LIDOCAINE

1
LIDOCAINE

• Hrach Ike Kasaryan

2
Mechanism

• lengthens phase 4 diastolic depolarization,
  decreases automaticity, and causes a decrease or
  no change in excitability and membrane
  responsiveness.
• Action potential duration and effective
  refractory period of Purkinje fibers are
  decreased

3
Dose for VTACH

• 1-1.5 mg/kg IV push, followed by 0.5-0.75 mg/kg
  IV push to a maximum of 3 mg/kg
• Continuous 14 mg/min infusion should be started
  after arrhythmia is suppressed

4
Contraindication

• Documented hypersensitivity to amide-type local
  anesthetics
• avoid in Adams-Stokes syndrome and
  Wolf-Parkinson-White syndrome
• avoid in severe sinoatrial, atrioventricular
  (AV), or intraventricular block if artificial
  pacemaker not in place

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ADVERSE REACTIONS

• The most common adverse effect of lidocaine is
  central nervous system (CNS) toxicity
• These side effects may be particularly frequent
  in the elderly or in those with congestive heart
  failure, settings in which CNS levels are
  increased due to a reduced volume of
  distribution.
• Tremor is a useful bedside sign of toxicity
• High plasma concentrations of lidocaine can also
  provoke seizures

6
Adverse Reactions

• Cardiac side effects are an infrequent
• generally well tolerated even by patients with
  significant underlying heart disease
• conduction through the sinus and atrioventricular
  nodes is suppressed
• may elevate fibrillation thresholds
• negative inotropic effect on the myocardium and
  direct peripheral vasodilation may occur, which
  can produce hypotension

7
Evidence?

• Lidocaine has never been tested against placebo
  control in the VF situation
• Amiodarone versus Lidocaine In pre-hospital
  Ventricular fibrillation Evaluation (ALIVE) trial
  
• compared the effectiveness of lidocaine with
  amiodarone in patients with out-of-hospital VF
  that persisted or recurred despite three
  defibrillations, adrenaline and a further
  defibrillation

8
Evidence?

• number of patients surviving to hospital
  admission (primary end point) was significantly
  greater in the group receiving amiodarone
  compared with the lidocaine group (22.7 compared
  with 11.0, respectively, P0.0043).

9
Evidence?

• Amiodarone in Out-of-Hospital Resuscitation for
  Refractory Ventricular Tachycardias (ARREST)
  trial
• amiodarone was tested against placebo
• Patients who received amiodarone were more likely
  to be resuscitated and admitted to hospital than
  those who received placebo (44 and 34,
  respectively)