HIGH-FREQUENCY OSCILLATORY VENTILATION IN PEDIATRIC RESPIRATORY-FAILURE

Objective. To evaluate the safety and effectiveness of high-frequency oscillatory ventilation using a protocol designed to achieve and maintain optimal lung volume in pediatric patients with respiratory failure. Setting. Tertiary care pediatric ICU in a university hospital. Design: A prospective, clinical study. Patients: Seven patients aged 1 month to 15 yrs with diffuse alveolar disease and airleak with a variety of primary diagnoses, including pneumonia, adult respiratory distress syndrome, and pulmonary hemorrhage. Interventions: After varying periods of conventional mechanical ventilation (16 to 216 hrs), patients were managed with high-frequency oscillatory ventilation using a ''high-volume'' strategy that consisted of incremental increases in mean airway pressure and lung volume to achieve an arterial oxygen saturation of greater-than-or-equal-to 90%, with an FIO2 of less-than-or-equal-to 0.6. Measurements and Main Results. Ventilatory settings, including FIO2 and mean airway pressure, hemodynamic parameters (cardiac index, systemic and pulmonary vascular resistance indices, oxygen delivery [DO2] and oxygen extraction ratio) and the oxygenation index (oxygenation index = [FIO2 x mean airway pressure x 100]/PaO2) were monitored during the transition to high-frequency oscillation and throughout the course of the high-frequency protocol. Six patients responded to high-frequency oscillatory ventilation with rapid and sustained reductions in mean airway pressure (p = .0001, repeated-measures analysis of variance [ANOVA]) and a trend toward decreasing oxygenation index (p = .08, repeated-measures ANOVA). In the four patients from whom hemodynamic data were obtained, there were no compromises of cardiac index or DO2 despite a significant increase in mean airway pressure (26 +/- 2 to 35 +/- 2 cm H2O) during conversion from conventional ventilation to high-frequency oscillation. Conclusions. High-frequency oscillatory ventilation, using a high-volume strategy, may be used safely and effectively in pediatric patients with respiratory failure and with high predicted mortality rates. High mean airway pressure during oscillatory ventilation does not appear to compromise DO2. Whether this technique can alter morbidity or mortality rates in this population awaits prospective randomized study.