Correlations between volume delivery (VTHF) in course of high frequency oscillatory ventilation (HFOV) and severity of respiratory distress.

The treatment of severe respiratory distress in infants (e.g. respiratory distress syndrome--RDS, meconium aspiration syndrome--MAS and pulmonary haemorrage) with HFOV can cause sometimes a volume delivery (VTHF) exceeding the anatomical dead space, with the possibility of an increased risk of volutrauma, implicated in the pathogenesis of chronic lung disease (CLD). The authors examined the possible correlations between VTHF and the severity of respiratory distress in order to limit the risk of ventilator-induced lung injury (VILI). Thirty-five infants in HFOV because of respiratory distress were studied. The median VTHF registered was 2.25 ml/Kg (range: 1.3-3.4) with a significant correlation to some parameters espression of severity of the respiratory distress: arterial/Alveolar ratio (a/AO2) (r = 0.519), oxygen index (OI) (r = 0.512) and mean airway pressure (MAP) (r = 0.543).