Medical-Surgical Nursing, 9th Ed., Lewis, Dirksen, Heitkemper & Bucher | Registered Nurse (RN) School Study Aid
Normal Electrolyte Lab Values
- Potassium (K+)
- 3.5 to 5.0 mEq/L
- Calcium (Ca2+)
- 8.5 to 10.5 mg/dL
- Phosphate (PO43–)
- 2.5 to 4.5 mg/dL
- Magnesium (Mg2+)
- 1.5 to 2.5 mEq/L
- Sodium (Na+)
- 135 to 145 mEq/L
- Chloride (Cl–)
- 95 to 105 mEq/L
Conversions: Pounds and Kilograms
- 2.2 lb (pounds)
- 1 kg (kilogram)
- Know Your Own Weight
Hypernatremia
- > 145 mEq/L Na+
- Change in LOC
- Extreme Thirst
- Orthostatic Hypotension
- Dry Flushed Skin
- Muscle Twitching
- Seizures
- Treat and Prevent Dehydration
- Hypotonic Solutions (0.225% or 0.45% NaCl)
- Sodium Restriction
- Diuretics
Hyponatremia
- < 135 mEq Na+
- Nausea and Vomiting
- Decreased LOC
- Confusion / Lethargy
- Seizures
- Assess Airway
- Reduce Diuretic Dosage
- Mannitol (Osmitrol)
- Fluid Restriction
- Hypertonic Solution (3% or 5% NaCl)
Hypokalemia
- < 3.5 mEq/L
- Muscle Weakness
- Arrhythmia
- U Wave
- Ileus
- Hyporeflexia
- IV K+ Infusion at 5-10 mEq/hr
- Give Orally with Food
- Monitor Respiratory Status
Hyperkalemia
- > 5.0 mEq/L K+
- Abdominal Cramps
- Muscle Weakness
- Diarrhea
- Arrhythmia
- Tall, Peaked T Waves
- IV Calcium
- Infusion of Glucose and Insulin
- Loop or Thiazide Diuretics
- Kayexalate
- Dialysis
- Prevention Education
Hypocalcemia
- Muscle Spasms
- < 8.5 mg/dL Ca2+
- Decreased Bone Density
- Tetany
- Chvostek's Sign
- Trousseau's Sign
- Increased DTR
- ECG Changes
- QT Prolongation
- Oral and IV Replacement of Ca2+
- Seizure Precautions
Hypercalcemia
- > 10.5 mg/dL Ca2+
- Pathologic Fractures
- Lethargy
- Hypercoagulation
- Constipation
- ECG Changes
- QT Shortening
- No Calcium Intake
- Chelating Drugs
- Calcitonin
- Bisphosphonates
- Loop Diuretics instead of Thiazide Diuretics
- Increased Risk for Renal Calculi
- Increase Fluids
Hypercalcemia Treatments
- Treat Underlying Disorder
- Hydration
- Dialysis
- Calcium Restriction
- Bisphosphonates
- Calcitonin
- Cinacalcet
- Glucocorticosteroids
- Denosumab
Hypocalcemia Causes
- Hypoalbuminemia
- Hypomagnesemia (Less Common Hypermagnesemia)
- Hypovitaminosis D
- Hypoparathyroidism
- Medications
- Hyperphosphatemia
- Malnutrition
- Acute Pancreatitis
- Alkalosis
- Sepsis
- Chronic Kidney Disease
Hypocalcemia Treatments
- Treat Underlying Disorder
- IV Calcium Gluconate
- Cardioprotective
- Calcium Carbonate
- Calcium Citrate
- Vitamin D Supplements
- Treat Hypomagnesemia
Hypermagnesemia
- Flushing
- Lethargy
- Muscle Weakness
- Decreased Deep Tendon Reflexes (DTRs)
- Decreased Respirations
- Bradycardia
- Hypotension
- Dialysis
- IV Calcium Gluconate
- Diuretics
- Avoid Antacids and Laxatives containing Mg2+
Magnesium Sulfate
- Muscle Relaxant
- Preterm Labor Contractions
- Preeclampsia
- Warm Feeling
- Hypotension
- Decreased Deep Tendon Reflexes (DTRS)
- Decreased Respiratory Rate
- Decreased Urine Output
- Paralytic Ileus
- Calcium Gluconate
Eclampsia
- Increased Central Nervous System Irritability
- Hyperreflexia
- Positive Ankle Clonus
- Headaches
- Visual Disturbances
- Epigastric or RUQ Pain
- Seizures
- Coma
- Don't Leave Bedside
- Magnesium Sulfate
Hypomagnesemia
- Confusion
- Increased Deep Tendon Reflexes (DTRs)
- Neuromuscular Irritability
- Seizures
- Muscle Cramps
- Tremors
- Insomnia
- Tachycardia
- Magnesium Sulfate
- Foods High in Magnesium
How to Interpret Acid Base Disorders
- pH, pCO2, HCO3 (Bicarbonate)
- pH
- Acidosis
- Alkalosis
- pCO2
- Opposite Direction As pH
- Respiratory Acidosis
- Respiratory Alkalosis
- HCO3 (Bicarbonate)
- Same Direction As pH
- Metabolic Acidosis
- Metabolic Alkalosis
Respiratory Acidosis Assessment
- Decreased pH < 7.35
- Increased PaCO2 > 45
- Reduced Respirations
- Anxiety
- Change in LOC
- Tachycardia
- Cyanosis
- Increased Electrolytes
- ECG Changes
- Muscle Weakness
- Hyporeflexia
Respiratory Alkalosis Assessment
- Increased pH > 7.45
- Decreased PaCO2 < 35 mmHg
- Hyperventilation
- Brainstem Stimulation
- Head Injury
- Shock
- Lightheadedness
- Tingling Lips or Fingers
- Trousseau's
- Chvostek's Sign
- Anxiety
Respiratory Alkalosis Interventions
- Treat Underlying Cause
- Decrease Tidal Volume and/or Respiratory Rate
- Give Adequate Pain Control and Sedation
- Sedatives
- Antidepressants
- Compensatory Drop in Serum Bicarbonate
- Calming Breathing Exercises
- Correct CO2 Slowly
Metabolic Acidosis Assessment
- Decreased pH < 7.35
- Decreased HCO3 < 22
- Abdominal Pain
- CNS Depression
- Coma
- Hypotension
- Arrhythmias
- Increased Respirations
- Kussmaul Respirations
- Flushed, Warm, Dry Skin
- Muscle Weakness
Metabolic Acidosis Interventions
- Raise Plasma pH > 7.20
- Treat Underlying Cause
- Sodium Bicarbonate
- Follow ABGs
- Continuously Monitor Patient
Metabolic Alkalosis Assessment
- Increased pH > 7.45
- Increased HCO3 > 26
- Excitable State
- Arrhythmias
- Paresthesias
- Muscle Cramps
- Muscle Weakness
- Decreased Respiratory Effort
Metabolic Alkalosis Interventions
- Treat Underlying Cause
- Stop Potassium (K+) Wasting Diuretics
- Spironolactone
- Acetazolamide
- IV Fluids
- Sodium Chloride
- Replace Potassium (K+)
- Monitor Respiratory Rate
- Monitor Heart Rate
- Seizure Precautions
IV Solutions
- Hypotonic (< 280 mOsm/L)
- 1/4 Normal Saline (0.225% NaCl)
- 1/2 Normal Saline (0.45% NaCl)
- Isotonic (280-300 mOsm)
- Normal Saline (0.9% NaCl)
- Lactated Ringer's (LR)
- Dextrose 5% in Water (D5W)
- Hypertonic (> 300 mOsm)
- 3% or 5% NaCl
- Dextrose 5% in 0.45% NaCl
- Dextrose 10% in Water (D10W)