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Paramedics are transporting a 5 month old male infant with respiratory distress, when he tires and stops breathing. The patient is bag mask ventilated with CPR in progress. On arrival in the emergency department, the patient is apneic, asystolic, and pulseless. The infant has no IV access. After brief bag mask ventilation, the patient is intubated with a tracheal tube. A colorimetric carbon dioxide capnometer detector device confirms proper tracheal tube placement. Findings now include:
1) Airway/breathing: Breath sounds are equal bilaterally, and there is good chest movement with ventilation.
2) Circulation: No pulse is palpable without chest compressions, and no heart sounds are heard. ECG shows asystole. Oxygen saturation is not obtainable.
3) Vital signs: Heart rate 0, respiratory rate 0, blood pressure unobtainable.
4) Attempts at IV access are unsuccessful.
Ventilations and chest compressions are continued. Epinephrine 0.5 mg of the 1:1,000 solution is given down the tracheal tube, and an intraosseous line (IO) is inserted into the proximal left tibia. Blood is obtained from the IO needle and is sent for a number of studies including a rapid glucose check. The airway is reassessed, ventilation and chest compressions are continued, and a second dose of epinephrine is given. The patient converts to a sinus bradycardia with a fair blood pressure. After several more minutes of further stabilization, the infant's heart rate is 120 and he is beginning to move and cough against the tracheal tube. The resuscitation is a success.
Although the etiology of pulmocardiac resuscitation (PCR) in children is different than adults, the immediate goal is the same, to immediately reestablish effective cardiac output and tissue delivery of oxygen through the use of artificial ventilation, external chest compressions, and the administration of pharmacologic agents.
The pathophysiology of PCA (pulmocardiac arrest) in children is different from that in adults. The most common etiology of PCA in infants and children is respiratory failure with subsequent cardiac arrest; hence the term pulmocardiac arrest instead of cardiopulmonary arrest and PCR (pulmocardiac resuscitation) instead of CPR (cardiopulmonary resuscitation) as in adults. Furthermore, PCA in children generally is the end result of preceding progressive deterioration and rarely occurs as a sudden event. Thus it is vital to be able to identify and manage respiratory distress in children, and thus prevent the deterioration into respiratory failure and subsequent PCA.
There are many causes of PCA in children but most fit into the classifications of respiratory (pneumonia, apnea, bronchiolitis, asthma, submersion, aspiration, epiglottitis, smoke inhalation, suffocation, anaphylaxis), infectious (septic shock, meningitis), cardiovascular (congenital heart disease, arrhythmia, myocarditis, congestive heart failure, pericarditis, shock), traumatic, or central nervous system diseases (hemorrhage/edema, shaken baby syndrome, seizures, meningitis, hydrocephalus with shunt malfunction, tumor). Respiratory diseases and SIDS account for one-third to two-thirds of all pediatric PCA. Helpful history and physical exam items include: age, recent illness, previous medical problems, current medications, recent trauma, time of day, location of patient during PCA, access to toxins, medicines, poisons, access to potential foreign bodies, length of downtime, overall appearance (congenital defects, "special needs"), vital signs, tracheal deviation, subcutaneous air, pupillary response, evidence of trauma (including retinal hemorrhages), surgical scars (especially sternal, scalp which suggest surgical heart disease and brain surgery respectively). Findings which suggest prolonged time since death include rigor mortis, dependent lividity and corneal clouding.
The age distribution of childhood PCA is skewed toward infancy, with about 50% of patients younger than one year, about 25% between one and four years of age, and about 20% older than four years of age. Equipment and skills preparedness for this young age range by all EMS (emergency medical services) responders and those caring for pediatric emergencies is crucial for achieving best outcomes.
The outcome of PCA in children is dependent upon: 1) site of occurrence (i.e., in-hospital or out-of-hospital, and 2) cause of PCA. In eight reviews published since 1983, only 96/542 (17.7%) of children experiencing out-of-hospital PCAs survived versus 137/342 (40%) of those experiencing in-hospital PCA. The survival rates for children experiencing isolated respiratory arrests ranges from 75 to 97%, while survival rates for children experiencing full cardiopulmonary arrests range from 4 to 16%. The latter statistic reflects the terminal nature of asystole in children which is usually preceded by prolonged respiratory insufficiency with long-standing tissue hypoxemia and acidosis. Therefore directing initial management toward improvement of oxygenation and ventilation is imperative to a successfully resuscitation.
The initial approach to resuscitation is the same as it is for adults: A (airway), B (breathing), C (circulation), D (drugs). Attention to proper positioning, oxygenation and ventilation come first, with drug therapy last. Physiologically the ABC's can better be described as VOP (ventilation, oxygenation, and perfusion). In order to best accomplish this, an organized approach is necessary, with priorities established as follows:
1) Determine the level of responsiveness (or unresponsiveness).
2) Position the patient properly on a firm surface, maintaining cervical spine immobilization (in children with suspected head or cervical spine injury).
3) Establish a patent airway.
4) Assure oxygenation.
5) Assure or establish ventilation (breathing) while protecting the cervical spine.
6) Assure adequate circulation.
8) Utilize appropriate drug therapy if required.
The Broselow tape is a pediatric resuscitation tool which uses the length of the patient as a resuscitation guide providing intubation and drug dosing recommendations for each length along the tape corresponding to the patient's length. This eliminates the need to estimate the patient's age and weight.
The most common cause of upper airway obstruction in the unconscious child is posterior displacement of the tongue. This obstruction can be relieved by either a head tilt/chin lift or jaw-thrust maneuver, by pulling the jaw forward into a sniffing position. Do not perform the head tilt/chin lift maneuver in children with potential cervical spine trauma. Foreign material or vomitus can also obstruct the airway. Therefore open the mouth, inspect and suction early and repeatedly. Consider the use of nasopharyngeal or oropharyngeal airways in selected patients. These type of airways should only be used in unconscious patients, because insertion of either a nasopharyngeal or oropharyngeal airway into a conscious patient will induce gagging and potential aspiration.
Assure oxygenation by administering supplemental oxygen. Although supplemental oxygen can be delivered to patients by a variety of different means, for the sickest patients, 100% oxygen should be administered, utilizing non-rebreather face masks at a flow rate of 10 liters per minute.
Children without adequate spontaneous breathing effort require positive pressure ventilatory support. Initially this is accomplished by bag mask ventilation. The American Heart Association Emergency Cardiac Care 2000 guidelines (1) refer to these the two bag mask ventilation devices as manual resuscitators which are: 1) the self-inflating bag and 2) the closed circuit anesthesia type bag (also called Rusch bag). The definitive airway, however, involves endotracheal intubation, which offers the most effective and secure means to deliver 100% oxygen and protect the airway. Tracheal tube (formerly called endotracheal tube) size should be determined according to one of the methods described in the intubation chapter, which also includes a description of the tracheal intubation procedure, placement and confirmation. The AHA ECC 2000 guidelines recommend secondary confirmation of proper tracheal tube placement by monitoring exhaled carbon dioxide using an end-tidal CO2 monitor or a colorimetric capnometer device (1). Adequate ventilation is determined by auscultation and chest movement (rise and fall).
Assuring adequate circulation does not mean just the blood pressure, but includes the evaluation of the overall appearance, heart rate, presence and strength of proximal vs. distal pulses, skin temperature and color, mucous membrane color, capillary refill time, alertness/responsiveness (brain perfusion) and blood pressure. With acute blood loss or any hypovolemic state, the protective/compensatory mechanisms of increasing the heart rate and increasing the systemic vascular resistance (poor perfusion with cool extremities) will maintain a child's SYSTOLIC blood pressure within a normal range in spite of losses as high as 30% of the child's circulating blood volume. Once these protective homeostatic mechanisms are no longer able to compensate for the hypovolemic state, the child's systolic blood pressure will then abruptly decompensate to a pressure that is now hypotensive for age.
If circulation is inadequate (i.e., absent or ineffectual pulses), then external cardiac chest compressions should be started. Optimally, these should be administered in a compression to ventilation ratio of 5:1. Current recommendations are that in infants, compressions be applied evenly over the midsternum (i.e., directly over the heart ventricles), utilizing the two thumbs on the chest with the hands encircling the chest technique. To avoid any liver trauma, compressions should not be applied over the lower third of the infant's sternum. For children (1-8 years of age), use the heel of one hand to compress the lower half of the sternum (with a compression to ventilation rate also equal to 5:1). For children over 8 years of age, the adult method of chest compressions should be utilized (heel of one hand over the lower half of the sternum with the other hand laid over the back of the first hand. The compression ventilation ratio is 15 compressions followed by 2 breaths) (1).
Vascular access must be established early. Even a small gauge IV can be used for resuscitation, which is better than no IV at all. Intraosseous (IO) infusion should be considered early, especially in the case of cardiac arrest, or decompensated shock. Although IO lines were previously recommended for children <6 years of age, there is no current age limit on the use of intraosseous infusion. The preferred site of IO placement is the proximal medial aspect of the tibia. Any intravenous preparation (medication or fluid) can be given intraosseously, and blood (if available) from the IO needle can be used for many laboratory tests.
After every step, reassess the patient. Pay attention to the VOP, physical exam (i.e., chest excursion, heart rate, skin color, perfusion, etc.) and to results of pulse oximetry or ancillary tests.
Drug therapy during resuscitation is reserved for those who do not respond adequately to the ABC's, and is the last line of therapy, NOT the first. While supplemental oxygen is typically utilized in all resuscitation scenarios, the majority of these resuscitations will not usually require a large number of medications. Drug doses are usually based on the patient's weight. The Broselow tape is an excellent tool to assist with this task. Some of the drugs utilized in pediatric resuscitation are noted here, but the entire list of resuscitation drugs is beyond the scope of this chapter. Epinephrine increases HR, contractility, and BP. Atropine increases HR in cases associated with increased vagal tone. Amiodarone and lidocaine (anti-arrhythmia agents) are used to convert ventricular fibrillation, pulseless ventricular tachycardia or ventricular tachycardia with a pulse. Amiodarone can also be used for certain atrial tachydysrhythmias. Dextrose reverses symptomatic hypoglycemia (which is an easily reversible cause lethargy, seizures and a potential element in shock and cardiac arrest). Sodium bicarbonate reverses the metabolic acidosis associated with most arrest situations; however, optimizing ventilation to reverse the respiratory component of an acidosis takes priority. Sodium bicarbonate is the treatment of choice for arrests due to cyclic antidepressant overdose (potentially lifesaving). Naloxone reverses cardiorespiratory and CNS opiate narcotic depression. Adenosine converts paroxysmal supraventricular tachycardia (PSVT). Dopamine improves BP. Dobutamine increases contractility.
There are also a number of drugs that can be given down the tracheal tube (TT) if vascular access cannot be established. The 4 medications which can be given via the TT can be remembered by the mnemonic "LANE" or "LEAN" which include lidocaine, atropine, naloxone and epinephrine. Epinephrine given down the TT is always given as "high dose" (i.e., 0.1mg/kg of the 1:1,000 solution).
The more common dysrhythmias that one may be confronted with during a pediatric resuscitation include bradycardia, asystole and pulseless electrical activity (PEA, formerly known as electromechanical dissociation or EMD). Ventricular fibrillation and ventricular tachycardia are not very common in children, but may be the presenting dysrhythmia in adolescent patients secondary to various drug overdoses. The key point in the treatment of PEA and asystole is to hunt for reversible causes. The mnemonic used to recall the reversible etiologies of asystole and PEA is "PATH", which stands for pneumothorax (tension), acidosis (severe), toxic ingestion, tamponade (cardiac), hypovolemia, hypoxia (severe), hyper/hypokalemia and hypothermia (so the mnemonic is actually PAT2H4). Although most of these can be ruled out by the history and clinical examination, the possibilities of hyper/hypokalemia and severe metabolic acidosis should also be quickly ruled out with a rapid bedside lab testing device which is much faster then sending a specimen to the lab. The most common cause of PEA in children is hypovolemia. Therefore a rapid fluid bolus (20 ml/kg of IV normal saline) should always be considered as a therapeutic option in a child with PEA who is not responding to epinephrine, CPR and adequate ventilation/oxygenation.
Although a complete discussion of all of the pediatric dysrhythmia algorithms is well beyond the scope of this textbook, a synopsis of the key treatment points for the various pediatric dysrhythmias is listed below:
Asystole and PEA: CPR, intubation, epinephrine and hunt for the cause.
Bradycardia: Assure adequate oxygenation and ventilation first then consider epinephrine, atropine and transcutaneous pacing.
Paroxysmal supraventricular tachycardia (hemodynamically stable): May attempt vagal maneuvers first, then consider adenosine.
Ventricular tachycardia (hemodynamically stable): Consider amiodarone or lidocaine or procainamide.
Any hemodynamically unstable tachydysrhythmia: Immediate synchronized cardioversion is the treatment of choice (unless vascular access is immediately available in the case of PSVT, in which case IV adenosine may be attempted first before cardioversion).
Ventricular fibrillation or pulseless ventricular tachycardia: Immediate defibrillation, epinephrine, intubation then consider antidysrhythmics such as amiodarone, lidocaine or magnesium sulfate (if torsades or hypomagnesemia).
Post resuscitation interventions include maintenance of normal ventilation (rather than hyperventilation), maintenance of normal temperature, glucose control, and management of post-ischemic myocardial dysfunction. Lastly, post arrest cardiogenic shock and septic shock must be treated aggressively with fluid, inotropes and pressors.
In summary, most seriously ill children experience respiratory distress followed by respiratory failure, or shock, before developing other organ system (i.e., cardiac) failure. Therefore a systematic approach to the early recognition and treatment of respiratory distress and compensated shock is the key to the prevention of pulmocardiac arrest. Oxygenation and ventilation must be established first. Without this, drugs, medication and resuscitation will be ineffective. The principles of ABC's (or VOP: ventilation, oxygenation and perfusion) must be followed by a trained skilled resuscitation team with proper equipment in a skilled facility.
1. The most common cause of pulmocardiac arrest in children is:
. . . . . a. Acute myocardial infarction
. . . . . b. Hemorrhagic shock
. . . . . c. Nonaccidental trauma
. . . . . d. Ventricular fibrillation
. . . . . e. Hypoxia and respiratory failure
2. Endotracheal intubation is not indicated for which of the following:
. . . . . a. Control and protection of the airway.
. . . . . b. Prolonged mechanical ventilation.
. . . . . c. Tension pneumothorax.
. . . . . d. Hyperventilation of the patient with a head injury.
. . . . . e. Improved oxygen delivery and ventilation.
3. The drug/treatment of choice for asystole in children is:
. . . . . a. Atropine
. . . . . b. Calcium chloride
. . . . . c. Adenosine
. . . . . d. Defibrillation
. . . . . e. Epinephrine
4. A 12 year old child comes to the ED pulseless. ECG reveals a wide complex tachycardia. Initial management should be:
. . . . . a. Immediate defibrillation.
. . . . . b. Immediate synchronized cardioversion.
. . . . . c. Adenosine
. . . . . d. Epinephrine
5. The most common cause of PEA in children is:
. . . . . a. Tension pneumothorax
. . . . . b. Metabolic acidosis
. . . . . c. Toxic ingestions
. . . . . d. Profound hypovolemia
. . . . . e. Hyperkalemia
6. The most common cause of bradycardia in children is:
. . . . . a. Hypokalemia
. . . . . b. Heart block
. . . . . c. Hypoxemia
. . . . . d. Toxic ingestions
. . . . . e. Myocarditis
1. The American Heart Association in collaboration with the International Liaison Committee on Resuscitation. Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Part 6: advanced cardiovascular life support: section 6: pharmacology II: agents to optimize cardiac output and blood pressure. Circulation. 2000;102(8 Suppl):I129-I135.
2. APLS - The Pediatric Emergency Medicine Course, Third Edition. AAP, ACEP, 1998.
3. Bell LM. Shock. In: Fleisher and Ludwig, editors Textbook of Pediatric Emergency Medicine, 4th edition. 2000, Philadelphia: Lippincott Williams and Wilkins, pp. 47-57.
4. Bhende MS, Thomson AE. Evaluation of an end-tidal CO2 detector during pediatric cardiopulmonary resuscitation. Pediatrics 1995;95(3):395-399.
5. Brown CG, Werman HA. Adrenergic agonists during cardiopulmonary resuscitation. Resuscitation 1990;19:1-16.
6. Brown CG, et al. A Comparison of Standard-dose and High-dose epinephrine in cardiac arrest outside the hospital. New Engl J Med 1992;327(15):1051-1055.
7. Brunette DD and Fischer R. Intravascular Access in Pediatric Cardiac Arrest. Am J Emerg Med 1988;6:577-579.
8. Goetting MG. Mastering pediatric cardiopulmonary resuscitation. Pediatr Clin North Am 1994;41(6):1147-1182.
9. Hazinski MF. Is pediatric resuscitation unique? Relative merits of early CPR and ventilation versus early defibrillation for young victims of prehospital cardiac arrest. Ann Emerg Med 1995;25(4):540-543.
10. Patterson M, et al. High dose epinephrine in pediatric cardiopulmonary arrest. Pediatr Emerg Care 1994;10:310.
11. Schindler MD, et al. Outcome of out-of-hospital (OOH) cardiac or respiratory arrest in children. New Engl J Med 1996;335:1473-1479.
12. Teach SJ, Moore PE, Fleisher GR. Death and resuscitation in the pediatric emergency department. Ann Emerg Med 1995;25(6):799-803.
13. Ushay HM, Notterman DA. Pharmacology of pediatric resuscitation. Pediatr Clin North Am 1997;44(1):207-233.
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Answers to questions
1.e, 2.c, 3.e, 4.a, 5.d, 6.c