What is the recommended treatment for hypercapnia during a Chronic Obstructive Pulmonary Disease (COPD) exacerbation?

From the Guidelines

The recommended treatment for hypercapnia during a COPD exacerbation is non-invasive ventilation (NIV) with targeted oxygen therapy, as stated in the BTS guideline for oxygen use in adults in healthcare and emergency settings 1. When managing hypercapnia in COPD exacerbations, it is crucial to avoid excessive oxygen use, as it can increase the risk of respiratory acidosis.

• The initial step is to monitor patients carefully for hypercapnic respiratory failure with respiratory acidosis, which may develop during hospital admission.
• If the patient is hypercapnic (PCO2 >6 kPa or 45 mm Hg) and acidotic (pH<7.35 or [H+]>45 nmol/L), NIV with targeted oxygen therapy should be started if respiratory acidosis persists for more than 30 min after initiation of standard medical management 1.
• The use of NIV is also recommended by the ERS/ATS guideline for the management of COPD exacerbations, which suggests its use for hospitalized patients with acute or acute-on-chronic hypercapnic respiratory failure due to a COPD exacerbation 1.
• Additionally, the BTS/ICS guideline for the ventilatory management of acute hypercapnic respiratory failure in adults recommends starting NIV when pH<7.35 and pCO2 >6.5 kPa persist or develop despite optimal medical therapy 1.
• Supplemental oxygen should be carefully titrated to maintain oxygen saturation between 88-92%, as excessive oxygen can worsen hypercapnia in COPD patients through suppression of hypoxic respiratory drive and increased ventilation-perfusion mismatch.
• NIV works by reducing the work of breathing, improving alveolar ventilation, and allowing respiratory muscles to recover, thereby helping to clear excess carbon dioxide.
• If NIV fails to improve the patient's condition within 1-2 hours or if the patient continues to deteriorate, endotracheal intubation and mechanical ventilation should be considered.

From the Research

Treatment for Hypercapnia in COPD Exacerbation

The recommended treatment for hypercapnia during a Chronic Obstructive Pulmonary Disease (COPD) exacerbation involves several approaches:

• Non-invasive ventilation (NIV) is considered the gold standard for treating acute hypercapnic respiratory failure in COPD patients with a pH between 7.25 and 7.35 2.
• NIV settings should aim to prevent overinflation and increase of intrinsic PEEP, and the implementation of NIV requires a skilled therapeutic team and close monitoring to avoid or perceive NIV failure in time 2.
• If severe hypercapnia and respiratory acidosis cannot be managed by mechanical ventilation, extracorporeal CO2 removal (ECCO2R) is a new treatment option, although its general and primary use without optimizing medical therapy and mechanical ventilation is not indicated 2.
• High-intensity NIV (HI-NIV) has been shown to be effective in stable COPD patients with chronic hypercapnic respiratory failure, with the goal of achieving normocapnia or the lowest partial arterial carbon dioxide pressure (PaCO2) values possible 3.
• First-line settings for NIV therapy to treat stable hypercapnia include Pressure Support Ventilation Modus, EPAP 5 cmH2O, IPAP 15 cmH2O, and Back Up rate 15/Minute, with the overall goal of reducing CO2 levels 4.

Benefits of NIV in Hypercapnic Respiratory Failure

The use of NIV in patients with acute hypercapnic respiratory failure due to COPD exacerbation has been shown to:

• Decrease the risk of mortality by 46% and the risk of needing endotracheal intubation by 65% 5.
• Reduce length of hospital stay, incidence of complications, and improve pH and partial pressure of oxygen (PaO2) levels 5.
• Improve symptoms and quality of life, although the evidence for these outcomes is less robust 5, 6.

Clinical Recommendations

Based on the available evidence, clinical recommendations for the treatment of hypercapnia in COPD exacerbation include:

• Early initiation of NIV in patients with acute hypercapnic respiratory failure due to COPD exacerbation 2, 5.
• Use of HI-NIV in stable COPD patients with chronic hypercapnic respiratory failure 3.
• Close monitoring and adjustment of NIV settings to optimize CO2 removal and prevent complications 2, 4.
• Consideration of ECCO2R as a rescue therapy in patients with severe hypercapnia and respiratory acidosis who are not responding to mechanical ventilation 2.