Abdominal Compression in Cardiopulmonary Resuscitation

Redding JS Anesthesia 1971 Vol 50 Pages 668-675 OF HISTORICAL INTEREST

The study re-examines compression of the abdomen as a method of increasing the effectiveness of external cardiopulmonary resuscitation and clarifying some of the effects on circulatory dynamics. One hundred and forty-five dogs between 5.5 and 18.1 kg. anaesthetized dogs had cardiac standstill produced by acute obstructive asphyxia. External cardiopulmonary resuscitation consisted of artificial ventilation by means of a piston respirator delivering air at a rate of 20 breaths/min. and tidal volume of 25 ml/kg, as well as closed chest cardiac massage compressing the sternum five times during each exhalation. Artificial ventilation was discontinued at the end of twenty minutes. Cardiac massage was discontinued at the end of twenty minutes, or sooner if spontaneous circulation was restored. In some of the animals, an adult blood pressure cuff was secured around the midabdomen and inflated during resuscitation. The cuff was then deflated if spontaneous circulation returned. Other dogs received methoxamine (a vasopressor) during resuscitation efforts. In the study, use of either methoxamine or abdominal compression was followed by a highly significant improvement (P<0.005) over CPR alone in restoring spontaneous circulation. There was a highly significant improvement (P<0.005) in the number of dogs showing evidence of returning consciousness on the day of the experiment (14/15) when abdominal compression rather than methoxamine was used (2/15) in conjunction with CPR. Similarly, the use of abdominal compression to augment CPR (9/15) was significantly more effective (P<0.05) than methoxamine (2/15) in the number of dogs surviving for 24 hours after resuscitation. In this regard, no further supportive treatment was given after the 20-minute period of resuscitation, and abdominal trauma did not occur more often after abdominal compression. The author concludes that both abdominal compression and the vasopressor drug increased the effectiveness of resuscitation by elevating aortic diastolic pressure.