Nitric oxide application during superimposed high-frequency jet-ventilation in patients with ARDS

Introduction

Inhaled nitric oxide (NO) reduces pulmonary hypertension in severe ARDS and improves arterial oxygenation by redistributing blood flow to areas with a normal ventilation/perfusion ratio [1]. As high peak inspiratory pressure (PIP) may contribute to pulmonary damage ventilatory strategies like high-frequency (HF) ventilation search to minimize PIP. This study was designed to evaluate the combined benefits of superimposed high-frequency jet-ventilation (SHFJV), a new HF jet-ventilation technique, with addition of inhalational NO.

Methods

10 patients with severe ARDS were evaluated. All patients where ventilated with a conventional respirator (Evita, Dräger, Germany). The indication for SHFJV was a Horrowitz Index below 100. An electronic prototype jet-ventilator (Alexander 1, Reiner, Austria) used for SHFJV provided simultaneous low-(14-20/min) and high-frequency (400-600/min) jet-streams, which were applied with a special jet-adapter. For application of NO we used the Pulmonox mini (Messer Griesheim, Austria) including a specially developed computer software for precise addition of NO (10 ppm) to the HF jet-stream during inspiration [2]. After 3 h of jet-ventilation we additionally applied NO.

Results

PaO₂/FiO₂ and Horowitz index increased during SHFJV and NO application, while PIP could be reduced maintaining the same levels of CO₂ (Table 1).

Conclusion

The beneficial effect of SHFJV on oxygenation can be combined with the selective effects of inhaled NO. Thereby, impaired pulmonary function can be further improved.

Table 1