Flexible bronchoscopy during mechanical ventilation. Why and why not

Flexible bronchoscopy has been utilized in the intensive care units and in mechanically ventilated patients for many decades. The procedure is reasonably safe and has wide range of diagnostic and therapeutic benefits in patients undergoing mechanical ventilation. Though guidelines exist for bronchoscopy in adults in general and for those in the intensive care units (ICU), there are no guidelines specifically established for bronchoscopy during mechanical ventilation. In this review, we try to summarize the indications (Why), physiologic effects of bronchoscopy, complications, and the contraindications (Why not) to the use of this procedure and the evidence behind it. Special section on the single use disposable bronchoscopes and the use of bronchoscopy during the COVID-19 era are discussed.