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Chapter 7: Oxygen Therapy Management
1. Key Oxygen Delivery Devices
Oxygen delivery systems are categorized as low-flow (deliver O₂ at flows that do not meet total inspiratory demand, so FiO₂ varies) or high-flow (deliver a fixed, precise FiO₂ at flows meeting or exceeding patient demand)
. Choosing the right device depends on how much O₂ is needed, the patient’s respiratory status, and risk factors like CO₂ retention
. Below are common devices, their features, indications, pros/cons, and nursing care points:
Nasal Cannula (NC):
Figure: Nasal cannula in place on a patient. A nasal cannula is a low-flow device with prongs in the nares to deliver supplemental O₂.
Description & FiO₂: Two small prongs in the nostrils attached to tubing. Delivers 1–6 L/min, providing approx 24–44% FiO₂ (each 1 L/min ≈ +4% FiO₂)
. Best for patients needing low O₂ support (e.g. mild hypoxia, stable COPD)
.
Indications: First-line for mild hypoxemia; comfortable for chronic therapy (e.g. home O₂ in COPD)
. Allows talking, eating, and is used for stable patients who require small O₂ increases.
Advantages: Simple, lightweight, inexpensive. Patients can eat and speak while wearing it
. Low cost and well-tolerated.
Disadvantages: FiO₂ varies with breathing pattern. Prongs can be easily dislodged; effectiveness drops if patient is a mouth-breather or has nasal obstruction
. Flow >4 L/min can dry nasal mucosa, causing irritation.
Nursing Considerations: Add humidification for flows >4 L/min to prevent drying of mucous membranes
. Assess the nares and ears for skin breakdown from the cannula and tubing. Encourage patient to breathe through the nose. If nasal passages are congested, treat or consider alternative device. For COPD patients, use NC at low flow (1–2 L/min) and titrate carefully – target SpO₂ ~88–92%
to avoid knocking out their drive to breathe (see hypoxic drive cautions below).
Simple Face Mask:
Description & FiO₂: A basic mask that covers nose and mouth with open exhalation ports
. Flow 6–10 L/min, delivering about 40–60% FiO₂
. Must use at least 5–6 L/min flow to flush exhaled CO₂ from the mask
.
Indications: Moderate O₂ needs (e.g. short-term for mild-moderate distress, or when nasal cannula is not sufficient or not tolerated). Often used post-op or in emergencies while preparing higher support.
Advantages: Simple to use and provides higher O₂ concentration than NC
. Useful for mouth-breathers since it doesn’t rely on nasal airflow.
Disadvantages: Mask is somewhat bulky; interferes with eating and speaking. It can feel claustrophobic, and patients may remove it due to discomfort
. Cannot be used during meals (patient will require nasal cannula during meals if continuous O₂ needed). FiO₂ is imprecise and varies with mask fit and patient’s breathing.
Nursing Considerations: Ensure a snug fit over nose and mouth for effectiveness. Never set flow <6 L/min (risk of rebreathing CO₂)
. Monitor for skin pressure/breakdown on face and ears from the mask straps. Provide oral care, as patients may feel dry. Plan for mask-off time during meals with alternative O₂ (switch to NC temporarily if able).
Non-Rebreather Mask (NRB):
Description & FiO₂: A mask with an attached reservoir bag and one-way valves
. One-way valves on the mask prevent room air from entering and ensure only O₂ from the bag is inhaled
. Exhaled air exits through separate ports. Flow must be high: 10–15 L/min, to keep the reservoir ~⅓–½ inflated at all times
. With a good seal, can deliver ≈60–80% FiO₂ (up to ~90% in ideal conditions)
. This is the highest O₂ concentration available without intubation.
Indications: Emergencies – for acute hypoxia, trauma, severe distress (e.g. shock, pulmonary edema) when you need to deliver high O₂ concentrations quickly to a breathing patient. Used short-term (e.g. while awaiting intubation or transfer)
. Patient must breathe independently (no ventilator assistance).
Advantages: Delivers the highest FiO₂ of all spontaneous-breathing devices (often 80–90% O₂)
. Can be lifesaving to quickly improve O₂ saturation in critical situations. Non-invasive and easy to apply.
Disadvantages: Not meant for long-term use. The one-way system means if O₂ source fails or flow is too low, the patient could suffocate (no room air entry)
. The mask is tight-fitting and uncomfortable; also interferes with talking and eating
. High O₂ for prolonged periods risks O₂ toxicity (see Complications). The reservoir bag must not collapse or it indicates inadequate flow. Also, the valves must function properly; if they stick, CO₂ buildup can occur.
Nursing Considerations: Pre-inflate the reservoir bag before putting it on the patient (to ensure immediate high FiO₂)
. Keep flow at 10–15 L/min and ensure the bag stays partially inflated during inspiration
– if it collapses completely when the patient inhales, increase the flow rate or check for kinks. Never leave an NRB on a patient unattended or for long periods, especially with one-way valves in place
(risk of sudden deoxygenation if O₂ stops). Frequently assess the patient’s status – if they become lethargic or RR drops, they may be retaining CO₂. In a patient with chronic CO₂ retention (e.g. severe COPD), use NRB with extreme caution and only if necessary, and monitor consciousness and ABGs (high FiO₂ can worsen hypercapnia in CO₂ retainers). Ensure a tight seal to maximize O₂ delivery. If the patient needs to eat or drink, they will require brief removal of the mask – plan supplemental O₂ and closely monitor during that time.
Figure: A Non-Rebreather Mask in use. Note the attached O₂ reservoir bag. One-way valves (at the bag connection and exhalation ports) prevent room air and exhaled gas from diluting the O₂, allowing delivery of high FiO₂.
Venturi Mask (Air-Entrainment Mask):
Description & FiO₂: A high-flow mask system with color-coded entrainment valves (adaptors) that mix O₂ with air to deliver a precise O₂ concentration
. Different adapter orifice sizes provide fixed FiO₂ (commonly 24%, 28%, 31%, 35%, 40%, 50% up to ~60%) at specified flow rates
. For example, a blue Venturi valve might give 24% at 4 L/min, green 60% at 12 L/min, etc.【33†】. The O₂ flow is set according to the adapter’s requirement; increasing the liter flow beyond recommended doesn’t increase FiO₂ (excess vents out).
Indications: Patients who require a specific, controlled FiO₂ – especially COPD patients with CO₂ retention, where giving too much O₂ is risky
. Venturi masks ensure the patient gets enough O₂ to prevent hypoxemia but not too much to cause respiratory depression. Also used when precise titration is needed (e.g. unstable oxygenation post-op or in certain critical patients).
Advantages: Delivers precise FiO₂ regardless of the patient’s breathing pattern
. The exact O₂ % can be dialed in by changing adapters, which is critical for at-risk patients. It’s high-flow, so it meets inspiratory demand – room air is not entrained (except what’s built into the venturi mechanism), thus the FiO₂ is consistent. Provides humidity (many Venturi setups have a nebulizer/humidity attachment) for comfort
. Great for COPD: avoids excessive O₂ while still treating hypoxemia.
Disadvantages: The mask can be somewhat noisy and also may feel confining (like other masks). The tubing and adapters are a bit complex; misconnections or wrong adapter use can result in incorrect FiO₂. Patient cannot eat with mask on and must switch to nasal cannula temporarily if needed. Requires either RT or knowledgeable nurse to set up correctly
.
Nursing Considerations: Verify the correct adapter (color or FiO₂ setting) is used as ordered. Ensure the flow rate is set exactly as per adapter’s requirement – e.g. if using the 40% adapter that calls for 8 L/min, use that flow (the FiO₂ is regulated by the adapter, so proper flow ensures the desired FiO₂)
. Check that entrainment ports (holes on the adapter) remain uncovered and clean, as blocking them alters FiO₂. Monitor patient’s respiratory status; Venturi is often used in COPD, so assess for signs of CO₂ retention or narcosis (e.g. decreased RR or LOC). Document the FiO₂ (%) rather than just liter flow, since that’s what Venturi specifies. If the patient’s needs change (e.g. requiring higher FiO₂ than Venturi can provide), communicate with the provider – may need to switch devices.
High-Flow Nasal Cannula (HFNC):
Description & FiO₂: A special nasal cannula system capable of delivering very high flow (up to 40–60 L/min) of warmed, humidified O₂, with adjustable FiO₂ from 21% up to 100%
. It includes an air/O₂ blender, humidifier, and heated tubing with nasal prongs that are larger and softer than standard NC. The high flow provides a slight positive pressure and flushes out CO₂ from anatomical dead space.
Indications: Patients in acute respiratory failure or critical illness who need more support than a standard device but may avoid intubation. HFNC is often used in ICU for severe hypoxemia (e.g. pneumonia, ARDS, COVID-19) or in step-down units for patients who need high FiO₂ but are still breathing on their own. It can also benefit some COPD exacerbations or heart failure patients by reducing work of breathing. Generally used when conventional O₂ devices are insufficient but the patient can still ventilate adequately.
Advantages: Provides very high O₂ concentrations with added positive end-expiratory pressure (PEEP)-like effect due to high flow, improving oxygenation. The heated humidification greatly improves comfort and helps keep secretions thin, allowing these high flows to be tolerated (prevents drying of mucosa). Patients can eat and speak more easily with HFNC compared to face masks. Studies show HFNC can reduce need for intubation in some patients by improving respiratory parameters.
Disadvantages: Requires special equipment and setup (often managed by respiratory therapists). The nasal prongs are larger; patients may feel some discomfort or claustrophobia from the high flow in their nose initially. It uses a lot of oxygen – ensure the O₂ supply is adequate (hospital wall supply or big tanks). Not portable for ambulation unless special transport setup is used. If patient’s breathing worsens, HFNC may delay necessary intubation if over-relied upon, so careful monitoring is needed.
Nursing Considerations: Ensure the humidifier is filled with sterile water and heating is functioning – HFNC is ineffective without adequate humidification (patient will not tolerate dry high flow). Check that the FiO₂ setting is as ordered (machine will display FiO₂ % and flow rate). Monitor patient’s respiratory status closely – HFNC patients are often critical; assess work of breathing, respiratory rate, and oxygenation. Because HFNC can deliver near 100% O₂, be vigilant for signs of O₂ toxicity or if oxygen requirements are escalating. Make sure the nasal cannula prongs fit properly (usually they sit loosely in the nares, not a tight seal). Skin protection over ears or cheeks might be needed for the tubing if used for extended time. Collaborate with RT for any adjustments. (Note: HFNC is generally an ICU-level intervention, but nurses should understand its use.)
Continuous Positive Airway Pressure (CPAP):
Description: CPAP is noninvasive positive pressure ventilation (NPPV) that delivers a continuous level of airway pressure throughout the breathing cycle to keep alveoli open. It involves a snug-fitting mask (over nose or nose+mouth) attached to a machine that provides pressurized air/O₂
. The pressure (measured in cmH₂O) is continuous (the same on inhale and exhale). FiO₂ can be titrated if connected to O₂. Often used at night (for sleep apnea) or during acute episodes (e.g. cardiogenic pulmonary edema) in hospital.
Indications: Obstructive Sleep Apnea (OSA) – gold standard for home treatment, prevents airway collapse during sleep
. Also used in acute care for hypoxemic respiratory failure (e.g. acute pulmonary edema or CHF exacerbation to improve oxygenation by forcing fluid out of alveoli). CPAP improves oxygenation by recruiting alveoli and providing PEEP. Unlike BiPAP, CPAP is generally for patients who need oxygenation support but can still eliminate CO₂ adequately on their own.
Advantages: Avoids invasive intubation in appropriate patients. The continuous pressure prevents airway collapse (useful in OSA, and in acute pulmonary edema it pushes fluid out of lungs, buying time for diuretics to work). Can deliver a set FiO₂ along with pressure, so improves oxygenation efficiently. Well-established therapy for home use with good success in OSA (improves sleep quality and prevents hypoxemia episodes).
Disadvantages: Patient must be breathing spontaneously and able to protect airway (mask ventilation is contraindicated if vomiting or very lethargic). The mask fit is tight and many patients feel claustrophobic or uncomfortable (adherence can be an issue). Continuous pressure can cause bloating from swallowed air, sinus discomfort, or dry mucous membranes if not humidified. Skin breakdown on the bridge of the nose or straps areas is common if not monitored. In hospital, requires monitoring for respiratory status – if patient fatigues or cannot tolerate, intubation may be needed.
Nursing Considerations: Ensure the mask has a good seal – air leaks reduce effectiveness. Check pressure settings and any FiO₂ setting as ordered (RT usually sets these). Monitor ABGs and O₂ saturation to gauge effectiveness (CPAP should improve PaO₂ and SpO₂). Assess the patient’s tolerance frequently: if patient is anxious, coach on slow breathing; consider a mild sedative if ordered (but be cautious – they must not be overly sedated). Use humidification on the CPAP circuit to prevent dryness (fill reservoir with sterile water as directed)
. Regularly inspect facial skin for redness or pressure sores; reposition mask or add protective dressings as needed. For OSA patients, stress the importance of nightly use and proper home care of equipment (clean mask and tubing to prevent infection). If alarms sound on the CPAP machine (indicating low pressure/leak or high pressure), troubleshoot promptly (check seal, check if patient is coughing or needs suction, etc.). Keep HOB elevated to reduce aspiration risk.
Bi-level Positive Airway Pressure (BiPAP):
Description: Another form of NPPV delivering positive pressure, but with two pressure levels – a higher pressure on inspiration and a lower pressure on expiration
. This dual setting (often written as “IPAP/EPAP”) assists ventilation: the inspiratory pressure helps with tidal volume, and the expiratory pressure (PEEP) keeps alveoli open. BiPAP is delivered via a tight-fitting mask similar to CPAP. FiO₂ can be added if needed.
Indications: Hypercapnic respiratory failure (e.g. COPD exacerbation with high CO₂) or when ventilatory support is needed in a patient who is still breathing spontaneously
. BiPAP is very useful in COPD because it reduces CO₂ by improving ventilation (blows off CO₂) while also aiding oxygenation – it’s often used to prevent intubation in COPD exacerbations or for acute asthma exacerbation. Also used in some cases of heart failure or neuromuscular weakness causing ventilatory insufficiency. Some patients with central sleep apnea or obesity hypoventilation syndrome may use BiPAP at home if CPAP is insufficient.
Advantages: Provides ventilatory assistance – the patient doesn’t have to work as hard to inhale, as the machine augments each breath. This can rest fatigued respiratory muscles in COPD exacerbation and improve gas exchange (lowers PaCO₂, raises PaO₂). BiPAP’s separate inspiratory/expiratory settings are often more tolerable for patients than CPAP’s continuous pressure (easier to exhale against a lower pressure)
. It can avert the need for intubation in some patients if started early in respiratory decline. Like CPAP, it’s noninvasive.
Disadvantages: Same mask-related issues as CPAP (comfort, claustrophobia, skin breakdown, aspiration risk if vomiting). Not appropriate for apnea or agonal breathing – patient must initiate breaths (though some BiPAP machines have a backup rate feature). BiPAP in acute settings requires close monitoring; if a patient tires out or mental status declines, intubation should not be delayed. Air leaks can be more problematic since proper cycling of IPAP/EPAP depends on sealing. Some patients may develop dryness or eye irritation from air leaks around mask.
Nursing Considerations: Similar care as CPAP regarding mask fit, skin care, and monitoring. Pay attention to exhalation ports or valves on the mask that allow CO₂ to escape; ensure they are not blocked. Monitor ABGs: BiPAP should show improving pH and decreasing PaCO₂ if effective. If the patient is retaining CO₂ despite BiPAP, or if oxygenation is not improving, notify provider – may need intubation. Keep the patient’s head elevated and consider an NG tube if on BiPAP for long duration to decompress the stomach (swallowed air can cause gastric distension). Provide oral care since the mask prevents eating/drinking; patients often mouth-breathe with BiPAP, causing dryness – frequent mouth care and lip moisturizer (water-based) helps. If alarms sound (many BiPAP machines alarm for high leak or if patient removes mask), respond quickly. Educate home BiPAP users similarly to CPAP (machine use, cleaning, when to seek help).
Special Considerations – COPD & CO₂ Retainers: Patients with chronic CO₂ retention (e.g. some COPD patients) have an altered respiratory drive. They rely more on hypoxemia to stimulate breathing (a “hypoxic drive”) instead of the normal CO₂-driven drive
. Giving too high an oxygen concentration can remove their stimulus to breathe, leading to oxygen-induced hypoventilation or apnea
. However, never withhold oxygen if the patient needs it – the key is to titrate carefully and monitor. Use devices like Venturi masks or low-flow NC to achieve a safe SpO₂ (commonly 88–92% for COPD patients)
. Signs that a CO₂-retaining patient is getting too much O₂ include decreased respiratory rate, lethargy, and rising CO₂ on ABG (CO₂ narcosis). If this occurs, you may need to slightly lower the FiO₂ (with provider guidance) and support ventilation. Always check orders for COPD patients’ target saturation, and obtain ABGs if concerned. In summary: treat hypoxia, but avoid overshooting. Venturi masks are excellent for these patients because they deliver precise low FiO₂
. Monitor LOC and breathing closely whenever a known CO₂ retainer is on supplemental O₂.
2. Indications and Contraindications for Oxygen Therapy
When is Oxygen Therapy Indicated? Oxygen is a medication for hypoxemia – it’s indicated whenever a patient isn’t getting enough O₂ on their own. Key indications include:
Low Oxygen Saturation or PaO₂: Generally, O₂ is indicated if SpO₂ < 90-92% on room air or PaO₂ < ~60 mmHg (per ABG) in most patients. For patients with acute illness, target SpO₂ is often ≥94% (or per protocol) to ensure adequate tissue oxygenation. Chronic lung patients may have lower targets as discussed (88–92%).
Respiratory Distress/Failure: Any acute respiratory distress (tachypnea, accessory muscle use, cyanosis) warrants supplemental O₂ to prevent further desaturation
. Example: acute asthma exacerbation – give O₂ to maintain O₂ levels while other treatments (bronchodilators, steroids) work
. In ARDS or severe pneumonia, high levels of O₂ may be needed due to impaired gas exchange.
Cardiac and Circulatory conditions: Shock, trauma, anemia, or hypotension – O₂ helps ensure tissues get oxygen when perfusion or carrying capacity is compromised. In acute myocardial infarction or chest pain, O₂ is given if O₂ sat is low or patient is dyspneic, to reduce cardiac workload (though routine O₂ in MI if sats are normal is no longer recommended). Heart failure with pulmonary edema often requires O₂ because fluid in lungs impairs oxygenation
.
Chronic Lung Disease with Hypoxemia: COPD, pulmonary fibrosis, etc., where patients have chronically low PaO₂. Long-term oxygen therapy (e.g. home O₂) is indicated if PaO₂ ≤ 55 mmHg or SpO₂ ≤ 88% at rest, as it improves survival and quality of life in COPD
. O₂ can also prevent complications like pulmonary hypertension in chronic hypoxemia
.
Perioperative & Procedural: Post-surgery or during sedation, patients may hypoventilate. Supplemental O₂ is often given in recovery to counteract effects of anesthesia and immobility
. During procedures requiring conscious sedation or in the ICU (e.g. during suctioning or intubation prep), short-term 100% O₂ is used to pre-oxygenate and prevent desaturation.
Carbon Monoxide Poisoning: Pulse oximetry is unreliable (it reads falsely high), but these patients need 100% O₂ (often via NRB or hyperbaric O₂) to displace CO from hemoglobin.
Bottom line: If a patient shows signs of hypoxia (low O₂ sat, cyanosis, confusion, dyspnea) or has a condition known to cause hypoxemia, oxygen therapy is indicated to maintain adequate tissue oxygenation
. Always follow the “ABC” priority – Airway, Breathing, Circulation – so breathing problems and oxygenation are top priorities. Oxygen relieves hypoxemia and its symptoms (restlessness, tachycardia, dyspnea) and prevents progression to respiratory failure
.
Contraindications & Safety Concerns: There are no absolute contraindications to oxygen in an emergency – if hypoxia is present, treat it. However, caution is needed in certain scenarios:
Chronic CO₂ Retention (COPD): As discussed, giving high FiO₂ to CO₂-retaining patients can lead to hypoventilation. This is not a true contraindication (we still give O₂; hypoxia kills quickly), but it’s a precaution. For these patients, avoid indiscriminate high O₂ flow. Instead, titrate to the lowest O₂ that relieves hypoxia and monitor closely
. Use Venturi masks or careful NC titration. Signs of CO₂ narcosis (drowsiness, decreased RR) indicate O₂ may be too high for them, or they need ventilatory support. Never deprive oxygen when clearly needed – just be mindful of the risk
.
Certain Congenital Heart Lesions: (Pediatric context) – in some congenital heart diseases, O₂ can affect ductal blood flow or systemic vs pulmonary circulation balance. While beyond med-surg scope, just note that neonates with specific heart defects may have ordered oxygen limits.
Paraquat Poisoning or Bleomycin Therapy: These are less common, but both can predispose lungs to oxygen toxicity. Bleomycin (a chemo drug) and certain toxins can cause the lungs to react poorly to high O₂
. In such patients, oxygen is used very carefully and only at lowest needed levels, since they are at higher risk for lung damage from O₂.
Fire/Explosion Risk: Oxygen supports combustion. Smoking or open flames in presence of enriched O₂ can be extremely dangerous
. In a sense, an environment with uncontrolled flame is a contraindication to oxygen use due to fire hazard. Always eliminate ignition sources before initiating O₂. (For example, no smoking signs, no sparking toys or electronics near an O₂ tent or cannula, etc.)
Hyperoxia in Newborns: In premature infants, high PaO₂ can cause Retinopathy of Prematurity (ROP) – an eye damage leading to blindness (see complications below). Thus, for neonates, clinicians keep O₂ at the minimum needed and use blended O₂ with precise targeting. This is a pediatric consideration; in adult med-surg, just recognize that too much O₂ can harm certain populations.
General Safety Measures: Oxygen cylinders must be stored upright and secured to prevent falls (they are heavy missiles if knocked over)
. Keep O₂ at least 5 feet (1.5 m) away from stoves, heaters, or any heat source
. Avoid petroleum-based products on patients’ lips/nostrils when using O₂ (use water-based lubricants) – petroleum jelly can ignite in high O₂ environments. All electrical equipment nearby should be in good repair (no frayed cords, to prevent sparks)
. Humidify high-flow O₂ to prevent mucosal drying and nosebleeds. And always remember: O₂ is a drug – adjust it only with an order or protocol, and document changes. Unneeded oxygen should be weaned off, as excessive use can be harmful over time.
3. Complications of Oxygen Therapy
While oxygen can be life-saving, too much or prolonged oxygen can lead to complications. Key ones include:
Oxygen Toxicity: High concentrations of O₂ over long durations can damage the lungs and other organs
. Excess O₂ leads to increased production of oxygen free radicals, which can injure cell membranes, inactivate enzymes, and damage lung tissue
. Signs/Symptoms: Initially, perhaps a substernal chest pain, dry cough, tracheal irritation, or pleuritic pain. Patients might report dyspnea and chest tightness. As it progresses: refractory hypoxemia (oxygen no longer seems to help as much), decreased lung compliance, alveolar infiltrates on CXR (similar to ARDS). In the central nervous system (usually with acute very high O₂, e.g. hyperbaric situations), signs can include nausea, dizziness, muscle twitching, vision changes, or seizures
(CNS toxicity is more with hyperbaric O₂ exposure; pulmonary toxicity with prolonged >50% FiO₂). Prevention: Use the lowest effective FiO₂ to maintain target SpO₂
. A traditional guideline is to try to keep FiO₂ ≤ 50% if on O₂ for more than 24–48 hours, to minimize risk. If high FiO₂ is needed, try to limit duration and wean ASAP, or use techniques like PEEP on a ventilator to allow lower FiO₂. Monitor patients on >50% O₂ for any new onset of breathing difficulty or chest pain. Also, certain drugs (bleomycin) and chemicals (herbicides) potentiate O₂ toxicity – in such cases be even more cautious
. If O₂ toxicity is suspected (e.g. patient on 100% O₂ for 2 days develops ARDS-like symptoms), interventions include reducing FiO₂, providing supportive care (PEEP, ventilation), and monitoring.
Absorption Atelectasis: Normally, room air is ~79% nitrogen, which stays in alveoli and helps keep them open (nitrogen is not absorbed into blood). With high FiO₂, nitrogen in the lungs gets replaced by oxygen. If a patient takes high O₂ for a while, the alveoli are filled mostly with O₂. That O₂ can get absorbed rapidly into the bloodstream, especially if the alveoli are small or if the patient has shallow breathing. With little nitrogen to splint them open, alveoli can collapse – this is absorption atelectasis
. It often occurs in patients on 100% O₂ or very high FiO₂, especially if they have areas of low ventilation (like post-surgical shallow breaths, or mucus plugging). Signs: Increased work of breathing, new crackles, or decreased breath sounds in affected areas, and drop in O₂ saturation. Patients might not have obvious symptoms, but it can increase shunting of blood through collapsed alveoli, causing hypoxemia. In fact, a patient on high O₂ who suddenly has lower O₂ saturation may be experiencing absorption atelectasis. Prevention: Use the lowest FiO₂ needed. Encourage patients on high O₂ to take deep breaths, use incentive spirometer, or periodically “sigh” to reopen alveoli. If on a ventilator, applying PEEP can mitigate atelectasis. Monitor for development of atelectasis on chest x-ray if patient is on high FiO₂ for extended time. Remember that even 50% O₂ significantly reduces alveolar nitrogen – prolonged high O₂ in sedated or post-op patients can cause this collapse. Good pulmonary hygiene and recruitment maneuvers help.
Retinopathy of Prematurity (ROP): This is a complication in premature infants exposed to high oxygen levels. The developing retinal blood vessels in a preemie’s eyes are very sensitive to O₂. Excessive O₂ causes vasoconstriction in the retina and disrupts normal vessel growth. Later, when oxygen is weaned, a rebound effect leads to abnormal vessel proliferation and scarring, which can detach the retina. The result is vision impairment or blindness. In the 1950s, studies confirmed that prolonged exposure to O₂ >40% in preemies dramatically increased blindness incidence
. Now, NICUs tightly control O₂; targets for SpO₂ in preemies are carefully set to balance oxygenation and risk of ROP. Prevention: Only give the minimal O₂ needed to neonates, and use blended oxygen with precise monitoring. For the purposes of this med-surg guide, just note that high O₂ is especially dangerous in neonates. (In adult practice, you won’t directly manage neonate O₂, but you should recall this if ever floated to NICU or dealing with newborns.)
Dry Mucous Membranes and Infection Risk: Less critical than the above, but worth noting: oxygen therapy, especially without humidification, can dry out the nasal and oral mucosa. This can cause nosebleeds, sinus irritation, or cracked lips. Humidification of O₂ >4 L/min is recommended to prevent this
. Also, equipment like nebulizers or humidifiers can harbor bacteria if not cleaned, potentially causing respiratory infections. Always use sterile water in humidifiers and follow infection control for O₂ equipment (change tubing per policy, etc.).
Pressure Injuries: Nasal cannulas and masks can cause skin breakdown – e.g. behind ears (from tubing), on nose/face (from mask). These pressure sores can be considered a complication of O₂ delivery. Padding and regular skin checks are important to prevent this.
4. Pharmacological Considerations
Oxygen therapy is often one part of a broader treatment plan for respiratory problems. Several medication classes are commonly used concurrently with oxygen to improve breathing and oxygenation:
Bronchodilators: These meds relax bronchial smooth muscles, thereby widening the airways (bronchodilation)
. By opening constricted airways, they allow more oxygen to reach alveoli and ease breathing. Examples: β₂-agonists (like Albuterol inhaler/nebulizer for quick relief in asthma or COPD flare; Salmeterol for long-acting), Anticholinergics (like Ipratropium bromide often combined with albuterol for COPD/asthma, or Tiotropium long-acting for COPD). Indications: Asthma attacks, COPD exacerbations, wheezing from bronchospasm. Nurses may administer these via a nebulizer connected to oxygen source (e.g. 6-8 L/min O₂ to drive a nebulizer treatment)
. Nursing considerations: Check breath sounds and HR before and after – bronchodilators often cause tachycardia, tremors (especially albuterol) and you should monitor for improved air entry (less wheezing). Ensure correct administration technique (if inhaler, use spacer if needed; if nebulized, make sure the mist is inhaled fully with slow deep breaths). Bronchodilators can increase oxygen demand transiently (from increased activity or heart rate), but ultimately should improve oxygenation by relieving bronchospasm. In an acute setting, coordinate giving a bronchodilator promptly for a patient in distress on O₂ – it can drastically improve their status.
Glucocorticoids (Corticosteroids): These reduce airway inflammation and thus help open air passages over time
. In conditions like asthma, COPD, or pneumonitis, inflammation narrows airways and impairs gas exchange. Examples: Prednisone or methylprednisolone (IV) for COPD/asthma exacerbation; Inhaled steroids like budesonide, fluticasone for chronic management. Indications: Acute exacerbations of asthma/COPD (IV or high-dose inhaled steroids given), allergic reactions causing bronchospasm, and other inflammatory lung diseases. Nursing considerations: Steroids have many side effects – monitor blood sugar (they cause hyperglycemia), watch for signs of infection (they are immunosuppressive), and if long term, remember to taper off (don’t stop abruptly if on chronic steroid therapy). Rinse the mouth after inhaled steroid use to prevent oral thrush. In the short term, an IV steroid given in ER for asthma will not act as fast as a bronchodilator, but it prevents late-phase inflammation, helping sustained improvement. So, ensure patients continue the full course as prescribed even if they feel better. Steroids will indirectly improve oxygenation by reducing swelling and mucus in airways over hours to days.
Mucolytics & Expectorants: These medications thin out thick bronchial secretions so that patients can cough them up more easily
. Retained secretions can block airways and impair oxygenation. Examples: Acetylcysteine (Mucomyst) nebulizer – breaks disulfide bonds in mucus, making it thinner; Guaifenesin (an expectorant, often oral) – increases hydration of secretions. Indications: COPD or bronchiectasis patients with thick sputum, pneumonia with difficulty expectorating phlegm, cystic fibrosis, etc. Nursing considerations: Ensure adequate hydration – mucolytics work better if patient is well-hydrated (encourage oral fluids if appropriate). Acetylcysteine neb can cause bronchospasm in some patients (it’s smelly and irritative); often it’s given with a bronchodilator or the patient should use a bronchodilator beforehand if they have reactive airways. Watch for cough reflex – if patient can’t effectively cough out loosened mucus, they may need suctioning after a mucolytic. Also, note that acetylcysteine is also the antidote for acetaminophen overdose; as a neb for mucus it might not be as commonly used unless thick secretions are a real issue (it smells like rotten eggs, which can be unpleasant). Nevertheless, thinning secretions can significantly improve air movement and thus oxygenation.
Antibiotics (for infection): If the cause of hypoxia is infectious (e.g. pneumonia), appropriate antibiotics are critical. They’re not exactly “used with oxygen” in a direct sense, but in many scenarios (pneumonia, COPD exacerbation often due to bronchitis), you’ll be giving O₂ and treating the underlying infection with antimicrobials. Nursing considerations: Get cultures before starting antibiotics when possible, monitor WBC, temperature, sputum color, and ensure full course is given. Improvement of infection will improve oxygenation over days.
Diuretics (for pulmonary edema): In acute heart failure with pulmonary edema, furosemide (Lasix) is often given IV along with high-flow oxygen or CPAP. The diuretic will reduce fluid in lungs, improving oxygenation as fluid is mobilized. Nurses need to monitor blood pressure, urine output, and electrolytes in this context.
Analgesics & Sedatives: Pain or anxiety can worsen oxygenation by causing shallow breathing or hyperventilation. For example, a post-op patient in pain won’t breathe deeply, risking atelectasis and low O₂ – giving analgesics like morphine can actually improve breathing depth (while closely watching for respiratory depression). In an anxious, hyperventilating patient, a mild sedative (like low-dose benzodiazepine) might break the anxiety-breathlessness cycle. Caution: Only use sedatives if absolutely needed, as they can depress respirations – in respiratory failure, we generally avoid them unless the patient is ventilated or it’s procedural sedation.
Administration Guidelines & Nursing: Many of these meds are inhaled (bronchodilators, some steroids, mucolytics). Know how to use nebulizer vs. MDI (metered dose inhaler) vs. DPI (dry powder inhaler) devices. If using a nebulizer with oxygen, ensure flow is at least 6–8 L to create mist
. Coordinate treatments with respiratory therapy if applicable. When giving multiple inhaled meds, the sequence usually is bronchodilator first (to open airways), then steroid last (so it can penetrate). Monitor the patient’s response: e.g., after albuterol neb, reassess breath sounds and ask about relief of dyspnea. For systemic meds like IV steroids or diuretics, monitor vital signs and lab values (steroids: glucose, diuretics: K+ and renal function). Document the patient’s tolerance and response – e.g., “SpO₂ improved from 88% to 94% after nebulizer and O₂ 2 L NC; patient expectorated mucus plug.” All these meds complement oxygen therapy by treating the cause of the oxygenation problem (bronchospasm, inflammation, fluid, etc.), so always think: why is my patient hypoxic, and what med addresses that cause?
5. General Nursing Considerations
Managing a patient on oxygen involves ongoing assessment, intervention, and education. Use the nursing process to ensure the therapy is effective and safe:
Assessment of Oxygenation Status:
Perform thorough respiratory assessments:
Airway Patency: Is the airway clear? (Any secretions, stridor, obstruction?) A compromised airway renders oxygen delivery useless, so first ensure the airway is open (suction if needed, position properly).
Breathing Effort & Rate: Check respiratory rate (normal 12-20). Tachypnea might indicate distress or compensation; bradypnea could signal fatigue or CO₂ retention. Observe work of breathing: use of accessory muscles, nasal flaring, retractions, tripod positioning – these suggest increased effort. Note the patient’s position (patients in distress often sit upright or lean forward).
Lung Sounds: Auscultate all lobes. Wheezing suggests bronchoconstriction (might benefit from bronchodilators), crackles could indicate fluid or atelectasis (may need diuretics, incentive spirometry), diminished sounds could mean poor air entry or collapse. Compare bilaterally. Also listen for secretions the patient can’t clear (rhonchi), which might need coughing or suctioning.
Oxygen Saturation (SpO₂): Use pulse oximetry continuously or spot-check. Know the patient’s goal (e.g. ≥92% for most, 88–92% for COPD). If the SpO₂ is below target or trending down, that’s a red flag to act (increase O₂, check equipment, etc.). Remember factors that can affect SpO₂ accuracy: motion, cold extremities, poor perfusion, nail polish, carbon monoxide poisoning (in CO exposure, SpO₂ will be falsely high)
.
Arterial Blood Gases (ABGs): In more critical cases or if CO₂ retention is a concern, review ABG results. Look at PaO₂ (should roughly correlate with SpO₂), PaCO₂ (is patient retaining CO₂?), pH (any respiratory acidosis from hypoventilation or alkalosis from hyperventilation?). ABGs are the gold standard for assessing gas exchange. For example, a COPD patient might have PaCO₂ 55 (chronically elevated) and PaO₂ 60 on 2 L – that might be acceptable. ABGs help fine-tune O₂ therapy in ICU and to detect CO₂ narcosis early
.
Heart Rate and Rhythm: Hypoxemia often causes tachycardia as the body tries to compensate. If a patient is suddenly becoming tachycardic or arrhythmic, consider possible hypoxia (as well as other causes). Conversely, bradycardia in a hypoxic patient can be an ominous, late sign of severe hypoxia.
Mental Status: The brain is very sensitive to O₂ levels. Restlessness, anxiety, confusion are often early signs of hypoxemia (the patient might appear agitated or not as oriented). Conversely, drowsiness, slow reactions, headache could indicate hypercapnia (high CO₂) or worsening hypoxia. If a patient on O₂ becomes increasingly somnolent, check CO₂ retention possibility. Always treat changes in LOC seriously – they may need more support.
Skin and Perfusion: Look for cyanosis – bluish color of lips, fingertips. Central cyanosis (tongue/mucosa) is a late sign of hypoxia. Also assess skin temperature and capillary refill; shock states can cause poor perfusion contributing to oxygenation issues.
Vital Signs overall: In hypoxia, blood pressure can initially rise (stress response) but may drop if severe or if patient is crashing. Watch trends.
Document baseline and ongoing assessments. For example: “RR 28, labored with accessory muscle use; SpO₂ 85% RA, improves to 94% on 4 L NC; diffuse wheezes heard; patient anxious and unable to speak full sentences.” This guides interventions.
Prioritization of Interventions:
Always apply the ABCs – Airway, Breathing, Circulation. If a patient is having trouble oxygenating:
Positioning & Airway – First, position the patient to maximize ventilation (high Fowler’s or tripod if they can) and ensure the airway is clear (suction secretions if needed, insert an airway if they’re obtunded and can’t maintain one).
Oxygen – Apply supplemental O₂ immediately for any significant hypoxia. Use a high-flow device (NRB mask) for critically low sats or severe distress while you gather further help. For moderate hypoxia, nasal cannula or simple mask might suffice. The key is don’t wait for an order in an emergency – most hospitals have protocols empowering nurses to start O₂ if sats drop, then get the order after. Preventing hypoxia is top priority
.
Notify & Collaborate – If increasing O₂ needs or acute deterioration, call the rapid response or physician promptly after initiating oxygen support. For example, if a COPD patient on 2 L NC is now in distress requiring NRB 15 L to keep SpO₂ ~88%, call for a higher level of care – they may need BiPAP or ICU transfer.
Treat Underlying Causes Concurrently: While O₂ is running, address what’s causing the problem. If bronchospasm – give bronchodilator neb STAT. If suspected pneumothorax – prepare for possible chest tube. Pulmonary edema – position upright, consider CPAP and diuretics. Always ask, “Why is this patient hypoxic and what else can I do about it?” This might involve getting stat portable CXR, drawing ABGs, starting an IV for meds, etc., in parallel.
Conserve Patient’s Energy: Cluster care and minimize unnecessary activity for a dyspneic patient – excessive movement can increase O₂ demand. Help with breathing techniques (pursed-lip, slow deep breaths) to control panic and improve ventilation.
Escalation: If current measures aren’t enough (e.g. still hypoxic on NRB, or rising CO₂ on BiPAP), anticipate the next step – perhaps intubation and mechanical ventilation. Prepare by having intubation tray and ambu bag available if things are heading that way. In an acute scenario, prioritize interventions that stabilize breathing before, say, starting an IV or drawing labs (those can be delegated once the patient is oxygenating).
Monitoring: After any intervention (turn up O₂, give nebulizer, etc.), reassess in a few minutes. Did SpO₂ improve? Is the patient less distressed? Prioritize continuous monitoring in the unstable phase.
Evaluation – Is Oxygen Therapy Effective?
You’ll know your interventions are working if:
Improved O₂ saturation: e.g. SpO₂ has risen into desired range (say from 88% to 94% on the new O₂ setting).
Better ABG values: PaO₂ improving towards normal (80-100 mmHg on ABG for most, or whatever is goal for that patient), and if hypercapnic before, perhaps PaCO₂ trending down (if ventilation improved via BiPAP). Also resolution of acidosis if it was due to respiratory cause.
Respiratory Rate normalizes: A previously tachypneic patient slows closer to normal RR once adequate oxygenation (and ventilation) is restored. Work of breathing decreases – less use of accessory muscles, patient can speak more easily, no nasal flaring.
Heart rate and BP stabilize: Tachycardia from hypoxia may resolve, and any hypertension from stress might come down. Skin may become less cool/clammy if circulation improves with better oxygenation.
Patient’s subjective improvement: They report less shortness of breath, less air hunger. Maybe their anxiety reduces once they can breathe easier.
Color and mentation: They look less cyanotic, more pink. Mental status returns to baseline – e.g. the confused hypoxic patient is now alert and oriented once oxygenated.
Lung sounds might improve if treatments administered (e.g. wheezing reduced after bronchodilator, crackles reduced after diuresis).
Effectiveness also means no adverse effects: check that there are no signs of O₂ toxicity developing (for those on high FiO₂) and that CO₂ retainers are not slipping into CO₂ narcosis (monitor LOC, RR). You should also evaluate equipment function – e.g. is the O₂ humidifier bubbling (if required), is the tubing connected, etc. Document the patient’s response: “After 15 minutes on 40% Venturi, patient’s SpO₂ is 90% (was 84%), RR 20 (down from 30), appears less distressed.” That shows efficacy.
If goals are not met, you escalate or change the plan (e.g. increase O₂, add a second intervention or call provider for new orders). It’s an ongoing cycle of titration and assessment.
Patient Education:
This is crucial, especially for those going home on O₂ or those with chronic needs. Key teaching points:
Oxygen Safety: Teach no smoking or open flames in the home (post “No Smoking – Oxygen in Use” signs). Instruct them and family about the fire risk – e.g. do not allow anyone to smoke in the house, keep O₂ at least 6 feet from gas stoves, candles, fireplaces. Oxygen itself doesn’t explode, but it feeds fires to burn hotter and faster
. Also caution about using flammable products (nail polish remover, oil-based aerosols) around oxygen. If the patient uses a nasal cannula, remind them not to use petroleum jelly in the nose for dryness – use water-based saline gels.
Operating the Equipment: If they have a home O₂ concentrator, show how to turn it on/off, check the filter, and what flow rate to set (as prescribed, usually in L/min). If portable tanks, demonstrate how to open the tank valve, read the pressure gauge (so they know when it’s running low), and attach the regulator. Emphasize securing tanks upright to prevent tipping. Ensure they know how to switch from one source to another (e.g. from concentrator to a portable tank for outings).
When to Use & How Much: Clarify the prescription – e.g. “2 L/min NC at rest, up to 3 L during exercise, aim to keep SpO₂ above 90%.” Encourage using O₂ continuously as directed (some patients feel better and try to wean themselves – caution them that even if they feel okay, their organs need the oxygen). If they have an order “PRN for SOB” ensure they understand what criteria to use it. Teach them how to adjust the flow meter correctly (align the center of the ball with the marking).
Maintenance: If a humidifier is in use, teach to fill with distilled water and clean it regularly (to prevent infection or mold). Instruct how often to change cannulas and tubing (typically every couple of weeks or if it becomes stiff/soiled). For CPAP/BiPAP users, review cleaning of masks and hoses (usually daily or weekly depending on part, using mild soap).
Signs to Seek Help: Educate on recognizing worsening symptoms – increased shortness of breath not relieved by rest/O₂, headache or confusion (could indicate CO₂ retention or O₂ device malfunction), chest pain, fever (if on O₂ for lung infection, fever could mean it’s worsening). If SpO₂ monitor is provided for home, instruct what readings are concerning (e.g. “if under 88% for more than a few minutes, apply oxygen and call doctor”).
Travel and Lifestyle: Discuss how to manage O₂ when going out. Portable concentrators or tanks can be used – plan with the supplier. They should not just stop O₂ to run errands. Many patients worry about mobility; encourage them that with portable systems they can still leave the house. If flying, they must arrange O₂ with the airline in advance.
No Smoking – worth repeating: If the patient is a smoker, this is a teachable moment for cessation. Not only for safety (lighting up with O₂ is extremely dangerous) but also because continuing to smoke defeats the purpose of therapy. Offer resources for quitting smoking.
Nutrition and hydration: Eating with a nasal cannula is fine (just leave it on). If on a mask, plan meals with cannula use. Encourage a high-protein diet if they have chronic lung disease to maintain respiratory muscle strength (and small frequent meals if a big meal makes them too breathless). Hydration helps keep secretions thin – drink adequate fluids unless contraindicated.
Breathing Exercises: Teach pursed-lip breathing (especially for COPD – inhale through nose, exhale slowly through pursed lips as if blowing a candle, which prevents airway collapse). Diaphragmatic breathing exercises can strengthen the diaphragm. If going home on O₂ after pneumonia or surgery, instruct on incentive spirometer use to continue expanding lungs.
Follow-up: They may need periodic re-evaluation of their O₂ levels by the provider. Pulse ox or ABG tests might be scheduled – ensure they keep those appointments to adjust O₂ therapy appropriately. Also, if they feel they are improving and want to wean O₂, emphasize they must discuss with their doctor and not just do it on their own.
Emotional support: Some patients fear dependence on O₂ or feel embarrassed. Provide reassurance that O₂ therapy can greatly improve their energy and organ function, and that many people use it and live active lives. It’s a treatment, not a life sentence – some can be weaned off if their condition improves (like after rehabilitation, weight loss in OSA, etc.). Encourage them to stay active as tolerated (with O₂ in place) – activity helps conditioning.
Education should be in simple terms, using teach-back to confirm understanding (“Can you show me how you would set your oxygen flow at home?” “What precautions will you take when your grandson visits with his birthday cake candles?”). If the patient is in hospital on oxygen, educate them and family along the way so they’re prepared if they need home O₂. Even for short-term O₂ use, explain what you’re doing: e.g. “I’m increasing your oxygen because your saturation is a bit low – this should help you breathe easier. It’s important you keep this on, even if the nasal prongs feel annoying, so that your body gets the oxygen it needs.” Involving the patient helps with cooperation and reduces anxiety.
6. Non-Pharmacologic Interventions
In addition to oxygen and medications, nurses utilize non-pharmacological strategies to improve oxygenation:
Positioning: Perhaps the simplest and most effective immediate measure.
High Fowler’s position (head of bed ~60-90°) maximizes chest expansion and oxygenation
. Gravity helps the diaphragm move downward and frees up space for lung expansion. Patients almost always breathe easier sitting up. In cases of unilateral lung disease (like one bad lung), the “good lung down” lateral position can improve oxygenation by matching perfusion to the better ventilated lung.
Tripod positioning: Instruct the patient to sit up and lean forward with arms propped on a table or their knees
. This posture optimizes the use of accessory muscles and helps expand the lungs. It’s often seen naturally in COPD patients during distress. As a nurse, you can provide a bedside table with pillow for them to lean on.
Proning (lying on the abdomen) is an advanced intervention primarily for ARDS patients in ICU, to improve oxygenation by recruiting posterior lung segments. It’s not typically a floor nurse-driven intervention, but be aware it exists.
Even simply turning and repositioning an immobile patient regularly helps prevent secretions from pooling and atelectasis from prolonged supine positioning (lying flat can reduce oxygenation by limiting diaphragm movement
). So avoid continuous supine position in a hypoxic patient unless contraindicated (like spinal injury).
Breathing Techniques & Exercises: Teach and encourage these to improve ventilation:
Incentive Spirometry (IS): A device that encourages slow, deep inhalations to inflate alveoli and prevent atelectasis. Post-op and immobilized patients should use it 5-10 times hourly while awake. It provides a visual goal (float a ball or sustain a piston) to help patients take deeper breaths than normal. It’s very effective at preventing atelectasis, which maintains better oxygenation.
Cough and Deep Breathe: Have patients take a deep breath, hold for a second, then cough forcefully. This helps clear secretions and open collapsed areas. Splint incision sites with a pillow if needed for comfort. Even if no sputum is produced, the act of deep breathing and coughing mobilizes lung expansion.
Pursed-Lip Breathing: Especially useful for COPD/emphysema. Instruct them to inhale through the nose and exhale slowly through lips as if whistling or blowing out a candle (usually exhale twice as long as inhale). This creates a slight back-pressure in airways, preventing premature airway collapse and helping blow off CO₂. It can immediately help reduce dyspnea in COPD during episodes of SOB.
Diaphragmatic (Belly) Breathing: Encourage using the diaphragm more than accessory shoulder muscles. Patient places a hand on abdomen, inhales slowly (feeling belly rise), then exhales and the belly falls. This technique increases ventilation efficiency and can strengthen the diaphragm over time. Often taught in pulmonary rehab for COPD.
Huff coughing or Huff breathing: Instead of a big cough that may close the throat, the patient does a series of “huff” exhales to move secretions up gradually. Good for those with thick sputum who get exhausted with normal coughing (like COPD or CF patients).
Relaxation breathing: In anxiety-induced hyperventilation, coaching slow deep breathing can prevent respiratory alkalosis and improve oxygenation by ensuring they’re not just shallow panting. Sometimes having them breathe with you, or into a paper bag for a short while (if appropriate), can balance things.
Hydration: Fluids help thin secretions, making them easier to cough out
. Encourage an intake of 2-3 L/day if not contraindicated (heart/renal issues may limit). Well-hydrated mucous membranes also function better in trapping and clearing microbes. If the patient can’t drink (e.g. intubated or NPO), ensure IV fluids as appropriate to maintain hydration. Monitor for signs of dehydration (thick, tenacious secretions are a clue) and advocate for fluid intake. Humidification of inspired air (through humidifiers or nebulizers) also hydrates the airways. Simple measures like a bedside humidifier or wet gauze in a vent mask can help, especially in dry hospital air or winter heating.
Chest Physiotherapy (CPT): For patients with significant sputum retention, techniques like postural drainage, percussion, and vibration can aid secretion clearance. Postural drainage uses gravity by positioning the patient so that secretions drain from lung segments (e.g. Trendelenburg for lower lobes). Percussion (“clapping” on the chest wall with cupped hands) and vibration (rapidly oscillating a flattened hand during exhalation) help loosen mucus. Often respiratory therapists perform CPT, but nurses may be trained as well. Devices like flutter valves or acapella (patient exhales into them causing vibrations in airways) can be given to patients to use independently to mobilize mucus. Clearing secretions greatly improves oxygenation in pneumonia, CF, COPD with chronic bronchitis, etc. Make sure to coordinate CPT with bronchodilator treatments (do CPT after bronchodilator if possible, to maximize mucus clearance). And schedule it not right after meals to prevent aspiration.
Suctioning: For patients who cannot cough effectively (e.g. neuromuscular disease, decreased LOC, or those with a tracheostomy), suctioning the airway is a vital non-pharm intervention. Oral suction (Yankauer) for oral secretions, or deeper nasopharyngeal/tracheal suction for lower secretions as needed. Suctioning clears the airway to allow better oxygenation but should be done cautiously (it can cause temporary desaturation or trauma if overdone). Always pre-oxygenate if doing deep suction and monitor sats during. Sterile technique for trach or nasotracheal suction to avoid infection.
Emotional Support and Breathing Control: Anxiety can make breathing worse – calming reassurance or the presence of a nurse can reduce the psychological load. Simple coaching (“slow down, breathe with me, you’re doing well”) can prevent hyperventilation. Sometimes using a fan or cool cloth can help the sensation of breathlessness (cool air to the face can reduce dyspnea). If appropriate, involve family to help calm the patient, or use relaxation techniques (guided imagery, music therapy) to ease anxiety that comes with dyspnea.
Environment: Ensure a restful environment to decrease O₂ demand – for instance, keep room temperature comfortable (shivering increases O₂ consumption), and minimize disturbances that aren’t necessary when patient is in respiratory distress. If the patient is on continuous pulse ox, set appropriate alarms so you’ll know if they drop, but tailor alarm limits to avoid constant false alarms that might stress the patient.
By combining these non-drug interventions with oxygen therapy, you address not just the oxygen supply but also improve the patient’s own respiratory function and comfort. Many of these measures (like positioning and breathing exercises) empower the patient to help themselves and are key parts of pulmonary rehabilitation.
7. NCLEX-Style Scenario Questions
Test your understanding with these practice questions. Choose the most appropriate answer and then check the rationale.
Q1. A 68-year-old patient with advanced COPD is admitted for pneumonia. He has chronic CO₂ retention and usually is on 2 L/min nasal cannula at home. Today his SpO₂ is 86% on 2 L, and he is dyspneic. Which oxygen delivery device is most appropriate to improve his oxygenation while minimizing the risk of depressing his respiratory drive?
A. Simple face mask at 8 L/min O₂
B. Non-rebreather mask at 15 L/min O₂
C. Venturi mask at 28% FiO₂
D. High-flow nasal cannula at 60% FiO₂
Correct Answer: C. Venturi mask at 28% FiO₂.
Rationale: A Venturi mask delivers a precise low FiO₂, which is ideal for CO₂-retaining COPD patients who need controlled oxygen
. In this scenario, 28% O₂ (about 2 L NC equivalent) can be titrated upward carefully while avoiding excessive FiO₂. A simple mask (A) at 8 L would give roughly 50% FiO₂ unpredictably – too high and not precise. A non-rebreather (B) provides 80-100% FiO₂, which could raise PaO₂ a lot and potentially knock out his hypoxic drive, plus it’s generally reserved for emergencies. High-flow nasal cannula (D) at 60% is also a high FiO₂ and typically for acute hypoxemic respiratory failure; it’s not indicated for someone who just needs a slight O₂ boost with controlled FiO₂. Thus, the Venturi mask allows safe titration to, say, 28%–35% FiO₂ with close monitoring – improving SpO₂ into 88-92% target range without a large risk of CO₂ narcosis
.
Q2. An hour ago, you initiated 100% O₂ via non-rebreather mask for a patient in acute respiratory distress. Now the patient is more stable, but you notice the reservoir bag on the NRB collapses completely on each inspiration. His SpO₂ is 98%. What is the appropriate action?
A. No action needed – reservoir collapse indicates the patient is improving.
B. Increase the oxygen flow rate to keep the reservoir bag partially inflated.
C. Switch the patient to a nasal cannula since SpO₂ is 98%.
D. Place the patient on CPAP instead of the NRB mask.
Correct Answer: B. Increase the oxygen flow rate to keep the reservoir bag partially inflated.
Rationale: On a non-rebreather mask, the reservoir bag should stay about 1/3 to 1/2 full when the patient inhales
. If it’s collapsing completely, the O₂ flow may be inadequate for the patient’s inspiratory demand. The correct action is to increase the liter flow to ensure the bag doesn’t deflate entirely
. (The NRB should be at 10-15 L/min, and often as high as needed to keep the bag inflated.) Option A is incorrect – reservoir collapse is not a good sign; it means the patient might not be getting enough O₂ flow. C (switch to NC) is unsafe at this point: a NC at 2-6 L would drastically drop FiO₂ from near 100% to maybe 40% or less, which could compromise him even if his SpO₂ is OK right now – plus SpO₂ on 100% O₂ doesn’t tell us if he still needs high FiO₂. We would wean gradually, not jump to NC. D, CPAP, is not indicated unless there’s a need for positive pressure; currently the issue is O₂ flow, not airway collapse or pulmonary edema that CPAP is used for. So, by increasing flow (choice B), we ensure the patient continues to get near 100% O₂ without entraining room air due to an empty bag. After that, if truly stable, we could consider weaning FiO₂, but the first fix is flow.
Q3. A patient with ARDS has been on 70% FiO₂ via mechanical ventilation for 3 days. Which assessment finding most strongly suggests the development of oxygen toxicity?
A. Productive cough with green sputum and fever.
B. Irritability and elevated heart rate.
C. New onset of restlessness and high blood pressure.
D. Substernal chest pain and increasing dyspnea.
Correct Answer: D. Substernal chest pain and increasing dyspnea.
Rationale: Oxygen toxicity can cause tracheobronchitis and chest pain as early symptoms, and patients often develop worsening dyspnea despite high O₂
. Substernal chest discomfort is a classic sign of oxygen toxicity from prolonged high FiO₂. Option A (productive cough with green sputum and fever) suggests infection (like pneumonia), not directly oxygen toxicity. Option B (irritability, high HR) could be general signs of hypoxemia or anxiety, but not specific to O₂ toxicity – and if anything, oxygen toxicity in lungs tends to cause more respiratory symptoms. Option C (restlessness, hypertension) are more general signs of early hypoxia or possibly hypercapnia, but not specific; plus if he’s on 70% O₂, hypoxia is less likely than oxygen toxicity or other issues. The ARDS patient would more likely show signs of lung damage from O₂: chest pain, dry cough, and eventually crackles if edema/atelectasis develop. Thus D is the best indicator of oxygen toxicity onset in this context.
Q4. The nurse is caring for a patient receiving 4 L/min O₂ via nasal cannula. The patient complains of nasal dryness and keeps removing the cannula to mouth-breathe. What is the best nursing intervention to enhance the patient’s comfort and oxygen intake?
A. Apply petroleum jelly inside the nostrils to soothe dryness.
B. Switch to a non-rebreather mask at 6 L/min to provide humidity.
C. Add a humidifier bottle to the oxygen delivery system.
D. Encourage the patient to drink less water to reduce rhinorrhea.
Correct Answer: C. Add a humidifier bottle to the oxygen delivery system.
Rationale: Flow rates above 4 L/min can cause nasal mucosa drying
, so the appropriate intervention is to humidify the oxygen flow
. Attaching a humidifier bottle (with sterile water) to the O₂ cannula will moisten the oxygen and relieve dryness, making the patient more comfortable and likely more compliant with therapy. Petroleum jelly (A) is contraindicated with oxygen because it’s petroleum-based and can be a fire hazard
; also it’s not water-soluble, so not recommended for mucosa. A non-rebreather at 6 L (B) is inappropriate: NRB masks require 10-15 L to work and are for high FiO₂ delivery, not comfort humidity. Also, 6 L on an NRB could cause CO₂ rebreathing; plus switching devices just for dryness is overkill. Reducing water intake (D) is opposite of what we want – hydration actually helps with secretions; there’s no indication of problematic rhinorrhea to warrant fluid restriction. So, (C) humidification is the correct comfort measure, and it will allow the patient to tolerate the NC and breathe through their nose to get the oxygen.
Q5. A nurse is teaching a patient who is about to be discharged on home oxygen at 2 L/min via nasal cannula. Which statement by the patient indicates a need for further education?
A. “I’ll make sure to keep my oxygen tank upright and secured in the cart when I move it.”
B. “I plan to smoke only in the kitchen, away from where I use my oxygen.”
C. “I’ll check the gauge on my portable tank to ensure I have enough O₂ before going out.”
D. “I will call my doctor if I consistently feel short of breath or if my oxygen levels run in the low 80s.”
Correct Answer: B. “I plan to smoke only in the kitchen, away from where I use my oxygen.”
Rationale: No smoking is allowed at all in the home while oxygen is in use, period. Option B indicates the patient thinks it’s okay to smoke as long as it’s in another room, which is unsafe. Oxygen can saturate clothing and hair; a flame or cigarette can ignite these even a distance away. The correct teaching is that the patient (and no one in the household) should smoke anywhere in the home or near the oxygen equipment
. Option A is correct behavior – O₂ tanks should be kept upright and secured to prevent them from falling
. Option C is also correct – always check the tank pressure to ensure enough O₂ for outings, and keep track of O₂ supply. Option D is correct – if the patient feels more SOB than usual or if they have an oximeter reading in the low 80s, that’s a sign to seek medical advice (could indicate condition worsening or equipment problem). So B is the dangerous misconception that needs correcting.
Q6. A patient with congestive heart failure is receiving oxygen at 4 L/min via nasal cannula for hypoxemia. He has coarse crackles in both lung bases, a respiratory rate of 24, and is coughing frothy sputum. His SpO₂ is 92%. Which intervention, in addition to oxygen, is the nurse’s priority to improve this patient’s gas exchange?
A. Increase O₂ flow to 6 L/min to eliminate the crackles.
B. Administer the PRN bronchodilator nebulizer for wheezing.
C. Assist the patient into high Fowler’s position with legs dangling.
D. Encourage incentive spirometer use to clear secretions.
Correct Answer: C. Assist the patient into high Fowler’s position with legs dangling.
Rationale: This patient’s presentation (crackles, frothy sputum, CHF) suggests pulmonary edema. Besides oxygen, an immediate helpful intervention is to sit him upright (High Fowler’s) possibly with legs dangling off the bed – this uses gravity to pool fluid in the bases and legs, reducing preload and improving lung expansion
. Positioning is noninvasive, can rapidly ease breathing, and in acute pulmonary edema it helps reduce the work of breathing. Option A (increase to 6 L) won’t “eliminate crackles” – crackles are due to fluid; more O₂ doesn’t remove fluid (and he’s already at 92% sat, so oxygenation is adequate at current flow). Option B, a bronchodilator, treats bronchospasm, but this patient’s issue is fluid, not bronchoconstriction (no wheezing mentioned, just crackles). Option D, incentive spirometer, is more for preventing atelectasis or mild secretion clearance; in acute pulmonary edema the priority is to remove fluid (likely via diuretics) and decrease cardiac workload – using IS won’t address the fluid issue and the patient probably can’t effectively do it while acutely fluid-loaded. So the best immediate step is to position him upright (and likely call the provider for diuretic orders, morphine, or maybe CPAP, but those aren’t in the choices). High Fowler’s will maximize oxygenation and is a classic intervention for acute pulmonary edema (often with legs down to reduce venous return).
Q7. A post-operative patient is drowsy and on a PCA pain pump. You find him supine in bed with a respiratory rate of 8 breaths/min and SpO₂ of 89% on 3 L/min nasal cannula. What is the priority action?
A. Arouse the patient and encourage him to take deep breaths.
B. Increase the oxygen flow to 5 L/min to improve saturation.
C. Stop the PCA pump and prepare to give naloxone (Narcan).
D. Call the Rapid Response Team for impending respiratory arrest.
Correct Answer: A. Arouse the patient and encourage him to take deep breaths.
Rationale: The first action should be to address possible hypoventilation from oversedation – by waking the patient up and prompting deep breathing, you may reverse the mild hypoventilation (RR 8) and improve oxygenation. Often, simple stimulation will increase respiratory rate and tidal volume, raising SpO₂. Option B (increase O₂) may be needed if SpO₂ doesn’t improve, but if the issue is hypoventilation due to sedation, increasing O₂ alone won’t fix CO₂ retention or low RR – better to first try to wake him and get him to breathe. Option C (stop PCA and give Narcan) might become necessary if he cannot be roused or if RR remains dangerously low, but as a first step, you assess responsiveness. In this scenario, he’s drowsy but we don’t yet know if he’s arousable – try that first before antagonizing pain meds. If he wakes and breathes, you may just need to lower the PCA dose. Option D is premature; while an RR of 8 is low, the patient is not in arrest yet – you have steps to try (stimulate, Narcan if needed) before calling a code or RRT. So, the priority: wake him up and coach breathing. This often raises SpO₂ above 90%. Then you would evaluate the need to adjust pain med dosing or administer Narcan if his respirations don’t improve with stimulation.
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