Continuous flow using an entrainer and t-piece vs drawover apparatus for inhalational induction of anesthesia in children

Background: Inhalational induction in children is easiest to perform with the Ayres t-piece & bag (Mapleson F). Drawover anesthesia systems may be used but have not been studied. The aim of this study was to examine the quality of induction of anesthesia in children comparing a continuous flow system using the Farman entrainer and the pediatric t-piece, to a pediatric drawover system. Methods: We conducted a randomized controlled trial in accordance with departmental and institutional standards with 60 subjects who received inhalational induction using either apparatus. Results: There was no evidence of a difference in the median Sp02 between the two methods (P = 0.626) neither was there a difference between the method of induction regarding abdominal distension (P = 0.348) or restraint (P = 0.186). Induction time using the pediatric drawover apparatus 240 (range 115-605) seconds was significantly greater than the Farman entrainer/t-piece 146 (range 65-535) seconds (P < 0.05). Conclusions: We consider that this difference is unlikely to be clinically significant in many cases; however, the increased speed using the entrainer and t-piece may sometimes confer an advantage.