Respiratory Acidosis Lecture Notes

Introduction

• Presented by Nurse Sarah from RegisteredNurseArian.com
• Focus on respiratory acidosis, a condition due to decreased lung ventilation.

Key Concepts

• Definition: Respiratory acidosis occurs when the body retains CO2, lowering blood pH.
• Normal Blood pH Range: 7.35 - 7.45

Causes of Respiratory Acidosis

• Decreased Breathing Rate:
  • Bradypnea: Less than 12 breaths/minute in adults.
• Damage to Gas Exchange Structures:
  • Alveolar damage affects oxygen and carbon dioxide exchange.
• Weak Respiratory Muscles:
  • Neuromuscular disorders affecting diaphragm strength.

Conditions Leading to CO2 Retention (Mnemonic: DEPRESS)

• D: Drugs (opioids, sedatives) depress respiratory rate.
• E: Diseases (neuromuscular diseases, e.g., Guillain-Barre syndrome).
• P: Pulmonary Edema - fluid in lungs impairs gas exchange.
• E: Emphysema - over-inflated alveoli impair gas exchange.
• S: Spasms of Bronchial Tubes (e.g., asthma).
• S: Sac Elasticity damage (e.g., COPD).

Pathophysiology of CO2 and Blood pH

• CO2 is a waste product from cell metabolism.
• Normal CO2 range: 35 - 45 mmHg. In acidosis, levels > 45 mmHg.
• CO2 binds with H2O to form carbonic acid, impacting blood pH.
• High hydrogen ion concentration lowers blood pH (< 7.35).

Relationship Between CO2 and pH

• High CO2 → High hydrogen ions → Low pH (Acidosis).

Diagnosis of Respiratory Acidosis

• Arterial Blood Gas (ABG) Analysis:
  • Blood pH: < 7.35 (Acidic)
  • PaCO2: > 45 mmHg (Increased CO2)
  • Bicarbonate (HCO3):
    • Normal (22-26): Uncompensated.

    • 26: Partial compensation (bicarbonate increasing to neutralize acidity).

Clinical Manifestations

• Neuro status changes (confusion, drowsiness).
• Hypoxia (low oxygen levels).
• Increased heart rate and potential low blood pressure.

Nursing Interventions

1. Administer Oxygen: Be cautious for COPD patients.
2. Monitor Respiratory Status: Observe breathing rate, rhythm, and neuro status.
3. Coughing and Deep Breathing: Teach use of incentive spirometry for better gas exchange.
4. Suctioning: If fluid/bacteria is present in lungs.
5. Bronchodilators: Improve airway dilation for better gas exchange.
6. Review Medications: Avoid those that decrease respiratory rate.
7. Monitor Electrolytes: Watch for potassium levels due to acidosis (risk of hyperkalemia).
8. Mechanical Ventilation: Prepare for intubation if CO2 levels are critically high.

Conclusion

• Understanding respiratory acidosis is vital for nursing care.
• Be attentive to signs and symptoms and monitor vital signs closely.
• Check out additional resources and videos on the topic.