Wednesday, February 6, 2013

Drowning related out-of-hospital cardiac arrests: characteristics and outcomes.

Drowning related out-of-hospital cardiac arrests: Characteristics and outcomes
Authors: Dyson K, Morgans A, Bray J, Matthews B, Smith K
Journal: Resuscitation, January 2013

This article is a retrospective review of data from the Victorian Cardiac Arrest Registry (VACAR), which aimed to answer the following questions:

  • Of those in cardiac arrest following drowning, what is the survival to hospital rate?
  • Of those in cardiac arrest following drowning, what is the survival to discharge rate?
  • What are some factors which determine these rates?
A total of 336 cases were analyzed, 77% of each involved patients < 18 years of age. The following are important findings:
  • 70.5% occurred in the ocean
  • 17.9% were witnessed
    • These individuals were more likely to receive bystander CPR
    • No significant difference in outcome directly related to bystander CPR
  • EMS resuscitation attempted in 48%
    • Only 8% of these survived to discharge
    • Poor survival for those who did not achieve return of spontaneous circulation with EMS
    • No survivors when EMS response time > 12 min
    • Upon arrival of EMS, majority of patients in PEA arrest of asystole
      • PEA: 20% survival to discharge
      • V fib: 30% survival to discharge
      • Asystole: 3% survival to discharge
This study has the following limitations
  • Performed in single region
  • Retrospective (although introduction stated "prospective")
  • Did not include data on lifeguard involvement, especially in cases of delayed EMS arrival
All in all I was very excited to see this study come out.  It is the type of study I would love to see done more in the US, as It gives Emergency Medicine professionals some objective data to base clinical prognosis on.  Unfortunately is does show an overall dismal outcome for those experiencing cardiac arrest due to drowning.  Further study should aim to include major interventions which may affect outcome and neurological outcome at discharge.