1,3ĪCMV still delivers a set tidal volume at a set respiratory rate, but also responds to a patient’s inspiration.

Accordingly, only an apneic or paralyzed and sedated patient would be ventilated using CMV. A set tidal volume is delivered at a set respiratory rate, with the patient unable to trigger the ventilator or to inspire gas freely through the airway circuit. CMV is the simplest form of mechanical ventilation. There are five common varieties of volume ventilation: controlled mechanical ventilation (CMV), assist/control mode ventilation (ACMV), intermittent mandatory ventilation (IMV), synchronized intermittent mandatory ventilation (SIMV), and pressure-regulated volume-control (PRVC). In general, volume ventilation is more common, but there may be a trend favoring pressure ventilation. There are roles for both volume and pressure ventilation. Exhalation, of course, is passive, no matter what ventilation mode is used. A volume-cycled ventilator delivers a set tidal volume, while a pressure-cycled ventilator delivers whatever tidal volume is needed to reach a set peak inspiratory pressure (PIP). Modes of Ventilation Positive-pressure ventilators can be either volume cycled or pressure cycled. Whether it is used for airway protection, hemodynamic control, or the correction of ventilation or oxygenation abnormalities, mechanical ventilation is an important part of the tool kit used to care for critically ill patients. Management of mechanical ventilation requires selection of the appropriate mode, careful patient monitoring, and observation for possible complications.

Pip in mechanical ventilation