Oxygen concentration threshold for explosion induced by high-frequency electric knife or argon knife at different energies / 中华麻醉学杂志

ABSTRACT

Objective:To determine the oxygen concentration threshold for explosion induced by high-frequency electric knife or argon knife at different energies.Methods:① In vivo experiment The smooth muscle tissue or adipose-rich tissue in 10 pairs of isolated porcine lungs and trachea was electrocauterized at 30 and 50 W with high-frequency electroknife or argon knife at different oxygen concentrations.The initial oxygen concentration was 20%, the oxygen concentration was gradually increased in increments of 5% until the oxygen concentration reached 80%.Each sample was electrocauterized 10 times at each concentration, and the number of explosion was recorded.As long as one explosion occurred, it could be considered that the concentration could induce explosion, and the minimum oxygen concentration inducing explosion was considered as the threshold.② Measurement of oxygen concentration in the airway of patients received bronchoscopic intervention Thirty patients scheduled for elective bronchoscopy with cryotherapy were selected, the oxygen concentration inhaled was reduced from 100% until 50% in decrements of 10%, and the oxygen concentration in airway was measured with the AIRVO 2 transnasal high-flow oxygen inhalation device.ICC consistency analysis was performed between the oxygen concentration in airway and oxygen concentration inhaled. Results:In adipose-rich tissues, the threshold of the oxygen concentration for explosion was 70% at 30 W and 65% at 50 W when using the high-frequency electric knife; the threshold of the oxygen concentration for explosion was 35% at 30 W and 30% at 50 W when using the high-frequency argon knife.In smooth muscle tissues, no explosion occurred at each oxygen concentration when using the high-frequency electric knife and argon knife at 30 or 50 W, and the threshold value was above 80%.There was moderate consistency (ICC value 0.722, 95% CI 0.537-0.850, P<0.001) between the oxygen concentration in airway and oxygen concentration inhaled. Conclusions:In smooth muscle tissues, explosion is not easy to occur at oxygen concentrations below 80% when using the high-frequency electric knife or argon knife.In adipose-rich tissues, explosion is not easy to occur at oxygen concentrations less than 70% at 30 W and at oxygen concentrations less than 65% at 50 W when using the high-frequency electric knife; explosion is not easy to occur at oxygen concentrations less than 35% at 30 W and at oxygen concentrations less than 30% at 50 W when using the high-frequency argon knife.The threshold of oxygen concentrations in airway can be determined using the oxygen concentration inhaled.