A mechanical ventilator is a device that provides mechanical ventilation by delivering oxygen-enriched air into and out of the lungs. It is used to treat conditions that cause inadequate breathing, such as respiratory failure. There are different types of ventilators that deliver breaths via positive or negative pressure. Modes of ventilation include controlled, assist-control, and synchronized intermittent mandatory ventilation. Nursing care for a patient on a ventilator involves frequent monitoring of vital signs and lung sounds, suctioning as needed, ensuring proper ventilator settings and alarms, turning/mobilizing the patient, and assessing readiness for weaning from the ventilator.