Blyth L, et al. Bedside focused echocardiography as predictor of survival in cardiac arrest patients a systematic review.Acad Emerg Med. 2012:1119-26.
Objective
o Determine if focused transthoracic echo can be used during resuscitation to predict cardiac arrest outcomes
Method
o Literature search of diagnostic accuracy studies using traditional medical search engines
o A hand search of references was performed and experts in the field were contacted
o Included studies for further appraisal and analysis only if the selection criteria and standards were met
o Appraised and scored by two independent reviewers using a modified quality assessment tool for diagnostic
accuracy studies (QUADAS) to select the papers included in the meta-analysis
Results
o Initial search had 2,538 unique papers
o 11 were determined to be relevant after screening criteria were applied by two independent researchers
o One additional study was identified after the initial search for a total of 12 papers
o Total number of patients was 568; all had echo during resuscitation to determine the presence or absence of kinetic cardiac activity and were followed up to determine ROSC
o Meta-analysis of the data showed as a predictor of ROSC during cardiac arrest;
- Echo had a pooled sensitivity of 91.6% (95% confidence interval [CI] = 84.6% to 96.1%)
- Echo had a pooled specificity of 80.0% (95% CI = 76.1% to 83.6%)
- Positive likelihood ratio for ROSC was 4.26 (95% CI = 2.63 to 6.92)
- Negative likelihood ratio was 0.18 (95% CI = 0.10 to 0.31)
- Heterogeneity of the results (sensitivity) was nonsignificant
Conclusion
o Echocardiography performed during cardiac arrest that demonstrates an absence of cardiac activity harbors a significantly lower (but not zero) likelihood that a patient will experience ROSC
o In other words if we look with a probe and see no activity, we can use it as an additional piece of information that makes it less likely to be ROSC
o In selected patients with a higher likelihood of survival from cardiac arrest at presentation, based on
established predictors of survival, echo should not be the sole basis for a decision to end resuscitative efforts
o Echo should continue to be used only as an adjunct to clinical assessment in predicting the outcome of resuscitation for cardiac arrest.
