Monday Morning Medical Director’s Message
Good morning. This week’s discussion leads us to our final topic for the month – Pediatric Cardiac Arrest. A child in cardiac arrest is unresponsive, apneic, and pulseless. Cardiac arrest usually results from profound hypoxia or shock, which leads to asystole, or pulseless electrical activity (PEA). It follows a primary respiratory arrest, often due to respiratory failure from common conditions such as pneumonia, bronchiolitis or asthma. The primary age group for pediatric cardiac arrest is infancy, when Sudden Unexpected Infant Death (SUID), infection, or child maltreatment precipitates respiratory failure. The cardiac monitor will show asystole, PEA, VT or VF. Asystole is the most frequent rhythm. It reflects profound hypoxia and ischemia. Myocardial infarction or cardiac dysrhythmias, which are frequent causes of cardiac arrest in adults, are extremely unusual in young children. Some other causes of cardiac arrest in children include Long QT Syndrome and Commotio Cordis. | 
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Survival from cardiac arrest depends on the presenting rhythm and time to CPR. The shorter the downtime before Basic Life Support (BLS), the better the outcome. As in adults, children who present to EMS in ventricular fibrillation (VF) are more likely to survive than those who present in asystole, as long as there is early CPR and early access to defibrillation. The only intervention associated with survival in pediatric asystolic cardiac arrest is the time to onset of CPR.
High-quality chest compressions are critical. When presented with a pediatric patient in cardiac arrest (asystole/PEA), there should be a great focus placed on high-quality CPR with an emphasis on chest compressions without interruption. The American Heart Association (AHA) stipulates using the Circulation – Airway – Breathing (CAB) sequence which emphasizes on starting compressions immediately and making them the focus. Note that compression techniques differ for a child and infant:
For an infant, as a single rescuer, one places 2 fingers at the nipple line and compresses at a rate of at least 100-120 per minute with a depth of at least 1.5 inches (4 cm) with complete recoil.
Two-rescuer for infants, technique is two fingers encircling the chest technique.
For a child, the hand(s) should be placed on the lower half of the sternum, rate should be at least 100–120 per minute, and compression depth should be at least 2 inches (5 cm) with complete recoil (to ensure adequate preload).
For a child and infant, when performing single rescuer CPR, the ratio is 30:2 and changes to 15:2 when there are two rescuers.
A ag valve mask or an airway adjunct can be used. If intubating, remember the calculation for an uncuffed ETT is (age in years / 4) + 4. Cuffed ETTs are sized half-size smaller. It is important to note that ETT insertion offers no known benefit to survival. Venous access can be obtained via IV or IO. Similarly, IV or IO needle insertion and medication delivery are helpful but not primary determinants of survival. Epinephrine is the drug of choice: 0.01 mg/kg (0.1 mL/kg or 0.1 mg/mL concentration) IV/IO. Pulse checks should be done every 2 minutes and epinephrine administered every 3-5 minutes.
Consider the H’s and T’s when treating Asystole/PEA. They are listed below:
| Six H's and Five T's |
| Hypovolemia | Tension Pneumothorax |
| Hypoglycemia | Tamponade, Cardiac |
| Hydrogen Ions | Toxins |
| Hypo / Hyperkalemia | Thrombosis (cardiac or pulmonary) |
| Hypothermia | Trauma |
Now, let us discuss Ventricular Fibrillation (VF). The typical VF case is a child out of the infant age group who has had a witnessed collapse. Etiologies for VF arrest in children include myocarditis (an infection in the heart muscle), long QT syndrome, a congenital cardiac issue, hypertrophic cardiomyopathy (hypertrophy of the ventricular septum and ventricles), and Commotio Cordis (when a child is struck in the chest by a ball, stick, fist or other blunt object). Perform rapid assessment for VF on all unresponsive children, begin CPR, and administer defibrillation if VF is present on the cardiac monitor. Be especially vigilant for VF when the child is older and has suffered a witnessed collapse. There is no demonstrated benefit to defibrillation of asystole, and this procedure will only delay the key interventions of chest compressions, ventilation and oxygenation.
Remember to treat pulseless Ventricular Tachycardia (VT) the same as V-fib. VF/VT management should start with high-quality CPR while attaching the AED and identifying a shockable rhythm. Start at 2 J/kg followed by 2 minutes of excellent CPR. Get IV or IO access. Airways can be achieved via bag valve mask. If there is no pulse, shock at 4 J/kg, continue CPR, then give epinephrine: 0.01 mg/kg (0.1 mL/kg or 0.1 mg/mL concentration) IV/IO; repeat every 3- 5 minutes. CPR is continued with pulse/rhythm checks every two minutes. Subsequent shocks are delivered at 4 J/kg but can be increased to 10 J/kg, not to exceed the adult dose.
Amiodarone may be given for refractory VF/pulseless VT at 5 mg/kg, repeated up to two times to a total of 15 mg/kg. Lidocaine may also be given at 1 mg/kg as a loading dose with maintenance of 20–50 mcg/kg/min by infusion. Repeat the bolus if the infusion is begun >15 minutes after the initial loading dose.
Of all children with out-of-hospital cardiac arrest, only 6% will survive. Predictors of survival include the presenting rhythm and early return of spontaneous circulation (less than 5 minutes) after BLS arrives on the scene. Survival from pulseless VT/VF is 15% vs Asystole at 3%. Although survival in unwitnessed out-of-hospital cardiac arrest is rare, EMS should continue resuscitative efforts and transport the child urgently to the closest ED equipped to care for the child. If you take anything from this discussion, remember that survival from pediatric cardiac arrest requires good BLS. Please do not leave a family member on scene with a deceased child without appropriate support. It is advised that agencies offer grief counseling for their staff. Critical Incident Stress Debriefing is vital. Witnessing and treating a pediatric cardiac arrest is traumatic for everyone involved.
This is it for the month of April. Thank you so much for all the work that you do.
Have a great summer. Stay safe.
Regina Yaskey, MD