Current issues of ACP Journal Club are published in Annals of Internal Medicine


Therapeutics

Interposed abdominal counterpulsation during cardiopulmonary resuscitation improved outcomes after in-hospital cardiac arrest

ACP J Club. 1992 May-June;116:65. doi:10.7326/ACPJC-1992-116-3-065


Source Citation

Sack JB, Kesselbrenner MB, Bregman D. Survival from in-hospital cardiac arrest with interposed abdominal counterpulsation during cardiopulmonary resuscitation. JAMA. 1992 Jan 15;267:379-85.


Abstract

Objective

To determine whether interposed abdominal counterpulsation (IAC) during cardiopulmonary resuscitation (CPR) improves outcome after in-hospital cardiac arrest.

Design

All consenting patients eligible for CPR were randomized at admission to receive either conventional CPR or IAC-CPR in the event of in-hospital cardiac arrest.

Setting

Cardiac care, medical intensive care, and telemetry units and the general medical and surgical floors of a tertiary care, university-affiliated hospital (mean CPR procedures, 350/y).

Patients

Over a 6-month period, 1723 of 4356 patients admitted were enrolled and randomized, 862 to conventional CPR and 861 to IAC-CPR. Cardiac arrest was defined as unresponsiveness, apnea, and absence of pulse. Patients with suspected pregnancy, age < 18 years, traumatic cardiac arrest, primary respiratory arrest, or abdominal aneurysm were excluded.

Interventions

Conventional CPR was done according to American Heart Association guidelines. IAC consisted of abdominal compressions with open hands over the umbilicus, at a pressure of approximately 100 mm Hg during the relaxation phase of precordial compression, at a rate of 80 to 100/min.

Main outcome measures

Return of spontaneous circulation, 24-hour survival, and survival to hospital discharge.

Main results

103 eligible patients (56 men and 47 women) had 135 episodes of cardiac arrest. The CPR team arrived a mean of 1.2 min (SD 0.6 min) after the code was called. The mean age of patients was 65 years (range 22 to 91 y); 43% had hypertension; 38% coronary artery disease; and 20%, diabetes. 29 of 48 patients (60%) randomized to IAC-CPR had restoration of spontaneous circulation compared with 14 of 55 patients (26%) randomized to conventional CPR (P < 0.001). {This absolute benefit increase (ABI) of 34% means that 3 patients would need to be treated (NNT) with IAC-CPR (compared with conventional CPR) to have 1 additional patient with restored spontaneous circulation, 95% CI 2 to 6; the relative benefit increase was 137%, CI 46% to 299%.}* More patients assigned to IAC-CPR survived for 24 h (16 [33%] vs 7 conventional CPR patients [13%]*, P = 0.02) {ABI 20%; NNT 5, CI 3 to 22; RBI 162%, CI 22% to 478%}* and until hospital discharge (12 [25%] vs 4 patients [7%], P = 0.02) {ABI 18%; NNT 6, CI 3 to 26; RBI 244%; CI 26% to 864%}*. No statistical differences in CPR-related injuries and neurologic outcome were shown.

Conclusion

Interposed abdominal counterpulsation during cardiopulmonary resuscitation improved outcomes after in-hospital cardiac arrest.

Source of funding: Not stated.

Address for article reprint: Dr. M.B. Kesselbrenner, Department of Medicine, St. Joseph's Hospital and Medical Center, Paterson, NJ 07503, USA.

*Numbers calculated from data in article.


Commentary

IAC during conventional precordial compression has been shown to increase forward blood flow, coronary perfusion pressure, and the rate of return of spontaneous circulation in animal models. The meritorious study by Sack and colleagues provides evidence that this technique may improve outcome in humans who have nontraumatic cardiac arrest. The potential benefit of IAC-CPR, however, seems restricted to patients who have an in-hospital cardiac arrest. In a randomized trial, Mateer and colleagues (1) compared IAC-CPR with conventional CPR for patients who had out-of-hospital cardiac arrest: IAC-CPR failed to improve initial resuscitation and survival to hospital discharge. It may be, therefore, that IAC is effective only when begun immediately after cardiac arrest.

Although possible injury to intra-abdominal viscera or regurgitation of gastric contents during IAC is a concern, increased risks have not been shown. It is also important to note that the patients in the study areas included in this trial had a higher incidence of cardiac arrest (7%) than in some previously reported studies: In a large university-affiliated tertiary care facility, the incidence of cardiac arrest in the combined medical and surgical service was 0.5% and the incidence for all patients hospitalized was 0.4% (2). It would have been helpful if the authors had reported the resuscitation outcome within each of the designated areas, that is, the cardiac care unit, medical intensive care unit, telemetry unit, and medical and surgical floors.

The study offers the hope that the currently dismal outcome of cardiac arrest can be improved by techniques that enhance conventional CPR. Additional large-scale trials would define the optimal use of IAC.

Raúl J Gazmuri, MD
Chicago Medical SchoolNorth Chicago, Illinois, USA

Raúl J. Gazmuri, MD
Chicago Medical School
North Chicago, Illinois, USA


References

1. Mateer JR, Stueven HA, Thompson BM, Aprahamian C, Darian JC. Ann Emerg Med. 1984;13:764-6.

2. Schein RM, Hazday N, Pena M, Ruben BH, Sprung CL. Chest. 1990;98:1388-92.