Improved oxygen delivery during cardiopulmonary resuscitation with interposed abdominal compressions

Abstract

The ability of a new modification of cardiopulmonary resuscitation (CPR) to deliver oxygen to tissues was evaluated. The method utilizes standard CPR techniques with the addition of manual abdominal compressions (100 mm Hg) interposed between chest compressions, and is termed interposed abdominal compression-CPR (IAC-CPR). Oxygen delivery was measured by a spirometer in a closed circuit designed to permit positive-pressure ventilation synchronized with mechanical chest compression. Ventricular fibrillation was induced electrically in 10 anesthetized dogs. In each dog, trials of IAC-CPR and standard CPR were alternated every five minutes during a 30-minute period. Arterial and central venous blood pressures, oxygen consumption, and Fick cardiac output were monitored. The addition of interposed abdominal compression significantly (P < 0.01) increased each of these hemodynamic indicators. Oxygen delivery increased from 4.12  0.39 ml O 2 /kg/min during standard CPR to 6.37  0.35 ml O 2 /kg/min during IAC-CPR. Arterial systolic blood pressure increased from 67  5 mm Hg to 90  5 mm Hg, while diastolic arterial blood pressure rose from 15  2 mm Hg to 33  3 mm Hg. Cardiac output increased from 19.9  2.6 ml/min/kg to 37.5  2.7 ml/min/kg.

Cardiac, thoracic, and abdominal pump mechanisms in cardiopulmonary resuscitation: Studies in an electrical model of the circulation

“…[11,12,26]. Such agreement tends to confirm an assumption underlying much published resuscitation research that the cardiovascular systems of dogs and human beings are fundamentally similar, despite overall differences in scale and certain relative differences in linear dimensions such as those of the hind legs.…”

“…Such agreement tends to confirm an assumption underlying much published resuscitation research that the cardiovascular systems of dogs and human beings are fundamentally similar, despite overall differences in scale and certain relative differences in linear dimensions such as those of the hind legs. Canine models of CPR are occasionally criticized for a variety of anatomical differences that are thought to be important in resuscitation, including a high-riding liver, keel-shaped chest, narrow sternum, and mobile mediastinum [27], and one might argue that such species-specific features are responsible for the favorable results of IAC that have been obtained in dogs [11,12], (White BC, personal communication, fall 1983). However, if this proposition were true, one would not expect to observe flow augmentation by IAC in an electrical model, which is completely independent of such anatomic subtleties.…”

“…Concurrently, Ralston et al [11] and Voorhees et al [12] found that abdominal counterpulsation during otherwise standard CPR essentially doubled cardiac output [11], diastolic arterial pressure, and oxygen uptake [12] in anesthetized dogs with ventricular fibrillation. The technique was termed IAC-CPR to indicate interposed abdominal compressions, which can be applied in the field with the bare hands of an additional rescuer.…”

Interposed abdominal compression CPR: a comprehensive evidence based review

“…Paper and pencil 6 6 of 6 studies positive (100 percent) Blood pressure [21][22][23][24] Oxygen uptake 25 CO 2 excretion/blood gasses 26 Survival and complications [27][28][29][30][31] Clinical models…”

“…Generally such models, summarized in Table 1 have found indices of blood flow during CPR to increase by 50 to 100 percent with the addition of IAC to the resuscitation protocol. Examples include increased carotid artery flow 22,23,30,52 , regional blood flow 16,18,19,25 , systemic and coronary perfusion pressures 14,19,25,29 , cardiac output 25 , and oxygen delivery 25 .…”