Inhaled Nitric Oxide and Prone Position: How Far They Can Improve Oxygenation in Pediatric Patients with Acute Respiratory Distress Syndrome?

摘要

Inhaled nitric oxide (iNO) and prone position (PP) are two of the new therapeutic modalities proposed in the treatment of patients with ARDS. To test the hypothesis that PP and iNO, each acting by a different mechanism to improve arterial oxygenation, could exert safe and additive beneficial effects when used in combination, in mechanically ventilated pediatric patients with ARDS. A prospective randomized controlled study was done in pediatric intensive care unit. Thirty-two patient aged 8 weeks to 10 years with diagnosis of ARDS, on mechanical ventilation were enrolled in the study. The present study period was 24 h. Patients were divided into three groups: (1) Supine position with NO inhalation (SP+iNO), (2) Prone position without NO inhalation (PP) and (3) Prone position with NO inhalation (PP+iNO). Oxygenation parameters including, ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (PaO₂:FIO₂) and oxygenation index (OI) were collected at baseline (T0), 1 h (T1), 20 h (T2), 24 h (T3). In the SP+iNO group the PaO₂:FIO₂ ratio increased significantly from the baseline value 135±8.4 mmHg at T0 to 152±15 mmHg at T1 (p = 0.05), to 153±14.1 mmHg at T2 (p = 0.05), then to 140±13.9 mmHg at T3 (p>0.08). In the PP group the PaO₂:FIO₂ ratio significantly increased (p 0.05). While in the PP+iNO group, the PaO₂:FIO₂ ratio increased significantly from 139±12.1 mmHg at T0 to 180±12.4 mmHg at T1 (p 0.05). However in the PP+iNO group the OI decreased also significantly from 16.5±1.9 at baseline to 11.5±1.4 (p = 0.03) at T1, 9.5±2.1 at T2 (p = 0.01) and then increased again to 11.6±0.5 at T3 (p = 0.035). Finally analyzing the results showed that the PP+ iNO group was the one achieved best oxygenation parameters compared to base line values, with sustained significant effect even after resuming supine position and cessation of iNO. No seriously adverse events were detected during the study. The present study showed that in mechanically ventilated pediatric patients with ARDS, the combined use of PP and iNO is safe and has an additive effect, which causes a greater sustained improvement in oxygenation than either treatment strategy alone.