A nurse is caring for a 68-year-old patient with acute exacerbation of chronic obstructive pulmonary disease (COPD) who is receiving oxygen therapy at 2 L/min via nasal cannula. The patient's oxygen saturation is 88%, respiratory rate is 28/min, and the patient appears anxious and restless. Which nursing intervention should the nurse implement first?

Assessment (ABG) is priority to evaluate hypoxemia and hypercapnia risk in COPD before interventions like oxygen increase or bronchodilators, which could worsen CO2 retention. Other options are important but secondary to initial assessment.

Understanding the Clinical Scenario
The patient is experiencing an acute exacerbation of COPD, evidenced by hypoxemia (SpO₂ 88%), tachypnea (RR 28/min), and signs of air hunger (anxiety, restlessness). While on 2 L/min of oxygen via nasal cannula, the SpO₂ remains below the typical target range of 88-92% for COPD patients, indicating the current therapy is insufficient. In this situation, the nurse must prioritize actions using the nursing process, with assessment being the first step before implementing new interventions.

Why Option 1 is the Priority
The correct first action is to assess the patient's blood gas levels and notify the healthcare provider. Pulse oximetry provides an estimate of arterial oxygen saturation (SpO₂), but it does not give any information about carbon dioxide (PaCO₂) levels or acid-base status. In a COPD patient with worsening respiratory distress, there is a high risk of hypercapnic acute respiratory failure, a condition where non-invasive ventilation (NIV) is a highly effective and safe treatment ^[2]. However, initiating or adjusting advanced therapies like NIV requires objective data from an arterial blood gas (ABG) analysis, which is the gold standard for assessing oxygenation and ventilation ^[3]. A study on prehospital NIV for acute exacerbation of COPD highlights that treatment guided by ABG analysis can improve early physiological outcomes ^[1]. Therefore, obtaining an ABG is the critical assessment that will provide the necessary data to guide the next steps in medical management, including the potential need for NIV as suggested by current evidence [1,2].

Why the Other Options are Not the First Action
- Option 2: Increasing the oxygen flow rate to 4 L/min is an intervention that should not be performed without a specific prescription or a new assessment. In COPD patients with chronic CO₂ retention, indiscriminately increasing supplemental oxygen can depress the hypoxic drive, potentially worsening hypercapnia and causing respiratory acidosis. The ABG must be checked first to understand the patient's ventilatory status.
- Option 3: Administering a prescribed bronchodilator is an appropriate intervention for an acute exacerbation, but it is not the absolute first priority. The immediate need is to determine the severity of the gas exchange impairment. The ABG results will inform the urgency and type of additional therapies, including whether the patient needs to be escalated to NIV [1,2].
- Option 4: Positioning the patient in high Fowler's position and teaching pursed-lip breathing are excellent, low-risk, independent nursing interventions that can be implemented immediately to optimize ventilation and reduce air trapping. However, they do not replace the need for a comprehensive assessment of the underlying physiological derangement. The nurse can perform this action concurrently or immediately after, but the priority task that will most directly guide definitive treatment is the ABG analysis.

Connecting the Evidence to Clinical Judgment
The research underscores a clear clinical pathway for acute exacerbation of COPD. While pulse oximetry is a useful non-invasive screening tool, it has limitations and may not perfectly correlate with the gold-standard ABG-derived SaO₂, especially in critically ill patients ^[3]. When a patient's clinical picture is deteriorating, relying solely on SpO₂ is insufficient. The priority is to obtain the precise data from an ABG—including pH, PaCO₂, and PaO₂—to definitively diagnose hypercapnic acute respiratory failure. This diagnosis is the key trigger for implementing evidence-based therapies like NIV, which has been shown to improve outcomes in this specific population [1,2]. The nurse’s role is to recognize the signs of decompensation, perform the critical assessment (ABG), and communicate the findings to the provider so that the treatment plan can be escalated appropriately based on objective data.