PEX7

Positive End-Expiratory Pressure
Specialty	{{#statements:P1995}}
MeSH	D010372

Positive End-Expiratory Pressure (PEEP) is a mode of mechanical ventilation that maintains a certain amount of pressure in the lungs at the end of expiration. This technique is used to improve oxygenation and prevent alveolar collapse in patients with respiratory distress.

Physiological Basis

PEEP works by increasing the functional residual capacity (FRC) of the lungs, which helps to keep the alveoli open and prevent atelectasis. By maintaining a positive pressure in the airways at the end of expiration, PEEP reduces the work of breathing and improves gas exchange.

Clinical Indications

PEEP is commonly used in the management of patients with:

• Acute Respiratory Distress Syndrome (ARDS)
• Chronic Obstructive Pulmonary Disease (COPD)
• Congestive Heart Failure
• Post-operative respiratory failure

Mechanism of Action

PEEP increases the end-expiratory lung volume and prevents the collapse of alveoli, thereby improving ventilation-perfusion matching. It also reduces the shunt fraction and increases the partial pressure of oxygen in arterial blood (PaO2).

Application in Mechanical Ventilation

In mechanical ventilation, PEEP is applied by setting a baseline pressure that is maintained throughout the respiratory cycle. This can be adjusted based on the patient's oxygenation status and lung mechanics.

Complications

While PEEP can be beneficial, it can also lead to complications such as:

• Barotrauma
• Decreased cardiac output due to increased intrathoracic pressure
• Volutrauma

Monitoring and Adjustment

The level of PEEP is carefully monitored and adjusted based on arterial blood gases, lung compliance, and hemodynamic parameters. The goal is to optimize oxygenation while minimizing potential adverse effects.

Also see

• Mechanical Ventilation
• Ventilator-Associated Lung Injury
• Oxygen Therapy
• Respiratory Failure