Peak and Plateau Pressures in Mechanical Ventilation

This set of vocabulary flashcards covers the definitions, physiologic representations, and clinical significance of peak and plateau pressures in mechanically ventilated patients.

Peak Pressure

The pressure the ventilator experiences when pushing a breath into the lungs, representing a combination of airway resistance and alveolar resistance.

Plateau Pressure

The pressure experienced during an inspiratory hold maneuver when air flow is paused, representing lung compliance and alveolar resistance.

Inspiratory Hold Maneuver

A technique where the ventilator pushes a breath in and then pauses flow (no air in or out) to measure the plateau pressure.

Barotrauma

Damage to the lungs or alveoli caused by excessive distention or over-inflation due to high pressures.

Acceptable Peak Pressure

A pressure measurement of less than $40$ centimeters of water.

Acceptable Plateau Pressure

A pressure measurement of less than $30$ centimeters of water.

Lung Compliance

How easily the airways and lung tissue distend outward and collapse back in; directly reflected by the plateau pressure.

Airway Resistance

The resistance encountered as air flows through the tubing and patient airways; it is identified when the peak pressure is significantly higher than the plateau pressure.

Lung Compliance Pathophysiology

Factors affecting lung distensibility, often categorized as blood (hemoptysis), water (pulmonary edema), pus (pneumonia), inflammation (pneumonitis), or fibrosis.

Main Stem Intubation

A condition where the endotracheal tube enters only one bronchus, causing high plateau pressures because the full tidal volume is forced into half the lung capacity.

Pneumothorax

A collapsed lung that can lead to high plateau pressures because the set tidal volume is being delivered to less lung tissue than expected.

Endotracheal Tube Pathology

Mechanical issues that increase airway resistance, such as a kinked tube, a patient biting the tube, or mucus buildup within the lumen.

Bronchospasm

A cause of high airway resistance where the bronchi spasm and narrow, commonly seen in patients with COPD or asthma.

Ventilator Desynchrony

A state where the patient is not cooperative with the ventilator's breath delivery, leading to increased peak pressures.

Pressure vs. Time Scalar

A visual graph on the ventilator screen that displays pressure changes over time to distinguish between peak and plateau values.