Supraventricular tachycardia (resuscitation)

A) If the patient is in a narrow complex tachycardia with a rate of 250 beats per minute or more, it is likely the pulse will be very small volume or impalpable although the patient is not in cardiac arrest. In this situation:

• give oxygen, obtain i.v. access
• provide sedation or ideally rapid sequence intubation
  • cardiovert (synchronised DC shocks) at 100J : 200J : 360J (or equivalent biphasic energies)

B) If the patient is in rapid atrial fibrillation, then manage as for atrial fibrillation

C) If the patient has a regular narrow complex tachycardia with a rate less than 250 beats per minute:

• give oxygen and obtain i.v. access
• try vagal manoeuvres:
  • carotid sinus massage (if no carotid bruits)
  • valsalva (ask patient to blow into a straw)
• if unsuccessful, try adenosine:
  • make sure patient is in a monitored environment
  • inform the patient that they will experience chest pain
  • use a reasonable sized cannula in a reasonable sized vein
  • chase each dose of adenosine with a flush (at least 20 ml normal saline)
  • start at 6 mg
  • if unsuccessful, increase to 12 mg and repeat up to a total of 3 doses of 12 mg
    • be cautious if known wolf parkinson white syndrome
    • be cautious in asthma as may precipitate bronchospasm
    • patients on dipyridamole, carbamazepine or denervated hearts may exhibit an exaggerated response
    • patients on theophylline may exhibit a diminished response
• if adenosine is unsuccessful then determine the presence of adverse signs:
  • systolic blood pressure less than 90 mmHg
  • pulse rate greater than 200 beats per minute
  • chest pain
  • heart failure
• if one or more adverse signs present:
  • provide sedation or ideally rapid sequence intubation
  • cardiovert (synchronised DC shocks) at 100J : 200J : 360J (or equivalent biphasic energies)
  • if unsuccessful, give i.v. amiodarone 150 mg over 10 minutes, then 300 mg over 1 hour and repeat cardioversion
• if no adverse signs present, consider:
  • i.v. verapamil 5 - 10 mg (but avoid if patient is beta-blocked)
  • i.v. amiodarone 300 mg over 1 hour
  • i.v. esmolol or an alternative short acting beta blocker
  • i.v. digoxin: 500 mcg over 30 minutes repeated as necessary