Defibrillation, CPR, gender predict survival after out of hospital cardiac arrest
MedWire News: A short delay to defibrillation, bystander cardiopulmonary resuscitation (CPR), and female gender are strong predictors of survival after out-of-hospital cardiac arrest (OHCA), a Swedish team reports.
In particular, the researchers found that a doubling in survival to 1 month after ventricular fibrillation corresponded with a marked increase in bystander CPR, over an 18-year period in Sweden.
Johan Herlitz (Sahlgrenska University Hospital, Göteborg) and colleagues followed-up 7187 patients who were found in bystander-witnessed ventricular fibrillation with a presumed cardiac etiology between 1992 and 2009, for the outcomes of survival to hospital admission with a pulse, and survival to 1 month.
The findings revealed that the proportion of patients who received bystander CPR increased from 46% in 1992 to 73% in 2009.
The median delay from collapse to defibrillation increased from 12 minutes to 14 minutes (p=0.0004).
The authors hypothesize that this could be due to resource limitations, as a greater burden was placed on emergency medical services in 2009 than in 1992.
Over the same time period, the number of patients who survived to hospital admission with a pulse increased from 28% to 45%.
The number of patients who survived to 1 month also increased, from 12% to 23%.
"This indicates that during the past decade post-resuscitation care has changed," write the authors.
Multivariate analysis revealed that female gender, OHCA at home, bystander CPR, and a long delay from collapse to defibrillation (>12 min) were strong predictors of survival to hospital admission (odds ratio [OR]=1.82, 0.77, 1.70, 0.30, respectively) and survival to 1 month (OR=1.43, 0.50, 2.47, 0.24, respectively).
Herlitz et al propose that the higher rate of survival to hospital admission and to 1 month observed in women is because they experience OHCA less frequently than men.
They add that factors such as comorbidity could explain why patients experiencing OHCA outside the home have higher survival rates.
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By Piriya Mahendra