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Three Part Question

[In patients with pseudo-PEA] does [synchronous CPR] [improve mortality]

Clinical Scenario

A 70 year old man presents in PEA cardiac arrest. An ED echocardiogram shows cardiac activity but no pulse is palpable. Pseudo-PEA is diagnosed. You wonder whether CPR timed to systole may improve his chances of survival.

Search Strategy

AMED (Allied and Complementary Medicine) <1985 to March 2020>(0)Embase <1974 to 2020 April 09>(21)
HMIC Health Management Information Consortium <1979 to March 2020>(0)
Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions(R) <1946 to April 09, 2020>(9)
30
1. pseudo pea.mp. [mp=ab, hw, ti, tn, ot, dm, mf, dv, kw, fx, dq, nm, kf, ox, px, rx, an, ui, sy]
2. pseudo emd.mp. [mp=ab, hw, ti, tn, ot, dm, mf, dv, kw, fx, dq, nm, kf, ox, px, rx, an, ui, sy]
3. synchronised.mp. [mp=ab, hw, ti, tn, ot, dm, mf, dv, kw, fx, dq, nm, kf, ox, px, rx, an, ui, sy]
4. CPR.mp. [mp=ab, hw, ti, tn, ot, dm, mf, dv, kw, fx, dq, nm, kf, ox, px, rx, an, ui, sy]
5. cardiopulmonary resucitation.mp. [mp=ab, hw, ti, tn, ot, dm, mf, dv, kw, fx, dq, nm, kf, ox, px, rx, an, ui, sy]
6. 1 or 2
7. 3 or 4 or 5
8. 6 and 7

Search Outcome

14 papers of which three were relevant to the clinical question

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Marill et al 2019 USA	Single pig MAP went from 55 mm Hg (time 7,017 seconds) to 60 mm Hg (7,027 seconds) to 83 mm Hg (7,056 seconds) durin	Proof of concept study	Blood pressure	Synchronized, but not unsynchronized, chest compressions were associated with increased blood pressure. MAP went from 55-60 mm Hg to 83 mm Hg	Single pig. No human evidence.
			Coronary perfusion pressure	Synchronized, but not unsynchronized, chest compressions were associated with increased coronary perfusion pressure. CPP went from 32-38 mm Hg to 60 mm Hg.
Larabee TM et al 2011 USA	7 pigs	A partial-asphyxial swine model of pseudo-PEA arrest was used. Cerebral perfusion pressure was measured over 2 minutes of chest compressions in either systole or diastole.	Cerebral perfusion pressure	Mean Cerebral perfusion pressure was significantly higher for systolic compressions compared to diastolic compressions (13.4+/-7.9 vs. 10.1+/-5.5 mmHg; p<0.001).	Pig models. No human evidence.
Paradis et al 2012 USA	8 pigs	A porcine asphyxial model of pseudo PEA comparing coronary perfusion pressure during chest compression synchronized with residual systole and diastole.	Aortic pressure	Systolic synchronization was association with increases in the relaxation phase aortic pressure (41.7 ± 8.9 mmHg vs. 36.9 ± 8.2 mmHg) p=0.0009	Pig models. No human evidence.
			Coronary perfusion pressure	Systolic synchronization was association with increases in coronary perfusion pressure (37.6 ± 11.7 mmHg vs. 30.2 ± 9.6 mmHg) p=0.0001

Comment(s)

The only available evidence is in pigs. The limited evidence shows no mortality benefit but the studies weren't designed to show a benefit in mortality. The studies showed benefits in cerebral and coronary perfusion pressure during chest compressions in systole.

Clinical Bottom Line

There is no human evidence of mortality benefit for synchronous chest compressions in pseudo PEA but the limited evidence in pig models shows improved cerebral and coronary perfusion pressure. Further research should be performed in humans to see if these benefits are transferable and lead to improved survival rates.

References

1. Marill et al Synchronized Chest Compressions for Pseudo-PEA: Proof of Concept and a Synching Algorithm Prehospital emergency care . (pp 1-13), 2019. Date of Publication: 07 Nov 2019
2. Larabee et al Synchronization of chest compressions with residual systolic cardiac activity during cpr is associated with improved cerebral perfusion pressures in a swine model of pseudo-pulseless electrical activi Annual Meeting of the Society for Academic Emergency Medicine Conference Publication: (var.pagings). 18 (5 SUPPL. 1) (pp
3. Paradis et al Coronary perfusion pressure during external chest compression in pseudo-EMD, comparison of systolic versus diastolic synchronization Resuscitation 2012-10-01, Volume 83, Issue 10, Pages 1287-1291