Fluids and Electrolytes

Vocabulary flashcards for Fluids and Electrolytes lecture.

Homeostasis Goal

Fluid and Electrolytes

Solvent Definition

Fluid

Solutes Definition

Particles/electrolytes/ions

Intracellular Fluid

Fluid inside the cell

Extracellular Fluid

Fluid outside the cell

Interstitial Fluid

Fluid located throughout the body, can lead to edema

Water Importance

Follows O2, primary fluid in the body

Average Adult Water Composition

60%

Water Content Factors

Greater in children, less in elderly; muscle holds water, fat detracts water; women less than men

Daily Water Need

2-3 L/day

Fluid Sources

Food and beverages (except alcohol)

1 Liter Equivalence

1 kg

Filtration Definition

Moves by hydrostatic pressure (greater to lesser). Water-pushing pressure

Filtration Clinical Sign

Edema

Diffusion Definition

Movement of solutes (particles) from high to low concentration

Diffusion Requirement

Particles in constant motion to reach equilibrium

Factors Affecting Diffusion Rate

Concentration gradient, temperature

Facilitated Diffusion

Requires help to move particles

Facilitated Diffusion Clinical Example

Glucose

Osmosis Definition

Movement of water only, water-pulling pressure

Osmosis Requirements

Membrane separating two fluid spaces, one contains solutes that cannot move

Isotonic Solution

Stays equal

Hypertonic Solution (Hyperosmotic)

Too many solutes, water pulled to dilute the space

Hypotonic Solution

Less solutes, water pushed to dilute the space

Osmosis and Filtration

Work together to maintain shifts between intracellular and extracellular fluid

Factors Affecting Fluid Balance

Age, gender, and fat content

Average Fluid Intake

2-3 L/day

Fluid Intake Sources

Thirst center, food

Fluid Loss Mechanisms

Kidneys, Skin, Lungs, GI tract, Drainage from wounds/GI suction/salivation

Insensible Water Loss

Loss via skin, lungs

Aldosterone Production Location

Adrenal cortex

Aldosterone Action

Reabsorbs sodium and water, prevents hyponatremia and hyperkalemia

Antidiuretic Hormone (ADH) Function

Prevents loss of fluid, creates vasoconstriction

Natriuretic Peptides (NPs)

ANP (atrial natriuretic peptide), BNP (brain natriuretic peptide)

Renin-Angiotensin-Aldosterone System

Compensatory response to low BP; kidneys are key player.

RAAS Cascade

Renin → Angiotensin (weak blood protein) → Angiotensin I → with ACE → Angiotensin II → Vasoconstriction = increased BP

RAAS Activation

Activated when the body is in shock or severe stress

UOP Indicator

Adequate perfusion

Hypertension Patient Teaching

Avoid sodium

Hypovolemia

Dehydration: intake or retention less than needed

Hypovolemia Risk Groups

Very young, elderly, cognitively impaired, and immobile patients

Hypovolemia Forms

Actual (fluid loss/not enough intake) and Relative (shifting of fluid)

Isotonic Dehydration

Water and electrolyte loss equally from ECF

Isotonic Dehydration Common Type

Most common type of fluid volume deficit

1 Kg Weight Change

1 L of water change in body weight (best indicator)

Patient Complaints in Dehydration

Ring or shoes tightness, palpitations, lightheadedness

Orthostatic Hypotension

Worsens with severe dehydration

Abnormal Fluid Losses

Sweating, salivation, diarrhea, wound drainage, vomiting, polyuria

Therapies Causing Fluid Loss

Surgery, excessive hypertonic enemas, diuretics, NG suction, NPO

Cardiovascular Symptoms of Dehydration

Increased HR, diminished/absent peripheral pulses, thready pulse, weight loss, decreased BP, decreased CVP, orthostatic hypotension, flat neck/hand veins

Respiratory Symptoms of Dehydration

Increased rate and depth, tachypnea, confusion, hypoxia

Integumentary Symptoms of Dehydration

Dry, scaly skin; poor turgor; dry oral mucous membranes; edema note pitting

Neurologic Symptoms of Dehydration

Decreased CNS, lethargic, comatose, mental status changes, fever

Renal Symptoms of Dehydration

Decreased UOP, increased specific gravity

Monitoring Dehydration

Daily weights and I&O

Psychosocial Symptoms of Dehydration

Flat affect, delirium, anxious, coma, restless, confused

Dehydration Lab Assessment

Combined labs with patient presentation/symptoms

Dehydration Nursing Diagnosis

Restoring fluid balance

Dehydration Treatments

Fluid replacement, diet, oral rehydration therapy, isotonic fluids

Dehydration Medications

Antidiarrheals, antiemetics, antipyretics

Decreased Cardiac Output Nursing Intervention

Assess heart rate, rhythm, and quality; assess BP; medications

Impaired Oral Mucous Membrane Nursing Intervention

Assessments; medications: IV fluid replacement and saliva substitutes; oral hygiene; avoid commercial mouthwash

Hypervolemia Definition

Excessive fluid in ECF

Hypervolemia Causes

Poor IV therapy control, decreased cardiac output (heart failure), renal failure, long term corticosteroid therapy, blood transfusions

Hypervolemia Dangers

Circulatory overload, edema, heart failure, pulmonary edema

Cardiovascular Symptoms of Overhydration

Increased HR, bounding pulse, increased BP, distended neck vein, weight gain

Respiratory Symptoms of Overhydration

Increased rate, shallow respirations, SOB, moist crackles with auscultation

Skin and Mucous Membrane Symptoms of Overhydration

Pitting edema in dependent areas, pale, cool skin

Neuromuscular Symptoms of Overhydration

Altered LOC, skeletal muscle weakness, headache, paresthesia, visual disturbances, seizures

Renal Symptoms of Overhydration

Decreased specific gravity

Gastrointestinal Symptoms of Overhydration

Increased motility, enlarged liver, diarrhea, ascites

Interventions for Overhydration

Patient safety: more frequent bathroom visits; medications: diuretics; nutritional therapy: fluid restriction + sodium restriction; I&O: Accuracy Consistency

Best Indicator of Fluid Retention

Rapid weight gain

Discharge Teaching for Overhydration

Daily weights: keep a journal; notify healthcare provider: gain of 3 lbs in a week or 2 lbs in 24 hours

Importance of Electrolyte Balances

Small changes = major problems

Normal Serum Sodium Level

135-145 mEq/L

Sodium Location

Outside the cell

Sodium Responsibilities

Water balance; maintains BP, supports network of nerves and muscles

Sodium Sources

Primarily food and fluid

Sodium Regulation

Primarily by kidneys via aldosterone, ADH, and NP

Sodium Role

Skeletal muscle contraction

Hyponatremia Definition

Serum sodium <135 mEq/L

Hyponatremia Occurrence

Often occurs with fluid imbalance

Hyponatremia Effects

Slows cell depolarization, cellular swelling, impaired function

Hyponatremia Causes (Increased Sodium Excretion)

Diuretics, wound drainage, excessive sweating

Hyponatremia Causes (Decreased Sodium Intake)

NPO or low sodium diet, freshwater drowning, excessive ingestion of hypotonic fluids, inadequate sodium intake

Hyponatremia Systemic Assessment (Cerebral)

Behavior and LOC alterations

Hyponatremia Systemic Assessment (Neurologic)

Motor strength and reflexes decrease

Hyponatremia Systemic Assessment (GI)

Bowel sounds increased

Hyponatremia Systemic Assessment (Cardiovascular)

Hypovolemia: rapid, weak, thready; Hypervolemia: bounding, edema, moist respirations

Hyponatremia Safety Precaution

Seizure precautions

Hyponatremia Medication Therapy (Hypovolemia)

IV NS infusions (increase % of sodium IVF)

Hyponatremia Medication Therapy (Hypervolemia)

Osmotic diuretics (mannitol- promotes excretion of water, not sodium) - Avoid other diuretics

Hyponatremia Diet Therapy

Increase oral intake - Restrict oral fluid intake - Monitor I&O

Hypernatremia Definition

Serum sodium level >145 mEq/L

Hypernatremia Initial Effect

Initially causes irritability of excitable tissue

Hypernatremia Later Effect

Later causes cellular dehydration and decreased response

Hypernatremia Common Cause

Actual increase- due to decreased sodium excretion - Renal failure, Corticosteroids, Cushing’s syndrome, Too much IV sodium, Relative increase- due to decreased water intake

Hypernatremia Systemic Assessment (CNS)

Normal or hypovolemia- agitation, seizures; Hypervolemia: lethargy, coma

Hypernatremia Systemic Assessment (Neuromuscular)

Mild rises: assess muscles (twitching) - Higher rises: assess hand grips (weakness)