New guidelines for pediatric life support

By Andrew J. Schuman, MD

The latest guidelines for providing pediatric life support—the first ones developed from an international perspective—recommend changes not only in the practice of cardiopulmonary resuscitation but also how it is taught.

The latest statistics from the American Heart Association (AHA) show that about 200,000 medical personnel are certified as providers of Pediatric Advanced Life Support (PALS) in the United States and that more than one million medical personnel are certified as providers for the Neonatal Resuscitation Program (NRP). Countless others have been trained to provide pediatric basic life support (BLS). Both the PALS and NRP training programs—developed jointly by the AHA and American Academy of Pediatrics (AAP)—are rolling out new courses this year that incorporate changes recommended by the International Guidelines 2000 Conference on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Not only is the content different from what has been taught in terms of drugs, equipment, and resuscitation techniques, but the approach is different as well, emphasizing simplified teaching and acquisition and reinforcement of basic skills.

Both courses now focus on advance preparation by students, requiring students to read the course textbook and, in the case of PALS, submit a pretest before participating in classes. The curricula use the latest in video teaching and, compared to past years, place a greater emphasis on practicing important resuscitation skills. The PALS and neonatal resuscitation textbooks published by the AAP have been extensively revised. The revised PALS textbook, which includes guidelines for BLS, is not available at the time this article is published, but the new neonatal resuscitation textbook is in print and features detailed illustrations, color plates, new resuscitation algorithms, and an interactive multimedia CD-ROM.¹ Before reviewing the latest changes in pediatric BLS, PALS, and neonatal resuscitation, let's look at how guidelines have evolved.

Resuscitation, then and now

Resuscitation techniques for adults and children have been around since the late 1950s and early 1960s. In 1958, Safar and colleagues proved that mouth-to-mouth resuscitation—a technique they developed based on the method used by midwives to revive newborn infants—was effective in treating adult respiratory arrest victims.² Two years later, Kowenhoven demonstrated that chest compressions could sustain life until further care was instituted.³ Over the next several years, these techniques were combined to form what we now know as basic cardiopulmonary resuscitation (CPR).⁴

The first conference on CPR was convened in 1966 by the National Academy of Sciences to standardize resuscitation techniques. The AHA has convened subsequent conferences, usually every six years since 1974, and issued guidelines based on available scientific evidence. PALS began as an offshoot of advanced cardiac life support, at a conference held jointly by the AHA and the AAP in 1983. It was decided at this conference that courses in pediatric and neonatal life support were needed. Five years later, the first courses in PALS and neonatal resuscitation were offered on a limited basis.

The AHA's Guidelines 2000 conference was the first international conference convened to produce guidelines based on a review of available scientific evidence.⁵ The International Liaison Committee on Resuscitation (ILCOR) is responsible for coordinating the development of new guidelines distributing new information throughout the world. The new guidelines are based on scientific research, and interventions are classified according to a system developed at the 1992 guidelines conference. Each intervention is assigned to one of five classes based on the level of evidence supporting its use and critical appraisal of the evidence by experts (Table 1).

TABLE 1
Classes of interventions in CPR and emergency cardiovascular care

Implementing the international guidelines has required adopting universal terminology to improve communication and understanding among all ILCOR participants. What was once called an endotracheal tube, for example, is now a "tracheal tube," and a bag-valve-mask device is called a "manual resuscitator." Revised age definitions have been introduced as well to emphasize and clarify the unique anatomy and physiology of children as they grow. "Newly born" (replacing newborn) refers to the first minutes or hours following birth. "Neonate" encompasses the first 28 days of life beyond the newly born period. "Infant" includes the neonatal period and extends to 1 year of age. From 1 year to 8 years of age a patient is a "child." (Patients 8 years and older are classified as adults.)

Changes in basic life support

This year, the AHA is presenting two types of BLS training, one for medical personnel and the other for the lay rescuer. Lay rescuers are no longer taught to perform a pulse check, but to look for "signs of life that include presence of movement or response to stimulation." There are several reasons for this change. Research has demonstrated that parents have difficulty finding the pulse and counting the heart rate in infants, that lay rescuers require much longer than the recommended five to 10 seconds to check a pulse in arrest victims, and that the pulse check as performed by lay rescuers has a low sensitivity and specificity in identifying cardiac arrest. In addition, the complication rate from chest compressions in infants and children is low.

Furthermore, lay rescuer courses do not include instruction in the complex skills necessary to relieve foreign-body airway obstruction (FBAO) in an unresponsive victim, but focus on relief of FBAO in the conscious victim and on CPR techniques. The reason for this is that the benefit of preventing cardiac arrest caused by complete airway obstruction in a conscious victim is far greater than the likelihood that an unsuspected FBAO would cause cardiac arrest or unresponsiveness.

Other changes in the BLS guidelines include:

• encouragement of training in the use of the automated external defibrillator (AED) for cardiac arrest victims 8 years of age and older with a body weight greater than approximately 25 kg

• preference for using the two-thumb (with hands encircling the chest) technique of chest compression rather than the two-finger compression technique for infants and young children when two or more rescuers are available. The two-thumb technique is not taught to lay rescuers.

Pediatric BLS continues to emphasize a "phone fast" approach to resuscitating infants and children under 8 years of age. This approach directs a lone rescuer to perform CPR immediately, before activating the EMS system. A "phone first" approach—activating the EMS system before performing CPR—is recommended for the lone rescuer attempting to resuscitate a child older than 8 years (to shorten the time to initial defibrillation). The reason for the different approaches is that dysrhythmias are an uncommon cause of cardiac arrest in children under 8 years. The new guidelines emphasize that lay rescuers should be taught the exceptions to these age-based guidelines—namely, that the phone first approach is recommended for the lone rescuer responding to the sudden collapse of a child with a known history of heart disease and the phone fast approach is recommended for the lone rescuer resuscitating a pediatric submersion victim of any age. Whenever two or more rescuers are present with a victim of any age, one rescuer remains with the patient to begin CPR while another activates the EMS system.

The new PALS

Besides incorporating a new approach to teaching advanced life support, the revised PALS course places increased emphasis on special resuscitation circumstances that require immediate intervention (such as hypothermia, anaphylaxis, and electrical injuries) and includes optional teaching modules on such topics as pediatric sedation, children with special healthcare needs (those on home respirators and those with tracheostomy tubes, for example), coping with death, and toxicology for special circumstances (such as overdoses involving cocaine, tricyclic antidepressants, narcotics, calcium- channel blockers and ß-adrenergic blockers). It also provides instruction in the use of innovative advanced life support technologies, including exhaled and end-tidal carbon dioxide detectors, the laryngeal mask airway (LMA), and the AED.

In adults, cardiopulmonary arrest is typically sudden and primarily cardiac in origin. In contrast, arrest in children usually follows progressive shock and respiratory failure. Arrest in a young child is most often associated with sudden infant death syndrome, sepsis, or trauma. Trauma is the most common cause of arrest in children older than 6 months. The success of any advanced life support intervention depends on early recognition of respiratory and circulatory compromise combined with aggressive management of the airway, treatment of rhythm disturbances, and expeditious fluid resuscitation.

Airway support may be provided by means of a manual resuscitator, endotracheal intubation, or an LMA, depending on the training and skill of the rescuers and the nature and circumstances of the arrest. There are two types of manual resuscitators (ventilation bags): The self-inflating resuscitator (ambu bag) uses a valve system to fill the bag with oxygen or air following a compression (Figure 1), whereas the flow-inflating bag (anesthesia bag) refills only with oxygen inflow, which must be regulated (Figure 2). A self-inflating bag is easier to use for most medical personnel but cannot be used to provide supplemental oxygen during spontaneous respiration and provides only room air unless it is connected to an oxygen source. An attached oxygen reservoir enables self-inflating bags to provide as much as a 95% inspired oxygen concentration.

The latest PALS guidelines recommend that the self-inflating bag be used for pediatric resuscitation (the flow-inflating bag can be used as an alternative by properly trained personnel to resuscitate a newly born). Rescuers should use a self-inflating bag with a minimum volume of 450 mL for full-term newly borns, infants, and children. Neonatal-sized (250 mL) manual resuscitators are no longer recommended because they may not support effective tidal volume and longer inspiratory times in full-term neonates and infants.

In regard to intubated pediatric patients, the new guidelines recommend confirming tracheal tube placement by using exhaled or end-tidal carbon dioxide detectors. Exhaled carbon dioxide detectors are colorimetric systems that change color if CO₂ is produced during exhalation. End-tidal carbon dioxide monitors measure and display the quantity of CO₂ at the end of exhalation.

The new guidelines also address the use of the laryngeal mask airway in young children. As shown in Figure 3, the LMA is a tube with a mask-like projection at the end. It is introduced into the hypopharynx, and a balloon cuff is inflated, securing the distal opening of the tube above the glottic opening. Many believe that an LMA can be inserted more readily than a tracheal tube. LMAs do not protect the airway from aspiration, and medications cannot be administered through them. They should not be used in a child with an intact gag reflex.

Vagal maneuvers have been added to the treatment algorithm for supraventricular tachycardia in children with milder symptoms who are hemodynamically stable. They may also be tried during preparation for cardioversion or drug therapy. Such maneuvers include applying ice water to the face (most effective in infants and young children), carotid sinus massage, and the Valsalva maneuver. External ocular pressure is not recommended. A 12-lead ECG should be obtained before and after performing a vagal maneuver, and the ECG should be monitored continuously during the maneuver.

Medications. To manage unresponsive asystolic and pulseless arrest, epinephrine is initially administered intravascularly or intraosseously in a dose of 0.01 mg/kg (0.1 mL/kg of 1:10,000 solution). The latest PALS guidelines recommend the same amount of epinephrine for second and subsequent doses instead of "high-dose" epinephrine. Although high-dose epinephrine is no longer recommended, it still may be considered in refractory arrest situations.

Bretylium is no longer recommended for managing ventricular fibrillation or pulseless ventricular tachycardia because of the risk of hypotension and the drug's lack of documented effectiveness in pediatric patients. Amiodarone, in a dose of 5 mg/kg, is now considered the drug of choice for ventricular fibrillation or pulseless ventricular tachycardia unresponsive to three initial defibrillation attempts. It can also be used to manage hemodynamically stable ventricular tachycardia refractory to cardioversion.

Automated external defibrillators. Medical evidence indicates that, in nontraumatic arrest, the incidence of ventricular fibrillation is only 3% in children under 8 years, but rises significantly—to 17%—in those older than 9 years. Based on this information, new PALS guidelines approve the use of AEDs for assessing heart rhythms and defibrillating children 8 years and older who collapse suddenly outside the hospital. AEDs, which have proved to be extremely useful in adults, are conveniently located in many public places (such as airports). They deliver an initial dose of 150 to 200 J, or fewer than 10 J/kg for most children older than 8 years— a dose that is believed to be safe. For a brief description of how to use an AED, see "A quick and simple guide to operating an AED". As previously noted, instruction in the use of an AED is encouraged in BLS training.

Intraosseous access. The new PALS guidelines have dropped the recommendation to attempt IV access before inserting an intraosseous (IO) line in a pediatric arrest victim. The guidelines now support using an IO line in children older than 6 years in an emergency situation.

Introducing the new NRP

The Neonatal Resuscitation Program has been extensively revised to reflect the latest neonatal research. Previously, NRP assessment steps were performed in sequence— that is, respirations were assessed and treated, then heart rate was assessed and treated, and so on. Now, the NRP guidelines recommend that, after performing the initial stabilization steps (positioning, clearing the airway, drying, and administering oxygen), the resuscitator evaluate respirations, heart rate, and color simultaneously. This change more closely reflects the real-world situation and has been incorporated into the new NRP flow diagram (Figure 4).

Perhaps the most striking new recommendation concerns management of a newly born infant delivered in meconium stained amniotic fluid. Previously, meconium was suctioned from the infant's trachea with a tracheal tube if respiratory efforts were depressed at birth or the amniotic fluid contained thick, particulate meconium. Under the new guidelines, the need for tracheal suctioning is determined not by the consistency of the meconium but by whether the baby has strong respiratory effort, good tone, and a heart rate over 100/min. Babies who do not meet any of these criteria should undergo suctioning. As in the past, the guidelines call for reintubation and suctioning until "little additional meconium is recovered" or "the heart rate indicates that resuscitation must proceed without delay."

The new NRP guidelines simplify several previous recommendations:

• Under previous guidelines, a newly born's heart rate was determined by auscultation with a stethoscope. The 2000 guidelines recommend that the heart rate be determined by palpating the umbilical cord. If an umbilical pulse is absent, then a stethoscope should be used to listen to the chest.

• Previously, chest compressions were indicated when the heart rate remained below 60/min or did not increase beyond 60­80/min after 15 to 30 seconds of positive pressure ventilation with 100% oxygen. The current recommendation is to ventilate with oxygen for a full 30 seconds initially and then proceed with chest compressions if the heart rate remains below 60/min.

• The former guidelines directed rescuers to perform chest compressions by depressing the sternum ¹/₂ to ³/₄ inch. The new recommendation is to depress the sternum to a depth equal to ¹/₃ of the anterior-posterior diameter of the chest. Another new recommendation calls for the rescuer to pause chest compressions, but not ventilation, long enough to determine the heart rate by palpating the umbilical cord.

The 2000 guidelines also contain a change of recommendations for using volume expanders and medications during the resuscitation sequence:

• Isotonic crystalloid solution (such as normal saline or Ringer's lactate) has replaced 5% albumin as the recommended volume expander.

• Epinephrine is now indicated only if the heart rate remains below 60/min after 30 seconds of assisted ventilation with 100% oxygen and an additional 30 seconds of ventilation accompanied by chest compressions. Previously, epinephrine was recommended if the heart rate remained below 80/min despite 30 seconds of ventilation with 100% oxygen and chest compressions or if the heart rate was zero.

Other, minor changes in the NRP guidelines include:

• an increase in the rate of free-flow oxygen from 5 L/min to 5 to 10 L/min

• an increase in the minimum duration of initial ventilation of the newly born from 15 seconds to 30 seconds

• a decrease in the peak pressure of the initial breath from 40 cm H₂O to "more than 30 cm" H₂O

• an increase from two minutes to "several minutes" of bag-and-mask ventilation before insertion of an orogastric tube.

Time to retrain

It is clear that, because of many changes in the 2000 resuscitation guidelines (Table 2), pediatricians are well advised to enroll in new PALS and NRP courses when they become available. Your local AHA chapter or state AAP chapter should be able to provide locations and dates. Although time to meet all our obligations as pediatricians is often at a premium, maintaining resuscitation skills should have high priority.

TABLE 2
Changes in guidelines for pediatric life support

REFERENCES

1. American Academy of Pediatrics: Textbook of Neonatal Resuscitation, ed 4. Elk Grove Village, Ill., American Academy of Pediatrics, 2001

2. Safar P, Escarraga LA, Elam JO: A comparison of the mouth-to-mouth and mouth-to-airway methods of artificial respiration with the chest-pressure arm-lift methods. N Engl J Med 1958;258:671

3. Kouwenhoven W, Jude JR, Knickerbocker GG: Closed-chest cardiac massage. JAMA 1960;173:1064

4. Cardiopulmonary resuscitation: Statement by the Ad Hoc Committee on Cardiopulmonary Resuscitation of the Division of Medical Sciences, National Academy of Sciences, National Research Council. JAMA 1966;198:372

5. American Heart Association, International Liaison Committee on Resuscitation: Guidelines 2000 for cardiopulmonary resuscitation and emergency cardiovasular care. An international consensus on science. Circulation 2000 (suppl);102(8):1

THE AUTHOR is adjunct assistant professor of pediatrics at Dartmouth Medical School, Lebanon, N.H., and practices pediatrics at Hampshire Pediatrics, Manchester, N.H. He is a contributing editor for Contemporary Pediatrics.

A quick and simple guide to operating an AED

Automated external defibrillators are available in several models, all of which operate basically the same way. The devices incorporate a rhythm analysis system and a shock advisory system. If possible, place the AED close to the supine patient's left ear to provide optimum access to the controls and facilitate placement of the electrodes.

Step 1: Turn on the AED. Do this by either lifting the monitor cover or screen to the upright position or pressing the power switch. This initiates voice prompts for subsequent steps.

Step 2: Attach the electrodes. Open and attach the two self-adhesive monitor-defibrillator electrode pads directly to the patient's skin. Place the pads on the right upper sternal border below the clavicles and lateral to the left nipple.

Step 3: Analyze the rhythm. Clear all nearby persons away from the patient. Some devices require that the operator press an "analyze" button to begin rhythm analysis, while others start analysis automatically when the electrode pads are attached to the chest. If the patient has ventricular fibrillation, the device will announce audibly or by a displayed message that a shock is indicated.

Step 4: Deliver a shock. Make sure all nearby persons are clear of the patient and no one is touching him. Press the shock button. Most AEDs automatically begin rhythm analysis after each shock and deliver a series of up to three shocks if needed. Some models require the operator to press the "analyze" button once a shock has been delivered. Do not interrupt the three-shock sequence to check circulation or perform CPR. If the patient does not show signs of circulation after three shocks, perform CPR for one minute.

Adapted from American Hospital Association, International Liaison Committee on Resuscitation⁴

 

Andrew Schuman. New guidelines for pediatric life support. Contemporary Pediatrics 2001;9:39.