Table 3
Author, date and countryPatient groupStudy type (level of evidence)OutcomesKey resultsStudy weaknesses
Menegazzi JJ et al, 1993, USA5 rescuers performing CPR on 7 swine with induced cardiac arrest. CPR performed with two fingers (TF) or two thumbs (TT)Randomised crossover trialDiastolic blood pressureHigher in TT group (21.8 v 18.5; p <0.001)No measure of force applied during techniques Differences statistically relevant, ?not clinically
Systolic blood pressureHigher in TT group (59.4 v 41.6; p <0.001)
Mean arterial blood pressureHigher in TT group (34.2 v 26.1; p <0.001)
Coronary perfusion pressureHigher in TT group (15.1 v 12.2; p <0.001)
Houri PK et al, 1997, USASwine with induced cardiac arrest. CPR performed with two fingers (TF) or two thumbs (TT)Randomised crossover trialDiastolic blood pressureNo significant differenceSternal compression force achieved was lower in the two fingers group when investigators tried to standardise this component
Systolic blood pressure25% increase with and 57% increase in two thumbs group when no force feedback was given
Dorfsman ML et al, 2000, USA21 rescuers performing CPR on adapted manikin. CPR performed with two fingers (TF) or two thumbs (TT)Randomised crossover trialDiastolic blood pressureHigher in TT group (mean 17.6 v 12.5 p <0.001)Only verbal instructions given in performing TT technique—all rescuers experienced in TF technique
Systolic blood pressureHigher in TT group (mean 68.9 v 44.8 p <0.001)
Mean arterial blood pressureHigher in TT group (mean 35.3 v 23.3p <0.001)
Perfusion pressureHigher in TT group (mean 51.4 v 31.2p <0.001)
Whitelaw CC et al, 2000, USA209 subjects performing CPR on manikin. CPR performed with two fingers (TF) or two thumbs (TT)Randomised crossover trialAdequacy of CPR on skill guideNo significant difference—40 participants produced adequate CPR using TT (95% CI 14 to 25%) and 38 using TF (95% CI 13 to 24%). TT produced more than 40 too shallow compressions in 40 participants compared with 15 in the TF group (p <0.005)Heterogenous group of participants with varying levels of experience. 71% of participants failed to give more than 60 adequate compressions in 2 minute period