[Randomized use of an active compression-decompression technique within the scope of preclinical resuscitation]

Despite its worldwide propagation, external chest compression is of limited efficacy. Recently a new method of cardiac resuscitation, active compression-decompression (ACD), was presented. In animals and a small series of patients resuscitated within the hospital ACD proved to augment blood flow during cardiac resuscitation as a result of greater intrathoracic pressure gradients.

We investigated whether ACD does provide superior survival in patients suffering from out-of-hospital cardiac arrest.

Doctors and paramedics of the mobile intensive care unit at Mannheim University Hospital were trained in the new method. 56 patients were randomly assigned to either standard chest compression according to recommendations of the American Heart Association, AHA (Group I, 30 patients) or to ACD (Group II, 26 patients). ACD was performed by use of a hand-held suction device (CardioPump, Ambu Int.). Compression (30-50 kp) and decompression (10-15 kp) were alternately applied to the patients' chest with a frequency of 80/min. Duration of compression was 50% of the cycle. In both groups advanced life support was performed according to AHA standards.

In Group I, 40% of the patients could be resuscitated; and 13.3% were discharged from hospital. In Group II, 38.5% of the patients regained spontaneous circulation, and 11.5% of the patients were discharged. (Group I vs. Group II: n.s.). One patient in each group survived with a severe neurological deficit. ACD caused greater physical efforts than standard chest compression. Furthermore ACD was difficult to perform in patients with ventricular fibrillation once electrode gel had been used. ACD was not feasible in five patients because of large breast (four women) and kyphoscoliosis (one patient). The rate of serious complications was lower in Group II.

Methods to verify the efficacy of ACD in dummy training should be developed. Paramedics performing ACD should relieve each other every 5 minutes. In patients resuscitated by ACD self-adhesive defibrillation paddles instead of electrode gel should be used. Modifications in the design of the CardioPump are desirable to enhance the efficacy of ACD. With regard to future multicentre trials all paramedics should be skilled in the new technique to reach more patients in a shorter period of time.