Effect of Automated Simultaneous Sternothoracic Cardiopulmonary Resuscitation Device on Hemodynamics in Out-of-Hospital Cardiac Arrest Patients.

BACKGROUND: An automatic simultaneous sternothoracic cardiopulmonary resuscitation (SST-CPR) device is an apparatus that performs CPR by providing simultaneous cyclic compressions of the thorax with a thoracic strap and compression of the sternum with a piston. OBJECTIVE: This study was conducted to compare the hemodynamic effects of CPR with an automatic SST-CPR device to those with standard CPR (STD-CPR) in cardiac arrest patients. METHODS: A randomized trial was performed on victims of out-of-hospital cardiac arrest resistant to initial 20 min of CPR after emergency department (ED) arrival. Patients were instrumented with femoral arterial and internal jugular venous lines before enrollment. Informed consent was waived per protocol. Patients were randomized to SST-CPR or STD-CPR based on the day of the month. The primary outcome was a comparison of the mean estimated coronary perfusion pressure (CPP) between SST-CPR and STD-CPR. The secondary outcome was a comparison of compression arterial systolic pressure, compression arterial diastolic pressure, right atrial systolic pressure, right atrial diastolic pressure, return of spontaneous circulation rate, survival to hospital admission, survival at 30 days, favorable neurologic outcomes at 30 days, and adverse events between two groups. RESULTS: Of 62 patients with non-traumatic, adult, out-of-hospital cardiac arrest who presented to the ED, 24 received CPR with an automatic SST-CPR device (SST-CPR group), and 38 received standard CPR (STD-CPR group). Acquisition and analysis of hemodynamic data were completed in 11 (46%) patients in the SST-CPR group and 14 (37%) patients in the STD-CPR group. Compression arterial systolic pressure, right atrial systolic/diastolic pressures, and end-tidal carbon dioxide tension were not different between the two groups. Median compression arterial diastolic pressure (femoral arterial pressure during relaxation) was 20 mm Hg (mean 22 mm Hg; 95% confidence interval [CI] 5 to 38 mm Hg) and 0 mm Hg (mean -2 mm Hg; 95% CI -21 to 18 mm Hg) in the SST-CPR group and the STD-CPR group (p = 0.002), respectively. Median estimated CPP was 10 mm Hg (mean 16 mmHg; 95% CI 1 to 31 mm Hg) and 2 mm Hg (mean 4 mm Hg; 95% CI -4 to 12 mm Hg) in the SST-CPR group and the STD-CPR group (p = 0.017), respectively. CONCLUSIONS: CPR with an automatic SST-CPR device results in higher estimated CPP compared to standard CPR in patients with non-traumatic, out-of-hospital cardiac arrest.