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

Objective: 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). Design: Prospective clinical study. Setting: Anaesthesiological ICU, referral centre for acute respiratory distress syndrome (ARDS) therapy, university hospital. Patients: 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 (less than or equal to10 mbar, n=115) PEEP under bronchoscopic guidance. Arterial blood gas tensions were measured immediately before and 1 and 24 h after PDT. Results: 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 PaO2/FIO2 ratio was lower (243+/-90 vs 285+/-78 mmHg) and PaCO2 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 I and 24 h after PDT (PaO2/FIO2: 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 PaO2/FIO2 averaging 130+/-42 mmHg (range 45-192 mmHg) at a PEEP of 17+/-4 mbar. Conclusions: 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.