What is the likely arterial blood gas (ABG) result for a chronic obstructive pulmonary disease (COPD) patient, diagnosed 2 years ago, not on oxygen therapy and non-compliant with medication?

From the Guidelines

A COPD patient who is non-compliant with medication and not on oxygen therapy would likely show an ABG with respiratory acidosis and hypoxemia, with a pH below 7.35, elevated PaCO2, and decreased PaO2. The most likely ABG result for this patient is B. pH-7.31, PCO2-6.8kpa, PO2-13kpa, HCO3–28, as it indicates a partially compensated respiratory acidosis, which is consistent with the patient's condition of having COPD for two years without proper management 1. The patient's non-compliance with medication and lack of oxygen therapy would lead to increased airway resistance, air trapping, and impaired gas exchange, resulting in a ventilation-perfusion mismatch. Key points to consider in this patient's management include:

• The need for careful monitoring for hypercapnic respiratory failure with respiratory acidosis, as stated in the BTS guideline for oxygen use in adults in healthcare and emergency settings 1
• The importance of avoiding excessive oxygen use in patients with COPD, as it may increase the risk of respiratory acidosis in patients with hypercapnic respiratory failure 1
• The consideration of oxygen therapy and potential prescription of long-term home oxygen (LTOT) for severe COPD, as outlined in the BTS guidelines for the management of chronic obstructive pulmonary disease 1
• The use of bronchodilators, such as short-acting b-agonist and/or Ipratropium MDI with spacer or hand-held nebuliser, as needed, and the consideration of corticosteroids and antibiotics, as recommended in the ATS/ERS position paper on standards for the diagnosis and treatment of patients with COPD 1.

From the Research

Arterial Blood Gas (ABG) Results for COPD Patients

The likely arterial blood gas (ABG) result for a chronic obstructive pulmonary disease (COPD) patient, diagnosed 2 years ago, not on oxygen therapy and non-compliant with medication, can be analyzed based on the provided options:

• Option A: pH-7.35, PCO2-6.5kpa, PO2-9kpa, HCO3-38
• Option B: pH-7.31, PCO2-6.8kpa, PO2-13kpa, HCO3–28

Analysis of ABG Results

Considering the patient's condition, the ABG results can be expected to show some degree of respiratory acidosis, characterized by an elevated PCO2 level, and possibly some degree of hypoxemia, indicated by a low PO2 level.

• The patient's non-compliance with medication and lack of oxygen therapy may exacerbate these conditions, leading to more severe ABG abnormalities 2, 3.
• Studies have shown that COPD patients who are not on oxygen therapy may experience worsening hypoxemia and hypercapnia, which can be reflected in their ABG results 4, 5.

Comparison of Options

Comparing the two options:

• Option A shows a relatively normal pH, slightly elevated PCO2, low PO2, and elevated HCO3, which could indicate some degree of respiratory acidosis and metabolic compensation.
• Option B shows a slightly acidic pH, elevated PCO2, low PO2, and normal HCO3, which is more consistent with the expected ABG profile for a COPD patient with respiratory acidosis and hypoxemia 6.

Likely ABG Result

Based on the analysis, Option B (pH-7.31, PCO2-6.8kpa, PO2-13kpa, HCO3–28) is more likely to represent the ABG result for a COPD patient diagnosed 2 years ago, not on oxygen therapy, and non-compliant with medication, as it reflects the expected degree of respiratory acidosis and hypoxemia in such a patient 2, 3, 4, 5, 6.