Confocal laser endomicroscopy (CLE) in patients with acute respiratory failure on the ICU

Introduction: Differentiating ARDS from other causes of respiratory failure can be challenging. CLE is a high resolution optical technique that, combined with conventional bronchoscopy, provides real-time, near-histology information about the alveolar compartment. Aim: To investigate feasibility and safety of CLE, and to describe different CLE characteristics of the alveolar compartment in patients with non-resolving respiratory failure on the ICU. Methods: Observational study of CLE imaging in mechanically ventilated patients with an indication for diagnostic bronchoscopy. Results: 10 patients were included with the clinical features of respiratory failure and bilateral chest opacities not fully explained by cardiac failure (ARDS). Dominant CT patterns were ground glass(n=4), consolidation(n=3), reticulation(n=1), other(n=2). High quality CLE imaging of the alveolar compartment was obtained in all patients without adverse events. 5 different CLE patterns (normal, alveolar filling with either fluid or cells, early and late fibrosis) were identified (Figure 1). Conclusion: This is the first study to show feasibility, safety and CLE characteristics of the alveolar compartment for various causes of respiratory failure in mechanically ventilated patients. CLE imaging has added value to chest CT and has the potential to distinguish between important causes of respiratory failure in critically ill patients at the ICU.