In auto racing, seconds can make the difference in winning or losing a race. NASCAR teams have proven the effectiveness of what’s referred to as the “pit crew” approach to rapid, coordinated, race car pit maintenance stops to avoid unnecessary delays, get critically important tasks completed in the minimum amount of time and avoid errors that can cost them time and, ultimately, the race.
In the race to save cardiac arrest patients, it’s now also been shown that the use of a “pit crew” approach by EMS crews can also make resuscitations more effective by reducing interruptions in compressions and peri-shock pauses, reducing delays in interpreting cardiac activity, eliminating pauses for airway management and reducing the time it takes to place and activate mechanical CPR devices.
This article focuses on three progressive EMS systems that have each been highly effective in standardizing their approach to cardiac arrest resuscitation by implementing the pit crew approach to resuscitation, using well-defined process and clinical procedure checklists and other methods to limit delays in the care and resuscitation of patients.
Wichita-Sedgwick County, Kan.
In 2012, the Wichita-Sedgwick County, Kan., EMS System (W-SCEMSS) modified the Austin-Travis County (Texas) EMS pit crew approach to resuscitation of cardiac arrest patients to meet the needs of the local system.
The goal was to not only produce a more consistent resuscitation team and a well-choreographed approach to resuscitation but to also produce better results from resuscitations, increasing the number of return of spontaneous circulation (ROSC) patients and patients who leave the hospital neurologically intact.
The pit crew model designs structure, consistency, efficiency and accountability into our approach to resuscitation.
W-SCEMSS took the basic Austin-Travis County design that had defined roles and responsibilities for each team member and the “sacred BLS triangle,” and made it its own by having its EMS providers refine it to be workable in the Wichita-Sedgwick County system. (See Figure 1 below.)
Figure 1: W-SCEMSS pit crew procedure
W-SCEMSS pit crew positions. Photo courtesy Kelly Ross/figure courtesy W-SCEMSS
Among other things, W-SCEMSS made a decision to have very specific equipment placement. For example, the cardiac monitor is specified to be placed so the rhythm and end-tidal carbon dioxide (EtCO2) information on the monitor can be seen immediately by more than one ALS provider and the BLS pit crew. This ensures that paramedic consensus regarding the rhythm occurs with minimum delay and without lengthening the CPR pause if there’s any question. It also provides real-time feedback regarding compression effectiveness and the potential ROSC to the entire team.
W-SCEMSS also chose to choreograph all actions to the number of compressions in a cycle rather than having crews try to watch a clock to keep time. With a metronome set at 110/minute, the cycles are 220 compressions rather than two minutes. Every 20 count is called out by the person in the airway position of the resuscitation team so the rest of the team knows when to perform other actions that are required at a specific time during the cycle.
Given the economy in recent years, W-SCEMSS has limited resources for quality improvement. Therefore, the choice of what would be monitored and evaluated needed to be very deliberate and focused so the medical director and clinical coordinators would know if the system was producing better results.
Traditionally, metrics such as response time have gotten a great deal of play in the EMS industry as worthy of measurement, mainly because they were relatively easy to measure. But in recent years, studies have shown that the time to get to the patient’s side likely plays much less of a role than what happens once the provider encounters the patient.1,2
W-SCEMSS’ first step in deciding on what metrics were worth measuring was to make a decision on what the most important endpoints to reach were. The ultimate goal was not only to deliver more pulsatile patients to EDs, but to also have more patients leave the hospital neurologically intact.
Because W-SCEMSS participates in the national Cardiac Arrest Registry to Enhance Survival (CARES), with its linkages to hospital outcomes and utilizing standardized definitions, the method of monitoring progress in achieving this ultimate goal and comparing to EMS agencies nationally was already in place.3,4
W-SCEMSS chose to monitor the impact of the pit crew approach in two areas and within several time frames:
First, how was the system complying with the simple targets set for each individual patient resuscitation based on the best currently available practices and evidence? The three items identified as most important were:
1. Minimal CPR interruptions (target less than 10 seconds);
2. Compression rate of at least 100/minute (including pauses), with CPR ratio of > 95% and compression ratio of ≥ 90%; and
3. Right-timed defibrillation (with minimal interruption, see #1).
These were encouraged in our pit crew model by the following processes and procedures:
- Joint education sessions for all providers on the critical importance of limiting compression pauses;
- Use of metronomes set at 110/minute; and
- Charging the defibrillator prior to each 220 compression pause for rhythm check to limit additional delay for charging.
The W-SCEMSS team also felt it important to provide prompt feedback on individual performance to all providers caring for a patient, so self-motivated behavior modification could take place without further supervisory intervention.
This was done by annotating each cardiac arrest (preferably within 72 hours) and providing the documentation to the crews and their supervisors.
Pause duration was specifically noted, as was CPR ratio, compression ratio, compression rate and compressions/minute.
Initial data was very encouraging, with targets being met. However, after about three to four months, system administrators noted a pronounced drop-off in compliance, with pause lengths creeping up over 30 seconds and compression ratios down from > 90% to 80%.
At this point, the system didn’t have enough patient data to prove that the changes that had been made were making a difference overall in neurologically intact survival to discharge. It would take at least nine to 12 months to potentially show a positive trend. But it was clear the system needed to reengineer its pit crew approach by creating simple process changes to develop a default path that would produce the desired result.
To meet the three targets outlined in Area #1, it was clear the primary issue to address was the length of any pauses occurring between cycles. To do this, W-SCEMSS made three process changes:
- The entire team is programmed to know that compressions are to restart after 16 metronome beats (8.7 seconds) of interrupted CPR. To ensure this process compliance, the team verbally counts metronome beeps during any pause in compressions. Because the metronomes are set at a rate of 110/minute, the audible count allows the crew to get their hands back on the chest at the 16th beat of the interruption interval and, by default, keeps pauses under the 10-second goal each cycle. The code commander can ask for a longer pause, but the default is a measured pause that’s less than 10 seconds or 16 metronome beats;
- The code commander keeps their fingers on the patient’s femoral pulse—starting at the 180th compression during each cycle—to monitor quality of CPR and know immediately if there’s any organized rhythm noted on the monitor that’s actually producing a pulse when CPR is stopped. This eliminates the need for someone to search for the pulse location, since it has already been confirmed during CPR; and
- The defibrillator is pre-charged beginning at the 200 count in each cycle—20 compressions before hitting the 220 mark. In this manner, as soon as CPR stops, the patient can be shocked immediately if a shockable rhythm is identified. This keeps the pause shorter and also limits the peri-shock pause; longer peri-shock pauses have been shown to decrease survival.5,6
By limiting pauses with these interventions, compression ratios came back up to the desired targets. These changes in pit crew choreography have resulted in significantly decreasing pauses and getting them back into the target range, and W-SCEMSS now consistently shows compression ratios of > 90%.
Looking at the big picture, the overall W-SCEMSS survival for the year after full pit crew implementation was 13.7% (compared to a national average of 9.4%), an Utstein survival of 48.6% (28.9% national average) and, of survivors who made it to discharge, 91.4% were neurologically intact with cerebral performance scores of 1 or 2 (79.6% national average). (See Table 1 below).
Implementation of the W-SCEMSS cardiac arrest initiative has been rewarding in other ways also. Neurologically intact survivors have returned to thank providers, and there’s no reward greater than that!
None of our success would’ve been possible without everyone in the system being open to learning and implementing a radical change in how we approach resuscitation, and each resuscitation team fully embracing the new practice pattern, supported by complete management buy-in.
Austin-Travis County, Texas
Leadership, a standardized approach and constant review have contributed to success in Austin-Travis County. Photo courtesy Austin-Travis County EMS
Many argue that running a cardiac arrest isn’t intellectually or clinically challenging and so they dismiss its complexity. Successful management of cardiac arrest, however, is far more difficult than we believe. What makes consistently well-run codes so elusive is the competing needs of various interventions, the need for constant attention in a chaotic environment, and our inherently poor perception of task time. Choreographed or pit crew CPR is a great example of EMS innovation and process engineering designed to address these challenges and those of the prehospital environment.
What has made choreographed CPR invaluable to Austin-Travis County and other systems across the outcome spectrum is the consistency it brings. Before utilizing the pit crew approach, every cardiac arrest was carried out in a different manner, adding to the variability of cardiac arrest management and making it difficult to define and describe. Now every cardiac arrest is engineered to be the same.
Like Wichita-Sedgwick County and Wake County (N.C.), Austin-Travis County uses a uniform process that allows us to better isolate and measure elements of cardiac arrest management. Over the last four years of pit crew, that consistency has contributed to improvement in our outcome measurement, feedback to providers, compression quality, timing of interventions and bystander CPR and AED availability initiatives. (See Table 2 below).
These represent the easily quantified benefits of choreographed CPR. But, like other EMS systems that have implemented the pit crew approach, we’ve found it improves far more than just the numbers. The following comments on the impact of pit crew are from system providers at different agencies. Their comments were provided independently without any input or knowledge of the others’ content.
Battalion Chief Michael Prather, EMT-P, of Lake Travis (Texas) Fire Rescue: When Lake Travis Fire Rescue adopted the pit crew model of CPR, it was a change to the standard American Heart Association training for cardiac arrest I’d been doing for years. After training to use the pit crew approach, I quickly realized it made perfect sense.
As firefighters on an engine company, we all have a designated assignment for a house fire. We know before arriving on scene that one firefighter is going to grab an attack line; the other firefighter is going to force entry to the house; the officer will do a 360 of the incident to look for hazards and formulate a plan; and the engineer will get the engine ready to supply water. So, why would we treat cardiac arrest differently?
The pit crew model allows personnel to know what their assignments are before we even walk through the door. It allows for CPR to start rapidly and be performed effectively throughout the duration of the code. (See Figure 2 below).
Figure 2: Lake Travis Fire Rescue pit crew assignment board/ Photo courtesy Michael Prather
A firefighter is positioned at each side of the patient filling the assignment of compressor giving 100–110 compressions a minute. They stay in cadence with the metronome and limit pauses during compressions.
The firefighter at the head maintains a mask seal or places an airway, while the person not compressing the chest ventilates the patient.
Initially we were skeptical of the pit crew model. However, after working several cardiac arrests and realizing that the codes ran smoother, everyone accepted the new approach. We all have an assignment that we’re all well-trained to manage. Those assignments allow us to work as a team, just like we would at a fire.
Once the medic unit arrives on scene, they have their assigned positions as well. We integrate additional providers and interventions without interruption of chest compressions or ventilations: we all become one team.
Commander Mark Karonika, EMT-P, FP-C; Austin-Travis County EMS: When we rolled out pit crew, we believed we were already managing cardiac arrest calls at a very high level. How could this improve it?
As a supervisor I respond to every cardiac arrest while on duty, and I have seen the difference this new approach makes. Today I can respond to any cardiac arrest with any first responder or EMS crew in our system and what I will see is the same.
The defibrillator charges, but no one stops what they’re doing until the last possible second. They know we need to keep CPR going to reduce the time off chest until the rhythm and pulse check.
Without being asked or told, compressions start again with a new compressor; a constant focus on high-quality CPR. I see the crews working to solve the problem, and thinking out loud. Any idea is welcome and everyone participates.
This leaves me time to attend to the family to explain what’s happening and care for everyone at the scene.
Our pit crew approach means we run a better and more consistent cardiac arrest but it has changed more than just that. It has changed our relationship with the first responders and fire departments. Now everyone has a role and is equally important to the outcome. Regardless of how you responded to the scene, or what your level of certification, we’re a team.
Wake County, N.C.
Over the past six years, the Wake County EMS System (WCEMSS) has used the pit crew approach to cardiac arrest management which has resulted in an increase of neurologically intact survivors. Each provider has a specific role aimed at the return of spontaneous circulation and neurological survivability.
WCEMSS has enough resources to dedicate a minimum of three ALS response units to every cardiac arrest so that quality care may be delivered on scene. This typically includes two ambulances, a district chief (DC) and/or an advanced practice paramedic (APP). In addition to these, each arrest will have one or more dedicated engine companies from a local fire department.
WCEMSS has developed a great working relationship with the local fire departments and other first responder agencies. Fire personnel primarily concentrate on continuous compressions, bag-valve mask ventilations and early AED defibrillation prior to EMS arrival. They’re essential members of the resuscitation team and are integrated from dispatch to ED transport.
Cardiac arrest resuscitation in Wake County is a well-organized delegation of responsibilities among personnel. Everything possible is done to ensure three paramedics are on scene to assume the responsibilities of code commander, airway management and IV/intraosseous establishment with medication administration. The code commander is the keystone to this team approach.
The code commander focuses on the overall resuscitation, with their primary focus being on the ECG monitor. This ensures that any rhythm changes are quickly identified and addressed. The code commander also oversees the overall pace and timing of critical interventions such as medication administration, two-minute rhythm checks, ventilation rate and compression rate aided by a metronome.
Per protocol, the code commander uses the cardiac arrest checklist, which is a valuable tool for both pre- and post-ROSC. This checklist encompasses all the necessary components of a successful resuscitation and is an important part of delivering the same standard of care to all patients. To download a PDF of the checklists, click the link below.
The most recognizable innovation to Wake County’s cardiac arrest management has been intra-arrest induced hypothermia. This critical intervention for neurological survival has been integrated into the resuscitation through the DCs and APPs who bring cold saline to the arrest.7
It’s imperative to the success of this intervention that receiving hospitals participate. WCEMSS has coordinated with multiple area EDs across multiple hospital systems to ensure cooling is continued.
In addition to supplying cold fluids, the DCs and APPs also fill a vital role in helping accomplish the systems goals of compassionate and clinically excellent care. By working with the patient’s family and loved ones, the DC or APP act as a liaison between the code commander and family.
Due to the emotionally traumatic nature of many cardiac arrests, DCs and APPs invite the family to observe the resuscitation efforts. By presenting the family with the facts of the resuscitation, they can assist them in making sound decisions regarding their loved one’s care. Families are encouraged to ask questions and understand each intervention of the resuscitation in an attempt to help them cope with the arrest and its ultimate outcome.
When utilizing the team approach, WCEMSS has discovered that it may be necessary to continue beyond the 30 minutes commonly recognized for resuscitation attempts. WCEMSS has demonstrated that patients 60 minutes or longer into an arrest may still have the possibility of surviving neurologically intact. (See the article “Reuscitating Beyond the 25-Minute Mark: Good neurological outcomes are likely in survivors of prolonged resuscitations.”)
Despite each responder having a defined role, prior to terminating resuscitation efforts, the code commander uses the collaborative knowledge of the personnel on scene, which is especially valuable in rare extended resuscitations.
Once ROSC has been established, the roles for each responder may change, but the concept remains the same. Emphasis is placed on maintaining continuous carotid or femoral pulse monitoring by a dedicated team member keeping a finger on the pulse. This is important during the movement of ROSC patients to the stretcher or ambulance in the case of re-arrest.
The results in Wake County have been significant with WCEMSS numbers for all cardiac arrests tracked in our CARES report (all rhythms, all codes that were witnessed, unwitnessed, or EMS-witnessed) exhibiting 42% sustained ROSC (194 of 463 patients) and 91% of all survivors are neurologically intact on discharge (63 of 69 patients).
For total bystander-witnessed arrests (all rhythms) our ROSC was 58% (97 of 169 patients), with a 95% confidence interval (CI) of 50–65%. And, for witnessed, shockable rhythms, our sustained ROSC using our pit crew approach and treatment modalities was 68% (39 of 57 patients), with 95% CI 55–79% and discharged alive 26 of 57 patients (46%), 95% CI 33–58%, all of whom were neurologically intact. (See Table 3 below.)
Utilizing the pit crew approach will improve outcomes for the citizens and the families you serve by assuring evidence-based therapies are consistently provided. It will also provide a framework to integrate new therapies. While interventions such as continuous compressions and early defibrillation are the cornerstones of resuscitation today, as we continue to improve our knowledge of resuscitation through research the team approach can be easily modified to incorporate future best practices with consistency.
1. Blackwell TH, Kline JA, Willis JJ, et al. Lack of association between prehospital response times and patient outcomes. Prehosp Emerg Care. 2009;13(4):444–450.
2. Blackwell TH, Kaufman JS. Response time effectiveness: comparison of response time and survival in an urban emergency medical services system. Acad Emerg Med. 2002;9(4):288–295.
3. National Center for Chronic Disease Prevention and Health Promotion, Division for Heart Disease and Stroke Prevention. (July 23, 2013.) CARES: Cardiac Arrest Registry to Enhance Survival. Centers for Disease Control and Prevention. Retrieved Sept. 9, 2014, from www.cdc.gov/dhdsp/cares.htm.
4. McNally B. The Cares Registry. [Conference presentation.] FDA Public Workshop on External Defibrillators: Silver Spring, Md., 2010. Retrieved Sept. 9, 2014, from www.fda.gov/downloads/MedicalDevices/NewsEvents/WorkshopsConferences/UCM238922.pdf.
5. Cheskes S, Schmicker RH, Christenson J, et al. Perishock pause: An independent predictor of survival from out-of-hospital shockable cardiac arrest. Circulation. 2011;124(1):58–66.
6. Cheskes S, Schmicker RH, Verbeek PR, et al. The impact of peri-shock pause on survival from out-of-hospital shockable cardiac arrest during the Resuscitation Outcomes Consortium PRIMED trial. Resuscitation. 2014;85(3):336–342.
7. Hinchey PR, Myers JB, Lewis R, et al. Improved out-of-hospital cardiac arrest survival after the sequential implementation of 2005 AHA Guidelines for Compressions, Ventilations, and Induced Hypothermia: The Wake County experience. Ann Emerg Med. 2010;56(4):348–357.