The treatment of out-of-hospital cardiac arrest (OOHCA) has long been one of the driving factors in determining what EMS care looks like in the U.S. From system design to equipment carried and techniques taught, much of what we do in EMS has been geared toward improving the survival rates for patients who suffer from this occurrence.
In the early years of ALS development and delivery, the focus was on the timely delivery of defibrillation. Although this treatment is still very important, the focus at the start of this century has been on the delivery of “high-quality” chest compressions.
Focus on Chest Compressions
In 2005, the AHA’s Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care summarized multiple studies and came to the succinct conclusion that “high-quality CPR” is that in which the “rescuers should push hard, push fast, allow for complete chest recoil between compressions, and minimize interruptions in compressions for all victims.”(1) In addition, it recommended that the “rate and tidal volume of ventilations should be decreased” to reduce inadvertent hyperventilation and reduce intrathoracic pressures, two things shown to worsen chances of survival for patients suffering from sudden cardiac arrest (SCA).(1) The studies that these guidelines were derived from all indicated that the application of high-quality CPR was a major variable in influencing the likelihood of survival from OOHCA.
The same year these guidelines were being distributed, two papers published in the Jan. 19 issue of JAMA reported poor performance of the application of CPR by prehospital and in-hospital providers when treating patients in cardiac arrest. Specifically, a high percentage of the time, chest compressions rates were too slow, chest compression depth too shallow and breath rates too high.(2,3)
These studies made it clear to me, as an EMS officer, that the challenge wasn’t going to be teaching these new techniques, but rather ensuring that the techniques were being applied in a consistent fashion that met the goals of high-quality CPR as outlined by the AHA.
Implementing the Standards
The Henderson (Nev.) Fire Department (HFD) is a CAAS- and CFAI-accredited department that provides an all-ALS, fire-based system that covers 276,000 people in 104 square miles of area south of Las Vegas.
Coverage for the city is provided from nine fire stations that each have ALS engine companies. Seven of the nine stations also have an ALS rescue unit staffed with two firefighter/paramedics. Calls for cardiac arrest account for approximately 3% of our total EMS call volume, which was 15,555 in 2009. (For more information, visit www.cityofhenderson.com/fire.)
In October 2005, the HFD began the process of implementing the new guidelines. One of our first established goals was to create a team-based approach to handling cardiac arrests. Four critical positions were identified:
Each position is responsible for accomplishing an overall goal and following steps to achieve this goal.
All cardiac arrests that occur in Henderson are sent the following resources: the nearest police department unit with an AED, an ALS rescue unit and an ALS engine/truck unit. This response force ensures that all positions for the team-based approach get filled and that a minimum of two paramedics are on every cardiac arrest call.
Based on the AHA guidelines, the most important position identified was the compression technician and, therefore, this position is filled first. This position’s goal is to ensure the application of high-quality chest compressions: compressions at a rate of 100 per minute and at least 1½ to 2 inches deep for adults, full chest recoil after each compression and interruption of compressions allowed only for defibrillation and kept to less than 10 seconds.
The monitor technician is the second position filled. Even if the only unit on scene is a rescue, the compression technician and the monitor technician positions are always filled. Because we’re an all-ALS system, a paramedic fills the monitor technician position and also assumes the position of code team leader. This person oversees the entire cardiac arrest, ensuring that high-quality chest compressions are delivered, applying proper electrical therapy to the patient when indicated, determining the correct pharmacological interventions and documenting the code using the event markers in the cardiac monitor.
The ventilation technician position is the third role filled. This team member is in charge of setting up the autoventilator. We chose to use an autoventilator so we could precisely control the tidal volumes delivered and the rates at which the patient is ventilated. This position switches with the compression technician every two minutes during the application of chest compressions to minimize rescuer fatigue.
The medication technician is the last position to be filled. This person establishes IV or IO access, and draws up and delivers medications based on the monitor technician’s orders. To serve as a second set of eyes and to minimize medication errors, this position is also filled by a paramedic.
Ensuring Consistent Application of the Standards
As we established this new process, our department’s implementation of and training for the team-based concept went well, and most of the quality improvement/quality assurance (QI/QA) metrics being evaluated, such as consistent application and knowledge of position responsibilities, were being met. However, one key metric was still not being observed on a consistent basis—the application of chest compressions that met all of the goals outlined by the AHA. This was occurring only about 15% of the time. Despite our best efforts, our system had no good way to provide feedback to the responders on the quality and consistency of the compressions being provided when they needed it most—during the call.
In 2008, the HFD upgraded its aging fleet of monitors and replaced them with equipment that incorporated real-time monitoring and feedback related to chest compressions and ventilations. The monitoring and feedback capability was immediately incorporated into our team-based approach to cardiac arrest treatment, and the initial training on its use was rolled out during CPR refresher training.
Initial use of the devices presented us with some surprising results. Unlike the studies from 2005 that showed that many prehospital personnel did not push fast enough or deep enough, we observed through the use of real-time chest compression and ventilation monitoring and feedback that our crews tended to push too fast (at an average of 140 compressions per minute) and that we did not routinely allow for adequate chest recoil.
Because our devices allowed for real-time feedback, human errors could be readily addressed at the time they were occurring either in training or in the field during patient care.
Five years after the AHA’s 2005 guidelines on CPR were published, our department has been able to refine our resuscitation processes and implement a team-based approach. We now have two complete years of experience using a CPR monitoring device on patients in our city.
Although we didn’t perform a controlled study, we believe high-quality chest compressions are having a significant impact on neurologically intact survival rates. In 2007, we began tracking cardiac arrest outcome data according to the Ütstein criteria. Survival rates are tracked by those patients who are discharged alive from the hospital with a Cerebral Performance Category Scale (CPC Scale) of 1–4. Since that time, we’ve seen our cardiac arrest survival rate increase from 13.5% in 2007 to 20.1% in 2009 for all patients treated for cardiac arrest. In addition, 7.3% of these patients are being sent home with a CPC score of 1 or 2. Review of CPR data post event has also helped us meet our QI/QA metric of ensuring that chest compressions are consistent with the 2005 AHA guidelines.
As we look to the future of the treatment of OOHCA, it’s clear that the application of high-quality chest compressions will continue to be important in the resuscitation of our cardiac arrest patients. Our experience and studies have shown that it can be difficult to meet AHA’s guidelines for chest compressions. However, by using unique approaches and tools, such as a CPR feedback device, we’ve been able to objectively evaluate the quality of our CPR, address issues through training and continue to monitor CPR quality. As a result, we feel we’re on the path to increasing the number of neurologically intact survivors from OOHCA.
Disclosure: The author has no conflicts of interest with the sponsors of this supplement.
1. 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Supplement to Circulation. 2005;24.
2. Abella BS, Alvarado JP, Myklebust H, et al. Quality of cardiopulmonary resuscitation during in-hospital cardiac arrest. JAMA. 2005:293;305–310.
3. Wik L, et al. Quality of cardiopulmonary resuscitation during out-of-hospital cardiac arrest. JAMA. 2005:293(2);305–310.
This article originally appeared in an editorial supplement to the September 2010 JEMS as “The Quest for High-Quality CPR: A team-based approach & feedback help the Henderson (Nev.) Fire Department improve CPR effectiveness.”