Cardiac & Resuscitation, Patient Care

High-Perfusion CPR Technology Dramatically Improves Cardiac Arrest Survival

Issue 12 and Volume 42.

New technology dramatically improves cardiac arrest survival in Collierville, Tenn.

Serving in the medical oversight role for nearly 30 EMS services in and around Memphis, Tenn., I have the challenging task of tailoring equipment and protocols to each site’s population, budget and needs.

Collierville is a Memphis suburb, with a population of around 45,000. Its residents are relatively affluent and well-educated, and community education efforts have improved the frequency and quality of bystander CPR.

It’s a perfect example of a small town that’s done very well in improving survival from cardiac arrest, which is why I felt additional technology could take the town to the next level.

Collierville Fire and Rescue (CFR) is a full-time department with approximately 70 personnel. CFR provides life safety, fire protection and customer service to the community through the delivery of fire suppression, ALS, specialized technical rescue operations and other services.

Each year, CFR responds to an average of 3,500 calls, 70% of which are EMS-related, including around 40 cardiac arrest calls each year. The department maintains an average response time of 4 minutes 50 seconds to all incidents from five strategically located firehouses throughout the community.

All firefighters are cross-trained in EMS and are licensed as paramedics or Advanced EMTs (AEMTs).

Historically, the incidence of bystander CPR was good in Collierville, the result of years of community education and training. The town’s EMS cardiac arrest protocol is comprehensive, including dispatch-assisted CPR instruction for 9-1-1 calls with immediate response by a fire apparatus that’s followed quickly by a contracted ambulance service.

Two engines are dispatched to every potential cardiac arrest call, providing a response of 9-1-1 personnel trained at both the paramedic and AEMT level to each cardiac arrest call.

Adopting New Tools

Shortly after the ResQCPR System was FDA-approved in March 2015, I recommended it to the CFR EMS team as a way of further improving their survival rates.

The FDA had reviewed data supporting the approval of the ResQCPR System, including a randomized clinical trial that compared survival rates of 813 subjects who received standard CPR to 842 subjects who received CPR with the ResQCPR System.1 The results showed that a larger number of subjects who received CPR with the ResQCPR System survived cardiac arrest long-term.

The ResQCPR System consists of two devices that are used together by trained rescuers while they’re performing CPR: 1) the ResQPUMP active compression-decompression CPR (ACD-CPR) device; and 2) the ResQPOD impedance threshold device (ITD). The devices have been shown to significantly improve the patient’s chances of surviving an out-of-hospital, non-traumatic cardiac arrest.2,3

I had been interested in the device combination since seeing demonstrations on its physiology in the laboratory. The device utilizes and enhances natural physiology, providing for better cardiac output and better cerebral blood flow.

Traditional CPR has a “push and relax” duty cycle, but the ResQPUMP-a handheld device with a suction cup that’s placed on the patient’s chest-actually allows the rescuer to pull up and actively re-expand the chest wall (i.e., “push and pull”). This ACD-CPR creates a vacuum in the intrathoracic cavity that increases blood flow to the heart and brain.

This vacuum is maintained and enhanced when used with the ResQPOD ITD in the airway circuit. As more blood is drawn back to the heart during the decompression phase, this enhanced preload results in a greater volume of blood flowing out of the heart (i.e., cardiac output) during the next compression.

The synergy of the two devices has been shown in studies to provide near normal blood flow during CPR.4-6 By facilitating high-perfusion CPR, it’s more likely patients who survive will be neurologically intact.

Training & Implementation

In spring 2015, CFR purchased six ResQCPR Systems. In conversations with department leadership, I conveyed that the science is supportive of the technology and that I was confident that the quality of CPR would be better than manual-or even mechanical-CPR.

Formal staff training was conducted over a period of one week. The ACD-CPR device is different from standard CPR, but it’s fairly intuitive, and the ResQCPR System provides real-time, electronic guidance to the rescuer to help them accommodate for the differences.

A force gauge provides information on compression and lifting forces, while the metronome guides the rescuer to compress at the appropriate rate. Timing lights on the ITD can be turned on to cue rescuers on the proper ventilation rate minimizing the likelihood of hyperventilation. These features help promote high-quality CPR at all times.

After the initial training, the cardiac arrest protocol was revisited to determine if it needed adjustment. Changing the protocol was simple and straightforward. It was updated to make it clear that any time a patient was in cardiac arrest, the ResQPOD ITD was to be used along with manual CPR to improve perfusion. As soon as the ResQCPR System arrives on scene, the ResQPUMP is utilized with the ResQPOD.

In the first eight cardiac arrests, CFR had seven neurologically intact saves, which was remarkably better than what they’d had before.

Results & Safety Benefits

Within 4-6 weeks from the time the devices were purchased, CFR staff were fully trained and the equipment was being used regularly.

Immediately after the teams started using the ResQCPR System, they experienced improved outcomes. Right off the bat, in the first eight cardiac arrests, CFR had seven neurologically intact saves, which was remarkably better than what they’d had before.

The one patient they weren’t able to resuscitate had suffered a cardiac arrest while riding his bike, causing him to fall and sustain a serious head injury. Although CFR crews were successful in restoring his heartbeat, he eventually succumbed to his head injury.

The early successes created confidence among the CFR EMS staff that the technology worked, and their enthusiasm has remained high.

The CFR EMS chief was initially pretty skeptical about the ResQCPR System, but then he started getting calls from family members thanking them for saving their loved ones’ lives. He told me, “I never got those before.”

CFR has also noticed something unique when using the ResQCPR System. In the past, they never had cases of patients in cardiac arrest responding to them during the resuscitation. However, when using these two devices, they experienced some patients literally reaching their arms out to the crews or trying to pull out their endotracheal tubes despite being in cardiac arrest.

They’ve never had to deal with this before. It tells me that the brain is being perfused well enough for patients to respond, despite being in cardiac arrest. That’s an encouraging sign.

As a result of patients experiencing these episodes of increased levels of consciousness, I added a new protocol for sedating cardiac arrest patients to prevent them from interfering with their treatment.

According to Pat McGrath, a paramedic lieutenant for CFR, the numbers support what the crews are seeing in the field. (See Figure 1.)

Prior to adopting the ResQCPR System, just 7% of patients where ROSC was achieved were discharged with normal neurological outcomes. After implementation, the number of neurologically intact patients climbed to 47%.

Figure 1: Annual ROSC rates (2014-2017*)

McGrath comments on this amazing difference, saying, “We have had some patients come by to see crews at the station. We know we have had a significant increase in saves.”

In addition to improving outcomes, the ResQCPR system improves safety for the crews who, in the past, would perform CPR during transport. As everyone knows, doing CPR on the move is extremely difficult to do without interruptions and changes in depth, and can be unsafe for the rescuers, who traditionally had to perform CPR unbelted in the patient compartment.

The ResQCPR System allowed CFR to change their approach toward cardiac arrest: patients are no longer immediately put into the ambulance and are instead kept on scene.

By working the cardiac arrest on scene, crews have the best chance of getting the patient’s heart going again. Transport is initiated once the patient is stable. While en route to the hospital, the airway is managed, medications are administered on board, and crews know the patient has been given the best possible opportunity to survive.

Lessons Learned

There are three primary takeaways that we learned by implementing this technology:

1. ResQCPR is different than standard CPR. Crews had to learn a new way of performing CPR and understand the three important differences.

First, the rate is slightly slower (80/min.) than conventional CPR, allowing the heart to refill longer.

Second, you’re actively lifting during decompression rather than just allowing the chest to relax on its own.

Third, you must use the ITD with ACD-CPR in order to optimize the intrathoracic vacuum and perfusion. Commitment to the training is critical to success. Crews may assume that if they’re already good at CPR, they don’t need to be trained on the system. However, if they don’t learn how to use it correctly, they won’t be taking full advantage of the improved perfusion the products provide.

2. You must first know how to do high-quality CPR before implementing these tools. If the quality of your CPR is poor today, you won’t be gaining much of anything by adding these tools. But if your crews are already doing high-quality CPR (rate of 100-110, depth of 2 inches and compression fraction > 90%), these devices will help make things even better. Systems that aren’t meeting those metrics need to focus on the basics first.

3. It’s better to work the patient on-scene instead of attempting CPR in the back of a moving vehicle. It’s virtually impossible to perform high-quality CPR safely in the back of a moving vehicle. CFR crews only transport after working the patient on scene using the ResQCPR System and getting a pulse back. If crews transport patients with ongoing cardiac arrest, the use of ResQCPR is discontinued. Ideally, patients transporting with ongoing cardiac arrest would be placed on an automated CPR device, however, CFR’s current ambulance contractor doesn’t utilize this technology.

Conclusion

The ResQCPR System, which is made up of two devices that enhance natural physiology, provides for better cardiac output and better cerebral blood flow during CPR, improving the patient’s likelihood of surviving an out-of-hospital, non-traumatic cardiac arrest. Implementing ResQCPR in a community like Collierville, where high-quality CPR was already the norm, has helped significantly improve cardiac arrest survival rates.

Real-time electronic guidance helps ensure accurate compression depth, lift height and compression rate.

References

1. Aufderheide TP, Frascone RJ, Wayne MA, et al. Standard cardiopulmonary resuscitation versus active compression-decompression cardiopulmonary resuscitation with augmentation of negative intrathoracic pressure for out-of-hospital cardiac arrest: A randomised trial. Lancet. 2011;377(9762):301-311.

2. Wolcke BB, Mauer DK, Schoefmann MF, et al. Comparison of standard cardiopulmonary resuscitation versus the combination of active compression-decompression cardiopulmonary resuscitation and an inspiratory impedance threshold device for out-of-hospital cardiac arrest. Circulation. 2003;108(18):2201-2205.

3. Plaisance P, Lurie KG, Vicaut E, et al. Evaluation of an impedance threshold device in patients receiving active compression- decompression cardiopulmonary resuscitation for out of hospital cardiac arrest. Resuscitation. 2004;61(3):265-271.

4. Lurie KG, Coffeen P, Shultz J, et al. Improving active compression-decompression cardiopulmonary resuscitation with an inspiratory impedance valve. Circulation. 1995;91(6):1629-1632.

5. Lurie KG, Lindner KH. Recent advances in cardiopulmonary resuscitation. J Cardiovasc Electrophysiol. 1997;8(5):584-600.

6. Lurie K, Zielinksi T, McKnite S, et al. Improving the efficiency of cardiopulmonary resuscitation with an inspiratory impedance threshold valve. Crit Care Med. 2000;28(11 Suppl):N207-N209.