Tachycardia may be a nonspecific sign of fear, anxiety, pain, or fever. It may also be life-threatening (hypoxia, cardiac abnormality, hypovolemia). Sinus tachycardia is the most common dysrhythmia in children. Treatment is generally limited to fluid administration, supplemental oxygen, pain medication, and transport. Use the PAT and ABCDEs to start your assessment. Always ask about a history of congenital heart disease and check for midline chest scars from surgery. Get an EKG if suspicion is high. Remember that there are two characteristics in rhythm strip:
- Heart Rate per minute
- Width of the QRS complex
Narrow complex tachycardia is present if the QRS complex is ≦ 0.09 seconds (< 2 ¼ standard boxes on the rhythm strip)
Wide complex tachycardia is present If QRS complex is > 0.09 seconds (> 2 ¼ standard boxes on the rhythm strip)
In narrow complex tachycardia, P waves are present. The heart rate is greater than 220 beats/minute in infants, and less than 180 beats/minute in children. Causes are usually from non-cardiac conditions (e.g. hypoxia, hypovolemia, hypothermia, hypoglycemia, metabolic abnormalities, fear, pain, or serious trauma to the chest). There is no specific therapy needed, but can be treated with fluids, oxygen, splinting, analgesia, or sedation as indicated by the associated condition.
Supraventricular tachycardia (SVT) is ≥220 beats/minute in an infant and ≥180 beats/minute in a child. P waves are absent. If the child has no previous history of SVT, and is stable, transport to the ED. If the patient has a prior history of SVT and is stable, consider vagal maneuvers first (place crushed ice in a plastic bag, glove or washcloth, and apply firmly to mid face (cheeks and bridge of nose) for approximately 15 seconds, until the rhythm changes or the patient’s condition dictates immediate cessation of the procedure. Remember not to occlude the nose and avoid ocular pressure; only attempt a vagal maneuver once. There is controversy over whether ice to the face for SVT has not been evaluated for efficacy or safety in the prehospital setting, especially in children. Give adenosine at 0.1 mg/kg up to a max first dose of 6mg rapid IV or IO push and follow immediately with a 2 – 5 mL bolus of normal saline. Use the IV/IO nearest to the heart. Use a three-way stopcock if available. Double the dose of adenosine to 0.2 mg/kg (max 12 mg) if rhythm does not convert after the first try. If the patient has an abnormal PAT (poor pulse quality, abnormal cap refill and temp, hypotension), is in shock or is unconscious, administer synchronized electrical cardioversion at 0. 5 – 1 J/kg, up to 2 J/kg. If electrical therapy fails to convert the child to sinus rhythm, consider amiodarone (5 mg/kg over 20 – 60 minutes) or procainamide (15 mg/kg over 20 – 60 minutes) as per local EMS guidelines.
If a patient is conscious and has adequate perfusion, an HR >150 beats/minute and a QRS >0.09 seconds, they are probably in stable ventricular tachycardia (VT). Sinus tachycardia with a conduction abnormality (bundle branch block) may look like VT but usually occurs in a child with a history of heart disease or cardiac surgery. Likewise, SVT with aberrant conduction can result in a wide complex rhythm. If the child is stable, provide oxygen and transport to the ED. If the rhythm is VT, an antiarrhythmic can be used per EMS guidelines. If the child has VT and shows signs of poor perfusion, treat with synchronized electrical cardioversion (0.5 – 1 J/kg). If a second shock (2 J/kg) is unsuccessful, or if the tachycardia recurs quickly, consider amiodarone (5 mg/kg over 20-60 minutes) or procainamide (15 mg/kg over 30-60 minutes) per EMS protocol. Do not give amiodarone and procainamide together. Coadministration may increase the risk of new arrhythmias, including Torsades de Pointes, due to additive depressant effects on cardiac conduction, which could lead to excessive QT prolongation. If the child has VT and shock without a pulse, treat as pulseless VT/VF. |