The 2010 ACLS guidelines have de-emphasized ventilations as an initial intervention for bystander CPR, going as far as changing the sacred cow “ABC” to “CAB” (compression/airway/breathing). When faced with an apparently lifeless victim, the citizen bystander is urged just to push on the chest: hard, fast (100/minute), and deep (2 inches). Chest compressions should not be stopped for more than a few seconds, even for electrical shocks. In addition, for EMS and the ED, supraglottic airways, like the King Airway, shown above, over tracheal intubation are now endorsed. Most emergency physicians still like to secure the airway with an ET tube, and can spend excessive time with multiple attempts with the laryngoscope when alternate adjuncts will temporarily ventilate just fine. Many EMS units have eschewed attempting traditional tracheal intubation entirely, and just go with a supraglottic device. Per the ACLS guidelines, capnography is a Class I recommendation to assess position and function of any airway device.
While most EPs have little interest in prosaic prehospital or EMS techniques and protocols, and are completely bored by the vicissitudes of CPR, a patient resuscitated by EMS often comes to the ED with issues relevant to ACLS guidelines. And, of course, patnts do arrest in the ED. Cardiac arrest is largely emergency medicine turf, and cardiologists are as rare as hen's teeth during real-life codes.
Nonetheless, but at least now with substantial EM input and contributors, the American Heart Association (AHA) has purloined the moniker of being the last word on cardiac arrest resuscitation. In October 2010, the AHA released its new guidelines for basic and advanced cardiac life support. While generally similar in recommendations and scope to the 2005 guidelines, there are some significant changes relevant to emergency medicine. Importantly, these guidelines are touted to be more evidence-based and without author conflicts.
The gargantuan document specifically addresses CPR and resuscitation sequencing, airway management, and a new approach to arrhythmias. The AHA also proffers guidelines concerning certain hospital and ED certifications, suggests who should go where after a field arrest, and promulgates some rather interesting recommendations for post-cardiac arrest care. Except for a few EMS geeks and researchers, most mere mortals will read the well-written executive summary in lieu of the laborious 300-page treatise.
2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care
Field JM, et al
2010;122(18 Suppl 3):S639
Although most clinicians consider CPR second nature and extant forever, closed chest cardiac massage was not documented to be successful until 1960. The first defibrillation was described in 1962. In 1966, the American Heart Association developed the first CPR guidelines, followed by periodic updates. While survival-to-discharge is still quite dismal regardless of the cause of cardiac arrest, CPR is a religion for some, and certainly the major occupation for thousands of paramedics. While only a few patients can be brought back from the dead if they suffer a cardiac arrest outside the ED or ICU, prehospital CPR does save a few. With the increasingly good but perhaps too-good-to-be-true reports of miraculous saves from post-arrest hypothermia, perhaps more will benefit.
While updates in EMS response and technology undergo constant improvement and the increased deployment of automatic external defibrillators (AEDs) define true progress, expedited CPR still requires citizen bystanders to be ready, willing, and able to act if these survival data are going to continue to improve. The AHA has acknowledged this axiom, and has tried to make new guidelines more bystander-friendly and significantly simplified. Survival rates vary greatly; only about four percent to six percent of patients suffering out– of-hospital cardiac arrest leave the hospital, and maybe up to 20 percent of in-hospital arrests can be expected to regain a normal life.
These guidelines emphasize the fundamental importance of high–quality CPR, the positive impact of bystander CPR on survival, and the caveat that chest compression-only CPR can achieve outcomes similar to conventional CPR.
The AHA continues to advocate high-quality CPR, concluding that properly performed CPR is essential for optimizing outcome. Many clinicians are skeptical of CPR in general, and certainly the lay population is hesitant to jump right in and give mouth-to-mouth resuscitation to a perfect stranger who has collapsed in the street. Hoping to increase bystander CPR, the new guidelines actually deemphasize ventilation as a first-line intervention, and clearly focuses the rescuer primarily on providing cardiac compressions. For adults, chest compression only, or “hands-only CPR,” appears to garner outcomes similar to conventional CPR (compression and rescue breathing). The AHA now deems it unnecessary for the somewhat-reluctant members of the general public to place their own mouths on the mouth of a seemingly dead stranger, and instead coaxes them only to pump vigorously and continuously on the sternum.
The rate of compressions should be 100 a minute, and when breathing is commenced, the compressions: breath ratio is 30:2. The quality of chest compression focuses on adequate depth, stated to be 2 to 2.5 inches in an adult, and religiously minimizing the interval between stopping compressions, even for delivering electrical shock. The new guidelines strongly advise against pausing chest compressions, even for a few seconds.
It is emphasized that merely minimizing the time between the last compression and the discharge of a defibrillator improves survival. In cited references, cessation of CPR for only 10 to 20 seconds results in a rather remarkable decrease in the resuscitation's success rate. Only a few seconds delay in applying the paddles or manipulating the AED or stopping compression for even a few cycles may mean difference between life and death if one believes the data presented.
Rescuers should continue chest compressions up to the very moment that defibrillation can be accomplished or EMS arrives. Maximizing the time of continuous compressions for prehospital VF/VT improves outcome significantly. In one study, return of spontaneous circulation and survival to discharge was achieved in 58 percent and 12 percent respectively of those receiving compression during only 20 percent of resuscitation time, compared with 79 percent and 23 percent respectively when compressions were continued for more than 20 percent of the code's duration. (Circulation 2009;120:1241.) I remain skeptical, but that's impressive!
Early rescue breathing is markedly deemphasized. In fact, first responders are advised not to breathe for the pulseless apneic victims but just to start compressing the chest vigorously — fast, hard, and deep. Theoretically, most adult codes are from sudden cardiac standstill, and for some time post-arrest (VF/VT), the victim's blood remains oxygen-laden enough to be beneficial to a cardiac-arrested brain. If the oxygenation was normal, hemoglobin saturation remains in a viable range for at least two to three minutes of apnea. (Br J Anaesth 1996;76:284.)
Delivering blood to the brain, even though it is not pristinely oxygenated or 100% saturated, is better than delaying compressions to provide breaths to blood that it is probably still adequately oxygenated. In addition, the acidosis of cardiac arrest favorably shifts the oxygen/hemoglobin dissociation curve to unload bound oxygen at the tissue level further. Stopping chest compressions to provide single-rescuer breathing, although previously emphasized and intuitively helpful, is probably an unnecessary intervention for the first few minutes of CPR.
Hands-only/compression-only CPR for the untrained lay rescuer is one of the major changes in the 2010 guidelines. The well known ABC abbreviation for airway, breathing, and cardiac compression has been changed to a different sequence of CAB. Compressions first, followed by Airway and Breathing. This sequence is also predicated on the observation that the most likely cause of the cardiac arrest in an adult is not primary cessation of breathing but cessation of cardiac output. You still have some adequately oxygenated blood waiting to be sent to the brain, so just circulate it.
Along the same lines, the new guidelines deemphasize the importance of prolonged checking for a pulse in an unresponsive patient. Knowing where and how to look for a pulse often leads to a delay in the initiation of chest compressions. The new guidelines state that one should search for a pulse for no longer than 10 seconds before assuming that the individual is pulseless. “Look, listen, and feel” is an axiom of the past, now deemed inconsistent and time-consuming by the AHA. No more “Annie, Annie, Annie, are you OK,” listening for breathing, chin lift, and prolonged attempts to find the carotid artery.
Early defibrillation still enlists the therapy most likely to ameliorate the most common cause of adult cardiac arrest: VF/VT. CPR should be resumed immediately after only a single shock has been delivered. No more stacking of three incremental shocks and checking for a pulse. Just shock once (360 J), and continue compressions. The AHA recommends the use of the newer, supposedly more efficient, biphasic wave defibrillators. Older studies suggesting that CPR for a few minutes prior to shocking will circulate blood and enhance defibrillation are now disproved. Cardiac pacing is no longer recommended for patients with asystolic arrest. Most clinicians who have attempted to pace asystole have met with no success, and it is just another distraction from other interventions. Successful resuscitation from asystole is a rare event indeed, and generally portends death.
There are several changes regarding airway management in the 2010 ACLS guidelines. The use of quantitative waveform capnography for confirmation and monitoring tube placement and adequate ventilation is a Class I recommendation. Capnography is considered the most reliable method of confirming device placement and monitoring adequacy of ventilations. The color-changing end-tidal CO2 devices can be used when capnography is not available. It is my observation that capnography is not universally used in the ED, but I have seen it on the EMS units in Philadelphia, and it has been standard of care in the operating room for some time.
While we are all hellbent on establishing an endotracheal tube during a cardiac arrest, often with multiple time-wasting attempts, the AHA supports the initial use of a variety of supraglottic advanced airway devices, such as the laryngeal mask airway (LMA), and other esophageal tubes (Combitube/King Airway) as alternatives to tracheal intubation during CPR. When properly used, they are as effective as bag/valve/mask or ET tube oxygen delivery.
Philadelphia EMS has switched to the immediate use of the King Airway, a supraglottic device that provides adequate ventilation for prolonged periods. Such devices have been used in the operating room in lieu of endotracheal intubation for years, and there is no reason a difficult intubation needs to be delayed when such devices are effective, readily available, and easily established. Many emergency physicians eschew these devices altogether, and persist with various laryngoscopic attempts at placing an ET tube. The video laryngoscope has revolutionized difficult intubation, and current technology makes it unnecessary to attempt to find the vocal cords with only a battery-drained standard laryngoscope.
As a side note, many physicians also fail to use a bougie to facilitate placement of a difficult ET tube. If you get even a minimal look at the trachea with your laryngoscope, simply pass the bougie (like the omnipresent blue plastic curved tip device) as opposed to attempting to negotiate the airway with a much larger ET tube. All alternatives to ET tube or laryngoscopy require an airway cart or an airway board to be readily available, certainly not an ideal mandate when the patient arrests in radiology or in the hallway.
The time-honored cricoid pressure maneuver during intubation in cardiac arrest is no longer recommended at all. It used to be heresy to intubate without cricoid pressure, and the late Brian Sellick, MD, would probably be quite distressed at having his maneuver branded a dinosaur in search of a tarpit. The AHA believes that cricoid pressure hhreduces effectiveness of ventilations, and interferes with placement of the supraglottic airways or endotracheal tube. Certainly having an assistant provide cricoid manipulation to bring the larynx into view is universally practiced, but one should resist the temptation to apply excessive pressure hoping to avoid aspiration of gastric contents.
A precordial thump, pacing of asystole, and open-chest cardiac massage are not supported by the guidelines, but post-arrest hypothermia is championed. The AHA does not recommend giving tPA routinely in cardiac arrest, but it can be considered if a massive PE is likely. Post-arrest hyperoxygenemia may be harmful, and should be avoided. Most can remember the days of a new CPR device coming on market or a better CPR technique being developed every few months, each with claims of superior physiology and improved outcomes. Such gadgets and tactics include compression and decompression, interposed abdominal compressions, prone CPR, a bevy of mechanical devices and machines, and a smattering of vests and other resuscitation adjuncts. Forget those reports. Defibrillation as soon as possible is still in vogue, but no fancy technique or mechanical CPR device improves long-term outcome after cardiac arrest. Feeling like an uneducated literature-challenged doofus or stretching the capital budget to buy the latest CPR machine can now be eschewed.
It has always been stated that no drug has been shown to improve long-term outcome after cardiac arrest, despite algorithm after algorithm and flow diagram after flow diagram recommending a variety of vasopressors, stimulants, anticholinergics, or pH adjustments. The new guidelines reiterate the concept that while some drugs may be used during CPR, chest compressions and defibrillations save the patient, not the latest pharmaceutical. The few drugs that remain on the ACLS list will be reviewed next month. It does not even appear that IV access is required for the initial stages of CPR, a welcome relief from multiple needlesticks and harried attempts to start a central line to deliver drugs that make no difference anyway.
The new guidelines have added a section on post-cardiac arrest care, emphasizing the importance of a comprehensive multidisciplinary approach following successful resuscitation. Of significant importance, and points often lost on first review of this massive document, are recommendations for official hospital and ED certifications aimed at designating institutions capable of receiving or treating patients after cardiac arrest.
The AHA states that performing and delivering a prehospital 12-lead EKG with advanced notification to the receiving facility is an important advance. If your hospital cannot receive 12-lead EKGs from the field, you may be bypassed by EMS even though you are the closest facility. My analysis of the value of the 12-lead EKG being faxed to the awaiting ED is that while it sounds really cool to have this gadget and it may minimally reduce time to the cath lab, reviews are mixed on specific benefit. It seems absurd to bypass the nearest facility for lacking such technology.
An even greater threat to the small community or struggling inner-city hospital is the guideline suggesting triage of a patient with cardiac arrest only to centers that have the capability of percutaneous coronary intervention and catheterization (PCI). The AHA goes so far as to deem it reasonable to include cardiac catheterization as a standard post-cardiac arrest intervention. Because the EKG may be insensitive or misleading following cardiac arrest, the guidelines take a further step of presuming that an adult cardiac arrest was due to an ischemic cardiac etiology, even in the absence of a clearly defined STEMI. Amazingly, routine PCI following resuscitation from cardiac arrest, even in the comatose patient, is suggested.
If I interpret these guidelines correctly, the following scenario is considered the preferred way to go: Initiate chest compression-only CPR with defibrillation as soon as possible. Continue CPR and ventilation en route to a center that is ready to take your recently dead patient to the cath lab, even though he is comatose, and does not show an acute MI on the 12-lead EKG that has been in the hands of the treating team before the patient arrives. A lot of hospitals in this country will stop receiving patients post-cardiac arrest if these guidelines are implemented or enforced. My administrators are already sweating and palpitating.
For some reason, the AHA deemed it reasonable to include guidelines for stroke care in their erudite treatise for cardiac arrest. With that in mind, they recommend that hospitals be notified of a patient with a possible stroke prior to arrival of EMS (a good idea for sure). Ostensibly, this is to initiate tPA therapy sooner. With a few caveats, the guidelines also recommend adhering to the ECASS-III data recommending the administration of tPA up to 4.5 hours post-stroke onset. The guidelines recommend that every hospital with an ED have a written plan that is communicated to the EMS system describing how patients with a possible acute stroke are to be managed at that institution. With this in mind, the AHA recommends that patients with acute stroke be triaged directly to a hospital that has an official stroke center designation. This is a Class I recommendation.
Patients ineligible for standard IV thrombolytic therapy may be considered for intra-arterial fibrinolysis or mechanical revascularization (both still experimental). I'm not sure how the ACLS guidelines garner stroke recommendations, but clinicians, hospital administrators, and our cardiology and neurology colleagues should be cognizant of potentially gargantuan changes on how and where patients gain ED access. I doubt that many interventional cardiologists will take a comatose cardiac arrest victim to the cath lab in search of a bypass or stentable lesion that has escaped the scrutiny of the 12-lead EKG.
Next month: An analysis of the new drug therapies and special situations addressed in the AHA guidelines.
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Readmissions through ED Climbing
Emergency department patients who have recently been hospitalized are more than twice as likely to be admitted as those who have not recently been in the hospital, according to new research from the Perelman School of Medicine at the University of Pennsylvania.
“Patients who return to the emergency department within seven days of hospitalization have both relatively high and increasing rates of readmission,” said Zachary F. Meisel, MD, an emergency physician and a Robert Wood Johnson Foundation Clinical Scholar at the Hospital of the University of Pennsylvania, who led the study. “These findings are important because they come at a time when there is a great effort underway to reduce hospital readmission rates, and they give us clues about how emergency departments can play a role in that process.”
Looking at data from the National Hospital Ambulatory Medical Care Survey, Dr. Meisel and his colleagues analyzed a sample of about 2.3 million emergency department visits from each year between 2005 and 2008, and found that hospital readmission rates for recently hospitalized patients increased for each year of the study, from 28.6 percent to 38 percent. Admission rates for patients not recently hospitalized increased at a lesser rate, from 15.3 percent to 17.2 percent. These findings do not appear to be driven by differences in age or the system of triaging sick or injured patients who seek help in the emergency room.
The findings suggest rich possibilities for future research, Dr. Meisel said. “These results tell us that most patients who come to an emergency department after a hospitalization are not being readmitted. This means that the emergency department plays a major role in preventing readmissions by taking care of these patients and sending them home,” he said. “However, because admission decisions are often made in the emergency department, we need to better understand why recently discharged patients are more likely to be admitted to the hospital than people who have not recently been in the hospital. For example, are they being treated extra cautiously? Is there a sense on the part of emergency physicians that their inpatient physicians know these patients better and can take better care of them in the hospital?”
The data also have policy implications, the researchers suggested, for better defining the role of emergency departments in determining the disposition of recently hospitalized patients. Hospitals might, for instance, identify ways to intervene at the time of discharge to reduce emergency department use in the coming days and weeks, or improve the capacity of their emergency departments to safely discharge the patients.
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