: results in hypernatremia due to an inability to retain water.

    • Signs and Symptoms:

    • Thirst, dry mucous membranes, confusion, seizures, coma.

    • Nursing Interventions:

    • Administer oral or intravenous fluids to rehydrate, monitor serum sodium levels, provide a low-sodium diet.

    • Educate patients about avoiding excessive salt intake and recognizing dehydration signs.

    • Hyponatremia: …

Key Electrolytes:

  • Potassium (K+): (3.5-5.0 mEq/L)

    • Major intracellular cation involved in muscle and nerve function.

    • The balance of K+ is essential for maintaining cellular activity and action potentials.

Hyperkalemia:

  • Definition: K+ > 5.0 mEq/L

  • Causes Include:

    • Excessive intake of potassium from supplements or potassium-rich foods (e.g., bananas).

    • Renal failure, preventing proper potassium excretion.

    • Medication side effects (e.g., potassium-sparing diuretics).

  • Signs and Symptoms:

    • Muscle weakness, fatigue, palpitations, and potentially dangerous arrhythmias.

    • Numbness or tingling in extremities.

  • Nursing Interventions:

    • Monitor ECG for signs of dysrhythmias.

    • Administer calcium gluconate, sodium bicarbonate, or insulin with glucose to shift potassium back into the cells.

Hypokalemia:

  • Definition: K+ < 3.5 mEq/L

  • Causes Include:

    • Inadequate dietary intake or excessive loss due to vomiting, diarrhea, or diuretics.

    • Chronic kidney disease.

  • Signs and Symptoms:

    • Muscle cramps, weakness, fatigue, cardiac arrhythmias.

  • Nursing Interventions:

    • Administer potassium supplements orally or intravenously.

    • Monitor electrolyte levels and cardiac rhythm closely.

Calcium (Ca2+): (8.5-10.5 mg/dL)

  • Vital for bone health, muscle function, and nerve signaling.

Hypercalcemia:

  • Definition: Ca2+ > 10.5 mg/dL

  • Causes Include:

    • Hyperparathyroidism, cancer, or excessive calcium or vitamin D intake.

  • Signs and Symptoms:

    • Nausea, vomiting, constipation, muscle weakness, cognitive disturbances.

    • Kidney stones due to increased calcium levels in urine.

  • Nursing Interventions:

    • Hydration with IV fluids to dilute calcium in the blood.

    • Medications (e.g., bisphosphonates or corticosteroids) to lower blood calcium levels.

Hypocalcemia:

  • Definition: Ca2+ < 8.5 mg/dL

  • Causes Include:

    • Vitamin D deficiency, hypoparathyroidism, or chronic kidney disease.

  • Signs and Symptoms:

    • Muscle twitching, cramps, or spasms (tetany).

    • Numbness/tingling in hands and feet.

  • Nursing Interventions:

    • Administer calcium supplements orally or intravenously.

    • Monitor for signs of seizures or cardiac arrhythmias.

Magnesium (Mg2+): (1.5-2.5 mEq/L)

  • Important for muscle contractions, nerve impulses, and energy production.

Hypermagnesemia:

  • Definition: Mg2+ > 2.5 mEq/L

  • Causes Include:

    • Renal failure, excessive intake of magnesium-containing medications (e.g., antacids, laxatives).

  • Signs and Symptoms:

    • Weakness, flushing, hypotension, respiratory depression

  • Nursing Interventions:

    • Administer IV calcium gluconate to reverse effects.

    • Monitor vital signs and cardiac rhythm.

Hypomagnesemia:

  • Definition: Mg2+ < 1.5 mEq/L

  • Causes Include:

    • Chronic diarrhea, malabsorption syndromes, or excessive diuretic use.

  • Signs and Symptoms:

    • Muscle twitching, cramps, weakness, seizures.

  • Nursing Interventions:

    • Administer magnesium supplements orally or IV.

    • Monitor for arrhythmias and neuromuscular changes.

Phosphorus (PO4 3-): (2.5-4.5 mg/dL)

  • Crucial for energy production and bone mineralization.

Hyperphosphatemia:

  • Definition: PO4 3- > 4.5 mg/dL

  • Causes Include:

    • Renal failure, excessive intake of phosphorus-rich foods or oral supplements.

  • Signs and Symptoms:

    • Itchy skin, muscle cramps, and potential calcification of tissues.

  • Nursing Interventions:

    • Manage underlying renal issues and dietary modifications.

    • Administer phosphate binders as prescribed.

Hypophosphatemia:

  • Definition: PO4 3- < 2.5 mg/dL

  • Causes Include:

    • Malabsorption, chronic alcoholism, or excessive antacid use.

  • Signs and Symptoms:

    • Muscle weakness, bone pain, and potential respiratory failure due to respiratory muscle weakness.

  • Nursing Interventions:

    • Administer phosphorus supplements orally or intravenously. Monitor for clinical signs and symptoms of muscle weakness or bone pain.