Oxygenation and Nebulization
Both oxygenation and nebulization are fundamental concepts in respiratory care, essential for treating hypoxia and airway diseases like asthma, COPD, and respiratory infections.
Oxygenation
Oxygenation refers to the process of delivering oxygen (O₂) to the body’s tissues via the lungs and bloodstream. It is crucial for cellular metabolism and survival.
Indications:
- Hypoxia (PaO₂ < 60 mmHg or SpO₂ < 90%)
- Respiratory failure
- Severe anemia
- Cardiac arrest
- Shock
- CO poisoning
- Postoperative support
Methods of Oxygen Delivery
1. Low-Flow Oxygen Systems (Delivers O₂ mixed with room air)
| Device | FiO₂ Delivered | Flow Rate |
|---|---|---|
| Nasal Cannula | 24–44% | 1–6 L/min |
| Simple Face Mask | 40–60% | 5–10 L/min |
| Partial Rebreather Mask | 60–80% | 6–10 L/min |
| Non-Rebreather Mask | 80–100% | 10–15 L/min |
2. High-Flow Oxygen Systems (Delivers fixed O₂ concentration)
| Device | FiO₂ Delivered | Flow Rate |
|---|---|---|
| Venturi Mask | 24–60% | 4–15 L/min |
| High-Flow Nasal Cannula (HFNC) | Up to 100% | >40 L/min |
| Mechanical Ventilation | 21–100% | Variable |
Oxygen Toxicity:
- Caused by prolonged exposure to FiO₂ > 60%
- Symptoms: CNS effects (seizures), lung damage (ARDS-like), retinopathy in neonates
Parts of Oxygenation System
Oxygenation systems are used to deliver supplemental oxygen to patients with hypoxia or respiratory distress. These systems consist of the following components:
A. Oxygen Source
✔ Oxygen Cylinder – Portable source of oxygen (Green-colored in many countries)
✔ Oxygen Concentrator – Extracts oxygen from room air (Used for home therapy)
✔ Central Oxygen Supply – Used in hospitals through wall outlets
B. Oxygen Delivery Devices
✔ Nasal Cannula (FiO₂: 24–40%) – Low flow, comfortable, used in stable patients
✔ Simple Face Mask (FiO₂: 40–60%) – Higher oxygen flow than a nasal cannula
✔ Venturi Mask (FiO₂: 24–50%) – Precise oxygen concentration control
✔ Non-Rebreather Mask (NRM) (FiO₂: 60–90%) – For severely hypoxic patients
✔ High Flow Nasal Cannula (HFNC) (FiO₂: Up to 100%) – Heated, humidified oxygen therapy
✔ Bag-Valve Mask (BVM) or Ambu Bag – Used for emergency resuscitation
✔ Mechanical Ventilator – Used in ICU for critically ill patients
C. Oxygen Flow Control System
✔ Flowmeter – Regulates oxygen flow (measured in liters per minute, LPM)
✔ Pressure Regulator – Controls pressure from the oxygen cylinder
✔ Humidifier Bottle – Adds moisture to prevent dryness in nasal passages and airways
Nebulization
Nebulization is a method of delivering medications in aerosolized form for inhalation into the lungs. It is commonly used for bronchodilation, mucolysis, and anti-inflammatory effects.
Indications:
- Asthma
- COPD
- Cystic fibrosis
- Respiratory infections
- Pulmonary edema (e.g., nebulized furosemide)
Types of Nebulizers
1. Jet Nebulizer (Pneumatic)
- Compressed gas (air/O₂) converts liquid medication into aerosol
- Common, cost-effective
2. Ultrasonic Nebulizer
- Uses high-frequency vibrations to generate mist
- More efficient but expensive
3. Mesh Nebulizer
- Uses vibrating mesh to create fine aerosols
- Portable, efficient, silent
Common Nebulized Medications:
| Drug Class | Examples | Indication |
|---|---|---|
| Bronchodilators | Salbutamol, Ipratropium | Asthma, COPD |
| Corticosteroids | Budesonide | Asthma, severe COPD |
| Mucolytics | N-acetylcysteine | Thick mucus, CF |
| Antibiotics | Tobramycin, Colistin | CF, pneumonia |
| Diuretics | Furosemide | Pulmonary edema |
Complications of Nebulization:
- Tachycardia (β₂-agonists)
- Tremors
- Dry mouth (anticholinergics)
- Oral thrush (steroids)
Nebulization System Parts
Nebulization systems are used to deliver liquid medications in aerosol form for respiratory treatment. These systems include:
A. Nebulizer Machine (Compressor Unit)
✔ Converts liquid medication into fine mist
✔ Types: Jet Nebulizer, Ultrasonic Nebulizer, Mesh Nebulizer
B. Medication Chamber (Nebulizer Cup)
✔ Holds the liquid medication
✔ Attached to the compressor via tubing
C. Nebulizer Tubing
✔ Connects the compressor to the nebulizer chamber
✔ Carries compressed air to generate mist
D. Nebulizer Mask or Mouthpiece
✔ Face Mask – Used for children or unconscious patients
✔ Mouthpiece – Preferred for adults to ensure better drug delivery
E. Medication for Nebulization
✔ Bronchodilators (Salbutamol, Ipratropium) – For asthma, COPD
✔ Corticosteroids (Budesonide, Fluticasone) – For inflammation
✔ Mucolytics (Acetylcysteine) – For thick mucus clearance
✔ Antibiotics (Tobramycin) – For infections in CF, bronchiectasis
Safety and Maintenance
✔ Check oxygen cylinder pressure & flow before use
✔ Avoid open flames near oxygen sources
✔ Clean nebulizer parts regularly to prevent infection
✔ Replace disposable filters and tubing as needed
Key Differences: Oxygenation vs. Nebulization
| Feature | Oxygenation | Nebulization |
|---|---|---|
| Purpose | Oxygen delivery | Drug delivery |
| Method | Nasal cannula, mask, ventilator | Jet, ultrasonic, mesh nebulizers |
| Indications | Hypoxia, respiratory failure | Asthma, COPD, CF |
| Side Effects | Oxygen toxicity | Drug-specific reactions |
FiO₂: FiO₂ (Fraction of Inspired Oxygen) means the percentage of oxygen present in the air a person breathes.
COPD (Chronic Obstructive Pulmonary Disease): COPD is a progressive (slowly progressing) lung disease in which airflow is obstructed, making it difficult for the patient to breathe. It is mainly caused by smoking, air pollution, and long-term exposure to occupational dust/chemicals.
COPD is a group of two main diseases:
A. Chronic Bronchitis: Called "Blue Bloater". Cough and mucus persist for at least 3 months in 2 years. Inflammation and mucus formation in the airways (bronchi), which obstructs air flow.
B. Emphysema: Called "Pink Puffer". The walls of the alveoli are destroyed, which affects gas exchange (O₂-CO₂). Main causes: Damage to the alveoli due to smoking and air pollution.
Cystic Fibrosis (CF): CF is an autosomal recessive genetic disease caused by mutations in the CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) gene. This disease is primarily caused by excessive formation of thick mucus in the lungs, digestive tract and other organs.