# A nurse is caring for a patient with acute asthma exacerbation who presents with the following arterial blood gas (ABG) results: pH 7.28, PaCO2 50 mmHg, HCO3- 24 mEq/L, PaO2 60 mmHg. The patient appears anxious and has wheezing with tachypnea at 30 breaths per minute. What is the priority nursing intervention? > source: MyMerci (mymerci.kr) > url: https://mymerci.kr/pages/nclex_q.php?qn_id=542693 > language: ko > subject: Fundamentals ## 문제 A nurse is caring for a patient with acute asthma exacerbation who presents with the following arterial blood gas (ABG) results: pH 7.28, PaCO2 50 mmHg, HCO3- 24 mEq/L, PaO2 60 mmHg. The patient appears anxious and has wheezing with tachypnea at 30 breaths per minute. What is the priority nursing intervention? ## 보기 1. Administer high-flow oxygen at 15 L/min via non-rebreather mask to improve oxygenation 2. Encourage deep breathing and coughing exercises every 2 hours to clear secretions 3. Position the patient in high Fowler's position and prepare for possible mechanical ventilation **✔ 정답** 4. Administer sodium bicarbonate as ordered to correct the metabolic acidosis **정답: 3** ## 해설 The ABG indicates uncompensated respiratory acidosis with hypoxemia. The anxiety, wheezing, and tachypnea (30/min) suggest severe respiratory distress, making positioning in high Fowler's and preparing for mechanical ventilation the priority to optimize ventilation and prevent respiratory failure. Other options are less immediate or inappropriate. ## 심화 해설 Clinical Context and ABG Interpretation The patient’s arterial blood gas (ABG) reveals a pH of 7.28 (acidemia), a PaCO₂ of 50 mmHg (elevated), and an HCO₃⁻ of 24 mEq/L (normal). This pattern defines an acute, uncompensated respiratory acidosis. In an acute asthma exacerbation, severe bronchoconstriction and airway inflammation cause air trapping and dynamic hyperinflation. The respiratory muscles initially compensate by increasing the work of breathing, which explains the tachypnea of 30 breaths per minute. However, when the patient’s compensatory mechanisms are exhausted, carbon dioxide (CO₂) elimination fails, leading to hypercapnic respiratory failure. The rising PaCO₂ is a critical sign of impending respiratory arrest, as it indicates the patient can no longer maintain adequate alveolar ventilation despite the rapid respiratory rate [1][2]. Rationale for Priority Intervention The priority is to immediately reduce the work of breathing and improve ventilation, not just oxygenation. Positioning the patient in high Fowler’s position optimizes chest expansion and diaphragmatic excursion by reducing pressure from the abdominal contents. More critically, the presence of hypercapnia with acidemia signals that the patient is at high risk for decompensation. According to the guidelines for respiratory distress assessment, the identification of hypercapnic respiratory failure requires preparation for ventilatory support . In severe asthma exacerbations complicated by hypercapnia, noninvasive ventilation (NIV) is often the first-line ventilatory strategy to avoid the complications of invasive mechanical ventilation (IMV), such as barotrauma and hemodynamic instability [1]. If NIV fails or the patient’s condition deteriorates further, IMV or even rescue therapies like extracorporeal membrane oxygenation (ECMO) may be necessary [2][3]. Preparing for possible mechanical ventilation involves gathering the necessary equipment, ensuring the availability of a skilled provider for intubation, and closely monitoring the patient for signs of further decompensation, such as a decreasing level of consciousness or rising PaCO₂. Analysis of Incorrect Options Administering high-flow oxygen at 15 L/min via a non-rebreather mask addresses the hypoxemia (PaO₂ 60 mmHg) but does not solve the primary problem of hypoventilation and CO₂ retention. In patients with severe airflow obstruction, high-flow oxygen can theoretically further suppress the respiratory drive, though this is more of a concern in chronic CO₂ retainers. The immediate threat is the hypercapnic acidosis, which requires ventilatory support. Encouraging deep breathing and coughing exercises is inappropriate for a patient in acute, severe distress with exhaustion; their work of breathing is already maximal, and this intervention would not reverse the underlying bronchoconstriction or the hypercapnia. Administering sodium bicarbonate is contraindicated in respiratory acidosis. The metabolic component is normal; the acidemia is purely respiratory. Bicarbonate administration would not improve ventilation and could worsen intracellular acidosis as the bicarbonate is converted to CO₂, paradoxically increasing the PaCO₂ load. The definitive treatment for respiratory acidosis is to improve ventilation.References (research sources) - [1]The Successful Use of Noninvasive Ventilation in Severe Asthma Exacerbation: A Case Report and Review of the Literature.Case reportGharti SB, Tan EFS, Schmidt M. (2026) · DOI: 10.7759/cureus.107025 - [2]Veno-Venous Extracorporeal Membrane Oxygenation as Rescue Therapy for Near-Fatal Asthma: A Case Report.Case reportMuflihul Haque M, Nessa SST, Huq SMR, Ahmed R, Rabbani R, Polash MI. (2026) · DOI: 10.7759/cureus.107865 - [3]The Evolving Role of Extracorporeal Carbon Dioxide Removal in Acute Respiratory Failure: A Narrative Review.Research articleSherrin S, Kaur J, Taneja V, Mustafa W, Garg K, Kunal K. (2026) · DOI: 10.7759/cureus.105631 ## 임상 시나리오 Clinical Assessment - Recognize acute asthma exacerbation signs: tachypnea, wheezing, anxiety, accessory muscle use. - Interpret ABG: pH < 7.35 with PaCO₂ > 45 mmHg and normal HCO₃⁻ indicates acute uncompensated respiratory acidosis. - Identify hypercapnic respiratory failure: rising PaCO₂ despite tachypnea signals ventilatory failure and impending respiratory arrest. Priority Interventions - Immediately position the patient in high Fowler's position (60-90 degrees) to optimize chest expansion and reduce work of breathing. - Prepare for non-invasive or invasive mechanical ventilation when hypercapnia and acidemia are present. - Administer oxygen to target SpO₂ 92-95% while preparing for ventilation; high-flow oxygen alone does not address ventilatory failure. Ongoing Monitoring - Continuously monitor respiratory rate, lung sounds, SpO₂, and ABG trends. - Assess for signs of worsening hypercapnia: somnolence, confusion, decreased respiratory effort. - Ensure emergency airway equipment and medications (bronchodilators, corticosteroids) are immediately available. ## 핵심 개념 - **Hypercapnic Respiratory Failure** — A state of inadequate alveolar ventilation leading to elevated PaCO2 (>45 mmHg) and acidemia, indicating exhausted respiratory muscles. - **Uncompensated Respiratory Acidosis** — An ABG pattern showing low pH and high PaCO2 with a normal HCO3-, signifying an acute ventilatory problem without renal compensation. - **High Fowler's Position** — An upright sitting position at 60-90 degrees that maximizes chest expansion and diaphragmatic excursion to reduce work of breathing. - **Dynamic Hyperinflation** — Progressive air trapping in the lungs due to incomplete exhalation before the next breath, common in severe asthma exacerbations. - **Arterial Blood Gas (ABG)** — A blood test measuring pH, PaCO2, PaO2, and HCO3- to assess acid-base balance and gas exchange. ## 같은 주제 문제 - [A nurse is analyzing arterial blood gas (ABG) results for a patient with asthma exacerbati…](https://mymerci.kr/pages/nclex_q.php?qn_id=542686) - [A nurse is caring for a patient with pneumonia who presents with fever, tachypnea, and cra…](https://mymerci.kr/pages/nclex_q.php?qn_id=542687) - [A nurse is analyzing arterial blood gas (ABG) results for a patient admitted with chronic …](https://mymerci.kr/pages/nclex_q.php?qn_id=542688) - [A nurse is caring for a client with asthma exacerbation who has developed respiratory acid…](https://mymerci.kr/pages/nclex_q.php?qn_id=542689) - [A nurse is caring for a patient with chronic obstructive pulmonary disease (COPD) who pres…](https://mymerci.kr/pages/nclex_q.php?qn_id=542690) - [A nurse is caring for a patient with chronic obstructive pulmonary disease (COPD) who pres…](https://mymerci.kr/pages/nclex_q.php?qn_id=542691) - [A nurse is caring for a patient with chronic obstructive pulmonary disease (COPD) who pres…](https://mymerci.kr/pages/nclex_q.php?qn_id=542692) --- More free questions: [기출문제](https://mymerci.kr/) _학습 참고용입니다. 실제 임상은 최신 지침과 소속 기관 프로토콜을 따르세요._