BACKGROUND AND OBJECTIVES: Ignition accidents during bronchoscopic laser irradiation have occasionally been reported, but the mechanisms responsible for the ignition accidents are not fully understood. We examined causative factors including ignition site, oxygen concentration, and role of airflow through the laser fiber. STUDY DESIGN/ MATERIALS AND METHODS: Porcine muscle tissue was placed in a bottle and irradiated by laser under various conditions. Also, a piece of porcine muscle was wedged in a main bronchus of the isolated porcine lungs and irradiated by laser in the same way. RESULTS: Flashing occurred on the tissue exposed to the laser, and this flashing reached the ignition when the oxygen concentration was above 30%. Increasing airflow through the laser fiber prevented the ignition even at an oxygen concentration at 100%. CONCLUSIONS: In laser irradiation, the tissue exposed to the laser can be the ignition site of fire. Increasing airflow through the laser fiber was an effective technique to prevent airway fire. Copyright 2002 Wiley-Liss, Inc.
BACKGROUND AND OBJECTIVES: Ignition accidents during bronchoscopic laser irradiation have occasionally been reported, but the mechanisms responsible for the ignition accidents are not fully understood. We examined causative factors including ignition site, oxygen concentration, and role of airflow through the laser fiber. STUDY DESIGN/ MATERIALS AND METHODS: Porcine muscle tissue was placed in a bottle and irradiated by laser under various conditions. Also, a piece of porcine muscle was wedged in a main bronchus of the isolated porcine lungs and irradiated by laser in the same way. RESULTS: Flashing occurred on the tissue exposed to the laser, and this flashing reached the ignition when the oxygen concentration was above 30%. Increasing airflow through the laser fiber prevented the ignition even at an oxygen concentration at 100%. CONCLUSIONS: In laser irradiation, the tissue exposed to the laser can be the ignition site of fire. Increasing airflow through the laser fiber was an effective technique to prevent airway fire. Copyright 2002 Wiley-Liss, Inc.