The Influences of Different Type of Ventilation Breathing Tube Among Children and Neonate Under General Anesthesia

In previous research, initial mechanical ventilator settings about children were as following: 1.tidal volume 6 to 10 ml/kg of ideal body weight; 2.delta pressures of respiratory pressure should be <10 cmH2O in healthy patients; 3. respiratory pressures could be kept less than 28 to 30 cmH2O in patient with lung injury; 4. positive end-expiratory pressure was necessary, although the optimal level is unknown.

However, few researches discussed about Influences of different types of ventilation breathing tube. The investigators want to clarify the character about length, diameter, and material of the ventilation breathing tube under the ventilation system in relation to tidal volume, end tidal carbon dioxide, compliance among children and neonate.

During this study, the participants will be 100 children who were ASA class1, 2 and performed non-emergency, non-cardiac surgery, who will receive general anesthesia . The participants will divide into three groups according to different body weights (Group N: <4.5kg; Group T: 4.5~20kg; Group C: >20kg), and would receipt total eight type of ventilator breathing tube test. Primary outcome will be the difference of tidal volume, end tidal carbon dioxide and compliance. Besides, secondary outcome will be the change of body temperate under different gas flow (2L, and 5L).