A nurse is caring for a 68-year-old patient with COPD exacerbation who is receiving oxygen therapy via nasal cannula at 2 L/min. The patient's oxygen saturation has dropped from 95% to 90% over the past hour, respiratory rate is 30/min, and the patient appears anxious and short of breath. What is the most appropriate nursing intervention?
1Increase oxygen flow rate to 6 L/min immediately
2Increase oxygen flow rate to 3-4 L/min and monitor closely✓ 정답
3Switch to a non-rebreather mask at 15 L/min
4Encourage deep breathing exercises without oxygen adjustment
해설
For COPD patients, oxygen must be titrated carefully to maintain oxygenation (88-92% SpO2) without suppressing hypoxic drive. Increasing to 3-4 L/min with close monitoring balances this need, while higher flows risk respiratory depression.
The patient is presenting with signs of worsening hypoxemia and increased work of breathing during an acute exacerbation of chronic obstructive pulmonary disease (AECOPD). The drop in oxygen saturation from 95% to 90%, accompanied by tachypnea at 30 breaths/min, anxiety, and dyspnea, indicates a decline in respiratory status that requires prompt, measured intervention. In COPD, the primary driver of respiratory drive can shift from the typical hypercapnic response to a hypoxic drive. This means that administering excessive supplemental oxygen can suppress the patient's stimulus to breathe, leading to further carbon dioxide retention and respiratory acidosis. Therefore, the goal of oxygen therapy in AECOPD is to correct hypoxemia to a target saturation range—typically 88% to 92%—without abolishing the hypoxic drive.
Analysis of the Intervention Options
The most appropriate initial step is a cautious titration of oxygen rather than an abrupt, high-flow intervention. Increasing the flow rate to 6 L/min immediately or switching to a non-rebreather mask at 15 L/min poses a significant risk of over-oxygenation, which can precipitate hypercapnic respiratory failure in this population. Conversely, encouraging deep breathing exercises without any adjustment to the failing oxygen delivery device neglects the immediate physiological need for improved oxygenation. The correct approach is to make a modest increase in the current therapy—from 2 L/min to 3-4 L/min—and then closely monitor the patient's response, including repeat oxygen saturation, respiratory rate, work of breathing, and mental status.
Pathophysiological Rationale and Evidence Synthesis
The management strategy is grounded in the delicate balance required during AECOPD. The scoping review by Kristensen et al. underscores that prehospital and emergency management of AECOPD is common but variably supported, highlighting the need for careful, evidence-informed titration of therapies [1]. The physiological risk of aggressive oxygenation is further contextualized by studies exploring advanced respiratory support. While the randomized cross-over trials by Guan et al. and Vieira et al. focus on non-invasive ventilation (NIV) and high-flow nasal cannula (HFNC) as modalities for hypercapnic respiratory failure, their underlying principle is relevant: the goal is to reduce breathing effort and improve gas exchange without causing harm [2, 3]. These studies demonstrate that even with advanced interfaces, careful titration is key to optimizing neurophysiological effects and CO2 clearance. In the current scenario, before escalating to such devices, the immediate nursing action is to optimize the existing low-flow oxygen therapy. This aligns with the foundational knowledge expected of emergency nurses, as assessed by Zhao et al., where a strong grasp of oxygen therapy principles directly translates to appropriate and safe clinical practice . A nurse’s ability to recognize the early signs of deterioration and titrate oxygen judiciously is a critical safety intervention that prevents iatrogenic hypercapnia and the potential need for more invasive ventilation.
References (research sources)
[1]
Prehospital treatment modalities for acute exacerbation of chronic obstructive pulmonary disease: a scoping review.Research articleKristensen JT, Bülow A, Jensen ASR, Gude MF. (2026) · DOI: 10.1186/s12873-026-01571-2
Clinical Management of Worsening Hypoxemia in AECOPD
Scenario: A 68-year-old patient with COPD exacerbation on 2 L/min nasal cannula exhibits a drop in SpO2 from 95% to 90%, tachypnea (RR 30/min), and increased anxiety. You suspect worsening hypoxemia.
Immediate Bedside Actions
Titrate Oxygen Cautiously: Increase the flow rate to 3-4 L/min via nasal cannula. The goal is to achieve a target SpO2 of 88-92%.
Continuous Monitoring: Closely observe respiratory rate, SpO2, level of consciousness, and work of breathing. A failure to improve or further deterioration necessitates escalation.
Patient Positioning: Assist the patient into an upright or tripod position to optimize lung expansion and reduce work of breathing.
Assess for Hypercapnia: Monitor for signs of CO2 retention such as somnolence, confusion, or headache. Have arterial blood gas (ABG) equipment ready.
Critical Safety Warning
Avoid Over-Oxygenation: Do not abruptly increase oxygen to high flows (e.g., 6 L/min or non-rebreather mask) in COPD patients. This can suppress the hypoxic respiratory drive, leading to hypoventilation, acute hypercapnic respiratory failure, and potential respiratory arrest.
Ongoing Management and Reassessment
If SpO2 remains below 88% on 3-4 L/min, further careful titration may be needed while preparing for ABG analysis and physician notification.
Conduct a focused respiratory assessment, including auscultation for wheezes or diminished breath sounds.
Administer prescribed bronchodilators and corticosteroids as ordered to address the underlying exacerbation.
Document all changes in oxygen therapy, vital signs, and the patient's response in the medical record.
Hypoxic Drive — A backup respiratory stimulus in some COPD patients where breathing is triggered by low blood oxygen levels rather than high CO2 levels.
Hypercapnic Respiratory Failure — A state of respiratory failure characterized by elevated arterial carbon dioxide tension (PaCO2), often precipitated by excessive oxygen therapy in COPD.
AECOPD — Acute Exacerbation of Chronic Obstructive Pulmonary Disease; a sudden worsening of respiratory symptoms requiring prompt medical intervention.
Target SpO2 in COPD — The recommended oxygen saturation range for patients with COPD or at risk of hypercapnic failure, typically between 88% and 92%.
Nasal Cannula — A low-flow oxygen delivery device that provides an approximate FiO2 of 24-44% at flow rates of 1-6 L/min.