Setting positive end-expiratory pressure in the severely obstructive patient

Area of Science:

• Pulmonary Medicine
• Critical Care Medicine

Background:

• Chronic obstructive pulmonary disease (COPD) presents unique challenges in mechanical ventilation due to underlying pathophysiology, including dynamic hyperinflation and intrinsic positive end-expiratory pressure (PEEPi).
• Dynamic hyperinflation and PEEPi significantly increase the work of breathing and can lead to ineffective triggering of mechanical ventilators in COPD patients during acute respiratory failure.

Approach:

• This review examines the pathophysiology of COPD, focusing on PEEPi and its clinical consequences.
• It evaluates the benefits of applying external PEEP during assisted ventilation in the context of existing PEEPi.

Key Points:

• External PEEP application in COPD patients with dynamic hyperinflation can reduce inspiratory effort and improve ventilator triggering.
• Optimizing ventilator settings and applying external PEEP at approximately 70% of the measured PEEPi level can minimize hyperinflation risks.
• Effective patient-ventilator interaction is enhanced through judicious use of external PEEP.

Conclusions:

• Low levels of external PEEP are beneficial for COPD patients with dynamic hyperinflation undergoing assisted mechanical ventilation.
• External PEEP can reduce work of breathing, facilitate ventilator triggering, and improve patient-ventilator synchrony.