Advanced life support versus basic life support in the pre-hospital setting: a meta-analysis.

Background: The scientific evidence of a beneficial effect of ALS in pre-hospital treatment in trauma patients or patients with any acute illness is scarce. The objective of this systematic review of controlled studies was to examine whether ALS, as opposed to BLS, increases patient survival in pre-hospital treatment and if so, to identify the patient groups that gain benefit.

Methods: A systematic review of studies published in the databases Medline (PubMed), EMBASE, Cochrane Library and Scopus up to July 31st, 2010. Controlled studies comparing survival after the pre-hospital ALS treatment versus BLS treatment in trauma patients or patients with cardiac arrest were included.

Results: We identified 1081 studies of which 18 met our inclusion criteria. In nine of 18 studies including 16,857 trauma patients in the intervention group, ALS care did not increase survival compared to BLS treatment (pooled OR 0.892, 95% CI, 0.775-1.026). In nine of 18 studies including 7659 patients with cardiac arrest in the intervention group, ALS care increased survival compared to BLS treatment (OR 1.468, 95% CI, 1.257-1.715). Most subgroup analyses revealed no significant interactions, but data from six trials, where ALS was provided by physicians, increases the probability of survival at hospital discharge even more (OR 2.047, 95% CI 1.593-2.631).

Conclusion: Implementation of ALS care to non-traumatic cardiac arrest patients can increase survival and further research is unlikely to change our confidence in the estimate of the effect. On the contrary, in trauma patients our meta-analysis revealed that ALS care is not associated with increased survival. However, only few controlled studies of sufficient quality and strength examining survival with pre-hospital ALS treatment exist.