Seven survivability tools lead to dramatic improvements in cardiac arrest outcomes
In the United States, an estimated 10% of cardiac arrest patients survive, with 90% never leaving the hospital.1 Are these acceptable cardiac arrest survival rates where you and your family live, work and play? They weren’t for the Rialto (Calif.) Fire Department (RFD), so the RFD embarked on a complete review and revision of their approach to cardiac arrest resuscitation.
This article describes the RFD’s journey toward increased SCA survival-a journey that, in 2016, resulted in a 71% (Utstein) survival rate from sudden cardiac arrest (SCA) in Rialto. This is due in large part to what the RFD unlearned about cardiac arrest; Rialto’s outcome-based data now shows that all of these assumptions are false:
- CPR should be done on a hard, flat surface;
- Always defibrillate ventricular fibrillation (v fib);
- Intubation attempts should be limited to 30 seconds;
- ALS actions are what saves lives;
- Prioritize epinephrine to improve cerebral perfusion and survival;
- Asystolic patients have essentially no survivability; and
- Rapid transport to the hospital improves outcomes.
After just two years, the RFD is seeing dramatic results, including a significant improvement of ROSC and patient survival.
The RFD’s mission is to be, “An organization that brings value to the community, measured in lives saved and quality of life protected.”2 To further this, the RFD embarked on a journey to improve neurologically intact survival from SCA.
The RFD enjoys an organizational structure that isn’t common in California. The RFD is both the fire-based first responder and the ambulance transport provider for the city of Rialto.
All RFD first responder and transport units are staffed with paramedics and all RFD personnel are trained to the same standards. The RFD doesn’t participate in the CARES registry and acquiring outcome data depends upon extending the RFD culture of teamwork to receiving facilities.
In 2016, the RFD developed the seven components of cardiac survivability, referred to as the RFD Cardiac Survivability Tools:
1. Continuous uninterrupted compressions utilizing an automated CPR device;
2. Apneic oxygenation;
3. Use of an impedance threshold device (ITD);
4. Heads-up CPR;
5. Delaying defibrillation for a certain subset of patient presentations;
6. Expanded utilization of waveform capnography; and
7. Deprioritizing epinephrine in the order of interventions.
When applying the RFD Cardiac Survivability Tools to cardiac arrest patients, the RFD realized a 60% return of spontaneous circulation (ROSC) for all non-traumatic adult arrests; not just the very small number of patients that fit into the Utstein measurement, but all patients in cardiac arrest. By working hard at this process and unlearning previous assumptions, the RFD gleaned some keys to success.
If the RFD could impart only one data-driven, outcome-oriented finding, it’s this: nothing trumps compressions, nothing! Not ALS or BLS, airway or venous access, defibrillation or definitive medical care; nothing should interrupt compressions. Uninterrupted compressions have been shown to be one of the key components to saving lives, so everything else should be support for those compressions.
The RFD has been using the AutoPulse automated CPR device since 2009. The generalized research on automated CPR devices hasn’t shown significant benefit in patient outcomes with their use.3Research conducted in 2015 illustrated ROSC rates to be 5% higher for all non-traumatic adult cardiac arrest patients in Rialto with use of automated CPR vs. manual CPR
However, it was when evaluating the use of automated CPR devices that the RFD had its first eureka moment-a moment that would set the stage for the data-driven, outcome-oriented cardiac survivability tools that would follow.
The RFD was using automated CPR in the same fashion it had previously used manual CPR-with too many pauses in compressions. Today, the RFD goal is to initiate and maintain continuous, uninterrupted compressions as soon as possible after patient contact, effectively maintaining a 100% compression fraction rate within the first 30 seconds of the resuscitation.
In practice, RFD crews will initiate manual CPR, transition to the AutoPulse device within 30 seconds and then never turn off the device; not for intubation, defibrillation, rhythm checks or pulse checks.
Under RFD’s cardiac arrest protocol, the automated CPR device can only be turned off for two reasons: termination of resuscitation efforts or if ROSC is achieved, as noted by a precipitous and persistent increase in end-tidal carbon dioxide (EtCO2).
To ensure compliance with the Cardiac Survivability Tools, the RFD uses software (ImageTrend ePCR report writer and ZOLL Case Review) to review all sudden cardiac arrests. Each compression, ventilation and all vitals are represented for the duration of the resuscitation in the program.
Those patients that achieve ROSC share an extended period of uninterrupted high-quality CPR as the underlying factor. Although patients in shockable rhythms generally achieve ROSC as a result of defibrillation, those who achieve ROSC from non-shockable rhythms generally have no discernable causal intervention other than the absence of breaks in CPR for several minutes prior to ROSC.
Patients that achieve return of spontaneous circulation share an extended period of uninterrupted high-quality CPR as the underlying factor.
For years, paramedics have been taught that 30 seconds is all the time they have to establish an advanced airway, or the intervention should be delayed and a round of pre-oxygenation ventilations should be instituted. Apneic oxygenation allows for passive oxygenation of a patient that’s already receiving continuous, uninterrupted compressions, capitalizing on the low tidal volume but high minute volume of ventilations generated by the automated CPR device.4
The RFD goal for this survivability tool is to initiate and maintain continuous oxygenation of patients from the time that continuous, uninterrupted CPR by automated CPR device is initiated until an advanced airway is secured.
In practice, crews place a nasal cannula on the patient at 15 liters per minute immediately after initiating the automated CPR device.
Providers can readily assess the effectiveness of apneic oxygenation through the use of pulse oximetry. The patient should maintain or improve their oxygen saturation and EtCO2 levels even when providers aren’t ventilating the patient to secure an advanced airway.
Applying this tool supports the entire process by avoiding interruption of CPR to secure an advanced airway and eliminates arbitrary time standards to secure the advanced airway based on the need to maintain patient oxygenation.
Regulating Intrathoracic Pressure
The RFD uses the ResQPOD ITD, a noninvasive device that delivers intrathoracic pressure regulation (IPR). The ITD acts as a one-way valve allowing oxygen to be delivered during ventilations but restricts ambient air from entering the thoracic cavity during the recoil phase of chest compressions and between ventilations. This lowers thoracic pressure, creating a vacuum which pulls more blood back to the heart, increases preload and decreases intracranial pressure (ICP), allowing for quality cerebral perfusion. It’s a blood in, blood out equation. Studies have shown that the ITD increases blood flow to the heart by 25% and increases cerebral perfusion by 50%.5-7
The RFD goal for this survivability tool is to increase cardiac and cerebral perfusion by initiating and maintaining the use of the ITD from the time an advanced airway is secured until ROSC is achieved. In practice, crews place the ITD inline of the ventilation circuit immediately after verifying placement and security of the advanced airway.
The RFD hasn’t found a definitive indicator that the ITD is providing increased circulation. However, for patients who subsequently achieve ROSC, there’s generally noted improvement in EtCO2 from the time of ITD placement. This improvement in EtCO2 occasionally occurs rapidly and, in several cases, has precipitated ROSC without additional intervention.
Performing heads-up CPR, with the patient’s head and torso in a 30-degree elevated position, has been found to optimize perfusion in the shock state of cardiac arrest. It’s a simple, yet effective way of decreasing ICP, increasing preload and enhancing post ROSC neurological function.8
By elevating the head to a 30-degree angle, venous pressure is relieved and allows gravity to drain blood back to the heart. Decreasing ICP and increasing preload allows for more blood in and more blood out of the brain. From an ergonomic and effectiveness perspective, heads-up CPR can only be performed with an automated CPR device and should only be performed with an ITD in place to maximize the pressure variant and cerebral perfusion. Heads-up CPR has a synergistic effect when provided as a concomitant therapy to the ITD.9
For heads-up CPR, the most recently implemented cardiac survivability tool, the goal is to initiate and maintain heads-up CPR from the time the ITD is placed until ROSC is achieved. In practice, once the automated CPR device is in place, crews move the patient onto the stretcher and then raise the head of the gurney to a 30-degree angle.
Although the RFD hasn’t found a definitive indicator that heads-up CPR is providing increased circulation, the same improvement in EtCO2has been seen in those patients who subsequently achieve ROSC when heads-up CPR is initiated immediately after the placement of the ITD.
After heads-up CPR was added as a survivability tool, RFD crews found that many patients who eventually achieved ROSC were noted to gasp or provide patient-initiated ventilation attempts within a short period of time after heads-up CPR was initiated. The gasping response hasn’t been historically documented and is an anecdotal corollary finding. It may not be caused by heads-up CPR; however, during heads-up CPR, gasps have been observed along with a discernable capnography waveform.
One of the links in the chain of survival is early defibrillation. Matching national data, 24% of RFD patients have an initial presenting rhythm of v tach or v fib, the two classic shockable rhythms of cardiac arrest.
The RFD provides early defibrillation to patients in shockable rhythms whenever possible. Unfortunately, the arrival of responders may occur after the window in which defibrillation will result in ROSC has closed.
There are three clinical findings that suggest the patient is outside the window for early defibrillation such that defibrillation may not be successful: 1) prolonged patient downtime in cardiac arrest; 2) very fine v fib (barely distinguishable from asystole);10 and 3) an EtCO2 reading of less than 20 mmHg.11 Patients with these clinical findings are acidotic and have hearts that are less receptive to electrical therapy. Before defibrillation, these patients require high-quality CPR to increase perfusion, correct hypoxia and resolve the acidosis.
For patients who meet one or more of the three clinical findings for deferred defibrillation, the RFD goal for this survivability tool is to implement the four previous tools (continuous, uninterrupted compressions utilizing an automated CPR device; apneic oxygenation; use of an ITD and heads-up CPR) for a minimum of five minutes prior to delivering defibrillation.
Case review and field providers have been able to assess the effectiveness of this practice by a decrease in the number of defibrillated patients that convert into asystole and an increase in the number of defibrillated patients that ultimately achieve ROSC.
The common practice of terminating resuscitation for an asystolic patient after two rounds of medications or 10-15 total minutes may be limiting survivability.
Expanded Use of Capnography
EtCO2 levels provide information that cells are alive and metabolically active. Waveform capnography can help verify the continued placement of an advanced airway, and it can help guide delayed defibrillation.
Waveform capnography can also be an indicator of a patient who may ultimately survive but may require additional time for resuscitation. The common practice of terminating resuscitation for an asystolic patient after two rounds of medications or 10-15 total minutes may be limiting survivability. The RFD uses EtCO2 to help guide this decision.
The goal for this valuable tool, which is integrated into the X Series monitor/defbrillator used by the RFD, is to ensure that patients who show signs that resuscitation may result in ROSC continue to receive care unless clinical findings determine otherwise.
In practice, the RFD only terminates resuscitation efforts if the EtCO2 is less than 15 mmHg and trending downward (after confirming that high-quality resuscitation is being performed with all of the previously noted cardiac survivability tools).
If a patient has an EtCO2 that’s greater than or equal to 15 mmHg and is trending upward, RFD crews remain on scene, providing all of the survivability tools for at least 30 minutes before transporting or terminating resuscitation.
Even providers who were initially highly skeptical of this requirement have seen positive results. The RFD rate of ROSC for the initial presenting rhythm of asystole, including unwitnessed arrests, is 26%. Of those patients, the average time from arrival of RFD crews until ROSC is 24 minutes. All of those patients had an initial EtCO2 greater than or equal to 15 mmHg. Half of those patients survived to hospital discharge.
The type, dosage and priority of administration of medications in cardiac arrest has varied dramatically over time. Matching national standards, local EMS protocols that the RFD operates under require epinephrine administration as the first pharmacological intervention for all cardiac arrest victims.
Prioritizing the administration of epinephrine has led to other demonstrably more impactful interventions being delayed.12 To address this, consistent with local protocol, the emphasis should be on high-quality uninterrupted CPR followed by appropriate interventions.
By sequencing the priority of interventions, it’s likely that epinephrine, when administered, will be given when the patient is more receptive to its pharmacological impact: after the patient has adequate perfusion, resolution of underlying acidosis and with an adequate EtCO2.
The RFD goal for this survivability tool is to emphasize the activities that are essential in the initial minutes of resuscitation and to subsequently defer epinephrine administration until priority treatments are realized. The RFD has seen an increase in survival-to-discharge as a result of this sequencing approach.
There’s no magic ingredient to successful cardiac arrest resuscitation. Although case review has shown increased ROSC rates associated with application of all of the RFD Cardiac Survivability Tools, the significant increase in survival-to-discharge is due to the implementation of the whole system rather than a single element.
The RFD’s system-based approach relies upon a strong quality improvement (QI) and training platform alongside one of the RFD’s core values: teamwork.
The most impactful QI actions have come from the RFD establishing post-resuscitation feedback that alerts providers and department leadership to compliance with the RFD Cardiac Survivability Tools. This allows for focused assessment of each incident and aids in establishing training needs so that small course adjustments can be made on a regular basis.
Figure 1: Percentage of patients where ROSC was achieved
So, let’s be clear, what we have been taught isn’t working! We have to stop doing what we have always done. We need to ask, in no uncertain terms, does every single thing I do in the cardiac arrest setting improve neurologically intact survival. If not, why do we do it?
The RFD is hopeful that you’ve unlearned some of the things you were previously taught and are motivated to evaluate this new paradigm and how it could increase cardiac survivability in your community.
1. American Heart Association. (2017.) CPR facts and stats. Retrieved Oct. 27, 2017, from http://cpr.heart.org/AHAECC/CPRAndECC/AboutCPRFirstAid/CPRFactsAndStats/UCM_475748_CPR-Facts-and-Stats.jsp.
2. Rialto Fire Department. (2017.) Rialto Fire Department operations manual. [Internal document.]
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