The Abcs Of Cpr

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HOURS

Continuing Education

A review of the latest changes to the American Heart Association’s cardiopulmonary resuscitation and emergency cardiovascular care guidelines.

Overview: Survival rates for cardiac arrests that occur in hospitals and outside them continue to be low (17% and 6%, respectively), and fewer than one-third of patients who have an out-of-hospital cardiac arrest receive cardiopulmonary resuscitation (CPR). Consequently, a number of changes were made to the 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. The changes were intended to simplify CPR in order to increase its use and effectiveness by both clinicians and nonprofessionals. This article summarizes the primary changes to the recommendations, including a universal 30-to-2 compression-to-ventilation ratio for all lone rescuers, the need for compressions of sufficient depth and number, and the replacement of the three-shock model of initial defibrillation with one that recommends a single shock, now seen as an adequate precursor to CPR.

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hy do they keep updating these guidelines? Didn’t they make changes just last year?” It does seem so. In 2005 the American Heart Association (AHA) published another version of its Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care,1 but it had been five years since the last published revisions. The AHA first established guidelines for cardiopulmonary resuscitation (CPR) in 1974 and has revised them five times since, in 1980, 1986, 1992, 2000, and 2005. The 2005 guidelines cover all aspects of emergency cardiac care; at the same time, they represent an attempt to simplify CPR procedures so that more health care professionals and lay rescuers might learn them and perform them correctly. (The complete guidelines are available online at http://circ.ahajournals.org/content/vol112/24_suppl.) Much is at stake. Despite decades of efforts to promote CPR, the survival rate for out-of-hospital cardiac arrest remains low worldwide, averaging 6% or less.2, 3 In the United States, sudden cardiac arrest is a leading cause of death,4-6 resulting in an estimated 330,000 out-of-hospital Linda Mutchner is an infusion nurse at Frederick Memorial Hospital in Frederick, MD. She also is a coowner of Core Training Consultants, Taneytown, MD, which offers courses in cardiopulmonary resuscitation, first aid, infusion, and chemotherapy. Contact author: [email protected]. The author of this article has no significant ties, financial or otherwise, to any company that might have an interest in the publication of this educational activity. Much of this article is adapted from the 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care, published in the December 13, 2005, Circulation supplement: Circulation 2005 Dec 13;112(24 Suppl):IV1-203.

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http://www.nursingcenter.com

By Linda Mutchner, BSN, RN, CRNI, OCN

deaths annually.7 Ventricular fibrillation plays a role in most cases of sudden cardiac arrest,3, 5, 8 and defibrillation in the first five minutes after collapse greatly increases the chances of survival.9 Too often, however, the time to defibrillation exceeds five minutes.2 Casinos, airlines, airports, and police forces that have “first-responder programs” involving the use of automated external defibrillators (AEDs) show survival rates to hospital discharge of 49% to 80%,10-13 but survival rates decrease 7% to 10% for each minute between collapse and defibrillation when CPR is not provided.14 When initiated as soon as possible after a patient’s collapse, CPR performed correctly and followed by defibrillation is a central aspect of the “chain of survival” for those who have a sudden cardiac arrest.15 Fewer than one-third of patients who have an out-of-hospital cardiac arrest receive CPR,15, 16 suggesting a need for better and more widespread training of nonprofessionals. And hospital nurses and physicians do not always perform CPR effectively.17, 18 The new AHA guidelines warn clinicians against hyperventilating patients (providing too many breaths at too great a tidal volume), interrupting compressions too often or for too long, and compressing the chest too slowly and too shallowly, with a resulting drop in coronary perfusion. At the same time, advanced interventions such as endotracheal intubation don’t make a significant difference in survival rates; according to one multisite, observational study, only 17% of patients who experience in-hospital cardiac arrest survive to discharge.19 INTERNATIONAL CONSENSUS The 2000 AHA guidelines resulted from a process begun in 1993, when the International Liaison [email protected]

Committee on Resuscitation (ILCOR) was formed to identify, review, and reconcile international research and practice related to CPR and emergency cardiovascular care. ILCOR’s founding member organizations were the AHA, the European Resuscitation Council, the Heart and Stroke Foundation of Canada, the Resuscitation Council of Southern Africa, and the Australian Resuscitation Council, later joined by the Consejo Latino-Americano de Resuscitación and the New Zealand Resuscitation Council. Since 1993 representatives from the ILCOR member councils have been evaluating research findings and working toward developing resuscitation guidelines, meeting 22 times. The AHA hosted the first ILCOR conference in 1999, recommendations from which were published in 2000.20 Researchers from the ILCOR member councils continued to evaluate research findings, in a process that culminated in the 2005 International Consensus Conference on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations (hereafter referred to as the 2005 consensus conference). The conferees undertook the most extensive review to date of international scientific evidence on CPR, using a carefully structured process of ongoing disclosure and management of potential conflicts of interest. They paid particular attention to streamlining the guidelines in order to reduce the amount of information that rescuers need to remember and to clarifying the fundamental tasks that rescuers should perform. More than 280 international experts were divided into six task forces, on basic life support, advanced life support, acute coronary syndromes, pediatric life support, neonatal life support, and overlapping topics such as education. (Additional AJN ▼ January 2007

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task forces—separate from the ILCOR process, although findings are summarized in the guidelines—were created to consider stroke and first-aid.) The task forces proposed hypotheses; one or two international experts were appointed to review research on each topic, determine levels of evidence, and develop a draft of recommendations for treatment. At the 2005 consensus conference such a draft was discussed, with a special focus on the quality of evidence and issues of financial disclosure and conflict of interest. The wording was refined, and prior to publication, the final document was approved by all ILCOR members and by an international editorial board. While universally applicable international guidelines may not be an achievable short-term goal— because of regional differences in health care and contradictory or weak evidence available on some topics—many treatment recommendations have been agreed upon and simplified in ways that should make the training of professionals and nonprofessionals more efficient and the delivery of CPR more effective. What follows is a look at changes in the guidelines as well as the scientific reasoning behind them. ADULT BASIC LIFE SUPPORT Major recommendations in the 2005 AHA guidelines were assigned to “classes” meant to reflect the level of current evidence found to support them and the weight they should be given in practice, with the caveat that much of the evidence we have currently is derived not from clinical trials but from nonrandomized or retrospective trials or from animal models. These are as follows (and appear throughout the text to indicate the strength of particular recommendations): • Class I: the benefit clearly outweighs the risk; the procedure, treatment, or assessment should be performed. • Class IIa: the benefit is likely to outweigh the risk. It’s reasonable to follow the recommendation. • Class IIb: the benefit is greater than or equal to the risk. Following the recommendation may be considered. • Class III: the risk is greater than or equal to the benefit. The procedure, treatment, or assessment is not helpful, may be harmful, and should not be performed. • Class indeterminate: research has not begun or is ongoing. No recommendations can be made at this time. Recommendations were also distinguished according to whether they were meant for health care providers, for lay rescuers, or for both. The following is a summary of changes in the guidelines for adult basic life support. 62

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Recognition and “activation”: avoid delays. Early recognition of sudden cardiac arrest is the key to increasing the chances of survival. For lay rescuers, checking the carotid pulse is an inaccurate method of confirming the presence or absence of circulation; according to research, they fail to recognize the absence of a pulse in 10% of pulseless victims (poor sensitivity) and fail to detect a pulse in 40% of victims with a pulse (poor specificity).20 Health care providers also often take too long in checking for a pulse and inaccurately assess its presence or absence.21, 22 There is no evidence that checking for movement, breathing, or coughing is any more reliable than checking for a pulse as a method of recognizing the signs of circulation. Taking too much time to check for a pulse delays the rescuer’s initiation of chest compressions (class IIb). Agonal respiration is common in the early stages of cardiac arrest and can mislead a rescuer into thinking that CPR isn’t required. Recommendations • If the person is unconscious (unresponsive), not moving, and not breathing (or has agonal breathing), lay rescuers shouldn’t check for pulse; they should dial 911, obtain an AED if one is available, perform CPR for two minutes (or approximately five cycles, with one cycle defined as 30 compressions and two ventilations), and then use an AED if they are trained to use one. (There are two types of AEDs—those sold before 2003 tend to be monophasic, delivering just one shock at a time, while the newer biphasic models deliver a dual shock of lower energy.) If an AED is not available, lay rescuers should continue CPR without interruption until emergency help arrives. • Clinicians should check for the absence of normal, adequate breathing and pulse (taking no more than 10 seconds to do so) before beginning CPR (class IIa). • Clinicians should adapt the sequence of rescue actions to the probable cause of arrest. If a lone health care provider sees someone collapse suddenly, the arrest is likely to be cardiac in origin and the provider should dial 911, obtain and use an AED (class I), and then provide CPR for two minutes (five cycles) before rechecking the rhythm. If an AED is not available, she or he should continue CPR until emergency medical services arrive. • If the lone health care provider did not witness the person’s collapse, she or he should perform CPR for two minutes and then use an AED, if available (class IIb). If the provider aids a victim of likely asphyxial (usually respiratory) arrest of any age, she or he should give five cycles of CPR before leaving the victim to dial 911 (class IIa). Airway: keep it simple. Maintaining the airway and providing adequate ventilation are crucial durhttp://www.nursingcenter.com

Table 1. Summary of Basic Life Support ABCD Maneuvers for Infants, Children, and Adults MANEUVER

(Maneuvers performed only by health care providers are indicated by “HCP”)

ADULT

(For lay rescuers, adults are defined as those 8 years of age or older; for HCPs, adolescent or older)

CHILD

INFANT

(For lay rescuers, children are those 1–8 years of age; for HCPs, 1 year to adolescent)

(For all rescuers, infants are defined as those under 1 year of age)

Activate (Call) emergency response number (lone rescuer)

Call when victim is found unCall after performing 5 cycles of CPR responsive HCP: if asphyxial arrest is likely, call For sudden, witnessed collapse, call after verifying after 5 cycles (2 minutes) of CPR that victim is unresponsive

AIRWAY

Head tilt–chin lift (HCP: if trauma suspected, use jaw thrust)

BREATHS

2 effective breaths at 1 second per breath

10 to 12 breaths per minute HCP: rescue breathing without chest compressions (1 breath every 5 to 6 seconds)

2 effective breaths at 1 second per breath 12 to 20 breaths per minute (1 breath every 3 to 5 seconds)

HCP: rescue breathing for 8 to 10 breaths per minute (1 breath every 6 to 8 seconds) CPR with advanced airway Foreign-body airway obstruction

Abdominal thrusts

Back slaps and chest thrusts

CIRCULATION HCP: pulse check (10 seconds or less)

Carotid artery (HCP can use femoral artery in child)

Brachial or femoral artery

Compression landmarks

Center of chest, between nipples

Just below nipple line

Compression method:

2 hands: heel of 1 hand, other hand on top

2 hands: heel of 1 hand with second on top or 1 hand: heel of 1 hand only

Compression depth

11/2 to 2 inches

Approximately 1/3 to 1/2 the depth of the chest

Compression rate

Approximately 100 per minute

Compression-to-ventilation ratio

30 to 2 (1 or 2 rescuers)

• push hard and fast • allow complete recoil

1 rescuer: 2 fingers HCP, 2 rescuers: 2thumb–encircling-hands technique

30 to 2 (single rescuer) HCP: 15 to 2 (2 rescuers)

DEFIBRILLATION Automatic external defibril- Use adult pads. Do not use child lator (AED) pads or a child system. HCP: for out-of-hospital response, you may provide 5 cycles (2 minutes) of CPR before shock if response time is longer than 4 to 5 minutes and arrest was not witnessed.

No recommendation for HCP: use AED as soon as possible for sudden and in- infants less than 1 year hospital collapse. All: after 5 cycles of CPR (out of hospital). Use child pads and system for child 1 to 8 years old if available. If child pads and system are not available, use adult AED and pads.

Note: information appropriate for use in newborns is not included. Used with permission from American Heart Association. Currents in Emergency Cardiovascular Care 2005–2006;16(4)15. [email protected]

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ing CPR (class I). The best method of opening an airway is the head tilt–chin lift maneuver (class IIa). The rescuer should reposition the head if the first ventilation does not cause the chest to rise. All such repositionings cause spinal movement, and studies in cadavers have shown that chin lifts (with or without head tilts) and jaw thrusts cause substantial movement of the cervical vertebrae,23 but no studies have evaluated the effects of these movements on people with suspected spinal injuries. When spinal injury is suspected, manual spinal motion restriction should be employed while the jaw thrust maneuver is used to open the airway. This is safer than using immobilization devices, which may interfere with the airway during CPR (class IIb). Recommendations • Lay rescuers should be taught only the head tilt–chin lift technique for both injured and uninjured people (class IIa). (The jaw thrust maneuver is considered too difficult for nonprofessionals to learn and perform.) • Clinicians should use the jaw thrust maneuver if injury to the cervical spine is suspected (class IIb); if that does not open the airway, the head tilt–chin lift technique should be used. If two health care professionals are present, one can manually stabilize the head and neck while the other performs CPR. Ventilation: practice moderation. After cardiac arrest with ventricular fibrillation, diminished cardiac output causes myocardial and cerebral ischemia, but the blood oxygen level remains high for the first several minutes. Therefore, administering breaths is not at first as important as administering chest compressions. During CPR, blood flow to the lungs is reduced to 25% to 35%, and achieving adequate oxygenation requires a lower tidal volume and fewer ventilations.24 Hyperventilation is unnecessary and even harmful; it increases intrathoracic pressure, decreases venous return to the heart, and diminishes cardiac output. Hyperventilation can also cause gastric distention leading to regurgitation and aspiration and can elevate the diaphragm, restricting lung movement and elasticity. It may, however, be necessary to provide high pressures to ventilate patients with an obstructed airway or poor lung compliance. Recommendations • Two rescue breaths, one second each (class IIa), should be given with enough volume to see the chest rise (class IIa). • Rapid or forceful breaths should be avoided. • For a victim with a pulse, 10 to 12 breaths per minute (one breath every five to six seconds) should be given; more can be dangerous (class IIa). 64

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Chest compressions: “push hard, push fast.” Effective chest compressions are essential (class I). The new guidelines strongly emphasize that compressions should be given at a rate of about 100 per minute, with a depth of 1.5 to 2 in., over the lower half of the sternum, allowing the chest to completely recoil (equal compression and relaxation time). (The guidelines state that the “compression rate refers to the speed of compressions, not the actual number of compressions.”) Studies have suggested that in almost 40% of cases, in-hospital chest compressions may be too shallow.17 Incomplete recoil of the chest and inadequate depth and rate of compressions may result from rescuer fatigue.25 Incomplete recoil is also associated with higher intrathoracic pressure, decreased coronary perfusion, and decreased cerebral perfusion.26 When chest compression is 20% to 50% of the total combined chest compression and relaxation time, coronary and cerebral perfusion increases, as shown in animal studies.27, 28 Studies involving clinicians performing CPR show that chest compressions may not be provided for as much as half of the total arrest time.17, 18, 29 In animal studies, interrupted chest compressions were associated with reduced coronary artery perfusion pressure, reduced return of spontaneous circulation, reduced survival rates, and reduced postresuscitation myocardial function.30-32 Recommendations • Chest compressions should be performed at a rate of 100 per minute, over the lower half of the sternum, at a depth of 1.5 to 2 in. (class IIa). • Complete recoil of the chest should be allowed between compressions; a duty cycle of 50% (that is, equal time given to chest compression and relaxation) is recommended because it is easy to achieve with practice.33 • CPR should be interrupted as infrequently as possible; interruptions should last no longer than 10 seconds, except for the performance of interventions such as defibrillation (class IIa). • Lay rescuers should be instructed not to stop CPR to check for signs of circulation. Compression and ventilation: a new ratio. Animal studies and theoretical calculations have been used to determine the compression-to-ventilation ratio most likely to increase the number of compressions given, reduce the likelihood of hyperventilation, minimize interruptions, and simplify instruction.34, 35 While more study is needed, a consensus has been reached in the current guidelines that a 30-to-2 ratio best meets these criteria. This ratio is, however, demanding to maintain; although rescuers may deny fatigue for up to five minutes of performing CPR, after one minute they often give compressions that are too shallow.25 http://www.nursingcenter.com

Recommendations • All rescuers should use acompression-to-ventilation ratio of 30 to 2—that is, giving 30 compressions for every two ventilations (class IIa). • During two-person CPR, compressions should be paused briefly to provide ventilations; in mechanically ventilated patients, eight to 10 ventilations per minute (one every six to eight seconds) should be given without a pause in compressions (class IIa). • When two rescuers are present, compressors should change every two minutes, switching in less than five seconds, if possible (class IIb). • Lay rescuers should be instructed to use only compressions if they are not willing or able to deliver rescue breaths (class IIa). DEFIBRILLATION: ADULTS Immediate defibrillation is the first and best response to witnessed cardiac arrest with a short time to intervention (class I). In cases of sudden cardiac arrest with prolonged ventricular fibrillation, survival rates are highest when CPR is provided immediately and defibrillation begins within three to five minutes.10, 14, 15, 36 Chest compressions generate a small but critical amount of blood flow and consequently oxygen to the brain and myocardium. Two studies found that when emergency providers’ time to arrival was four or five minutes or longer, victims who received one and a half to three minutes of CPR before defibrillation had increased rates of initial resuscitation, survival to hospital discharge, and one-year survival than did those who received immediate defibrillation.37, 38 But one randomized trial found no improvement in outcomes when 90 seconds of CPR was performed before defibrillation in patients with ventricular fibrillation or tachycardia.39 When ventricular fibrillation is present for several minutes, the heart consumes most of the oxygen and electrolytes it needs to contract effectively. Even if a shock does terminate ventricular fibrillation, the heart probably won’t pump effectively for several minutes because of the inadequate oxygen supply. Data obtained from a Seattle first-responder team equipped with AEDs showed survival rates actually decreased as a result of a focus on initiating defibrillation instead of CPR.37 A period of CPR before shock delivery will provide some oxygen to cardiac muscle, thus making a shock more likely to convert it to a normal rhythm. At the time of the consensus conference there had been no studies comparing a one-shock protocol with a protocol of three stacked shocks. Animal studies, however, strongly suggest that interruptions in the administration of compressions are associated with a decreased probability that ventricular [email protected]

tion will convert.31, 40 Analysis of AED data shows that a three-shock sequence delays delivery of chest compressions by up to 37 seconds (from delivery of the first shock to administration of the first postshock compression).32 This delay was found difficult to justify in light of the fact that the first shock using either biphasic or monophasic defibrillators has been found to convert ventricular fibrillation more than 90% of the time.41, 42 If one shock fails to eliminate ventricular fibrillation, the incremental benefits of another shock are low and resuming CPR is likely to lead to greater efficacy from subsequent shocks because it will provide needed oxygen to the heart. Recommendations • Clinicians should ensure an efficient coordination between CPR and defibrillation (class IIa). • For witnessed out-of-hospital cardiac arrest, the clinician and trained rescuer should use the AED as soon as it is available, giving just one shock followed by five cycles of CPR (class IIb). • When ventricular fibrillation is present and the arrest is unwitnessed, the lone rescuer should give five cycles of CPR, deliver just one shock, and then immediately resume CPR, beginning with chest compressions (class IIa). There should be no delays or interruptions to check for pulse or rhythm. • When two rescuers are on hand, the rescuer operating the AED should be prepared to deliver a first shock as soon as the compressor removes her or his hands and the “all clear” is given. When possible, the compressor should continue with chest compressions while the other rescuer is attaching the AED. After five cycles of CPR, the AED should be used to analyze the rhythm and deliver another shock, if indicated (class IIb). • If the AED detects a rhythm other than ventricular fibrillation, it may instruct the rescuer to resume CPR immediately, beginning with chest compressions (class IIb), although some AEDs may only instruct the rescuer to reassess the victim and determine whether CPR is needed. Concerns that chest compressions might provoke recurrent ventricular fibrillation in the presence of a postshock organized rhythm do not appear to have a basis.43 FOREIGN-BODY AIRWAY OBSTRUCTION: ADULTS Early recognition of foreign-body airway obstruction is crucial. Signs of severe airway obstruction, such as difficulty breathing, silent cough, cyanosis, or the inability to speak, should prompt an immediate response. The use of back slaps, abdominal thrusts, and chest thrusts are all effective ways of relieving an obstruction, but about half of obstructions aren’t relieved by a single technique.44 A comAJN ▼ January 2007

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bination of back slaps, abdominal thrusts, and chest thrusts increases the chances of success.44 In cases of foreign-body airway obstruction, CPR should be performed when the person is unconscious. Studies of cadavers and anesthetized volunteers show that higher sustained airway pressures can be generated using chest thrusts instead of abdominal thrusts.45, 46

Initiating cardiopulmonary resuscitation before dialing 911 remains the best approach to responding to an unresponsive child. Recommendations • For simplification of training, a rapid sequence of abdominal thrusts is advised for the conscious victim of foreign-body airway obstruction until the obstruction is relieved (except for infants under one year of age) (class IIb). • Chest thrusts should be used for obese victims or those in the late stages of pregnancy (class IIb). • If the victim is unconscious, the rescuer should first dial 911 and then begin CPR (using the 30-to-2 compression-to-ventilation ratio), having looked for and removed the object (only if it is clearly visible) before ventilation (class indeterminate). CPR should not be interrupted to search the airway for a foreign body. PEDIATRIC BASIC LIFE SUPPORT Recognition. Because hypoxia–ischemia resulting from asphyxia is the most common cause of cardiac arrest in infants and children—and ventricular fibrillation is the cause in just 5% to 15% of pediatric cases47, 48—the rescuer’s actions should be determined by the cause of the arrest, not the age of the victim. Initiating CPR before dialing 911 remains the best approach to responding to an unresponsive child. Recommendations • All rescuers should respond according to the cause of the arrest. In children whose collapse is unwitnessed or not sudden, CPR should be initiated immediately and performed for five cycles before 911 is dialed. In the case of a witnessed, sudden collapse—for example, during an athletic event— the cause is likely to be ventricular fibrillation and the rescuer should phone for help, get and use the AED (if trained to do so), and begin CPR. Airway. No new evidence was obtained to merit changes to the recommendation for pediatric air66

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way management (other than those made for adults). Several points, however, were emphasized. Rescuers who have difficulty obtaining an adequate seal over an infant’s mouth and nose should provide mouth-to-mouth ventilations while pinching the nose closed. Adequate ventilation remains the priority, even when spinal injury is suspected. The health care provider should use the jaw thrust maneuver, as with the adult victim, if adequate ventilations can be achieved. If not, the head tilt–chin lift technique should be used. Nonprofessionals should use the head tilt–chin lift technique only. Ventilation. There are no recommended changes to the 2000 guidelines concerning ventilation techniques. The 2005 guidelines do note, however, that when rescuers are using a mask system, they should make sure the mask size is appropriate to the infant or child; ensuring a tight seal can take time away from CPR and requires training and periodic retraining. Hyperventilation should be avoided with the infant and child as it is with the adult. Recommendations • Two rescue breaths of one second each should be given (class IIa), with enough volume to see the chest rise (class IIa). Rapid or forceful breaths should be avoided. • Rescuers should deliver 12 to 20 rescue breaths per minute (one breath every three to five seconds) when the victim has a pulse greater than or equal to 60 beats per minute (only professionals should attempt to palpate the pulse) and signs of adequate perfusion, such as improved color or warmness to the touch (class IIa). Chest compressions. Profound bradycardia (heart rate lower than 60 beats per minute) in the presence of poor perfusion (pallor or cyanosis) indicates that cardiac arrest may soon follow; chest compressions should begin immediately. A heart rate at which chest compressions should be initiated in children hasn’t been identified; the guidelines recommend starting compressions at a rate of fewer than 60 beats per minute with signs of poor perfusion because it’s easy to teach and remember. Infants. The two-thumb–encircling-hands technique—performed by encircling the infant’s chest with both hands, spreading the fingers around the thorax, and placing the thumbs over the lower half of the sternum—is recommended for health care providers when two rescuers are present. The thumbs compress the sternum; the fingers provide counterpressure on the infant’s back (class IIa). Studies using animals and mechanical models show that the two-thumb–encircling-hands technique produces higher coronary perfusion pressures and more consistently correct depth and force of compressions than the two-finger technique does.49-52 Lay http://www.nursingcenter.com

rescuers or a lone rescuer should use the two-finger technique, placing the fingers just below the intermammary line (since it’s impossible to encircle the infant’s chest, compress the chest with two fingers, and provide ventilations at the recommended rate). Children. No new data show the superiority of the one-hand over the two-hand compression technique (class indeterminate). Most important are that the depth of compressions be about one-third to one-half the depth of the chest and that there be complete recoil and minimal interruptions, as with adults. Recommendations • The two-finger technique is considered best for the lone rescuer to decrease the time between compressions and ventilations and to minimize interruptions in compressions. The two-thumb– encircling-hands technique should be used when there are two rescuers. • Both the one-hand and two-hand techniques for chest compressions in children are acceptable; rescuers can be taught the same technique (twohand) for both the adult and child victims. • As with the adult, compressions should be performed at a rate of 100 per minute for both the infant and the child, to a depth of one-third to one-half of the chest. Complete chest recoil should be allowed, with equal time for compression and release. Compression-to-ventilation ratio. In a study using pediatric manikins, “rescuers” were told to adhere to a compression-to-ventilation ratio of 5 to 1 and a compression rate of 100 per minute; however fewer than 60 compressions per minute were performed, although these were ideal circumstances.53 Interruptions in compressions for ventilation and attachment of the AED can result in a significant decrease in cardiac-perfusion pressure.40 Animal studies, manikin studies, and mathematical models have examined various ratios (15 to 2, 5 to 1, and others) and failed to provide adequate data to identify an optimal compression-to-ventilation ratio for infants and children.34, 40, 54 Recommendations • Lone rescuers should use a compression-toventilation ratio of 30 to 2 for all age groups. • When health care providers are rescuing, they should use a compression-to-ventilation ratio of 15 to 2. • Interruptions in CPR should be as infrequent as possible and limited to no longer than 10 seconds, except for specific interventions such as intubation. • When two rescuers are present, compressors should switch every two minutes, doing so in less than five seconds, if possible. When there is no advanced airway, a short pause must be taken to [email protected]

allow for ventilations. For patients with an advanced airway such as an endotracheal tube, eight to 10 ventilations should be given per minute, without attempting to synchronize with compressions. DEFIBRILLATION: CHILDREN AND INFANTS Children whose sudden collapse is witnessed (as can occur during an athletic event) are likely to have ventricular fibrillation or pulseless ventricular tachycardia and require immediate CPR and defibrillation. Institutions that care for children and have an AED program should have an AED capable of recognizing shockable rhythms in children and a pediatric “doseattenuating system”—a feature that automatically adjusts the dose the device delivers. Data show that AEDs can be used safely and effectively in children one to eight years of age.55-57 If an AED with a pediatric dose-attenuating system is not available in an emergency, a standard AED should be used. A standard adult AED should be used for children older than age eight and for those weighing more than 25 kg (55 lbs.). Standard AEDs may also come equipped with adult and pediatric pads and cables or contain a key or switch system for selecting a lower dose. As with adults, there’s insufficient evidence to support a one-shock protocol over a three-stackedshocks protocol for children; however, one shock is recommended. Recommendations • When rescuers witness the sudden collapse of a child, they should dial 911, get and use an AED if trained to do so, and then perform CPR if needed. • For the unwitnessed collapse of a child, the rescuer should perform five cycles of CPR, then dial 911 and obtain an AED, if available. • There is insufficient evidence to make a recommendation for or against using any AED in infants less than one year of age (class indeterminate).55, 56 • Coordination between CPR and defibrillation is important to reduce interruptions, and CPR should be resumed immediately after defibrillation without checking for pulse. FOREIGN-BODY AIRWAY OBSTRUCTION: CHILDREN AND INFANTS No new recommendations have been made for the management of foreign-body airway obstruction in the child and infant. For the child, abdominal thrusts should be performed until the object is removed or the victim becomes unconscious. For the infant, administer five back slaps and five chest thrusts until the object is removed or the victim becomes unconscious. When the infant becomes AJN ▼ January 2007

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unconscious, initiate CPR at a ratio of 30 to 2 when the rescuer is alone and 15 to 2 if two health care professionals are present; look for the object and remove it if it can be seen prior to ventilation. Do not interrupt CPR to check for the object. FUTURE DIRECTIONS Continuous quality improvement is one way of monitoring the quality of CPR delivered and of tracking outcomes up to hospital discharge. In an effort to compile more accurate statistics on outcomes, the Centers for Disease Control and Prevention has begun collecting data that include survival to hospital discharge and whether or not the patient is mentally intact. Defibrillators equipped to collect data on compression rate, depth of compression, and ventilation rate will help to improve outcomes of cardiac arrest. The science of resuscitation is evolving rapidly and it would not be in patients’ best interest for providers to wait another five years to make changes to their practice. ILCOR members will continue to review new research and, when necessary, publish interim advisory statements to update the guidelines. ▼ REFERENCES 1. 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 2005;112(24 Suppl):IV1-203. 2. Nichol G, et al. A cumulative meta-analysis of the effectiveness of defibrillator-capable emergency medical services for victims of out-of-hospital cardiac arrest. Ann Emerg Med 1999;34(4 Pt 1):517-25. 3. Rea TD, et al. Incidence of EMS-treated out-of-hospital cardiac arrest in the United States. Resuscitation 2004;63(1):17-24. 4. Chugh SS, et al. Current burden of sudden cardiac death: multiple source surveillance versus retrospective death certificate-based review in a large U.S. community. J Am Coll Cardiol 2004;44(6):1268-75. 5. Vaillancourt C, Stiell IG. Cardiac arrest care and emergency medical services in Canada. Can J Cardiol 2004;20(11):1081-90. 6. Zheng ZJ, et al. Sudden cardiac death in the United States, 1989 to 1998. Circulation 2001;104(18):2158-63. 7. American Heart Association. Sudden cardiac death. 2006. http://www.americanheart.org/presenter.jhtml?identifier=14. 8. Cobb LA, et al. Changing incidence of out-of-hospital ventricular fibrillation, 1980-2000. JAMA 2002;288(23):3008-13. 9. Weisfeldt ML, Becker LB. Resuscitation after cardiac arrest: a 3-phase time-sensitive model. JAMA 2002;288(23):3035-8. 10. Caffrey SL, et al. Public use of automated external defibrillators. N Engl J Med 2002;347(16):1242-7. 11. O’Rourke MF, et al. An airline cardiac arrest program. Circulation 1997;96(9):2849-53. 12. Valenzuela TD, et al. Outcomes of rapid defibrillation by security officers after cardiac arrest in casinos. N Engl J Med 2000;343(17):1206-9. 13. White RD, et al. Evolution of a community-wide early defibrillation programme experience over 13 years using police/fire personnel and paramedics as responders. Resuscitation 2005;65(3):279-83. 14. Larsen MP, et al. Predicting survival from out-of-hospital cardiac arrest: a graphic model. Ann Emerg Med 1993; 22(11):1652-8.

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15. Valenzuela TD, et al. Estimating effectiveness of cardiac arrest interventions: a logistic regression survival model. Circulation 1997;96(10):3308-13. 16. Gallagher EJ, et al. Effectiveness of bystander cardiopulmonary resuscitation and survival following out-of-hospital cardiac arrest. JAMA 1995;274(24):1922-5. 17. Abella BS, et al. Quality of cardiopulmonary resuscitation during in-hospital cardiac arrest. JAMA 2005;293(3):30510. 18. Abella BS, et al. Chest compression rates during cardiopulmonary resuscitation are suboptimal: a prospective study during in-hospital cardiac arrest. Circulation 2005;111(4): 428-34. 19. Peberdy MA, et al. Cardiopulmonary resuscitation of adults in the hospital: a report of 14720 cardiac arrests from the National Registry of Cardiopulmonary Resuscitation. Resuscitation 2003;58(3):297-308. 20. American Heart Association, International Liaison Committee on Resuscitation. Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Part 3: adult basic life support. Circulation 2000;102(8 Suppl): I22-59. 21. Eberle B, et al. Checking the carotid pulse check: diagnostic accuracy of first responders in patients with and without a pulse. Resuscitation 1996;33(2):107-16. 22. Moule P. Checking the carotid pulse: diagnostic accuracy in students of the healthcare professions. Resuscitation 2000; 44(3):195-201. 23. Hauswald M, et al. Cervical spine movement during airway management: cinefluoroscopic appraisal in human cadavers. Am J Emerg Med 1991;9(6):535-8. 24. Baskett P, et al. Tidal volumes which are perceived to be adequate for resuscitation. Resuscitation 1996;31(3):231-4. 25. Greingor JL. Quality of cardiac massage with ratio compression-ventilation 5/1 and 15/2. Resuscitation 2002; 55(3):263-7. 26. Yannopoulos D, et al. Effects of incomplete chest wall decompression during cardiopulmonary resuscitation on coronary and cerebral perfusion pressures in a porcine model of cardiac arrest. Resuscitation 2005;64(3):363-72. 27. Halperin HR, et al. Determinants of blood flow to vital organs during cardiopulmonary resuscitation in dogs. Circulation 1986;73(3):539-50. 28. Feneley MP, et al. Influence of compression rate on initial success of resuscitation and 24 hour survival after prolonged manual cardiopulmonary resuscitation in dogs. Circulation 1988;77(1):240-50. 29. Wik L, et al. Quality of cardiopulmonary resuscitation during out-of-hospital cardiac arrest. JAMA 2005;293(3):299304. 30. Berg RA, et al. Chest compressions and basic life supportdefibrillation. Ann Emerg Med 2001;37(4 Suppl):S26-35. 31. Kern KB, et al. Importance of continuous chest compressions during cardiopulmonary resuscitation: improved outcome during a simulated single lay-rescuer scenario. Circulation 2002;105(5):645-9. 32. Yu T, et al. Adverse outcomes of interrupted precordial compression during automated defibrillation. Circulation 2002;106(3):368-72. 33. Handley AJ, Handley JA. The relationship between rate of chest compression and compression:relaxation ratio. Resuscitation 1995;30(3):237-41. 34. Dorph E, et al. Quality of CPR with three different ventilation:compression ratios. Resuscitation 2003;58(2):193-201. 35. Sanders AB, et al. Survival and neurologic outcome after cardiopulmonary resuscitation with four different chest compression-ventilation ratios. Ann Emerg Med 2002; 40(6):553-62. 36. Holmberg M, et al. Survival after cardiac arrest outside hospital in Sweden. Swedish Cardiac Arrest Registry. Resuscitation 1998;36(1):29-36. http://www.nursingcenter.com

37. Cobb LA, et al. Influence of cardiopulmonary resuscitation prior to defibrillation in patients with out-of-hospital ventricular fibrillation. JAMA 1999;281(13):1182-8. 38. Wik L, et al. Delaying defibrillation to give basic cardiopulmonary resuscitation to patients with out-of-hospital ventricular fibrillation: a randomized trial. JAMA 2003;289(11): 1389-95. 39. Jacobs IG, et al. CPR before defibrillation in out-of-hospital cardiac arrest: a randomized trial. Emerg Med Australas 2005;17(1):39-45. 40. Berg RA, et al. Adverse hemodynamic effects of interrupting chest compressions for rescue breathing during cardiopulmonary resuscitation for ventricular fibrillation cardiac arrest. Circulation 2001;104(20):2465-70. 41. Bain AC, et al. Multicenter study of principles-based waveforms for external defibrillation. Ann Emerg Med 2001; 37(1):5-12. 42. Mittal S, et al. Comparison of a novel rectilinear biphasic waveform with a damped sine wave monophasic waveform for transthoracic ventricular defibrillation. ZOLL Investigators. J Am Coll Cardiol 1999;34(5):1595-601. 43. Hess EP, White RD. Ventricular fibrillation is not provoked by chest compression during post-shock organized rhythms in out-of-hospital cardiac arrest. Resuscitation 2005;66(1):7-11. 44. Redding JS. The choking controversy: critique of evidence on the Heimlich maneuver. Crit Care Med 1979;7(10): 475-9. 45. Ruben H, MacNaughton FI. The treatment of food-choking. Practitioner 1978;221(1325):725-9. 46. Guildner CW, et al. Airway obstructed by foreign material: the Heimlich maneuver. JACEP 1976;5(9):675-7. 47. Hickey RW, et al. Pediatric patients requiring CPR in the prehospital setting. Ann Emerg Med 1995;25(4):495-501. 48. Appleton GO, et al. CPR and the single rescuer: at what age should you “call first” rather than “call fast”? Ann Emerg Med 1995;25(4):492-4. 49. Dorfsman ML, et al. Two-thumb vs. two-finger chest compression in an infant model of prolonged cardiopulmonary resuscitation. Acad Emerg Med 2000;7(10):1077-82. 50. Houri PK, et al. A randomized, controlled trial of twothumb vs two-finger chest compression in a swine infant model of cardiac arrest. Prehosp Emerg Care 1997;1(2): 65-7. 51. Menegazzi JJ, et al. Two-thumb versus two-finger chest compression during CRP in a swine infant model of cardiac arrest. Ann Emerg Med 1993;22(2):240-3. 52. Whitelaw CC, et al. Comparison of a two-finger versus two-thumb method for chest compressions by healthcare providers in an infant mechanical model. Resuscitation 2000;43(3):213-6. 53. Srikantan SK, et al. Effect of one-rescuer compression/ ventilation ratios on cardiopulmonary resuscitation in infant, pediatric, and adult manikins. Pediatr Crit Care Med 2005;6(3):293-7. 54. Babbs CF, Nadkarni V. Optimizing chest compression to rescue ventilation ratios during one-rescuer CPR by professionals and lay persons: children are not just little adults. Resuscitation 2004;61(2):173-81. 55. Atkinson E, et al. Specificity and sensitivity of automated external defibrillator rhythm analysis in infants and children. Ann Emerg Med 2003;42(2):185-96. 56. Cecchin F, et al. Is arrhythmia detection by automatic external defibrillator accurate for children?: sensitivity and specificity of an automatic external defibrillator algorithm in 696 pediatric arrhythmias. Circulation 2001;103(20):2483-8. 57. Samson RA, et al. Use of automated external defibrillators for children: an update: an advisory statement from the pediatric advanced life support task force, International Liaison Committee on Resuscitation. Circulation 2003; 107(25):3250-5. [email protected]

3

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Continuing Education

EARN CE CREDIT ONLINE

Go to www.nursingcenter.com/CE/ajn and receive a certificate within minutes. GENERAL PURPOSE: To provide registered professional nurses a summary of the recommendations in the 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.

LEARNING OBJECTIVES: After reading this article and taking the test on the next page, you will be able to • discuss the changes in the guidelines for the emergency cardiovascular care of adults. • describe the changes in the guidelines for the emergency cardiovascular care of children and infants.

TEST INSTRUCTIONS To take the test online, go to our secure Web site at www.nursingcenter.com/CE/ajn. To use the form provided in this issue, • record your answers in the test answer section of the CE enrollment form at page 72. Each question has only one correct answer. You may make copies of the form. • complete the registration information and course evaluation. Mail the completed enrollment form and registration fee of $24.95 to Lippincott Williams and Wilkins CE Group, 2710 Yorktowne Blvd., Brick, NJ 08723, by January 31, 2009. You will receive your certificate in four to six weeks. For faster service, include a fax number and we will fax your certificate within two business days of receiving your enrollment form. You will receive your CE certificate of earned contact hours and an answer key to review your results. There is no minimum passing grade.

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PROVIDER ACCREDITATION LWW, publisher of AJN, will award 3 contact hours for this continuing nursing education activity. LWW is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center’s Commission on Accreditation. LWW is also an approved provider of continuing nursing education by the American Association of CriticalCare Nurses #00012278 (CERP category A), District of Columbia, Florida #FBN2454, and Iowa #75. LWW home study activities are classified for Texas nursing continuing education requirements as Type 1. This activity is also provider approved by the California Board of Registered Nursing, provider number CEP 11749 for 3 contact hours. Your certificate is valid in all states.

TEST CODE: AJN0207

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