Feasibility and safety of transglottic bronchoscopy in mechanically ventilated sheep.

PURPOSE

Although bronchoscopy can be safely performed through endotracheal tube in most intubated critically ill patients, sometimes it could lead to complications such as hypoxia and high airway pressures. Theoretically, transglottic bronchoscopy (TGB) does not interfere with mechanical ventilation and could avoid these complications. In a two-period crossover study, we compared this technique with trans-endotracheal tube bronchoscopy (TEB) in normal anesthetized sheep.

METHODS

In five sheep, we did TGB first. The bronchoscope was introduced through the nasal nares and passed into the trachea via space between endotracheal tube and vocal folds. Heart rate, V(T), P(peak), and O(2) saturation were recorded. One week later, we did TEB. In another five sheep, we did TEB first and TGB later.

RESULTS

P(peak) increased and V(T) and O(2) saturation decreased during TEB (53.2 ± 5.7 vs. 27.6 ± 0.6, P = 0.002; 210 ± 32 vs. 285 ± 26, P = 0.002; 94.3 ± 1.3 vs. 97.5% ± 0.5, P = 0.041, respectively), but not during TGB. The only statistically significant abnormal finding during TGB was a mild tachycardia (96.7 ± 5.7 vs. 94.7 ± 5.5, P = 0.034).

CONCLUSION

Although TGB is time consuming and less convenient than TEB, it has minimal interference with mechanical ventilation. Expertise with this technique could be useful in patients with anticipated significant hypoxia and high airway pressures during bronchoscopy.