Q: How are modes of mechanical ventilation classified?
The various techniques used in mechanical ventilation to help patients breathe are called modes. Generally, modes are controlled or assisted. In controlled ventilation, the ventilator initiates the breath and does all the work of breathing. In assisted ventilation, the patient initiates and terminates some or all the breaths, with the ventilator giving various amounts of support throughout the respiratory cycle. Hence, the modes of ventilation vary in the degree of the patient’s effort versus ventilator support.
The mode chosen for a particular patient is determined by how much of the work of breathing the patient ought to perform. In full ventilatory support, the ventilator performs all the work of breathing. In partial ventilatory support, both the patient and the ventilator contribute. With some modes, adjustments can be made in the ventilator settings to provide gradations from partial to nearly full ventilatory support...