The following modes of ventilation may be used for weaning off patients from mechanical ventilation except:

A i.e. Controlled mechanical ventilation Controlled mechanical ventilation (CMV) is best reserved for patients capable of little or no ventilatory effo. In this mode, VT and ventilatory rate are fixed (minute ventilation) regardless of patient effo, because patient can not breathe spontaneously. So this mode will pay no role in weaning a patient from mechanical ventilation, setling to limit inspiratory pressure guard against pulmonary barotraumaQ. In Assist control ventilation (ACV) by incorporating a pressure sensor in breathing circuit, the patients inspiratory effo can be used to trigger inspiration. The ventilator can be set for a fixed ventilatory rate, but each patient effo of sufficient magnitude will trigger the set VT (tidal volume). And if the spontaneous inspiratory effos are not detected the machine functions as if in the control mode. Criteria for Discontinuing (weaning) of Mechanical Ventilation Mechanical Criteria Weaning Modes - Inspiratory pressure < 25cm.1-120 - Synchronized Intermittent mandatory ventilation (SIMV) Q - Tidal volume > 5m1/kg - Intermittent mandatory ventilation (IMV) - Vital Capacity > 10m1/kg - Pressure suppo ventilation(PSV)Q - Minute ventilation < 10m1 - Weaning with a T-piece or CPAP (continuous positive - Rapid shallow breathing index < 100 airway pressure) - Assist control ventilation (ACV) Q+-