Objectives The aim of this manikin study was to compare the efficiency between overlapping (OP) and adjacent thumb positions (AP) for cardiac compressions using the encircling method in infants.

Methods The study conducted from December 2010 to August 2011 involved 48 volunteers who were students in the emergency medical technician course. The authors let volunteers practice OP and AP as a crossover design. The authors monitored the simulated mean arterial pressure (MAP) generated during a 5-min chest compression. The fatigue level of the volunteers after the chest compression was evaluated with the Likert scale.

Results There were no significant differences in MAP between the dominant hand and the non-dominant hand as the lower thumb of OP. Significant differences were observed in simulated systolic blood pressure, MAP and simulated pulse pressure between OP and AP at 1, 2, 3, 4 and 5 min. There were no significant differences among the changes in heart rate, respiratory rate and end-tidal CO₂ during a 5-min chest compression by OP and AP. The Likert scale scores (1 no fatigue to 5= extreme fatigue) during the 5-min chest compressions were higher in AP than in OP at 2, 3 and 5 min.

Conclusion Higher intrathoracic pressures were achieved by OP in this study. However, further studies are needed to validate these effects of overlapping thumbs technique in infant cardiopulmonary resuscitation, not manikin.