Wide Complex Tachycardia Uncertain Origin

Section 4 - CARDIAC 4.10

WIDE COMPLEX TACHYCARDIA – UNCERTAIN ORIGIN (Heart rate >160 beats/minute)

• INITIAL MEDICAL CARE (2.01) - OXYGEN @ 100% via NRB mask or assist with BVM.

STABLE and SVT highly likely:

• ADENOSINE (Adenocard) 6 mg rapid IVP over 1-3 seconds
• If no response in 2 minutes, ADENOSINE 12 mg rapid IVP over 1-3 seconds
• If no response in 2 minutes, repeat ADENOSINE 12 mg rapid IVP over 1-3 seconds

STABLE and unknown wide complex or ventricular tachycardia likely:

• LIDOCAINE 1 mg/kg IV over 3-5 minutes If no response, LIDOCAINE 0.5-0.75 mg/kg IV over 3-5 minutes (may repeat to a maximum of 3 mg/kg administered. In patients over age 70 or in those with known hepatic disease, administer LIDOCAINE boluses at 0.25 mg / kg until maximum of 1.5 mg / kg.

UNSTABLE WIDE COMPLEX TACHYCARDIA:

• SYNCHRONIZED CARDIOVERSION @ 100 Joules.
  • If IV established prior to patient becoming UNSTABLE, may administer VERSED 2-5 mg IVP, IO or IN and repeat 2 mg every 30 seconds to 1 minute if patient is conscious.
• If tachycardia converts refer to STABLE section for administration of LIDOCAINE.
• If NO response, SYNCHRONIZED CARDIOVERSION @ 200 Joules.
• If NO response. SYNCHRONIZED CARDIOVERSION @ 300 Joules.
• If NO response, SYNCHRONIZED CARDIOVERSION @ 360 Joules.
• Following electrical cardioversion if no antiarrythmic agent was given,
  • Administer LIDOCAINE 1.0 mg/kg IV bolus. Use ½ dose if hypotensive. Follow with continuous infusion at 2-4 mg/min Contraindicated if ventricular escape rhythm
• If LIDOCAINE was given previously
  • Follow with continuous infusion at 2-4 mg/min Contraindicated if ventricular escape rhythm.
• If HYPERKALEMIA suspected in any wide complex Tachycardia, Suspect in patients with any of the following:
  • Diagnosis of Renal Failure or any form of Kidney insufficiency
  • Widening QRS,
  • Increased K+ in diet (excessive consumption of cherries, bananas, melons or citrus) , Acidosis, or Shock.
  • Note last dialysis TX.
  • CALCIUM CHLORIDE 1 gm IV (Avoid if patient is on digoxin/lanoxin)
  • SODIUM BICARBONATE 1 mEq/kg IV

Physician's Orders: If no response, contact Medical Control for consult.

Discontinue boluses in patients who now manifest tachycardia with hypotension, altered mental status, or widening of the QRS complex.

This Standing Order is divided between the care and treatment of the stable patient verses the unstable patient. As a matter of definition agreed upon by the Medical Directors, the UNSTABLE patient is one who presents with any of the following: SIGNIFICANT CARDIAC, SUSPECTED CARDIAC, SIGNIFICANT DYSPNEA, ALTERED MENTAL STATUS, OR HYPOTENSION WITH SIGNS OF DECREASED TISSUE PERFUSION, OR SIGNIFICANT COMPROMISE OF AIRWAY, BREATHING, AND/OR CIRCUATION.

If the patient presents with one or more of the above UNSTABLE criteria, DEFIBRILLATION should be administered to avoid delays associated with synchronization.