Fibreoptic-aided retrograde intubation: Is it useful to combine two techniques?

Sir,

I congratulate Das et al. for the successful airway management in a patient of oral cancer using fibreoptic bronchoscope for retrograde intubation.[1] I feel that there are certain facts about this technique that need to be discussed.

Firstly, although flexible fibreoptic bronchoscopy requires more skill than the retrograde intubation, yet it is the established method of choice for coping with difficult tracheal intubation.[23] Retrograde intubation is also a very useful technique and has been included in the difficult airway algorithm, but it is a complex, unfamiliar technique that requires practice. The reason for rare teaching and practice is the perceived invasive nature of this procedure. Training methods such as audio-visual materials, manikin simulators and cadavers have been suggested for training in retrograde intubation.[4] Moreover, some operator skill with fibreoptic scope is also required for finding and negotiating the larynx to reach the trachea while performing fibreoptic-aided retrograde intubation.[5] Thus, the combination of the two techniques requires skill for both the procedures.

Secondly, the use of the suction channel of the fibreoptic scope to guide it over a retrograde guide is dependent on a dry field for vision.[5] As the author performed this technique in a patient of oral cancer, the retrieval of guidewire through nose or mouth could lead to trauma and bleeding. Thus, the chances of successful fibreoptic intubation as well as fibreoptic-aided retrograde intubation decreases. A blind use of fibreoptic bronchoscope in the presence of secretions or blood may cause further trauma or may damage this costly equipment.

Thirdly, retrograde intubation, being an invasive procedure, may lead to various complications such as bleeding at the puncture site and inside the trachea, peritracheal and mediastinal haematoma, local surgical emphysema, pneumomediastinum and pretracheal abscess.[5] Complications of both retrograde intubation and fibreoptic intubation are possible with this combined technique.[6]

Besides fibreoptic bronchoscope, various other items (suction catheter, guidewire sheath, multilumen catheter, etc.) have been used as anterograde guide. Tracheal tube exchanger has also been used as an effective aid to facilitate retrograde intubation.[7] Unlike fibreoptic bronchoscope, it is cheaper, widely available and does not need dry field or great expertise to use. Also, the use of fibreoptic scope does not offer advantage over other anterograde guides to combat the problem of folding of endotracheal tube or impingement on arytenoids, while passing it across the airway.[6]

It is beyond doubt that, for a trained anaesthetist, retrograde tracheal intubation is a useful technique in difficult intubation situations, especially when the fibreoptic broncoscope or expertise to use it is unavailable, or blood and secretions preclude its use. But, combining these two techniques requires greater skill and expertise, dry field for vision and extra vigilance for a higher complication rate.