Intermittent mandatory ventilation in the neonate.

Intermittent Mandatory Ventilation (IMV) provides an alternative method of support to assisted and controlled mechanical ventilation in neonates with acute respiratory failure. Specific advantages include the use of only the level of mechanical support which is required on an individual basis. Because intrapleural pressure ventilation (IPPV), venous return and cardiac output are maintained at more nearly normal levels, with or without positive end-expiratory pressure (PEEP). Duration of mechanical ventilatory support is reduced, weaning enhanced, and the incidence of pulmonary barotrauma decreased with IMV. Physiological homeostasis in terms of acid-base changes is more readily maintained as a result of precise regulation of alveolar ventilation. Newer concepts in mechanical support, such as "reversed" inspiratory:expiratory ratio (I:E ratio) ventilation, are possible with IMV because of the lower ventilator rates employed compared to IPPV.