A nurse is analyzing arterial blood gas (ABG) results for a patient with chronic obstructive pulmonary disease (COPD). The results show: pH 7.32, PaCO₂ 58 mmHg, HCO₃⁻ 30 mEq/L, PaO₂ 65 mmHg. What is the nurse's priority assessment?

The ABG shows compensated respiratory acidosis with hypoxemia, prioritizing respiratory assessment for ventilation failure. Other options focus on metabolic or cardiovascular aspects, which are less immediate.

Core Nursing Explanation Key Concept Analysis: This question tests the interpretation of Arterial Blood Gas (ABG) results and the identification of the Key Point! priority nursing assessment based on the patient's primary problem. The patient has Chronic Obstructive Pulmonary Disease (COPD), a condition characterized by chronic airflow limitation. The ABG values are: pH 7.32 (acidosis), PaCO₂ 58 mmHg (elevated), HCO₃⁻ 30 mEq/L (elevated), PaO₂ 65 mmHg (low). This pattern indicates a Partially Compensated Respiratory Acidosis with hypoxemia. The primary, life-threatening issue is ventilatory failure (inability to exhale CO₂ effectively), which directly affects oxygenation and acid-base balance.

Answer Rationale: Key Point! The priority assessment is Assess the patient's respiratory rate, depth, and use of accessory muscles. In respiratory acidosis, the elevated PaCO₂ (Hypercapnia) is the root cause. The nurse must immediately evaluate the patient's work of breathing and ventilatory status. Tachypnea, shallow breathing, retractions, and use of accessory muscles (neck, shoulder) are signs of respiratory distress and impending failure. This direct respiratory assessment guides urgent interventions like oxygen therapy adjustment, bronchodilator administration, or preparing for non-invasive ventilation (e.g., BiPAP).

Distractor Analysis:

• Option ② (Check serum electrolytes): While electrolyte imbalances (like hyperkalemia in acidosis) can occur, they are a consequence of the primary respiratory problem. Assessing them is important but not the immediate priority when the patient is in acute respiratory distress.
• Option ③ (Monitor BP and HR): Cardiovascular changes (tachycardia, hypertension initially) can result from hypoxemia and hypercapnia. However, monitoring these is a secondary assessment to evaluate the systemic effects of the primary respiratory issue.
• Option ④ (Evaluate LOC and neuro status): Watch out for confusion! This is a critical assessment for a patient with hypercapnia, as CO₂ narcosis (somnolence, confusion, coma) can occur. However, the question asks for the priority assessment. Before a detailed neurological exam, the nurse must first ensure the patient is breathing adequately. A change in LOC is a late sign of severe respiratory failure. The initial priority is to assess the mechanism of breathing itself.

Related Concepts: The nursing process dictates addressing the most immediate threat to life (Airway, Breathing, Circulation - ABC). Here, Breathing is the compromised component. Understanding the renal compensation (elevated HCO₃⁻) in chronic respiratory acidosis is key for COPD patients.

Concept Summary

ABG Parameter	This Patient's Value	Interpretation	Normal Range
pH	7.32	Acidosis	7.35 - 7.45
PaCO₂	58 mmHg	Respiratory Acidosis (Primary Problem)	35 - 45 mmHg
HCO₃⁻	30 mEq/L	Metabolic Alkalosis (Compensatory)	22 - 26 mEq/L
PaO₂	65 mmHg	Hypoxemia	80 - 100 mmHg

Side-by-Side Comparison!

Condition	ABG Pattern (Example)	Primary Problem	Priority Nursing Assessment
Acute Respiratory Acidosis (e.g., Asthma attack)	pH 7.25, PaCO₂ 55, HCO₃⁻ 24	Sudden CO₂ retention	Airway patency, Work of breathing
Chronic Respiratory Acidosis (COPD - this case)	pH 7.32, PaCO₂ 58, HCO₃⁻ 30	Chronic CO₂ retention with renal compensation	Respiratory effort, Oxygen saturation
Metabolic Acidosis (e.g., DKA)	pH 7.20, PaCO₂ 32, HCO₃⁻ 12	Loss of HCO₃⁻ or acid gain	Kussmaul respirations, Mental status, Fluid balance

Anatomy, Physiology & Pharmacology Points

• Pathophysiology: In COPD, damaged alveoli and narrowed airways impair gas exchange. CO₂ (a volatile acid) is retained, lowering pH. The kidneys compensate over days by retaining bicarbonate (HCO₃⁻).
• Oxygen Therapy Caution: For COPD patients with chronic hypercapnia, high-flow oxygen can suppress the hypoxic drive to breathe. Oxygen should be titrated to a target SpO₂ of 88-92% to avoid worsening respiratory acidosis.
• Drug Mechanism: Bronchodilators (e.g., albuterol, tiotropium) reduce airway obstruction, facilitating CO₂ exhalation.

Memory Tips

• ROME: Respiratory Opposite, Metabolic Equal. If pH and PaCO₂ move in opposite directions (pH down, PaCO₂ up = Respiratory Acidosis), it's a primary respiratory disorder.
• ABC for ABGs: When analyzing, always think Airway & Breathing first. The priority action almost always relates to the respiratory system if PaCO₂ is abnormal.

High-Frequency NCLEX Topics NCLEX loves to test priority-setting with ABG results. You must not only interpret the values but also decide what to do first. Remember: Assess the system that is causing the problem first. Respiratory problem? Assess breathing. Metabolic problem? Assess for underlying cause (e.g., diarrhea, kidney function).

Watch Out for Question Variations!

• Instead of "priority assessment," the question could ask: "The nurse should prepare for which intervention first?" (Answer: Administer supplemental oxygen via nasal cannula at low flow or prepare for BiPAP).
• The scenario could change to a patient with Diabetic Ketoacidosis (DKA) showing metabolic acidosis. The priority assessment then shifts to respiratory pattern (Kussmaul respirations) and level of consciousness.

Nursing Clinical Practice Guide Clinical Scenario: You are the nurse on a medical-surgical unit. Mr. Johnson, a 68-year-old with a 40-pack-year smoking history and severe COPD, is admitted for increased shortness of breath and fatigue. His morning ABG results are as above. When you enter his room, you find him sitting upright in bed, leaning forward on the overbed table (tripod position), with pursed-lip breathing.

Nursing Intervention Strategy:

1. Immediate Assessment (Priority): Approach calmly. Visually assess his work of breathing: count respiratory rate (you note 28/min), observe for nasal flaring, intercostal or supraclavicular retractions, and use of sternocleidomastoid muscles. Auscultate lung sounds (you expect diminished breath sounds with possible wheezes). Check oxygen saturation via pulse oximeter.
2. Intervention: Ensure his prescribed oxygen is running at the correct low liter flow (e.g., 2 L/min via nasal cannula). Administer scheduled bronchodilators (nebulizer or inhaler) promptly. Position him for maximum lung expansion (High Fowler's).
3. Monitoring & Communication: Reassess respiratory status after interventions. Monitor for signs of worsening hypercapnia (increased somnolence, headache, confusion). Report ABG results and your assessment to the provider. Prepare for possible non-invasive positive pressure ventilation (NIPPV) orders.
4. Patient Education: Coach on pursed-lip breathing techniques. Educate on the importance of taking medications as prescribed and recognizing early signs of exacerbation.

Patient Safety and Precautions:

• Key Point! Never automatically increase oxygen flow for a COPD patient without a specific order. High FiO₂ can cause Oxygen-induced hypoventilation.
• Closely monitor for CO₂ narcosis: sedation, confusion, coma. This is a medical emergency.

Nursing Procedure & Medication Flow Administering a Nebulized Bronchodilator (e.g., Albuterol):

1. Verify order and perform hand hygiene.
2. Assemble nebulizer cup, connect to air/oxygen source. Pour medication into cup.
3. Place mouthpiece between patient's lips or apply mask securely.
4. Turn on compressor. Instruct patient to take slow, deep breaths through the mouth.
5. Monitor for therapeutic effect (easier breathing) and side effects (tachycardia, tremor).
6. Encourage oral care after treatment to prevent oral thrush if a corticosteroid was also nebulized.

A Word from Your Senior Nurse "Remember, numbers on a lab slip represent a real person struggling to breathe. Your keen assessment skills are the first line of defense. Seeing those ABG results, your mind should immediately go to your patient's bedside – not just to document the values, but to look at them, listen to them, and touch their hand to assess their perfusion. In COPD care, we walk a fine line between treating hypoxemia and preventing CO₂ retention. That critical thinking – understanding the 'why' behind the low-flow oxygen order – is what makes you a safe and exceptional nurse. On the NCLEX and at the bedside, always link the lab value to the live patient in front of you."