DIN EN ISO 11990-2:2010-12

A fire in the airway is always a serious matter. In addition to local damage in the larynx, injury can occur to the lower airway and the lung tissue. The products of combustion may be blown into the lungs. Laser airway surgery brings together an oxygen-enriched atmosphere, combustible substances and high power, which could create a fire when occurring together. The likelihood that a laser beam will contact the tracheal tube during airway procedures is high. This fact has led to the development of the test method described in ISO 11990-1 to assist the clinician in the decision which tracheal tube shaft was the most laser-resistant under a defined set of conditions. Unfortunately, fires within tracheal tubes, whose shafts were considered laser-resistant according to ISO 11990-1, have continued to occur. Investigations have shown that the cuff, and not the shaft, of the tracheal tube is the area of lowest laser resistance and most likely to be contacted with the laser beam, even when used according to the manufacturer's instructions. Clinical experience has shown that not only perforation of the parts of the shaft below the cuff has happened, but also ignition of the outer surface of the cuff. This could then ignite other parts of the tracheal tube, such as the tip, which is normally unprotected. This part of ISO 11990 specifies a method of testing the continuous wave (cw laser) resistance of the cuff regions of tracheal tubes designed to resist ignition by a laser. Other components of the system, such as the inflation system and shaft (as defined in ISO 11990-1) are outside of the scope of this part of ISO 11990. The International Standard has been prepared by ISO/TC 172/SC 9/WG 4 "Laser systems for medial applications". CEN/TC 123 "Lasers and photonics" is responsible on the European level. On the national level Joint Working Group DKE/NAFuO "Laser in der Medizin" ("Lasers in medicine") (NA 027-01-18-04 GAK) at NAFuO is responsible for the standard.