The alarm sounds and dispatch keys up the radio: "60-year-old male, jogger, witnessed collapse, bystander CPR in progress." Radio in hand, my partner calls us "en route" and navigates the afternoon traffic as our cadet and I run through our code check list: AED, airway/O2 kit, suction. The police are already on scene, pads and AED attached, chest compressions in progress.
The patient looks younger than 60. His grey sweatpants tore at one knee when he fell, his navy T-shirt already a victim of trauma shears, sunglasses cracked and broken on the pavement, iPod blaring from his pocket.
With ALS and BLS on scene, my cadet takes over compressions, vocalizing landmarks and counting out loud, as much for herself as for everyone else. My partner takes the airway and I attach the monitor. A small crowd is forming and a bystander's voice cracks as he bears witness to what may be the last minutes of this man's life: "He was just jogging, and then he grabbed his chest and fell."
Someone is waiting for him to come home.CPR AND RESUSCITATION CARE
Since its development in the 1950s, CPR has been the mainstay of cardiac arrest treatment and has consistently demonstrated improvement of outcomes when delivered promptly and correctly to arrest victims. The importance of CPR is emphasized in our introductory field training in basic and advanced cardiac life support, and the American Heart Association (AHA) provides on-going CPR guideline updates as new and innovative research becomes available. The most recent update in 2005 introduced a significant change in ventilation-to-compression ratio for adults from 2:15 to 2:30 in order to increase circulation time to oxygen-starved tissues.
While the AHA updates its guidelines every five years, a question remains for EMS professionals: What can I do now to improve my care and survival rates from cardiac arrest without waiting for the next guidelines update?
The key to survival improvement in the short term truly brings us back to basics. Recent investigations have shown that both in- and out-of-hospital CPR quality during actual cardiac arrest care is highly variable.1-3 In these studies, CPR providers were monitored and their actual performance was compared to guidelines recommendations. These guidelines included rate and depth of compressions, rate of ventilations and "no flow" time, or periods of time without chest compressions and therefore without circulation of oxygen to tissues.
The results of these evaluations were surprising. Marked deficiencies were found: Continuous chest compressions were performed for less than 50% of the duration of cardiac arrest, compressions were too shallow, ventilations were too fast, and "no flow" time was significantly greater than the time built in for pulse/rhythm checks.IMPROVING CPR
These findings are especially important in the context of recent work showing how delivering more and better CPR can make a big difference in real outcomes. Arizona emergency physician Bentley Bobrow et al performed a pioneering study in which EMS crews delivered what they termed "minimally interrupted cardiac resuscitation" (MICR) and demonstrated an increase in survival rates of witnessed cardiac arrest victims with shockable rhythms from 4.7% with standard CPR to 17.6% with MICR.4 Similarly, another variant of CPR that emphasizes compressions over ventilations, termed "cardiocerebral resuscitation" (CCR), strongly advocates for strict attention to the amount of time spent "off the chest," with the goal of neurologically intact survival—giving patients their best chance at returning to their normal lives after cardiac arrest. Additionally, it is important to realize that EMS providers tend to arrive between 4–10 minutes after collapse, when chest compressions appear to provide the best chance at survival when followed by defibrillation. This fact lends even more support to the theory of MICR, as high-quality compressions before defibrillation improve the chance of shock success.
In the same vein, it stands to reason that laypeople may contribute to lifesaving efforts through continuous chest compressions (CCC). Training through public service announcements and simplification of the bystander role by focusing solely on CCC (removing the element of mouth-to-mouth) may increase bystander participation and potentially improve survival rates. This too, however, will require further investigation.
However, despite this significant improvement in outcomes, even these studies note room for improvement in the delivery of CPR. Bobrow et al speculated that survival rates could have been even better with improved MICR compliance resulting from more training, retraining and feedback. Another MICR implementation study by Wisconsin MD Michael Kellum et al noted initial improvement that peaked at an impressive 48% survival rate after one year before declining over the next two years.5 While there is no concrete explanation for this trend, the authors suggested lack of retraining and quality assurance efforts throughout the life of the study as potential contributors— two themes that make frequent appearances in CPR research.
So there is a disconnect between the theoretical guidelines and practical application that may limit the ability to deliver excellent resuscitation care. How can this gap be narrowed? Can training and retraining be made practical, and can it really be effective?
There are three possible periods of time during which efforts to improve CPR can be considered: pre-arrest, during the acute event and post-event (see Figure 1). Just as this division provides a framework for the course of a cardiac arrest scenario, it also suggests potential areas of improvement in CPR/CCR performance:
- The pre-arrest phase includes training/retraining and education.
- The acute event phase includes real-time feedback of CPR performance during the arrest.
- The post-arrest phase includes staff debriefing and quality assurance programs.
Each portion of this three-pronged resuscitation map has room for provider improvement, and several new and promising initiatives have been suggested as new technology becomes available.PRE-ARREST TRAINING AND EDUCATION
"Practice is the best of all instructors." Publius Syrus (Roman author, 1st century BCE)
When it comes to care during unpredictable occurrences, pre-event training is the most readily controllable. This is the time leading up to the event in which we have the freedom to prepare, to make algorithms and backup plans, to practice, so when called upon, we can act swiftly and efficiently to bring about the best possible outcome.
Unfortunately, just as this is one of the first and most important steps toward success, it may also be one of the first places where the system of CPR performance breaks down.
For example, a recent study demonstrated that even during controlled, monitored training sessions, CPR quality was suboptimal —shallow chest compressions and prolonged "no flow" time persisted despite the 2005 guideline update.6 These data are concerning, because they show that the educational experience of CPR training is often not maximized. Other studies have also confirmed that CPR education likely does not go far enough with quality assurance and objective metrics of training (e.g., only passing a student who demonstrates correct rate and depth of compressions, not just any compressions).
Training experiences also may not adequately train for the pressure and chaos of an actual code. As noted in one recent publication on CPR performance, "it is possible that the highly complex physical and mental situation of treating a patient with cardiac arrest is too different from the training situation on mannequins, making the performance dramatically different and possibly less efficient."3 As many of us have experienced in training courses, the realities of medical management (inability to gain IV access, difficult airway, unfamiliarity with or malfunctioning equipment) and time pressure are not frequently included in practical training scenarios. This makes it easy to breeze through the basics, but may be underpreparing us for real-life situations. Providers should consider training scenarios that are more immersive, with time pressure built in, scenarios that are a surprise to trainees, or involving "actors" to add bystander stress to the environment.
Similarly, Belgian physician Thierry Verplancke et al noted large gaps in both exposure to retraining experiences (18 months for non-critical care nurses) and to actual cases requiring CPR/CCR (59 months for non-critical care nurses).7 In many EMS systems, it is likely that a crew member can go the entire 2 years until CPR recertification while treating only a few cardiac arrest patients. These prolonged gaps in training/exposure may be contributing to the variability of delivered CPR.
As noted in the Verplancke article, training and retraining should be addressed in future research. It stands to reason that frequent practice and review should help to hone resuscitation skills. Training and retraining should ideally ingrain these skills as second nature or reflexes.SIMULATION TRAINING
An increase in training/retraining is only part of the pre-arrest improvement picture. Another solution may be seen in the use of high-fidelity simulation training with computerized manikins whose vital signs and physical findings can be manipulated in real time by a computer program to give more realistic practice scenarios. Many studies have shown that high-fidelity simulation is an effective form of training, is better for retention than tabletop/textbook learning and is frequently seen as a more helpful educational tool by students.
As technology becomes more advanced, more complicated scenarios can be performed on a single manikin. There are simulation models that allow for IV access, airway management, including difficult airway, and other invasive procedures including chest tubes and thoracotomies. These devices give the ability to run training resuscitation scenarios that are more true-to-life, with incorporated practical skills and time pressure without the fear of harming the patient.IMPROVING CARE DURING RESUSCITATION
Preparation and practice are crucial to success; however, as noted, there is often a disconnect between training and actual events. What can be done during cardiac arrest itself in order to further focus efforts? Even the most experienced team leaders often have difficulty focusing on the breakdowns in the fundamentals of care during a code. How can resuscitative efforts be maximized?
One solution that has been recently explored is the notion of real-time automated feedback—an attempt to use technology to improve CPR quality. In two recent studies, prototype defibrillators were used that provided both verbal and visual feedback during real cardiac arrests.8,9 Defibrillators were equipped with special sensors to evaluate rate and depth of compressions, as well as the rate and volume of ventilations. This CPR quality information collected by the sensors was analyzed by the defibrillator, which then verbally and visually (via the defibrillator LCD display) prompted rescuers as to how to adapt their compressions.
Norwegian physician Jo Kramer-Johansen et al showed that the rate and depth of compressions and rate of ventilations improved to consistently follow international guidelines with real-time automated feedback when compared to standard CPR (without feedback).8 Most rescuers (86%) felt that automated feedback improved their performance. Most important, 2.9% of the baseline group survived, and 4.3% of the feedback group survived to discharge. A similar study by coauthor Benjamin Abella et al showed similar results using feedback in the hospital setting—namely, CPR quality improves when real-time feedback is employed.9 Another potential benefit from this technology is that the automated feedback system never gets tired or distracted, allowing the rescuer consistent help in CPR quality and the team leader to delegate this responsibility to the defibrillator. A number of different versions of feedback defibrillators are currently on the market via several manufacturers. Free-standing feedback sensors are also available, allowing for use even when a defibrillator is not immediately present at a code.IMPROVING CARE POST-ARREST
The third and final time period with the opportunity for improvement comes after completion of resuscitation. Review of a cardiac arrest case goes hand-in-hand with real-time feedback. Just as new sensing technology allows for the detection and measurement of mechanical aspects of CPR, they can also record and replay them, thus allowing for case-by-case review (see Figure 2). By attempting to maximize CPR quality during an event, the groundwork is prepared for additional improvement when the adrenaline has subsided.
Two studies within the last year have shown that post-arrest debriefing appears to help improve CPR quality in hospital settings. One study found a significant decrease in hyperventilation and increase in compression depth that correlated with an increase in the return of spontaneous circulation in cardiac arrest patients when the rescuers reviewed and discussed resuscitation efforts in weekly debriefing sessions.10 The second study found that when real-time feedback was combined with debriefing, compression rate guideline compliance significantly improved, from 45% to 84%, and both rate and depth of compressions improved from 29% to 64%, nearly doubling the measured quality of CPR.11DEBRIEFING IN EMS
While the concept of debriefing is not new, the application of debriefing sessions in the prehospital setting may not be the same or as frequent as with in-hospital settings. However, one good example of field debriefing can be seen in the military's After Action Report, or AAR (sometimes referred to as a "hot wash" after larger scale drills). An AAR has three main objectives: identify areas that need improvement, recommend ways to improve, and discuss the key lessons learned. While it is frequently used in the discussion and future planning of training exercises, an AAR may be applied to real cases or operations. Generally, all team members are included, so everyone has an opportunity to make recommendations for future scenarios.
The AAR includes a case overview, goals and objectives of review (in this case, quality assurance of CPR), analysis of outcomes, analysis of critical task performance, a concluding summary and recommendations, including what each individual team member can to do improve his or her performance. While the AAR/"hot wash" system can be complicated in large-scale scenarios, it stands to reason that a more simplified version could potentially benefit these smaller operations, especially when employed directly following the case.CONCLUSION
From MICR to CCR to the new real-time feedback defibrillators, new innovations and cutting-edge research demonstrate both that CPR quality is elusive and that it can be improved dramatically. It is our responsibility to combine our skills and technology to give patients the best possible chance at survival. Through improvements in pre-event training/retraining, use of high-fidelity simulations, real-time CPR quality improvement with the aid of automated feedback, and consistent, honest debriefing and review, the likelihood of successful resuscitations can be increased.REFERENCES
1. Abella BS, Sandbo N, Vassilatos P, et al. Chest compression rates during cardiopulmonary resuscitation are suboptimal: A prospective study during in-hospital cardiac arrest. Circulation 111:428–34, 2005.
2. Abella BS, Alvarado JP, Myklebust H, et al. Quality of cardiopulmonary resuscitation during in-hospital cardiac arrest. JAMA 293:305–310, 2005.
3. Wik L, Kramer-Johansen J, Myklebust H, et al. Quality of cardiopulmonary resuscitation during out-of-hospital cardiac arrest. JAMA 293:299–304, 2005.
4. Bobrow BJ, Clark LL, Ewy GA, et al. Minimally interrupted cardiac resuscitation by emergency medical services for out-of-hospital cardiac arrest. JAMA 299:1158–65, 2008.
5. Kellum MJ, Kennedy KW, Barney R, et al. Cardiocerebral resuscitation improves neurologically intact survival of patients with out-of-hospital cardiac arrest. Ann Emerg Med 52:244–252, 2008.
6. Perkins GD, Boyle W, Bridgestock H, et al. Quality of CPR during advanced resuscitation training. Resuscitation 77:69–74, 2008.
7. Verplancke T, De Paepe P, Calle PA, et al. Determinants of the quality of basic life support by hospital nurses. Resuscitation 77:75–80, 2008.
8. Kramer-Johansen J, Myklebust H, Wik L, et al. Quality of out-of-hospital cardiopulmonary resuscitation with real time automated feedback: A prospective interventional study. Resuscitation 71:283–292, 2006.
9. Abella BS, Edelson DP, Kim S, et al. CPR quality improvement during in-hospital cardiac arrest using a real-time audiovisual feedback system. Resuscitation 73:54–61, 2007.
10. Edelson DP, Litzinger B, Arora V, et al. Improving in-hospital cardiac arrest process and outcomes with performance debriefing. Arch Intern Med 168:1063–1069, 2008.
11. Dine CJ, Gersh RE, Leary M, et al. Improving cardiopulmonary resuscitation quality and resuscitation training by combining audiovisual feedback and debriefing. Crit Care Med 36:2817–2822, 2008.
Colleen M. Donovan, MD, is a resident in emergency medicine at the University of Pennsylvania and a former EMT from New Jersey.
Benjamin S. Abella, MD, MPhil, is the clinical research director at the Center for Resuscitation Science, and attending physician, Department of Emergency Medicine, University of Pennsylvania. He has received research funding and honoraria from Philips Healthcare and Cardiac Science Corporation.