Safety of percutaneous dilational tracheostomy in patients ventilated with high positive end-expiratory pressure (PEEP).

Abstract

To assess the impact of bronchoscopically guided percutaneous dilational tracheostomy (PDT) on oxygenation in patients with severe respiratory failure ventilated with high positive end-expiratory pressure (PEEP). Prospective clinical study. Anaesthesiological ICU, referral centre for acute respiratory distress syndrome (ARDS) therapy, university hospital. Mechanically ventilated patients with indication for PDT. Two hundred three consecutive PDTs were performed in 198 patients on either high (>10 mbar, n=88) or low (</=10 mbar, n=115) PEEP under bronchoscopic guidance. Arterial blood gas tensions were measured immediately before and 1 and 24 h after PDT. Positive end-expiratory pressure averaged 16.6+/-4 mbar in the high PEEP and 7.6+/-2.2 mbar in the low PEEP group. In the high PEEP group the PaO(2)/FIO(2 )ratio was lower (243+/-90 vs 285+/-78 mmHg) and PaCO(2) higher (45+/-9.4 vs 39+/-7.1 mmHg) when compared to the low PEEP group. Nevertheless, PDT did not significantly decrease oxygenation in either group 1 and 24 h after PDT (PaO(2)/FIO(2): 223+/-83 and 260+/-86 mmHg in the high PEEP group and 280+/-88 and 302+/-82 mmHg in the low PEEP group, respectively). Furthermore, oxygenation did not deteriorate with PDT even in patients with gravely impaired gas exchange (lowest quartile) with a PaO(2)/FIO(2) averaging 130+/-42 mmHg (range 45-192 mmHg) at a PEEP of 17+/-4 mbar. Bronchoscopically guided PDT in our patients on high PEEP did not jeopardise oxygenation 1 h and 24 h following PDT. Accordingly, high PEEP and hypoxic respiratory failure should not be considered a general contraindication for PDT.