Initial steps

The Pediatric Bradycardia with a Pulse and Poor Perfusion Algorithm depicts a sequence for the management of pediatric bradycardia. The first action is to identify and treat the underlying cause of the patient’s condition, and then perform immediate oxygenation and ventilation support. The team performs the ABCs, supporting the airway and assisting breathing via a high concentration of oxygen with a nonrebreather mask or by providing bag-mask ventilation. 

Oxygenation is assessed with a pulse oximeter. Circulation is evaluated by monitoring blood pressure and assessing perfusion. The child should be connected to a defibrillator with an ECG monitor. IV access should be obtained.  

A 12-lead ECG and laboratory studies such as potassium, glucose, ionized calcium, magnesium, an arterial blood gas for pH monitoring, and a toxicology screen are indicated to determine the cause of bradycardia. For AV block, the provider should consider transcutaneous pacing.

After the initial intervention, the patient is reassessed to determine if the condition has improved or worsened. Hypotension, altered mental status, and signs of shock are indications that the patient has deteriorated into cardiopulmonary compromise.

If the patient develops a heart rate < 60 bpm despite oxygenation and ventilatory support, high-quality CPR with chest compressions should be initiated. After 2 minutes of CPR, the team should determine if bradycardia has resolved. If the patient’s condition improves, then the provider supports the patient’s ABCs and prepares for transport to the critical care unit for further observation with expert consultation and care.

Medical Management of Bradycardia

Epinephrine or atropine should be considered if the patient has not improved after CPR has been performed for 2 minutes. When there is persistent symptomatic bradycardia despite adequate oxygenation and ventilation, epinephrine is the medication of choice. Epinephrine increases the heart rate and contractility of the heart. It also causes vasoconstriction. 

Epinephrine is given via IV bolus at a dose of 0.01 mg/kg (0.1 mL/kg) every 3–5 minutes as needed until the patient’s condition improves. There is no maximum dose of epinephrine. Intravenous infusions are also feasible and given at a rate of 0.1–0.3 mcg/kg per minute titrated based on the patient’s clinical response.

Atropine is an anticholinergic agent that accelerates the sinus and atrial pacemakers and increases atrioventricular conduction. Atropine is the medication of choice when bradycardia is due to second-degree or third-degree AV block, an increase in vagal tone, or a cholinergic drug overdose. In these instances, atropine may be better than epinephrine since epinephrine is known to cause ventricular arrhythmias when the heart is hypoxic or ischemic with chronic disease. Atropine is given as an IV bolus of 0.02 mg/kg and can be repeated every 5 minutes until the desired effect is achieved.

Atropine should not be used if the bradyarrhythmia is caused by secondary bradycardia from treatable causes such as hypoxia and acidosis. Symptomatic AV block may not improve after giving atropine, so the clinician must also be prepared to provide electrical pacing.

Transthoracic pacing is a temporary life-saving procedure in symptomatic bradycardia caused by a complete heart block or abnormal sinus node infection. It is indicated if AV block ensues after surgical correction of congenital heart disease.

Related Video – Transcutaneous Pacing

Treating the Causes of Bradycardia

If there is secondary bradycardia, then the provider must treat the underlying causes. The most common causes of symptomatic bradycardia are increased vagal tone and hypoxia. Hypoxia is treated with high concentrations of oxygen and assisted ventilation as needed. Respiratory acidosis secondary to hypercarbia requires adequate ventilation; sodium bicarbonate may be considered if severe metabolic acidosis is suspected. 

If the patient presents with hyperkalemia, interventions to normalize potassium levels are required. If the patient comes in due to accidental hypothermia, the child should be warmed. Atropine, other chronotropic drugs, or electrical pacing may be needed if there is an AV block. A child with head trauma and bradycardia may have increased intracranial pressure and impending uncal herniation. A brief period of hyperventilation may improve the patient’s condition. 

If pulseless arrest develops at any time during treatment despite performing the corrective measures mentioned above, then the team immediately follows the pediatric cardiac arrest algorithm.

Related Video -Understanding the Pediatric Bradycardia with a Pulse and Poor Perfusion Algorithm