The effect of the external chest compression appliance (AutoPulse) on cardiac arrest in the emergency department and influence on blood gas and N-terminal B-type natriuretic peptide

Abstract

To investigate the value of AutoPulse in the patients with cardiac arrest (CA) in emergency department. Patients with CA seen in the Emergency Department of Chaoyang Hospital, Affiliated to Capital Medical University from September 2008 to August 2009 were divided into standard manual external chest compression group (n=42) and mechanical chest compression group with AutoPulse (n=43), based on the method of the external chest compression . Tracheal intubation was performed and mechanical ventilation instituted in all the patients. Other rescue measures, such as intravenous infusion of fluids, electrocardiogram, electric shock for defibrillation were performed following the cardiopulmonary guideline of 2005. The patients with restoration of spontaneous circulation in 20 minutes were excluded. Among patients with resuscitation over 20 minutes, there were 29 cases in AutoPulse group and 28 cases in standard manual external chest compression group. The blood gas and N-terminal B-type natriuretic peptide (NT-proBNP) from the blood samples obtained from the femoral artery 20 minutes after resuscitation were determined, and the survival rate at 2 hours and 24 hours in both groups was recorded. Twenty minutes after cardiopulmonary resuscitation, the pH value and the arterial partial pressure of oxygen (PaO(2)) of the AutoPulse group (n=29) were significantly higher than those of the standard manual external chest compression group [n=28, pH value: 7.142±0.134 vs. 7.010±0.136, PaO(2) ( mm Hg, 1 mm Hg= 0.133 kPa): 71.92±9.59 vs. 65.61±7.66, both P<0.01], the arterial partial pressure of carbon dioxide (PaCO(2)) and NT-proBNP were significantly lower than those of the standard manual external chest compression group [PaCO(2) (mm Hg): 39.43±14.09 vs. 51.07±16.31, NT-proBNP (ng/L) : 548.18±256.93 vs. 699.40±303.35, P<0.01 and P<0.05]. The 2-hour survival rate in AutoPulse group was higher than that in the standard manual external chest compression group, the disparity of the two groups was statistically significant [74.4% (32/43) vs. 52.4% (22/42), P<0.05]. Though the 24-hour survival rate of AutoPulse group was higher than that of the standard manual external chest compression group, the difference was not statistically significant [9.3% (4/43) vs. 4.8% (2/42), P>0.05]. The device of AutoPulse can improve the tissue perfusion in patients with CA. Though this device may give rise some benefit in resuscitation for a short time, there is no decisive improvement in term of outcome of the patient.