Related Experiment Videos
Heated breathing tubes affect humidity output of circle absorber systems
P P Kleemann1, B K Schickel, J P Jantzen
1Department of Anaesthesiology, Johannes Gutenberg-University Medical School, Mainz, Germany.
Study Objective:
To verify whether the airway climate in circle systems can be improved with heated breathing tubes.
Design:
Randomized, controlled, prospective clinical study.
Setting:
Operating theater of the Department of Maxillofacial Surgery.
Patients:
26 adult patients undergoing prolonged anesthesia.
Interventions:
A total of 26 prolonged anesthetics were conducted in adult patients using a minimal fresh gas flow rate (0.6 L/min) and silicon breathing tubes (16 mm internal diameter) containing a heated coil. Group 1 (n = 10 patients) was the control group; breathing tubes were unheated. In Group 2 (n = 10 patients), breathing tubes were heated to 30 degrees C. In Group 3 (n = 6 patients), breathing tubes were heated to 36 degrees C.
Measurements And Main Results:
Humidity and temperature were measured at the Y-piece. Inspiratory temperature on Group 2 was significantly higher than in Group 1. In Group 3, both inspiratory temperature and absolute humidity were significantly higher than in Group 1. After 5 minutes of ventilation, water content and temperature of inspiratory gases were significantly higher in Group 3 than in Group 1.
Conclusion:
Low-flow systems need at least 120 minutes to achieve a satisfactory airway climate. Heated breathing tubes effectively reduce this delay.