Fluid and Electrolyte Imbalance
Comprehensive Nursing Notes
Evidence-Based Clinical Guide for Nursing Students
Table of Contents
Introduction
Fluid and electrolyte balance is fundamental to human physiology and critical for nursing practice. The human body is approximately 60% water, with intricate mechanisms maintaining homeostasis through complex regulatory systems involving the cardiovascular, renal, endocrine, and respiratory systems.
Cardiovascular
Maintains blood pressure and circulation
Renal
Regulates fluid and electrolyte excretion
Respiratory
Maintains acid-base balance
Pathophysiology
Fluid Compartments
Intracellular Fluid (ICF)
- 67% of total body water
- High potassium, magnesium, phosphate
- Low sodium, chloride
- Regulated by sodium-potassium pump
Extracellular Fluid (ECF)
- 33% of total body water
- High sodium, chloride, bicarbonate
- Low potassium, magnesium
- Includes plasma and interstitial fluid
Regulatory Mechanisms
Hormonal Regulation
Antidiuretic Hormone (ADH)
Increases water reabsorption in collecting ducts
Aldosterone
Increases sodium reabsorption, potassium excretion
Atrial Natriuretic Peptide (ANP)
Promotes sodium and water excretion
Renal Mechanisms
Glomerular Filtration
Initial filtration of blood plasma
Tubular Reabsorption
Selective reabsorption of substances
Tubular Secretion
Active transport into urine
Types of Fluid and Electrolyte Imbalances
Fluid Imbalances
Hypovolemia (Fluid Volume Deficit)
Causes:
- Excessive fluid loss (vomiting, diarrhea, diuretics)
- Inadequate fluid intake
- Third-spacing (burns, peritonitis)
- Hemorrhage
Clinical Signs:
- Decreased skin turgor
- Dry mucous membranes
- Hypotension, tachycardia
- Concentrated urine
Hypervolemia (Fluid Volume Excess)
Causes:
- Heart failure
- Renal disease
- Excessive sodium intake
- Liver cirrhosis
Clinical Signs:
- Edema, weight gain
- Jugular vein distension
- Crackles in lungs
- Hypertension
Major Electrolyte Imbalances
Sodium (Na+) Imbalances
| Condition | Normal Range | Causes | Signs & Symptoms |
|---|---|---|---|
| Hyponatremia (<135 mEq/L) | 135-145 mEq/L |
|
|
| Hypernatremia (>145 mEq/L) | 135-145 mEq/L |
|
|
Potassium (K+) Imbalances
| Condition | Normal Range | Causes | Signs & Symptoms |
|---|---|---|---|
| Hypokalemia (<3.5 mEq/L) | 3.5-5.0 mEq/L |
|
|
| Hyperkalemia (>5.0 mEq/L) | 3.5-5.0 mEq/L |
|
|
Calcium (Ca2+) Imbalances
| Condition | Normal Range | Causes | Signs & Symptoms |
|---|---|---|---|
| Hypocalcemia (<8.5 mg/dL) | 8.5-10.5 mg/dL |
|
|
| Hypercalcemia (>10.5 mg/dL) | 8.5-10.5 mg/dL |
|
|
Magnesium (Mg2+) Imbalances
| Condition | Normal Range | Causes | Signs & Symptoms |
|---|---|---|---|
| Hypomagnesemia (<1.3 mEq/L) | 1.3-2.1 mEq/L |
|
|
| Hypermagnesemia (>2.1 mEq/L) | 1.3-2.1 mEq/L |
|
|
Clinical Assessment
Systematic Assessment Approach
A comprehensive assessment is essential for early detection and management of fluid and electrolyte imbalances.
Physical Assessment
Cardiovascular System
- Heart rate and rhythm
- Blood pressure (orthostatic changes)
- Jugular vein distension
- Peripheral pulses
- Capillary refill time
Respiratory System
- Respiratory rate and pattern
- Lung sounds (crackles, wheezes)
- Work of breathing
- Oxygen saturation
Neurological System
- Level of consciousness
- Mental status changes
- Muscle strength and tone
- Deep tendon reflexes
- Chvostek’s and Trousseau’s signs
Laboratory Assessment
Basic Metabolic Panel
- Sodium (135-145 mEq/L)
- Potassium (3.5-5.0 mEq/L)
- Chloride (98-107 mEq/L)
- CO2/Bicarbonate (22-28 mEq/L)
- BUN/Creatinine
- Glucose
Additional Tests
- Calcium (8.5-10.5 mg/dL)
- Magnesium (1.3-2.1 mEq/L)
- Phosphorus (3.0-4.5 mg/dL)
- Serum osmolality
- Urine specific gravity
- Arterial blood gases
Monitoring Parameters
- Daily weights
- Intake and output
- ECG changes
- Vital signs trending
Assessment Flowchart
Vital signs, mental status, skin assessment
Medications, recent illness, diet, symptoms
BMP, ABG, additional electrolytes as needed
Identify imbalance type and severity
Clinical Manifestations
System-Based Manifestations
Clinical manifestations of fluid and electrolyte imbalances affect multiple body systems and can range from subtle to life-threatening.
Neurological
Hyponatremia:
- Confusion, altered LOC
- Seizures, coma
- Headache
Hypernatremia:
- Restlessness, irritability
- Muscle twitching
- Hyperreflexia
Calcium Imbalances:
- Tetany (hypocalcemia)
- Weakness (hypercalcemia)
- Paresthesias
Cardiovascular
Hypovolemia:
- Hypotension, tachycardia
- Weak, thready pulse
- Decreased CVP
Hypervolemia:
- Hypertension
- Bounding pulse
- Elevated CVP, JVD
Potassium Imbalances:
- Arrhythmias
- ECG changes
- Cardiac arrest risk
Respiratory
Hypervolemia:
- Pulmonary edema
- Crackles, dyspnea
- Orthopnea
Hypocalcemia:
- Laryngospasm
- Bronchospasm
- Respiratory arrest
Hypermagnesemia:
- Respiratory depression
- Shallow breathing
- Respiratory failure
Critical Warning Signs
Immediate Intervention Required
- Hyperkalemia >6.0 mEq/L: Peaked T-waves, widened QRS
- Severe Hypocalcemia: Laryngospasm, seizures
- Severe Hyponatremia (<120 mEq/L): Altered consciousness, seizures
- Severe Hypernatremia (>160 mEq/L): Neurological deterioration
Life-Threatening Complications
- Cardiac arrest from severe K+ imbalance
- Cerebral edema from rapid Na+ correction
- Respiratory failure from Mg2+ excess
- Pulmonary edema from fluid overload
Nursing Interventions
Evidence-Based Nursing Care
Nursing interventions focus on prevention, early detection, safe administration of treatments, and patient education to maintain fluid and electrolyte balance.
Priority Nursing Diagnoses
Primary Diagnoses
- Fluid Volume Deficit related to excessive losses
- Fluid Volume Excess related to compromised regulatory mechanisms
- Risk for Imbalanced Electrolytes related to altered intake/output
Secondary Diagnoses
- Risk for Falls related to weakness/confusion
- Impaired Gas Exchange related to pulmonary edema
- Knowledge Deficit related to dietary restrictions
Specific Interventions by Imbalance
Hypovolemia (Fluid Volume Deficit)
Immediate Interventions
- Assess vital signs every 15 minutes initially
- Monitor orthostatic changes
- Insert large-bore IV (18G or larger)
- Administer prescribed fluids (NS, LR)
- Monitor urine output hourly
- Daily weights (same time, same scale)
Ongoing Monitoring
- I&O monitoring every shift
- Assess skin turgor and mucous membranes
- Monitor lab values (BUN, creatinine, Hct)
- Assess mental status changes
- Monitor for signs of fluid overload
- Patient positioning for comfort
Hypervolemia (Fluid Volume Excess)
Immediate Interventions
- Position patient in high Fowler’s
- Administer prescribed diuretics
- Restrict fluids as ordered
- Monitor respiratory status closely
- Apply oxygen as needed
- Monitor BP and heart rate
Ongoing Monitoring
- Daily weights (expect 1-2 lb loss/day)
- Assess for edema progression
- Monitor electrolytes post-diuresis
- Skin care for edematous areas
- Activity modification
- Sodium restriction education
Electrolyte-Specific Interventions
Potassium Imbalances
Hypokalemia:
- Never give IV K+ as bolus
- Maximum 20 mEq/hour via central line
- Maximum 10 mEq/hour via peripheral IV
- Monitor cardiac rhythm continuously
- Encourage K+-rich foods
Hyperkalemia:
- Continuous cardiac monitoring
- Prepare for calcium gluconate
- Administer insulin/dextrose if ordered
- Consider sodium polystyrene
- Prepare for possible dialysis
Calcium Imbalances
Hypocalcemia:
- Keep calcium gluconate at bedside
- Monitor for tetany, seizures
- Test Chvostek’s and Trousseau’s signs
- Maintain quiet environment
- Seizure precautions
Hypercalcemia:
- Promote mobility and weight-bearing
- Increase fluid intake
- Monitor for kidney stones
- Assess neurological status
- Administer loop diuretics if ordered
Patient Safety Considerations
Fall Prevention
- Bed in lowest position
- Call light within reach
- Assist with ambulation
- Non-slip socks
- Clear pathways
Cardiac Monitoring
- Continuous telemetry for K+ imbalances
- Alarm parameters set appropriately
- Document rhythm strips
- Report critical changes immediately
- Emergency medications ready
IV Safety
- Use infusion pumps for electrolytes
- Double-check concentrations
- Monitor injection sites
- Never push K+ or Mg2+
- Follow facility protocols
Pharmacological Management
Common Medications
Diuretics
| Class | Example | Action | Nursing Considerations |
|---|---|---|---|
| Loop Diuretics | Furosemide (Lasix) | Blocks sodium reabsorption in loop of Henle | Monitor K+, Mg2+, hearing. Give IV slowly. |
| Thiazide | Hydrochlorothiazide | Blocks sodium in distal tubule | Monitor K+, may increase Ca2+, glucose |
| Potassium-Sparing | Spironolactone | Aldosterone antagonist | Risk of hyperkalemia, gynecomastia |
Electrolyte Replacements
Potassium Supplements
Potassium Chloride (KCl)
- IV: Never push, max 20 mEq/hr central, 10 mEq/hr peripheral
- PO: Give with food, full glass of water
- Monitor for GI irritation
- Check renal function before giving
Calcium Supplements
Calcium Gluconate
- Preferred for IV administration
- Less irritating than calcium chloride
- Monitor for infiltration
- Check compatibility with other drugs
Emergency Medications
Hyperkalemia Treatment
Calcium Gluconate 10%
1-2 ampules IV push over 2-3 minutes
Stabilizes cardiac membrane
Regular Insulin + Dextrose
10 units insulin + 50 mL D50 IV
Shifts K+ intracellularly
Sodium Polystyrene (Kayexalate)
15-60 g PO or PR
Binds K+ in GI tract
Hypocalcemia Treatment
Calcium Gluconate 10%
1-2 ampules in 50-100 mL NS over 10-20 min
For symptomatic hypocalcemia
Calcitriol (Rocaltrol)
0.25-2 mcg PO BID
Active form of vitamin D
Medication Safety Tips
Five Rights
- Right patient
- Right medication
- Right dose
- Right route
- Right time
High-Alert Meds
- Concentrated electrolytes
- IV potassium
- Magnesium sulfate
- 3% saline
- Calcium preparations
Documentation
- Time given
- Patient response
- Vital signs
- IV site condition
- Any adverse effects
Memory Aids & Mnemonics
Learn Faster, Remember Longer
Use these memory aids to master fluid and electrolyte concepts for exams and clinical practice.
Electrolyte Functions – “SICKENED”
Hypokalemia Signs – “A SIC WALT”
Cardiac dysrhythmias, U-waves
Respiratory muscle weakness
Mood changes, weakness
Altered mental status
Muscle weakness, paralysis
pH imbalance
Polyuria
Weak, irregular pulse
Hypercalcemia – “STONES, BONES, GROANS, THRONES”
Kidney stones from hypercalciuria
Bone pain, osteoporosis, fractures
Nausea, vomiting, constipation
Psychiatric moans (confusion, depression)
IV Fluid Types – “ICE”
ISOTONIC
Same osmolarity as blood
- Normal Saline (0.9% NaCl)
- Lactated Ringer’s
- D5W (initially)
CONCENTRATED
Hypertonic solutions
- 3% Saline
- 5% Saline
- D10W, D50W
EXPANDED
Hypotonic solutions
- 0.45% Saline
- 0.33% Saline
- D5W (after glucose metabolized)
Quick Reference – Normal Values
Sodium
135-145
mEq/L
Potassium
3.5-5.0
mEq/L
Calcium
8.5-10.5
mg/dL
Magnesium
1.3-2.1
mEq/L
Implementation in Nursing Practice
Evidence-Based Practice Integration
Successful management of fluid and electrolyte imbalances requires systematic application of evidence-based nursing practices across all healthcare settings.
Assessment Implementation
Systematic Approach
- Establish baseline measurements on admission
- Use standardized assessment tools
- Document findings using objective measurements
- Trend data over time for pattern recognition
Technology Integration
- Electronic health records for trend monitoring
- Digital intake/output monitoring systems
- Mobile apps for calculation assistance
- Automated alert systems for critical values
Care Planning and Prioritization
Priority Setting Framework
Life-Threatening
Severe K+ imbalances, fluid overload with respiratory compromise
Safety Concerns
Fall risk from weakness, cognitive changes
Comfort/Teaching
Patient education, symptom management
Interdisciplinary Collaboration
Key Team Members:
- Primary physician/nurse practitioner
- Clinical pharmacist
- Registered dietitian
- Physical/occupational therapy
Communication Strategies:
- SBAR format for critical changes
- Multidisciplinary rounds participation
- Clear documentation of interventions
- Prompt notification of providers
Quality Improvement Initiatives
Performance Metrics
Early Detection Rate
Percentage of imbalances identified before becoming severe
Medication Error Reduction
High-alert medication safety protocols
Patient Satisfaction
Education effectiveness and symptom management
Continuous Learning
Regular Competency Testing
Annual validation of knowledge and skills
Case Study Reviews
Learning from complex patient scenarios
Evidence-Based Updates
Incorporating latest research findings
Patient Education Implementation
Assessment of Learning Needs
Health literacy, cultural factors, preferred learning style
Teaching Methods
Visual aids, hands-on practice, written materials, digital resources
Evaluation of Understanding
Teach-back method, return demonstrations, follow-up assessments
Key Education Topics
- Dietary modifications and restrictions
- Medication compliance and side effects
- When to seek medical attention
- Daily weight monitoring techniques
- Fluid intake guidelines
- Activity modifications