Every five years, the American Heart Association updates its CPR guidelines
Photo credit: Mike Legeros
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- Discuss the key changes to the chain of life and cardiopulmonary resuscitation
- Explain the rationale for prioritizing chest compressions in C-A-B
- Identify the updates to advanced life support interventions during cardiac arrest
- Introduce the importance of and priorities in post-arrest patient management
Every five years, the American Heart Association (AHA) convenes with the world's leading authorities on cardiac care to evaluate the most current research studies and ideas and update its guidelines for cardiopulmonary resuscitation (CPR) and emergency cardiac care (ECC). The 2010 update to CPR and ECC, which marked the 50th anniversary of updates to modern CPR, is arguably the most thoroughly researched to date, with important and dynamic changes for how EMS provides care. Because nearly 175,000 out-of-hospital cardiac arrests occur in the U.S. annually,it is important for all EMS providers to be up to date with the most current practices.1 This month's article highlights the changes that impact EMS care the most.
Science is not always precise, even though we would like it to be. And it is not always clear when research is evaluated how beneficial different medications and interventions may actually be. To help users understand these recommendations, there are four different classes, each identified with the level of evidence supporting it. Table 1 highlights the different classes of recommendations, ranging from class I to III. In a change from the 2000 recommendations, the "class indeterminate" recommendation level that was used when there was no evidence for or against a drug's use has been eliminated. Every recommendation in this year's guidelines is supported with its respective level of evidence (LOE) and is graded A through C (Table 2).
Chain of Survival
The chain of survival has been a staple of CPR courses and EMS programs for years. With the new addition of the fifth link in the chain--comprehensive post-cardiac arrest care--EMS's role in delivering patients to hospitals that can appropriately manage their care becomes even more important. Researchers believe that accurate use of all five links in the chain of survival can boost cardiac arrest survival to nearly 50%.1
Each link in the chain builds on proper utilization of the previous link. For example, quality early CPR cannot happen without early recognition; good BLS care is the foundation of post-cardiac survival.3 In an effort to support early CPR, the AHA has established a class I (LOE B) recommendation that all emergency medical dispatchers (EMDs) be trained to recognize pre-cardiac arrest symptoms, including agonal breathing, and coach laypersons to perform chest compressions immediately without a pulse check.3 It is preferred and easier to coach chest compressions only rather than traditional CPR. Considering the low frequency of serious injury from chest compressions on patients not in cardiac arrest, the benefits far outweigh any risks of unnecessary chest compressions.
The sequence of CPR has taken a dramatic change. Since we now know that even the best chest compressions result in a cardiac output roughly 20% of normal, it is essential to appreciate the lifesaving importance of beginning chest compressions as early as possible and maintaining them without interruption throughout resuscitation. To promote this, there has been a switch from the long-used ABC algorithm to CAB: circulation, airway and then breathing. Laypersons will no longer be taught pulse checks in their CPR and first aid courses; instead, they will be instructed to immediately begin chest compressions on patients who are unresponsive with abnormal or no breathing.3 When a caller is not trained in CPR, 9-1-1 dispatchers should instruct the person in how to perform chest compressions. The AHA hopes that EMS crews will begin to see CPR being performed more often upon their arrival; however, EMS crews will need to accurately and quickly assess the patient to determine their true status. Expect some patients receiving CPR to have a pulse. When evaluating these patients, limit pulse checks to less than 10 seconds; continue chest compressions, unless there is no doubt the patient has a strong pulse.3
Once compressions are resumed, perform the same 30 compressions to 2 breaths as recommended in 2005. Chest compressions are one of the few class I interventions that we know help patients. When performing CPR, be sure to "push hard and push fast," as there has been a change in the rate and depth of compressions. On adult patients, the rate has changed from about 100 per minute to at least 100 per minute, and compression depth is now at least 2 inches. Both of these changes are class IIa recommendations.3 While initially these seem like subtle changes, they actually are quite significant. Increasing compression depth and rate helps improve cardiac output and generates a greater circulatory pressure.
The compressions rate for adult patients of at least 100 per minute (class IIa) is not the actual number performed, but rather the speed. Since there are breaks, or periods of time when no compressions are performed, the actual number of compressions is quite a bit lower. One study correlated the best ROSC when there are at least 80 compressions per minute. There has been some research on "high-frequency" chest compressions with rates exceeding 120 per minute. These studies are very limited and have small sample sizes, but do show that high-frequency compressions improve the patient's hemodynamics, although they have not impacted survival. Thus, while these 2010 recommendations do not recommend the routine use of high-frequency compressions, when properly used, they are an acceptable alternative (class IIb).4
Research has shown that the quality of compressions deteriorates rapidly over time as rescuers fatigue, leading to inadequate oxygenation of the brain and heart. EMS crews need to ensure proper and quality depth compressions are performed throughout cardiac arrest to provide the patient with the best opportunity for survival, which is accomplished by changing compressors every two minutes and ensuring complete chest recoil. Rescuer fatigue deteriorates the quality of chest compressions after about 1 minute; however, rescuers often do not note it for up to 5 minutes.4 This timing is designed to eliminate extra stops in compressions and prevent excessive fatigue.
Allowing chest recoil improves the negative pressure inside the chest, which is essential for the circulatory system to have good preload--the pressure that helps the heart fill with blood. Negative pressure occurs normally when we breathe (chest expansion) and during a cardiac arrest, when the chest returns to its normal shape following compressions. This negative pressure not only causes air to be drawn into the chest, it also pulls blood through the inferior and superior venae cavae toward the heart. If there is as little as 10 pounds of pressure on the chest, the equivalent of leaning with both arms on the chest just before a compression, the pressure change inside of the chest causes a decrease in the amount of blood that can flow through the venae cavae. With less blood flowing, less blood returns to the heart and pressure within the system decreases. Incomplete recoil has clear links to decreased coronary and cerebral perfusion. To prevent this, allow hands to release pressure on the chest in between each compression. Also consider using a cardiac monitor with built-in, real-time feedback devices that can tell you if compressions are not deep enough or if chest recoil is not adequate.
Chest compressions now begin before ventilations (Class IIb). The goal of this change is to shorten the delay to compressions and thus return of some circulation. This means that as soon as a patient is known to be pulseless, or a rescuer is not positive he feels a pulse, begin compressions. The compression-to-ventilation ratio remains the same at 30:2 (class IIb), based on expert consensus. The ideal ratio has not been determined and is under further research. Once an advanced airway is in place, class IIa recommends continuous compressions with an interspaced breath every 6-8 seconds.
While lay rescuers will be taught and coached to provide compressions-only CPR, all EMS providers are expected to also provide ventilations at an appropriate rate once they arrive on scene.
There has been no change in the recommendation to limit pulse and rhythm checks to two-minute intervals (five cycles of 30:2 CPR); however, pulse checks are deemphasized. Detecting a carotid or femoral pulse in the back of a moving ambulance is difficult even when patients have an adequate blood pressure. If a pulse is not definitely felt, or there are no signs the patient is breathing normally within 10 seconds of beginning a pulse check, immediately resume chest compressions (class IIa).3
There is significant concern over delays in chest compressions. Any interruption in continuous chest compressions rapidly depletes cerebral perfusion pressure. Following an interruption, it takes one minute of continuous compressions to restore pre-interruption perfusion pressures.3
Particularly in the out-of-hospital setting, there are many reasons chest compressions are interrupted, including pulse checks, rhythm analysis, defibrillation, moving the patient, intubation and IV/IO access. Remember to coordinate these interventions to limit interruptions. Whenever possible perform interventions while performing chest compressions. If an intervention requires a pause in compressions, try to time it with the rhythm/pulse check after each two-minute CPR cycle.
Respirations and Rescue Breathing
The introduction of CAB over ABC is designed to help reinforce understanding of the growing importance of circulation and that establishing an airway has a secondary role. Airway maneuvers and adjuncts need to be performed quickly and while compressions are being performed.
Opening the airway with a head-tilt chin-lift remains the staple for patients not suspected of a head or neck injury. When a head or neck injury is suspected, attempt to open the airway with the jaw-thrust; however, if the jaw-thrust does not adequately open the airway, utilize a head-tilt chin-lift. Remember, in blunt trauma, the neck is injured between 0.12% and 3.7% of the time,3 so the benefits of opening the airway outweigh the risks of spine injury.
The normal, healthy adult breathes 8-10 mL/kg of air with each breath in order to maintain normal oxygen and carbon dioxide levels. During cardiac arrest with quality CPR, cardiac output is estimated at 25%-33% of normal. As a result, the body's oxygen consumption and carbon dioxide delivery to the lungs are both reduced by nearly 75%. Because of this, it is reasonable to ventilate these patients with tidal volumes that are lower than normal,3 meaning fewer breaths per minute. The class IIa recommendation is to provide just enough air to produce chest rise 12 times per minute.
Applying cricoid pressure is a skill of the past. Seven randomized studies demonstrated that cricoid pressure delays advanced airway placement and still permits aspiration, even when applied correctly. In several studies, expert practitioners displayed difficulty performing the skill on manikins; thus, its routine use is now a class III recommendation, except in special circumstances.3
Use of Electrical Therapy
In the 2005 recommendations, unwitnessed cardiac arrests were managed with two minutes of CPR prior to defibrillation. Now, after five years of research and data analysis, three different studies demonstrated no improvement in return of spontaneous circulation (ROSC) with a delay in defibrillation for CPR in these patients. Two subgroups did show some increase in survival to hospital discharge, but the data were not considered statistically significant. As a result, the AHA recommends always using a defibrillator as soon as it is available.3 Remember, although defibrillation pads can be placed on the patient while compressions are being performed, once the defibrillator is ready, do not delay initial rhythm analysis. Even though most AEDs and manual defibrillators cannot filter out compressions on an EKG, the AHA recommends manufacturers design AEDs that can perform rhythm analysis while compressions are still being performed. Also, when charging an AED or manual defibrillator, perform chest compressions. The shorter the time interval from the last compression to shock delivery, the higher the likelihood of successful defibrillation. Compressions during this time interval are a class I LOE B intervention.5
In line with the 2005 CPR updates, the one-shock-then-CPR mentality has been continued; however, several studies have now demonstrated incremental (stacked) shocks are unlikely to terminate VF, and it is clearly known delays in CPR reduce survival.6 As a result, one-shock-then-CPR has been upgraded from a class IIb to a class IIa recommendation.6
Consensus research experts recommend monophasic defibrillators continue to be used at a 360-joules energy level, but caution that biphasic defibrillators appear to improve survival. There are no new recommendations for how to use a biphasic defibrillator. Continue to follow the manufacturer's recommended energy level for shocks. When the recommended level is unknown, consider using the maximum energy level available (class IIb).6
The potential fire hazard surrounding defibrillation is being stressed during these ECC updates, citing several case studies looking at what happens when oxygen blows across the chest during shock delivery. It is feasible for a spark or arching to cause a fire when supplemental oxygen flows across the chest. To avoid this oxygen-enriched atmosphere on the chest, use self-adhesive defibrillation pads, remove the patient's oxygen supply and direct it away from the patient just prior to defibrillation (class IIb).6
The precordial thump used to be a standard treatment when a defibrillator was not available; however, it has been shown ineffective in managing ventricular dysrhythmias in over 98% of cases,4 and has been shown to cause complications, including sternum fracture, stroke and irreversible cardiac dysrhythmias. Because of this, the precordial thump is a class III intervention for unwitnessed out-of-hospital cardiac arrests. It may be considered (class IIb) immediately following the development of witnessed unstable ventricular tachycardia when no defibrillator is available.4 Fortunately, this situation is highly improbable in the prehospital setting, since nearly all EMS monitors are also cardiac defibrillators.
CPR Assist Devices
Active compression and decompression devices that compress the sternum have a suction cup attached which physically lifts the anterior chest wall during its decompression phase to improve negative intrathoracic pressure. Research has shown mixed results. When patients do survive, they appear to have improved neurological function; however, there has been no improvement in the percentage of patients experiencing ROSC or survival to hospital discharge.4 As a result, the active compression-decompressions have a class IIb recommendation.
Mechanical piston devices are used to provide consistent chest compressions throughout management of a cardiac arrest. These devices compress the sternum a set depth with each compression without variation. Older versions, such as the Thumper, and newer versions, such as the Lund University Cardiac Arrest System (LUCAS), are both used in many EMS systems. These devices have been shown to improve circulation during a cardiac arrest when monitored by blood pressure and end-tidal carbon dioxide levels. It goes without saying that, once applied, these devices provide more consistent CPR than even the best-trained providers over the course of patient care, and they eliminate breaks in chest compressions. However, there has been no benefit shown when compared with conventional CPR regarding patient survival to hospital discharge or ROSC. These devices are a class IIb recommendation. The AHA neither recommends nor discourages their use.4
Circumferential chest-squeezing devices, known as load distribution bands, like the ZOLL AutoPulse, rhythmically squeeze the chest to perform chest compressions and are shown to improve circulation hemodynamics during a cardiac arrest. This suggests they will help circulate any administered drugs and oxygen better. Like the mechanical piston devices, however, load distribution bands showed no improvement in four-hour patient survival and were actually shown to worsen the neurologic outcome of patients who survived.4 The question has thus arisen whether these devices are harmful to patients, although this research is unclear and ongoing. The AHA believes that load distribution bands can be considered during cardiac arrests by specifically trained providers in undefined "specific settings." However, they are a class IIb recommendation, and the AHA does not recommend their routine use.
Impedance threshold devices (ITDs) like the ResQPOD were popular class IIa recommendations in the 2005 ECC recommendations. After five years of research, their true benefit is being reconsidered. The theory behind ITDs is that they limit passive air entry during the decompression phase of CPR. Air can be pushed out of the lungs when the chest cavity is compressed, but, because of a valve, air is not allowed back in. This improves the negative pressure within the chest, which improves preload and blood return to the heart. To work properly, the ITD must have a sealed airway, whether it is a cuffed endotracheal tube or a face mask with a constant seal on the patient's face. Current research has demonstrated that the ITD improves patient survival during out-of-hospital cardiac arrest to hospital admission, and improves ROSC, but the ITD does not improve neurological function or long-term survival to hospital discharge. Because this latter research result is different than what was reported in the 2005 recommendations, for now, the ITD is only a class IIb recommendation.4
Advanced Cardiac Life Support
It is no secret that prehospital intubation has taken a lot of negative press lately. However, early intubation improves 24-hour survival for cardiac arrest patients. In the prehospital setting, this is within 12 minutes of arrest.5 The endotracheal tube is a class IIa LOE A airway alternative used during cardiac arrest. When performing intubation, the routine use of cricoid pressure is now a class III intervention because it is associated with increased intubation times. Additionally, intubations can be performed while chest compressions are performed; should compressions be paused, limit the pause to less than 10 seconds. Following successful intubation, the new gold standard for airway monitoring and confirmation is numerical and waveform capnography (Figure 2). Waveform capnography is a class I LOE A recommendation because it is 100% sensitive and specific for identifying tube placement.5
There is new emphasis in this year's recommendations on having a backup airway management strategy, and supraglottic airways are considered reasonable alternatives. Studies and recommendations were established for the Combitube, the King LT and the laryngeal mask airway (LMA). As a group they are class IIa LOE B alternatives, because, when properly placed, they can ventilate the patient just as effectively as an endotracheal tube.5 The Combitube is a class IIa alternative to intubation and, depending on the study, produces effective ventilation 62%-100% of the time.5 There is limited research for the King LT airway during cardiac arrest management, but, when placed properly, it has an 85% successful ventilation rate. During cardiac arrest, it is a class IIb LOE C alternative. The two most significant reasons for ineffective ventilations are cuff rupture during placement and aspiration. It is impossible to suction the trachea through a King LT. Even though LMAs do not prevent aspiration, they can provide ventilations equivalently to the endotracheal tube. It is noted to be particularly beneficial in confined spaces or when airway access is difficult. It is a class IIa LOE B alternative, but the AHA stresses having a backup available, because some patients are not able to be ventilated with the LMA.5
There are many reasons to provide continuous waveform capnography, also called end-tidal CO2 (EtCO2) monitoring, on all cardiac arrest patients. Even when an alternative airway is used, capnography still works; it is just not as effective. During a cardiac arrest, the CO2 waveform will be fairly flat and the CO2 levels relatively constant. However, once ROSC occurs, there will be a nearly immediate return of a normal capnography waveform.
Normal numerical capnography readings are 35-45 mmHg, but these won't be seen during a cardiac arrest. Any abrupt increase to near normal EtCO2 levels suggests ROSC. Good chest compressions will return CO2 to the lungs throughout the arrest state, but in a volume less than normal. If consistent chest compressions are performed, the CO2 level should be relatively consistent (the number will vary with each patient). Poor compressions result in low CO2 readings. Particularly when EtCO2 readings are less than 10 mmHg, try to improve the quality of chest compressions. Consistent EtCO2 readings below 10 mmHg are a predictor that ROSC is unlikely. The closer to normal the CO2 reading, the greater the chances of ROSC become.
Research no longer supports routine use of sodium bicarbonate during cardiac arrest management. It is a class III recommendation now because its administration compromises cerebral perfusion pressure, inhibits oxygen release, and worsens cerebral and myocardial acidosis. Its use is now limited to special circumstances, such as known metabolic acidosis, hyperkalemia and tricyclic antidepressant overdose.
Sodium bicarbonate is likely to cause a rise in numerical EtCO2 readings. This is a result of the chemical reaction occurring from the sodium bicarbonate and shouldn't be confused with a rise in EtCO2 consistent with ROSC.5 Vasopressor therapy may cause transient decrease in EtCO2 because it causes a relative decrease in cardiac output. A drop in EtCO2 readings shortly after vasopressor administration is expected and should wear off within a few minutes.5
Drug therapy during cardiac arrest is not what saves lives; early quality CPR and early defibrillation save lives. Intravenous drug therapy doesn't need to be considered until pulselessness persists for at least 2 minutes (Class IIb). When preparing for drug therapy, IV/IO placement does not require a pause in compressions. Once begun, remember that the peak effect of drugs is delayed at least 1-2 minutes during the arrest state. To optimize time for drugs to circulate, try to administer them as early in a two-minute compression cycle as possible. Following a drug, administer a bolus 20 mL of saline to push the drug toward central circulation. Raising the arm is purely theoretical and has no evidence to support its efficacy.5 Just as in 2005, the drugs of choice for managing VF and pulseless VT remain epinephrine (Class IIb LOE A) and amiodarone (Class IIb LOE B). Lidocaine remains an alternative when amiodarone is not available (Class IIb LOE B). New to 2010, when managing asystole and pulseless electrical activity (PEA), a vasopressor is the drug of choice; atropine is no longer indicated. The goal of a vasopressor (Class IIb LOE A) is to improve myocardial and cerebral blood flow. The research performed on atropine suggests it is unlikely to have any therapeutic benefit (Class IIb LOE B). While it isn't harmful, it doesn't help, so it has been removed from the arrest algorithm.5
Epinephrine is the primary vasopressor during cardiac arrest, with 1 mg given every 3-5 minutes (Class IIb LOE A). There was no increased ROSC with high-dose epinephrine administration. Three trials comparing epinephrine to vasopressin found no difference in ROSC or survival rates when either is used as the first-round vasopressor.5 One trial has shown that while repeated doses of epinephrine improve ROSC, repeating vasopressin does not. This is why vasopressin can be used for either of the first two doses of vasopressor during cardiac arrest (Class IIb LOE A). There is no study that demonstrates vasopressors administered during cardiac arrest improve the percentage of patients with a good neurological outcome, although they do increase ROSC.5
No research has shown that administering an antiarrythmic at any point during a cardiac arrest increases survival to hospital discharge; however, amiodarone has been shown to increase short-term survival compared with lidocaine and placebos in the out-of-hospital setting.5 Lidocaine does have an association with improved hospital rates when given in the out-of-hospital setting compared with no antiarrhythmic, but it is not strong enough evidence to support routine use when amiodarone is available.
Magnesium use has changed. Several studies failed to identify a benefit during routine use for VF patients. It is a class III recommendation unless torsade de pointes is present, in which case it is a class IIb LOE C recommendation. The mechanism by which magnesium terminates torsade de pointes is unclear.
There is a rapidly growing understanding of the importance of systematic post-cardiac arrest management, as it improves patient survival and neurological recovery. EMS can play a very important role in initiating many post-arrest interventions. The initial objectives of post-arrest care include:7
- Optimize cardiopulmonary function
- Access appropriate hospitals specializing in coronary care
- Core body temperature control
- Identify acute coronary syndrome
- Optimize mechanical ventilation
- Assess prognosis and assist survivors.
Following ROSC, EMS can perform several immediate interventions while coordinating transport to an appropriate cardiac hospital. Elevating the head 30 degrees reduces cerebral edema, aspiration and risk of pneumonia. Monitor SpO2 and titrate oxygen to the lowest level that maintains an oxygen saturation of at least 94%. While providing 10-12 ventilations per minute, adjust the tidal volume (volume of air per breath), monitor capnography to maintain EtCO2 between 35-40 mmHg.7 Also closely monitor the patient's blood pressure and provide isotonic IV fluids or vasoactive drugs to maintain a systolic blood pressure of at least 90 mmHg or a mean arterial pressure of at least 66 mmHg. Finally, check blood glucose and work to bring it to normal levels.
When capable, perform a 12-lead EKG to look for signs of myocardial ischemia or injury. STEMI is one cause of sudden cardiac arrest, and early detection is essential to early intervention. Besides STEMI, look for other causes for the cardiac arrest, the most common of which are listed in the H's and T's of Table 3.
The only intervention proven to improve neurological outcome is therapeutic hypothermia (class I LOE B), which is indicated for all patients who cannot respond to commands following ROSC. Immediate cooling protects brain function while the body recovers from the event. Work with a medical director to set up a therapeutic hypothermia protocol for your program. Services of all levels of care can help initiate hypothermia. BLS interventions include applying ice to the axilla and groin and wrapping the patient with cold, wet blankets. Advanced providers can infuse 30 mL/kg of iced normal saline. There is no optimal cooling strategy, but several studies have shown the earlier cooling is initiated, the better the patient's outcome.7 During cooling, be sure to monitor the patient's temperature. Oral, axillary and tympanic thermometers are inaccurate in assessing cooling; the best devices are rectal, esophageal and bladder probes.
What Might the Future Bring?
Research is ongoing, and until all interventions performed during cardiac arrest are class I interventions, researchers will be constantly looking for ways to improve cardiac survival. Following are some studies currently being completed and reviewed.
A few non-randomized studies of out-of-hospital arrests have shown improved survival rates when prehospital providers use a compression-to-ventilation ratio of 50:2, or when continuous compressions without ventilations are provided. These are being prepared into a nationwide multi-site trial to try to determine the optimal compression-to-ventilation ratio.
One study has been performed on current-based defibrillation and suggests that using current may be superior to our present energy-based defibrillation. This is being evaluated to look for optimal current levels to terminate VF and VT.6 In 2015, this may be cutting-edge technology that will lead to significant changes in how we defibrillate.
In the next updates, electrode size may come under closer scrutiny. Currently, it is recommended that adult pads and paddles be at least 50 cm2, but it is now believed that pads with a 12-cm diameter have higher success rates than pads 8 cm in diameter. It is also believed that small pads (4.3 cm in diameter), like those used on pediatric patients, can be potentially harmful and may cause myocardial necrosis. These smaller pads, while effective in terminating VF, result in very high transthoracic impedence, which impairs energy and current delivery.6 Don't be surprised if by 2015 defibrillation pads change shape and/or size.
Research has also started analyzing the waveform of ventricular fibrillation to predict if a shock will be successful. To date, no human studies have been performed, but research is ongoing.
1. Travers AH, Rea TD, Bobrow BJ, et al. Part 4: CPR Overview. 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 122:S676-S684, 2010.
2. Sayre MR, O'Connor RE, Atkins DL, et al. Part 2: Evidence Evaluation and Management of Potential or Perceived Conflicts of Interest. 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 122:S657-S664, 2010.
3. Berg RA, Hemphill R, Abella BS, et al. Part 5: Adult Basic Life Support. 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 122:S685-S705, 2010.
4. Cave DM, Gazmuri RJ, Otto CW, et al. Part 7: CPR Techniques and Devices. 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 122:S720-S728, 2010.
5. Neumar RW, Otto CW, Link MS, et al. Part 8: Adult Advanced Cardiovascular Life Support. 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 122:S729-S767, 2010.
6. Link MS, Atkins DL, Passman RS, et al. Part 6: Electrical Therapies: Automated External Defibrillators, Defibrillation, Cardioversion, and Pacing. 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 122:S706-S719, 2010.
7. Peberdy MA, Callaway CW, Neumar RW. Part 9: Post-Cardiac Arrest Care. 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 122:S768-S786, 2010.
Kevin T. Collopy, BA, FP-C, CCEMT-P, NREMT-P, WEMT, is an educator, e-learning content developer and author of numerous articles and textbook chapters. He is also a flight paramedic for Spirit Ministry Medical Transportation in central Wisconsin and a lead instructor for Wilderness Medical Associates. Contact him at firstname.lastname@example.org.
David J. Heegeman, MD, is an emergency room physician for Marshfield Clinic in Marshfield, WI. He is also a training center faculty member of the Marshfield Clinic AHA Training Center and ACLS regional faculty. He can be reached at Heegeman.email@example.com.
Scott R. Snyder, BS, NREMT-P, is the EMS education manager for the San Francisco Paramedic Association in San Francisco, CA, where he is responsible for the original and continuing education of EMTs and paramedics. Scott has worked on numerous publications as an editor, contributing author and author, and enjoys presenting on both clinical and EMS educator topics. Contact him at firstname.lastname@example.org.