Early administration of inhaled nitric oxide to pediatric acute respiratory distress syndrome patients and its effects on oxygenation and ventilator settings: prospective preliminary report of ten patients

RESUMO

Aim: To establish a protocol for the early introduction of inhaled nitric oxide (iNO) therapy in pediatric acute respiratory distress syndrome (ARDS) patients and to assess its acute and sustained effects on oxygenation and ventilator settings. Patients and methods: Ten children with ARDS aged 1 to 132 months (median, 11 months) with arterial saturation of oxygen menor 88 por cento while receiving a fraction of inspired oxygen (FIO2)3 0.6 and a positive end-expiratory pressure of 3 10cm H2O were included. The acute response to iNO was assessed in a fourhour dose-response test, and positive response was defined as an increase in the PaO2/FIO2 ratio of 10mm Hg above baseline values. Conventional therapy was not changed during the four-hour-test. In the following days, patients who had shown positive response continued to receive the lowest iNO dose. Hemodynamic, PaO2/FIO2 oxigenation index (OI), gas exchange, and methemoglobin levels were obtained when needed. Inhaled nitric oxide withdrawal followed predetermined rules. Results: At the end of the four-hour test, all the children showed significant improvement in the PaO2/FIO2 ratio (63,6 por cento) and the OI (44,9 por cento) from the baseline values. Prolonged treatment was associated with improvement in oxygenation, so that FIO2 and peak inspiratory pressure could be quickl and significantly reduced. No toxicity from methemoglobin or nitrogen dioxide was seen during the study. Conclusions: 1 - The iNO causes acute and sustained improvement in oxygenation without adverse effects; 2 - There is an early reduction in ventilator settings during iNO treatment;3) iNO administration to pediatric patients is safe. Key words: inhaled nitric oxide, acute respiratory distress syndrome, arterial oxygenation, mechanical ventilation