[Pressure support ventilation in neonatal age: lights and shadows].

Pressure Support Ventilation (PSV) is one of the most frequently applied modes of partial ventilatory assistance, in which inspiratory time, respiratory rate, tidal volume and minute ventilation are under patient's control. Due to this peculiarity, i.e. during PSV the patient keeps the control of breathing pattern, this mode of ventilatory support is now widely used in neonatal intensive care units. By definition, PSV is a pressure-targeted and flow-cycled method of ventilation, in which each breath is patient-triggered and supported by means of a positive pressure synchronized with the inspiratory effort of the newborn. In comparison to others modes of partial ventilatory support, PSV has the advantage of being one of the less complex because the main setting is the pressure level. The physiological effects of PSV in the newborn are: changes in breathing pattern (such as reduction of respiratory rate and increase of tidal volume), improvement of gas exchange (explained by the increase in alveolar ventilation), decrease in the work of breathing by means a more adequate support of the respiratory muscles, an improved patient-ventilator interaction. Nevertheless, also the newborn under PSV may encounter patient-ventilator asynchrony, with consequent discomfort, increased oxygen consumption and possible ineffective efforts. Moreover, since no controlled breaths are present, alveolar hypoventilation may occur in some categories of newborns. In conclusion, PSV represents a modality of ventilation that ca be used in stable newborns, while its use is contraindicates in critically newborns with abnormal central respiratory drive.