1. Lock Haven University PA Program
Mechanical vs. Manual CPR for Cardiac Arrest in Adult Patients
Linda Hume
Lock Haven University PA Program
February 25, 2009

2. PICO Question
Patient: Cardiac arrest patients 18 years of age and older who are brought to the ER
Intervention: Mechanically delivered CPR
Comparison: Manually delivered CPR
Outcome: Survival to hospital hospital admission
Question:
In cardiac arrest patients 18 years of age and older who are brought to the ER, does mechanically delivered CPR offer an advantage over manual CPR in survival to hospital admission?

3. Cardiac Arrest
About 350,000 sudden cardiac arrest deaths occur in the United States each year (Cooper et al, 2006, p 2839)
This represents over 1/3 of all deaths in the country) (Ong et al, 2006, p 2629)
CPR was introduced in 1969 (Gaxiola and Varon, 2008, p 923)
Between 225,000 and 700,000 people receive CPR each year (Gaxiola and Varon, 2008, p 923)
Initial rhythm in 40% of out-of-hospital arrests is ventricular fibrillation – a treatable/“shockable” rhythm (American Heart, 2005, p IV-19)

4. Risks for a Poor Outcome
Unwitnessed collapse
Older patient age
Long EMS response time
Studies vary between 6.6 and 8 minutes (Hallstrom et al, 2006, p 2626) (Ong et al, 2006, p 2636)
Most communities have a response time of 7-8 minutes (American Heart, 2005, IV-19)
Nonpublic location
Initial rhythm of asystole or pulseless electrical activity
(Hallstrom et al, 2006, p 2625)

5. Surviving Arrest
Early defibrillation is key to survival of cardiac arrest
Important to maintain circulation while waiting for defibrillation to be available and appropriate for use
Studies have indicated that defibrillation within 3 minutes of cardiac arrest results in a 74% increase in chances of survival
(Cooper et al, 2006, p 2847)

6. Importance of CPR
Each minute of cardiac arrest without CPR equates to a 7-10% decrease in chances of return of spontaneous circulation (ROSC) (Cooper et al, 2006, p 2846)

7. CPR
CPR consists of a compression (ejection) phase and a decompression (refilling) phase (Gaxiola and Varon, 2008, p 924)
Goal of providing CPR is to increase time a patient is in a “shockable” rhythm until defibrillation is available (American Heart, 2005, p IV-19)
Also provides perfusion to the brain, coronary arteries, and lungs, allowing O2 transport in the body
Each minute that CPR is provided following a witnessed collapse, chances of ROSC decline 3-4% per minute (compared to 7-10% without CPR) (American Heart, 2005, p IV-19)
Coronary Perfusion Pressure is another important determinant in ROSC
A CPP of at least 15 mmHg is necessary for ROSC to occur (Australian Government, 2008, p 2)
Levels over 40 mmHg are associated with diminished outcome (Gaxiola and Varon, 2008, p 927)
Current gold standard therapy is manually delivered CPR

8. Flowchart for CPR (Updated 2005):

9. Cons of Manual CPR
Chest compressions are interrupted due to provider fatigue, patient transport, and “hands off” time for defibrillation (Hallstrom et al, 2006, p 2621)
Manual chest compressions are dangerous for EMS providers in the back of moving vehicles (Zoll, 2006)
Chest compressions are often not delivered at an appropriate depth
Typically only 14 mmHg of CPP is provided (Ong et al, 2006, 2634)
Standard CPR provides only ~13% of normal CPP (Ong et al, 2006, p 2635)
Failure to allow full chest re-expansion (decompression)
Providers must keep track of both compression counts and respiration counts

10. Common Errors in Resuscitation
Failure to recognize arrest
Failure to act rationally
Failure to anticipate the next move
Failure to remain calm and focused
Failure to keep skills current
Failure to provide effective compressions
Failure to provide effective ventilations
Failure to know and locate necessary equipment
Failure to debrief or problem solve after a code
(Strzyzewski, 2006, p 10-14)

11. Mechanical CPR Devices
Shortly after the introduction of CPR, interest arose in the development of mechanical devices that could decrease exhaustion associated with performing CPR, and control consistency of depth and force of compressions
First machine was developed by Bramson: it used compressed gas to drive a spring loaded piston with a force of lbs onto the patient’s sternum
(Gaxiola and Varon, 2008, p )

12. Cooper et al, 2006, p 2846

13. AutoPulse/LifeBelt CPR
Cooper et al, 2006, p 2846
Developed in 2000 by Zoll, the AutoPulse has been on the market for 4 years, and approved for use in PA for 2 years (Zoll, 2006)
Provides compression of sternum and lateral walls of thorax
Provides better blood flow – “forward flow” (Cooper at al, 2006, p 2645)
Generates 36% of normal blood flow, and a CPP of 20 mmHg (Gaxiola and Varon, 2008, p 928)
Provides a consistent depth of compressions over a larger area of the chest
Delivers the correct frequency of chest compressions
Not interrupted by transport or defibrillation
Not compromised by provider exhaustion

14. ACDR/ACDC
Hand-held device with a suction cup to provide compressions and active decompressions (Lafuente-Lafuente and Melero-Bascones, 2008, p 1)
Increases intrathoracic flow during decompression to allow for a greater volume of blood flow with next compression
Developed after anecdotal evidence of successful resuscitation using a toilet plunger (Cooper et al, 2006, p 2845)
Pressure gauge in device provides compression and decompression force feedback for user to alter effort (Lafuente-Lafuente and Melero-Bascones, 2008, p 3)
Many different models of this device have been developed by different manufacturers
Models involving pneumatically delivered compressions are available in hospitals, however these are not practical for out-of-hospital use
Cooper et al, 2006, p 2846

15. Manual CPR vs. Mechanical CPR Studies

16. Manual Chest Compression vs
Manual Chest Compression vs. Use of an Automated Chest Compression Device Following Out-of-Hospital Cardiac Arrest
2006 randomized trial by Hallstrom et al
Conducted in Calgary, Alberta; Columbus, OH; Pittsburgh, PA; Seattle, WA; and Vancouver, BC
1,377 patients were involved in the study
Initial improvement in survival of patients who received the mechanical CPR device 4 hours after 911 call
Indicates increased survival rate to hospital admission
Not a statistically significant improvement 24.7% (manual) vs. 26.4% (mechanical)
(Hallstrom et al, 2006, p )

17. Manual Chest Compression vs
Manual Chest Compression vs. Use of an Automated Chest Compression Device Following Out-of-Hospital Cardiac Arrest
No significant improvement to hospital discharge was seen
Cannot be explained: all research prior to conducting the trial indicated an improvement was to be expected
Explanations offered for this outcome include:
Increased time to machine application due to set up
Application of the machine to candidates in whom manual CPR would not be considered
A synergistic effect of the machine with medications
Attributed to difference in study protocol at one site that was associated with most of the adverse outcomes associated with the AutoPulse
(Hallstrom et al, 2006, p )

18. Use of an Automated, Load-Distributing Band Chest Compression Device for Out-of-Hospital Cardiac Arrest Resuscitation
2006 study conducted by Ong et al
Conducted in Richmond, VA
1,067 patients involved in the study
An improvement in survival to hospital admission was seen in patients who had the automatic CPR device applied
11.1% (manual) vs. 20.9% (mechanical)
Mechanical CPR provided higher intrathoracic pressures than were safely possible with manual CPR
(Ong et al, 2006, p )

19. Use of an Automated, Load-Distributing Band Chest Compression Device for Out-of-Hospital Cardiac Arrest Resuscitation
Increased CPP was also evident
15 mmHg (manual) vs. 20 mmHg (mechanical)

20. Use of an Automated, Load-Distributing Band Chest Compression Device for Out-of-Hospital Cardiac Arrest Resuscitation
Greater percentage of coronary and cerebral flow was evident
When combined with medications, patients were provided normal heart and brain flow levels and pressures

21. Use of an Automated, Load-Distributing Band Chest Compression Device for Out-of-Hospital Cardiac Arrest Resuscitation
Greater survival to hospital discharge
2.9% manual CPR, 9.7% mechanical CPR

22. Out-of-Hospital Cardiopulmonary Resuscitation with the AutoPulse
2007 study conducted by Krep et al involving 46 patients
Studied the safety, effectiveness, and practicability of the AutoPulse machine
The results demonstrate that the AutoPulse is:
Effective in providing adequate compressions
Determined by end-tidal CO2 volumes which correlate with cardiac output
Safe for patients in cardiac arrest
No severe compression injuries were seen (rupture of liver, rib fracture)
Only injury noted was mild abrasions over the lateral chest area
Practical for use in cardiac arrest situations
In 2/3 of the applications, set up was performed within 2 minutes
Lightweight design makes the AutoPulse easy to carry to the patient
AutoPulse is the same shape as a backboard and fits easily on a cot for patient transfer, or can be used for transfer itself
(Krep et al, 2007, p 86-94)

23. Active Compression-Decompression for Cardiopulmonary Resuscitation
2008 Cochrane review
Evaluated ten trials which used the ACDR method of resuscitation, eight were conducted in out-of-hospital settings
Out-of-hospital trials involved a total of 4,162 patients
No differences were found in the group who had the ACDR device applied when compared with those who received manual CPR in survival of arrest or complications from resuscitation
Authors concluded that ACDR resuscitation is not associated with a clear benefit during resuscitation
(Lafuente-Lafuente and Melero-Bascones, 2008, p 1-4)

24. Active Compression-Decompression for Cardiopulmonary Resuscitation
Many of the benefits associated with a device such as the AutoPulse were not provided by ACDR devices
Not a true mechanical device – requires constant manual manipulation to operate
Also requires more training than standard manual CPR
Consistency of depth of compressions is regulated by provider alteration of effort
Frequency of compressions are not regulated
Does not allow for constant compressions during transport
Requires interruptions for defibrillation
Increase in provider fatigue
Requires greater physical effort
(Lafuente-Lafuente and Melero-Bascones, 2008, p 1-4)

25. Summary of Studies
Use of ACDR in the out-of-hospital field is not true mechanical CPR and is associated with no improvement in survival to hospital admission (Lafuente-Lafuente and Melero-Bascones, 2008, p 2)
The use of an automated CPR device such as the AutoPulse is associated with an increase in survival to hospital admission (Hallstrom et al, 2006, p 2625) and (Ong et al, 2006, p 2633)
Hallstrom et al: 26.4% vs. 24.7%
Ong et al: 20.9% vs. 11.1%
The AutoPulse is also safe, effective, and practical for use in out-of-hospital cardiac arrests (Krep et al, 2007, p 86)

26. Benefits of Mechanical CPR
Consistent compression rate
Consistent compression depth
Increase in CPP
Increase in coronary and cerebral blood flow
Continuous CPR during transport and defibrillation
Use of a mechanical CPR device also allows EMS providers to concentrate on other aspects of resuscitation such as defibrillation and respirations
Mechanical CPR devices allow EMS providers to remain seated during patient transport which results in fewer injuries to EMS workers and less use of the hospital
(Zoll, 2006)

27. Application of Findings
Use of mechanical CPR devices allows for better patient care and outcomes following cardiac arrest
Allotting money for the future purchase of the AutoPulse should be considered in all EMS agencies
$15,000 - $17,000 per unit (Zoll, 2006)
Ong et al also found that patients who received field CPR while waiting for application of the AutoPulse had a 16 fold increase in survival over those who do not (p 2636)
All patients should receive manual CPR while waiting for application of the AutoPulse
Defibrillation should be administered as soon as it is available and appropriate

28. References
American Heart Association. (2005) American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation: Journal of the American Heart Association, 112(24), IV 19 – IV 34. Retrieved February 11, 2009 from
Australian Government Department of Health and Aging. (2008). Horizon Scanning Technology Prioritising Summary: Autopulse Automated Compression Device for CPR. Australia and New Zealand Horizon Scanning Network. Retrieved January 11, 2009 from
Bobrow, B.J., Clark, L.L., Ewy, G.A., et al. (2008). Minimally Interrupted Cardiac Resuscitation by Emergency Medical Services for Out-of-Hospital Cardiac Arrest. The Journal of the American Medical Association, 299(10) Retrieved January 18, 2009 from
Cooper, J.A., Cooper, J.D., Cooper, J.M. (2006). Cardiopulmonary Resuscitation: History, Current Practice, and Future Direction. Circulation: Journal of the American Heart Association, 114, Retrieved January 18, 2009 from
Ewy, G.A. (2007). Continuous-Chest-Compression Cardiopulmonary Resuscitation for Cardiac Arrest. Circulation: Journal of the American Heart Association, Retrieved January 18, 2009 from
Gaxiola, A., Varon, J. (2008). Evolution and New Perspective of Chest Compression Mechanical Devices. American Journal of Emergency Medicine, 26, Retrieved January 11, 2009 from

29. Hallstrom, A. , Rea, T. D. , Sayre, M. R. , et al. (2006)
Hallstrom, A., Rea, T.D., Sayre, M.R., et al. (2006). Manual Chest Compression vs. Use of an Automated Chest Compression Device During Resuscitation Following Out-of-Hospital Cardiac Arrest: A Randomized Trial. The Journal of the American Medical Association, 295(22), Retrieved January 11, 2009 from
Krep, H., Mamier, M., Breil, M., et al. (2007). Out-of-Hospital Cardiopulmonary Resuscitation with the AutoPulse System: A Prospective Observational Study With a New Load-Distributing Band Chest Compression Device. Resuscitation, 73, Retrieved February 11, 2009 from
Lafuente-Lafuente, C., Melero-Bascones, M. (2008). Active chest compression-decompression for cardiopulmonary resuscitation (Review). The Cochrane Collaboration, John Wiley and Sons. Retrieved January 11, 2009 from
Ong, M.E.H., Ornato, J.P., Edwards, D.P., et al. (2008). Use of an Automated, Load-Distributing Band Chest Compression Device for Out-of-Hospital Cardiac Arrest Resuscitation. The Journal of the American Medical Association, 295(22) Retrieved January 11, 2009 from
Steen, P.A. (2005). The Future of CPR. Acta Anaesthesiologica Scandinavica, 49(7) Retrieved January 11, 2009 from
Strzyzewski, N. (2006). Common Errors Made in Resuscitation of respiratory and Cardiac Arrest. Plastic Surgical Nursing, January-March 2006, 26(1) Retrieved January 11, 2009 from
Zoll. (2006). Autopulse: Consistent Compressions. No Interruptions. Zoll Medical Corporation. Buyers Information Packet. Chelmsford, MA.

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