Mechanical Ventilation

A set of flashcards focusing on key concepts related to mechanical ventilation, including definitions of important terms and mechanisms.

Pleural Layers

The lungs are surrounded by two pleural layers: visceral (on lung) and parietal (on chest wall).

Pleural Pressure

Normal pleural pressure is approximately −5 cm H₂O.

Compliance

Refers to the lung's ability to stretch; low compliance indicates stiff lungs.

Static Compliance

Measured without airflow; dynamic compliance includes airway resistance.

Airway Resistance (Raw)

The pressure required to move gas through the airways.

Barotrauma

Injury to lung tissue caused by excessive pressure; keep plateau pressures ≤ 30 cm H₂O to prevent it.

Negative Pressure Ventilation

Mimics natural breathing, as seen in devices like the iron lung.

Positive Pressure Ventilation

Forces air into the lungs and is the standard in clinical care.

Dead Space

Ventilation with no perfusion, such as in pulmonary embolism.

Shunt

Perfusion with no ventilation, such as in atelectasis or ARDS.

Volume Control Ventilation (VCV)

Delivers a preset volume; pressure will vary depending on lung mechanics.

Pressure Control Ventilation (PCV)

Delivers a preset pressure; volume will vary depending on lung mechanics.

Trigger (Mechanical Ventilation)

Initiates a breath based on either time or patient effort.

Cycling (Mechanical Ventilation)

Determines how a breath ends—by time, flow, or volume.

PEEP

Positive End-Expiratory Pressure improves oxygenation by preventing alveolar collapse.

FiO₂

Fraction of Inspired Oxygen; should be titrated to maintain SpO₂ ≥ 90%.

Auto-PEEP

Air trapping in the lungs due to incomplete exhalation during mechanical ventilation.

Complications of Mechanical Ventilation

Include barotrauma, volutrauma, ventilator-associated pneumonia, and auto-PEEP.