Oxygen Therapy: Delivery Methods, Indications, and Monitoring for Hypoxemia

Comprehensive Guide to Supplemental Oxygen Administration

Oxygen therapy aims to correct hypoxemia (low arterial PaO₂) and improve tissue oxygenation. Delivery method depends on severity, patient tolerance, and clinical setting.

Delivery Devices & FiO₂ Ranges

Device	Flow Rate	Approx. FiO₂	Indications
Nasal Cannula	1–6 L/min	24–44%	Mild hypoxemia, chronic COPD, comfort
Simple Face Mask	5–10 L/min	40–60%	Short-term, moderate hypoxemia
Partial Rebreather Mask	6–10 L/min	60–80%	Moderate-severe; reservoir bag
Non-Rebreather Mask	10–15 L/min	80–95%	Severe hypoxemia, pre-intubation
Venturi Mask	Device-specific	24–50% (precise)	COPD (controlled O₂), precise titration
High-Flow Nasal Cannula (HFNC)	Up to 60 L/min	21–100% (titrated)	Acute hypoxemic failure, pre-oxygenation, comfort
CPAP / BiPAP	Pressure-based	Variable	Obstructive sleep apnea, cardiogenic pulmonary edema, COPD exacerbation
Mechanical Ventilation	Ventilator settings	21–100%	Respiratory failure, ARDS, post-arrest, neuroprotection

Adjunctive Therapies

• Bronchodilators: Beta-agonists, anticholinergics → reduce airway resistance.
• Corticosteroids: Reduce inflammation (asthma, COPD, COVID-19).
• Antibiotics: For infectious causes (pneumonia, bronchitis).
• Diuretics: For cardiogenic pulmonary edema.
• PEEP (Ventilator): Prevents alveolar collapse, improves FRC.
• Positioning: Upright/semi-Fowler's → improves V/Q matching.

Monitoring & Titration

• Continuous pulse oximetry (SpO₂ target: 92–96% most; 88–92% COPD).
• Serial ABG/VBG for PaO₂, PaCO₂, pH.
• Assess work of breathing, mental status.
• Wean per protocol; avoid oxygen toxicity (prolonged >0.6 FiO₂).