A mechanical ventilator (sometimes called a breathing machine or life support machine) is a device that delivers controlled breaths to a patient who cannot breathe effectively on their own. It connects to the patient via an endotracheal tube (passed through the mouth into the windpipe) or a tracheostomy tube.
The ventilator can take over all breathing (controlled ventilation, used when the patient is heavily sedated or paralysed), assist the patient’s own breathing efforts while providing support (assist-control or pressure support modes), or deliver non-invasive support through a tight-fitting mask rather than a tube (non-invasive ventilation, or NIV).
Key settings adjusted by the critical care team include the tidal volume (the amount of air delivered with each breath), the respiratory rate, the oxygen concentration of the delivered gas, and the positive end-expiratory pressure (PEEP, which keeps the small air sacs of the lung open between breaths). Blood gas analysis guides how these settings are adjusted to maintain safe oxygen and carbon dioxide levels.
Most cardiac arrest survivors admitted to critical care require mechanical ventilation, at least initially, particularly if they have received targeted temperature management requiring sedation. Duration of ventilation varies widely depending on the patient’s neurological and respiratory status. Weaning from the ventilator is a gradual process, culminating in extubation. Prolonged ventilation carries risks including ventilator-associated pneumonia, diaphragm weakness, and post-intensive care syndrome.
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