Ventilators Health Article

Definition

A ventilator is a device used to provide assisted respiration and positive-pressure breathing.

Purpose

Ventilators are used to provide mechanical ventilation for patients with respiratory failure who cannot breathe effectively on their own. They are also used to decrease myocardial gas consumption or intracranial pressure, provide stability of the chest wall after trauma or surgery, and when a patient is sedated or pharmacologically paralyzed.

Description

Different types of ventilators can be programmed to provide several modes of mechanical ventilation. A brief overview of each type and mode follows.

Negative-pressure ventilators

The original ventilators used negative pressure to remove and replace gas from the ventilator chamber. Examples of these include the iron lung, the Drinker respirator, and the chest shell. Rather than connecting to an artificial airway, these ventilators enclosed the body from the outside. As gas was pulled out of the ventilator chamber, the resulting negative pressure caused the chest wall to expand, which pulled air into the lungs. The cessation of the negative pressure caused the chest wall to fall and exhalation to occur. While an advantage of these ventilators was that they did not require insertion of an artificial airway, they were noisy, made nursing care difficult, and the patient was not able to ambulate.