Fundamentals of Nursing: The Art and Science of Person-Centered Care, 10th Ed., Taylor, Lynn & Bartlett | Registered Nurse (RN) School Study Aid
Blood Acid-Base Control
- In a State of Acidemia
- Medullary Chemoreceptors Control Ventilation Rate
- Expulsion of CO2 through Lungs Increases pH
- Bicarbonate Reabsorption from the Kidney Increases pH
- Kidney Excretion of H+ Increases pH
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
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
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
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
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
Hypomagnesemia
- Confusion
- Increased Deep Tendon Reflexes (DTRs)
- Neuromuscular Irritability
- Seizures
- Muscle Cramps
- Tremors
- Insomnia
- Tachycardia
- Magnesium Sulfate
- Foods High in Magnesium
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+
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 Alkalosis Assessment
- Increased pH > 7.45
- Increased HCO3 > 26
- Excitable State
- Arrhythmias
- Paresthesias
- Muscle Cramps
- Muscle Weakness
- Decreased Respiratory Effort
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