Study objective: To test the hypothesis that two-thumb chest compression generates higher arterial and coronary perfusion pressures than the current American Heart Association-approved two-finger method.
Design: Randomized, crossover experimental trial.
Setting and participants: Animal laboratory experiment with seven swine of either sex weighing 9.4 kg (SD, 0.8 kg), representing infants less than 1 year old.
Interventions: Animals were sedated with IM ketamine/xylazine, intubated with a 6.0 Hi-Lo endotracheal tube, anesthetized with alpha-chloralose, and paralyzed with pancuronium. ECG was monitored continuously. Left femoral arterial and Swan-Ganz catheters were placed. Cardiac arrest was induced with an IV bolus of KCl and verified by ECG and pressure tracings. Five American Heart Association-certified basic rescuers were randomly assigned to perform external chest compressions for one minute by either the currently recommended two-finger method or the two-thumb and thorax-squeeze method. After all five completed their first trial, rescuers crossed over to the other method for a second minute of compressions. Ventilation was performed with a bag-valve device, and no drugs were given during CPR. After three complete cycles, the fourth through sixth cycles of compressions were recorded. Every compression was analyzed for arterial systolic, diastolic, mean, and coronary perfusion pressures. One thousand fifty compressions were analyzed with repeated-measures analysis of variance and Scheffé multiple comparisons.
Results: Systolic blood pressure, diastolic blood pressure, mean arterial pressure, and coronary perfusion pressure were all significantly higher (P < .001) with the two-thumb thoracic squeeze technique: systolic blood pressure, 59.4 versus 41.6 mm Hg; diastolic blood pressure, 21.8 versus 18.5 mm Hg; mean arterial pressure, 34.2 versus 26.1 mm Hg; and coronary perfusion pressure, 15.1 versus 12.2 mm Hg.
Conclusion: The two-thumb method of chest compression generates significantly higher arterial and coronary perfusion pressures than the two-finger method in this infant model of cardiac arrest.