An improved percutaneous jetting system for use during microlaryngeal operations.

Studies carried out in the laboratory have shown that an S-shaped cannula for trans-laryngeal jet ventilation provides a distinct advantage over conventional straight ones. Tidal volumes are larger and the cannula is more stable in position. The tendency of perforate the posterior wall of the trachea during introduction is also minimal. Blood gas data obtained from patients being operated upon with this technique of anaesthesia show that it provides very adequate ventilation and can be effectively used with balanced anaesthesia if a nitrous oxide-oxygen blender is incorporated into the jetting system. It can be put in position before induction of anaesthesia to enable preoxygenation and assist ventilation and can be left in place at the end of the operation until the patient is breathing adequately. If necessary, a tracheostomy can be done with the cannula in situ. It is not proposed that this should be the standard mode of anaesthesia or ventilation for patients undergoing operations on the larynx, but in stituations where other methods are not adequate and when significant upper airway obstruction is present, this is an excellent alternative.