Use of esmolol after failure of standard cardiopulmonary resuscitation to treat patients with refractory ventricular fibrillation

Driver. Resuscitation 2014;(85),1337-1341. http://dx.doi.org/10.1016/j.resuscitation.2014.06.032

Clinical Question

• In patients with refractory ventricular fibrillation does the use of esmolol improve mortality?

Design

• Retrospective observational analysis
• Non-randomised
• Non-blinded

Setting

• Single centre, tertiary Emergency Department, USA
• January 2011 – January 2014

Population

• Inclusion:
  • ED diagnosis coded as: cardiac arrest, ventricular fibrillation or pulseless VT
  • initial rhythm: VF or VT
  • had received at least 3 defibrillation attempts, 300mg amiodarone and 3mg adrenaline and remained in cardiac arrest
• Exclusion: received esmolol before cardiac arrest or after return of spontaneous circulation
• 25 patients included

Intervention

• Esmolol
  • loading dose 500mcg/kg
  • followed by infusion: 0-100mcg/kg/min

Control

• Patients that did not receive esmolol

Outcome

• Primary outcome: not defined
  • survival with good neurological outcome
    • 50% in esmolol group vs. 11% in control group, P=0.07
  • no significant difference in rates of ROSC or survival to discharge

Authors’ Conclusions

• Prospective studies of beta-blockade in cardiac arrest are warranted. In patients with refractory VF beta-blockade should be considered

Strengths

• Clear inclusion/exclusion criteria
• Standardised dosing of esmolol
• Reported use of therapeutic hypothermia and emergent cardiac catheterisation
• Reported patient-orientated outcomes

Weaknesses

• Retrospective
• Small sample size
• Non-randomised, non-blinded. Unclear why some patients treated with esmolol and others were not. Unclear why different rates of therapeutic hypothermia and emergent cardiac catheterisation between the two groups