All Falling Apart for Epinephrine

A staple of resuscitative care, epinephrine is enshrined in the ACLS algorithms for the pulseless patient.  And, what seems to be clear – flogging the heart with vasoactive agents produces, at least, a temporary physiologic response.  Unfortunately, such sympathomimetic abuse results in multiple adverse effects, included coronary and cerebral vasoconstriction – and the net effect, perhaps, is negative.

This is a retrospective review of 1,556 patients admitted to a “cardiac arrest center” in Paris, France, evaluating cerebral performance outcomes depending upon pre-hospital administration of epinephrine.  Of the 1,134 patients who received epinephrine, 17% ultimately had good outcome.  Of the remaining 422 patients who did not receive epinephrine, 63% ultimately had good outcome.  The authors also demonstrate worsening outcomes for epinephrine administration in a dose-dependent fashion.  Cheers.

Of course, it should follow naturally the patients receiving epinephrine probably did so because they were judged to need it – whereas, contrariwise, those not receiving epinephrine probably did not receive it because they were sufficiently stable.  And, then, failure to achieve initial return of spontaneous circulation begets additional doses of epinephrine.  Thus, you have a selection bias in which sicker patients were naturally allocated to epinephrine and less-sick patients to non-treatment – and an accounting for the dose-response relationship.  The authors perform multiple adjustments and propensity matches in an attempt to prove the outcome disparity durable to these validity challenges, but the astute reader may find them insufficient.

This study, nor any of the observational studies preceding it, definitively prove the harms of use of epinephrine pre-hospital outweighs the benefits.  I have, at least, stopped routinely using epinephrine in undifferentiated cardiac arrest, and rather try to select specific patients for whom the underlying etiology seems appropriate.

“Is Epinephrine During Cardiac Arrest Associated With Worse Outcomes in Resuscitated Patients?”