Prehospital Care Manual online - Contra Costa Health Services

UNSTABLE SVT
• May need immediate synchronized cardioversion
• Signs of poor perfusion include moderate to severe chest pain, dyspnea, altered mental status,
blood pressure less than 90 or CHF
• If rhythm not regular, SVT unlikely
• If wide QRS complex, consider ventricular tachycardia
CONSIDER
ADENOSINE
CONSIDER
SEDATION
SYNCHRONIZED
CARDIOVERSION
6 mg rapid IV - followed by 20 ml normal saline flush
If not converted, 12 mg rapid IV 1-2 minutes after initial dose, followed by 20 ml
normal saline flush
Prepare for CARDIOVERSION. If awake and aware, sedate with
MIDAZOLAM - initial dose 1 mg IV, titrate in 1-2 mg increments (max. dose 5 mg)
100 joules (low energy setting – 75 W/S)
200 joules (low energy setting – 120 W/S)
300 joules (low energy setting – 150 W/S)
360 joules (low energy setting – 200 W/S)
Key Treatment Considerations
• Document rhythm during treatment with continuous strip recording
• Rhythm analysis should be based on review of P and QRS waves on printed strip, not monitor screen or
computerized readout of 12-lead ECG
• Be prepared for previously stable patient to become unstable
• Proceed to cardioversion if patient becomes unstable
• Hypoxemia is a common cause of tachycardia. Focus on determining if oxygenation is adequate.
• Adenosine should not be administered to patients with acute exacerbation of asthma
• If sedation used for cardioversion, monitor respiratory status closely and support ventilation as needed