Wednesday, December 21, 2011

Nitroprusside Saves Pigs - How About Humans?

Essentially, no ACLS medication therapy has been shown to be terribly efficacious with regard to meaningful patient outcomes.  Epinephrine - if we could find a way to satisfactorily preserve neurologic and cardiovascular status after return of spontaneous circulation - seems to have a small helpful effect, but has all sorts of deleterious effects on LV function and cerebral perfusion.  Otherwise, nothing is proving useful other than CPR, shock ventricular arrhythmias, and hope for the best.

I posted about this back in April, and it's another article - from the same masters of porcine resuscitation up in Minneapolis - about a second series of protocols they used to evaluate "sodium nitroprusside enhanced CPR"(SNPeCPR).  The CPR is the same.  The SNPe part is multiple doses of IV sodium nitroprusside and an impedance threshold device, along with a more limited role for epinephrine administration.

They ran two protocols for this study.  Protocol A was a ventricular fibrillation model with 6 standard CPR pigs, 6 CPR + impedance threshold, and 12 SNPeCPR pigs.  Protocol A favored ROSC in SNPeCPR - 0/6, 0/6, and 12/12.

Protocol B was a PEA model with 8 pigs of standard CPR vs 8 pigs of SNPeCPR.  Protocol B favored ROSC in SNPeCPR - 0/6 vs. 7/8.

I think they might be onto something here, but I am still a little wary about the results because both these articles are from the same institution and they keep using these idealized perfusion platforms.  Other investigators should heed this research to evaluate whether their methods are externally valid and warrant human trials.

"Sodium nitroprusside-enhanced cardiopulmonary resuscitation improves resuscitation rates after prolonged untreated cardiac arrest in two porcine models"

1 comment:

  1. Nitrates may be much more effective than the drugs we currently use for resuscitation, but we need to use studies with enough patients and with high quality CPR.

    High dose nitroglycerin treatment in a patient with cardiac arrest: a case report.
    Guglin M, Postler G.
    J Med Case Reports. 2009 Aug 10;3:8782.
    PMID: 19830240 [PubMed]

    The full text is available for free at PubMed Central.

    We are terrified of the effects of high-dose nitrates, but high-doses seem to preferentially decrease afterload.

    Pressors seem to have the opposite effect.

    Maybe we need to be able to identify which subsets of patients might benefit from which drugs and which benefit from no drugs.



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