Interposed abdominal compression as an adjunct to cardiopulmonary resuscitation

Abstract

The addition of interposed abdominal compression (IAC) to otherwise standard CPR provides external pressure over the abdomen in counterpoint to the rhythm of chest compression. Interposed abdominal compression is a simple manual technique that can supplement the use of adrenergic drugs to increase both coronary perfusion pressure and total blood flow during CPR. Mechanistically, manual abdominal compressions induce both central aortic and central venous pressure pulses. However, owing to differences in venous versus arterial capacitance, the former are usually greater than the latter, so that systemic perfusion pressure is enhanced. Moreover, practical experience and theoretical analysis have suggested subtle refinements in the hand position and technique for abdominal compression that may further improve the ratio of arterial to venous pressure augmentation. Clinical studies confirm that IAC-CPR can improve perfusion pressures and carbon dioxide excretion during CPR in humans. The incidence of abdominal trauma, regurgitation, or other complications is not increased by IAC. Randomized trials have shown that short-term and long-term survival of patients resuscitated in the hospital by IAC-CPR are about twice that of control patients resuscitated by standard CPR. The technique of IAC has thus evolved to become a highly promising adjunct to normal CPR, which is likely to be implemented in an increasing number of clinical protocols.

Design of near-optimal waveforms for chest and abdominal compression and decompression in CPR using computer-simulated evolution

“…Yet it seemed to recapitulate 50 years of resuscitation research in about two days of total computing time on a Pentium III machine. Simulated evolution discovered the principles of interposed abdominal compression CPR 3,7,50 and of active compression-decompression CPR 51,52 . If one chooses to optimize coronary perfusion pressure at shorter duty cycles and rates over 80/min, then evolution also discovered high impulse CPR 53,54 .…”

“…There is evidence that this belief, first articulated to the author by Peter Safar, is true. Clinical trials of interposed abdominal compression CPR by Sack and coworkers 1 showed double the probability of immediate survival, 24-hour survival, and discharge survival using a technique shown in the laboratory to produce about twice the blood flow of standard CPR 2,3 . Recently, Aufderheide, Lurie, and coworkers showed similar effects using an impedance threshold valve attached to the airway during otherwise standard CPR to augment negative pressures in the chest between compressions [4][5][6] .…”

“…A large literature points to the potential of a combination, whenever feasible, of abdominal and chest compressions 3,7 and also to a combination of both compression and decompression (with the aid of an only slightly modified plumber's plunger for the chest, or an adhesive pad for the abdomen) 8,9 . That is to say, optimal CPR is likely to have 4 phases-including compression and decompression of both the chest and the abdomen.…”

Optimal Control Theory Applied to a Difference Equation Model for Cardiopulmonary Resuscitation

“…Over the past half century, the challenge of improving resuscitation success has attracted many investigators, who have proposed several modifications of conventional external CPR with three letter acronyms. These include SVC-CPR for simultaneous ventilation and compression 4 , IAC-CPR for interposed abdominal compression 5,6 , HIC-CPR for high impulse compression 7,8 , ACD-CPR for active compression-decompression 9,10 , and, more recently, CCC-CPR for continuous chest compression CPR without ventilation [11][12][13] . Although large numbers of patients are needed to achieve statistical significance when baseline survival rates are low 14 , significant improvement in resuscitation success in humans across multiple studies has been demonstrated for three-rescuer IAC-CPR 15,16 , and recently for standard CPR with an impedance threshold valve, designed to augment negative pressures in the chest between compressions, and thereby improve pump filling [17][18][19] .…”