[Hypercapnic respiratory failure. Pathophysiology, indications for mechanical ventilation and management]

Area of Science:

• Pulmonary Medicine
• Critical Care
• Respiratory Physiology

Background:

• Acute hypercapnic respiratory failure commonly affects patients with Chronic Obstructive Pulmonary Disease (COPD) and Obesity Hypoventilation Syndrome (OHS).
• This condition can be associated with hypoxemic respiratory failure and presents significant challenges for mechanical ventilation management.

Purpose of the Study:

• To present current knowledge on the indications and management strategies for mechanical ventilation in patients experiencing hypercapnic respiratory failure.
• To review the literature concerning the optimal use of ventilation techniques for this patient population.

Main Methods:

• A comprehensive review of existing medical literature was conducted.
• The focus was on identifying and synthesizing information regarding mechanical ventilation in hypercapnic respiratory failure.

Main Results:

• Non-invasive ventilation (NIV) is the primary choice for hypercapnic respiratory failure with pH < 7.35, provided no contraindications exist.
• Careful patient selection, experienced teams, and close monitoring are essential for successful NIV, especially in severe respiratory acidosis.
• Ventilator settings for COPD exacerbations should prioritize long expiratory and short inspiratory times to prevent hyperinflation and intrinsic PEEP.
• Management must be tailored to the specific pathophysiology in OHS and overlap syndromes.
• Extracorporeal CO2 removal is a potential option for refractory cases, with emerging reports in awake patients.

Conclusions:

• NIV is the predominant treatment for hypercapnic respiratory failure, but vigilant monitoring is required to timely escalate to invasive ventilation if necessary.
• Further research and evaluation are needed for extracorporeal CO2 removal techniques, particularly in non-intubated patients.