Biomechanics of two-thumb versus two-finger chest compression for cardiopulmonary resuscitation in an infant manikin model

OBJECTIVE: The loading force applied in infant external chest compression (ECC) has not been determined. The objective of this crossover study was to quantify the actual force involved in two-thumb (TT)-encircling hands and two-finger (TF) methods during infant cardiopulmonary resuscitation. METHODS: A total of 42 emergency medical professionals performed lone rescuer infant external chest compression (ECC) with TF and TT methods. The order of two methods was arranged randomly, with an interval of 30 min in between. The force was collected by MatScan as primary outcomes. The secondary outcomes, quality of chest compressions, and fatigue level were also recorded by SkillReporter and perceived exertion scale. RESULTS: Using the TT method, the rescuers performed cardiopulmonary resuscitation (CPR) with higher ECC quality, but more incomplete recoil than they did using the TF method. The mean compression forces delivered in the first and second minutes were 3.53 ± 1.27 kg and 3.22 ± 1.11 kg (P = 0.012) for TF and 4.11 ± 1.80 kg and 4.04 ± 1.83 kg (P = 0.568) for TT, respectively. Pairwise comparison indicates that the compression force delivered through the TF method during the first and second minute of ECC were inferior to that delivered through the TT method. The TF method involved greater perceived exertion than the TT method (5.27 ± 4.69 vs. 4.02 ± 2.31; P = 0.007). The median perceived exertions for the TF and TT methods were 5 and 4, respectively. CONCLUSION: For infant CPR, the TT method involved greater loading force, lower fatigue, and higher overall ECC quality than the TF method. The optimal compression force is about 3.8-4.3 kg.