Administering Oxygen Therapy

Oxygen therapy treats respiratory insufficiency by delivering supplemental oxygen to maintain adequate blood oxygen saturation. You will use it across emergency care, the ICU, and chronic care.

What is Oxygen Therapy?

Oxygen therapy gives supplemental oxygen to patients with hypoxemia (low blood oxygen), improving oxygenation so vital organs and tissues function. It is used in chronic obstructive pulmonary disease (COPD), pneumonia, asthma exacerbations, heart failure, and surgical recovery, delivered through nasal cannulas, face masks, or mechanical ventilators depending on need and severity.

Purpose of Oxygen Therapy

• Increase arterial oxygen levels to maintain tissue oxygenation and prevent hypoxia.
• Reduce the work of breathing, easing the effort of the respiratory muscles.
• Decrease the workload on the heart, since better oxygen delivery means the heart does not pump as hard.
• Alleviate symptoms of hypoxemia, such as shortness of breath and fatigue.

Indications

• Acute respiratory distress: immediate relief by increasing oxygen supply, preventing respiratory failure.
• COPD: long-term therapy maintains oxygen levels, reduces pulmonary hypertension risk, and improves exercise tolerance.
• Pneumonia: supplemental oxygen offsets impaired gas exchange from inflammation and fluid.
• Asthma exacerbations: restores oxygen while bronchodilators and steroids take effect.
• Heart failure: improves oxygenation, reduces cardiac work, and eases shortness of breath.
• Post-operative recovery: maintains oxygen during reduced lung function from anesthesia, pain, or immobility.
• Acute myocardial infarction: reduces cardiac workload, preserves myocardial tissue, and eases chest pain.
• Hypoxia from trauma or shock: stabilizes the patient by improving oxygenation and supporting organ function.

Contraindications and Cautions

• Hypoventilation: excessive oxygen can further reduce respiratory drive, risking depression or failure.
• COPD with CO2 retention: high oxygen can worsen hypercapnia and cause respiratory acidosis.
• Certain pneumothoraxes: oxygen can worsen a poorly managed pneumothorax.
• Inflammatory lung conditions (ARDS, severe pneumonia): excessive oxygen can worsen lung damage.
• Hyperbaric oxygen therapy: avoid or use cautiously in untreated pneumothorax or certain cardiovascular conditions, due to barotrauma risk.
• Absence of a clear diagnosis: oxygen can mask underlying conditions and delay treatment.
• Oxygen toxicity risk: prolonged high concentrations damage lung tissue and the CNS (seizures).
• Certain cardiovascular conditions (severe heart failure, unstable angina): manage high concentrations carefully.

Oxygen Delivery Systems

Low-flow and high-flow systems differ by oxygen requirement, comfort, and developmental need. Low-flow systems use small-bore tubing (nasal cannulas, face masks, oxygen tents, transtracheal catheters); the patient breathes room air plus supplemental oxygen, so the fraction of inspired oxygen (FiO2) varies with respiratory rate, tidal volume, and flow rate.

High-flow systems deliver a precise, consistent FiO2 regardless of breathing pattern. The Venturi mask, with large-bore tubing, delivers a specific, steady FiO2.

Devices Used in Oxygen Therapy

Low-Flow Systems

1. Nasal cannula: a thin tube with two prongs in the nostrils, comfortable for small to moderate supplemental oxygen (up to 6 liters per minute), allowing mobility and communication, good for long-term therapy in COPD.
2. Face mask: covers the nose and mouth, delivering higher concentrations than a cannula (up to 10 liters per minute), for moderate to high oxygen needs. Types include simple, partial rebreather, and non-rebreather masks.
3. Face tent: an alternative when masks are poorly tolerated, delivering varying concentrations, typically 30% to 50% at flow rates of 4 to 8 L/min. Check the facial skin for dampness or chafing and keep it dry.
4. Partial rebreather mask: a face mask with a reservoir bag capturing exhaled gases, providing higher concentrations (60-90% FiO2) by re-inhaling some oxygen-rich air, without significant CO2 retention.
5. Oxygen tent: a large transparent enclosure over the bed, often for pediatric patients, providing a humidified oxygen-rich atmosphere without the discomfort of a mask.
6. Transtracheal catheter: a small tube inserted into the trachea through a surgical opening, delivering oxygen efficiently at lower flow rates, for long-term therapy in patients who do not tolerate cannulas or masks.

High-Flow Systems

1. Venturi mask: large-bore tubing delivering precise, consistent concentrations by mixing oxygen with room air through adjustable entrainment ports, ideal for patients needing a stable FiO2, such as those with COPD.
2. Non-rebreather mask: a face mask with a reservoir bag and one-way valves preventing rebreathing, delivering the highest concentration available with face masks (up to 100% FiO2) at flow rates of 10-15 liters per minute, for emergencies or severe hypoxemia.
3. High-flow nasal cannula (HFNC): delivers high-flow warmed, humidified oxygen at precise high concentrations (up to 100% FiO2) with better tolerance than face masks, for acute respiratory failure or severe hypoxemia.
4. Mechanical ventilator: assists or replaces spontaneous breathing, delivering controlled breaths often enriched with oxygen through endotracheal tubes, tracheostomy tubes, or non-invasive masks.

Administering Oxygen by Cannula, Face Mask, or Face Tent

Assessment

1. Assess skin and mucous membrane color for cyanosis, and note mucus or sputum that signals infection or airflow impairment.

2. Assess breathing patterns, including depth, rate, and abnormal patterns like tachypnea, bradypnea, or orthopnea, to gauge distress and therapy effectiveness.

3. Assess chest movements for retractions (intercostal, substernal, suprasternal, supraclavicular, or tracheal), which indicate increased work of breathing or obstruction.

4. Assess chest wall configuration for kyphosis, barrel chest, or unequal expansion, which reflect chronic respiratory conditions.

5. Auscultate lung sounds for wheezing, crackles, or decreased breath sounds, indicating asthma, pneumonia, or pleural effusion.

6. Assess for clinical signs of hypoxemia: tachycardia, tachypnea, restlessness, dyspnea, cyanosis, and confusion (confusion indicating severe deprivation).

7. Assess for clinical signs of hypercarbia (hypercapnia): restlessness, hypertension, headache, lethargy, tremor, which can occur in COPD.

8. Monitor vital signs, especially pulse rate and quality and respiratory rate, rhythm, and depth.

9. Determine whether the patient has COPD, where a high CO2 level may be the primary breathing stimulus rather than low oxygen. Monitor arterial blood gas levels (PaO2 and PaCO2) to prevent oxygen-induced hypercapnia.

10. Determine results of diagnostic studies such as chest x-rays for lung pathology.

11. Determine hemoglobin, hematocrit, and complete blood count to evaluate oxygen-carrying capacity and detect anemia or polycythemia.

12. Determine oxygen saturation levels (SpO2) with a pulse oximeter for real-time effectiveness.

13. Determine arterial blood gas levels (ABGs) for acid-base balance, oxygenation, and ventilation status.

14. Determine pulmonary function tests (PFTs) for lung volumes, capacities, and flow rates.

Delegation

Starting oxygen therapy is treated like administering medication and should not be delegated to unlicensed assistive personnel (UAP). UAPs may reapply the delivery device and observe and document the patient's response during routine care, but the nurse verifies and interprets any abnormal findings and confirms the appropriate delivery method.

Implementation

1. Determine the need and verify the order. Evaluate oxygen saturation, respiratory rate, and signs of hypoxemia (cyanosis, dyspnea), since therapy is warranted only with a documented deficiency. Verify the physician's order for the prescribed flow rate, method, and duration, to prevent over- or under-oxygenation.

2. Prepare the patient and support people, explaining the purpose and process and addressing concerns to reduce anxiety and gain cooperation.

3. Assist the patient to semi-Fowler's position if possible (sitting at an angle between 30 and 45 degrees) for optimal lung expansion and ventilation.

4. Introduce yourself and confirm the patient's identity per agency protocol.

5. Explain the procedure, its purpose and necessity, how the patient can participate, and how the results will guide future care.

6. Perform hand hygiene and observe infection prevention procedures.

7. Maintain privacy where applicable.

8. Set up the oxygen equipment and humidifier:

• Connect the flow meter to the wall outlet or tank, in the off position, to prevent accidental flow during setup.
• Fill the humidifier bottle, preferably before approaching the patient.
• Securely attach the humidifier bottle to the base of the flow meter.
• Connect the prescribed oxygen tubing and delivery device to the humidifier.

9. Turn on the oxygen at the prescribed rate and verify function:

• Check that oxygen flows freely with no kinks and airtight connections.
• Observe bubbles in the humidifier, confirming proper moistening.
• Confirm oxygen at the outlets of the cannula, mask, or tent.
• Set the flow rate accurately.

10. Apply the appropriate delivery device.

Nasal cannula:

• Position the cannula so the prongs fit snugly in the nostrils and the tubing secures around the ears.
• If it does not stay, tape it to the sides of the face.
• Pad the tubing over the ears and cheekbones to enhance comfort and prevent pressure sores.

Face mask:

• Apply from the nose downward to cover nose and mouth.
• Fit it to the contours of the face for a secure seal.
• Secure the elastic band snug but comfortable.
• Pad the band behind the ears and over bony prominences.

Face tent:

• Place the tent over the face, enclosing nose and mouth while allowing some ambient air, useful for patients who cannot tolerate a mask or have facial injuries.
• Secure the ties around the head.

11. Assess the patient regularly. Monitor vital signs, anxiety, color, and ease of respiration, addressing complaints like claustrophobia. Assess every 15 to 30 minutes depending on condition, watching for hypoxia, tachycardia, confusion, dyspnea, restlessness, and cyanosis, and review SpO2 or ABG results.

Nasal cannula:

• Check the nostrils for encrustation or irritation, applying a water-soluble lubricant to soothe the mucous membranes.
• Check the tops of the ears for irritation or pressure, padding with gauze to prevent skin breakdown.

Face mask or tent:

• Check the facial skin for dampness or chafing.
• Dry the skin and treat as needed to prevent irritation or infection.

12. Frequently check the equipment to ensure correct oxygen delivery:

• Verify the liter flow rate and humidifier water level every 30 minutes and during each care session.
• Ensure no water collects in the dependent loops of tubing, which obstructs airflow.
• Confirm all safety guidelines are followed, including proper handling and storage.

Documentation

13. Document findings in the patient record using forms or checklists with narrative notes when appropriate, for continuity of care and to inform other providers.