Laser surgery in the airway

We would like to report an alternative method of ventilation for laser surgery of the larynx, which in our opinion reduces the risks of anaesthesia in connexion with laser surgery. An ordinary suction catheter iscovered longitudinally with self-adhesive aluminium foil. A matt finish is produced on the foil with fine sandpaper before it is stuck on the catheter. The foil should cover the distal 25 cm except for the most distal 1 mm. The proximal end of the catheter is connected with a Luer-Lock connector to the injector-jet ventilator (Wolf 2125 Riwomat). After induction of anaesthesia the suction catheter is passed orally between the vocal cords with the distal end 2-5 cm above the carina. Anaesthesia and relaxation are continued with intermittent fentanyl and thiopentone and a suxamethonium infusion. The injector-jet ventilation is started with 100% 0,; frequency 20 per min; inspiration: expiration ratio I : 3; the injector pressure is adjusted between 2.0-4.5 bar according to chest movement. Control is achieved after 1&15 min. The method has several advantages. Compared with tracheal tubes, size 5-7 covered with aluminium foil, the suction catheter takes up less space, and allows the surgeon a better view of the operational field. It has been mentioned that the edge of aluminium foil could cut in the tracheal mucosa.’ However, we think this risk is reduced when the foil is applied longitudinally. Occlusion of the tracheal tube by compression and kinking of the foil has been reported as a risk.* Kinking has not been a problem to us, probably because of the very flexible material of which suction catheters are made and because of the high intraluminal pressure. The high intraluminal pressure and unidirectional flow eliminate the possibility of ignition of accidentally placed organic material inside the catheter, which is reported to be a risk.’ The risk. of acute airway obstruction from loosened aluminium foil is reduced by cutting the foil in one piece and applying it longitudinally. Using injector-jet ventilation through the laryngoscope the combustion products formed by the action of the laser can be flushed distally into the deeper airways but, with the suction catheter technique, there is an outgoing flow, which brings the combustion products out of the airway and reduces the risk of toxic inhalation. The runningcost softhejet ventilation arequitesmall, as a roll of aluminium foil tape (25 m) costs about E6.50 and a suction catheter fO.O1. To this one has to add the price of the injector ventilator, but the ventilator can also be used advantageously in traditional endoscopy of the larynx, trachea and bronchi. Moreover, the system can be operated with an ordinary manual jet-injector.