Comparing fiberoptic bronchoscopy- and a tracheal tube-mounted camera-guided percutaneous dilatational tracheostomy

Excerpt

In a small, prospective, randomized trial comparing fiberoptic bronchoscopy (FOB) and an endotracheal tube-mounted camera (VivaSight TM-SL tube [VST]; ETView, Misgav, Israel) for optical guidance of percutaneous dilatational tracheostomy (PDT), Grensemann et al. [1] concluded that visualization of PDT with the VST is not non-inferior to the FOB, but ventilation is superior with less hypercarbia when using the VST. We note that in the FOB group, a thick FOB with an outer diameter of 4.9 mm (Olympus BF-P60; Olympus Medical Systems Corp., Tokyo, Japan) was used. The readers were not provided with the sizes of endotracheal tubes used in the FOB group, but placement of such a thick FOB into an adult endotracheal tube can significantly impair ventilation, especially for critically ill patients requiring PDT [2]. This may be a main reason for the inferior ventilation with more hypercarbia using FOB in this study. We argue that different results would have been obtained if a thin adult FOB, such as Olympus BF-DP with an outer diameter of 3.1 mm, was used. Furthermore, it was unclear whether a comparable fresh gas flow was used for mechanical ventilation during the PDT procedure. This could confuse the interpretation of more hypercarbia with the FOB. …