Heretic

[Guest guest]

Call be a heretic, but, I'll bet 2-3 years from now we will be giving NO

medications for cardiac arrest:

Effects of epinephrine and vasopressin on cerebral microcirculatory flows

during and after cardiopulmonary resuscitation.

Ristagno G, Sun S, Tang W, Castillo C, Weil MH.

Weil Institute of Critical Care Medicine, Rancho Mirage, CA, USA.

OBJECTIVES: Both epinephrine and vasopressin increase aortic and carotid

arterial pressure when administered during cardiopulmonary resuscitation.

However, we recently demonstrated that epinephrine reduces cerebral cortical

microcirculatory blood flow. Accordingly, we compared the effects of

nonadrenergic vasopressin with those of epinephrine on cerebral cortical

microvascular flow together with cortical tissue Po2 and Pco2 as indicators

of cortical tissue ischemia. DESIGN: Randomized, prospective animal study.

SETTING: University-affiliated research laboratory. SUBJECTS: Domestic pigs.

MEASUREMENTS AND MAIN RESULTS: The tracheae of ten domestic male pigs,

weighing 40 +/- 2 kg, were noninvasively intubated, and the animals were

mechanically ventilated. A frontoparietal bilateral craniotomy was created.

Microcirculatory blood flow was quantitated with orthogonal polarization

spectral imaging. Blood flow velocity in pial and cortical penetrating

vessels measuring <20 microm was graded from 0 (no flow) to 3 (normal).

Cerebral cortical tissue carbon dioxide and oxygen tensions (Pbco2 and Pbo2)

were measured concurrently using miniature optical sensors. Ventricular

fibrillation, induced with an alternating current delivered to the right

ventricular endocardium, was untreated for 3 mins. Animals were then

randomized to receive central venous injections of equipressor doses of

epinephrine (30 microg/kg) or vasopressin (0.4 units/kg) at 1 min after the

start of cardiopulmonary resuscitation. After 4 mins of cardiopulmonary

resuscitation, defibrillation was attempted. Spontaneous circulation was

restored in each animal. However, postresuscitation microvascular flows and

Pbo2 were greater and Pbco2 less after vasopressin when compared with

epinephrine. We observed that a significantly greater number of cortical

microvessels were perfused after vasopressin. CONCLUSIONS: Cortical

microcirculatory blood flow was markedly reduced after epinephrine,

resulting in a greater severity of brain ischemia after the restoration of

spontaneous circulation in contrast to the more benign effects of

vasopressin.

__________________________________________________________

Ann Emerg Med. 2007 May 23; [Epub ahead of print] Links

Survival Outcomes With the Introduction of Intravenous Epinephrine in the

Management of Out-of-Hospital Cardiac Arrest.

Ong ME, Tan EH, Ng FS, Panchalingham A, Lim SH, Manning PG, Ong VY, Lim SH,

Yap S, Tham LP, Ng KS, Venkataraman A; Cardiac Arrest and Resuscitation

Epidemiology Study Group.

Department of Emergency Medicine, Singapore General Hospital.

STUDY OBJECTIVE: The benefit of epinephrine in cardiac arrest is

controversial and has not been conclusively shown in any human clinical

study. We seek to assess the effect of introducing intravenous epinephrine

on the survival outcomes of out-of-hospital cardiac arrest patients in an

emergency medical services (EMS) system that previously did not use

intravenous medications. METHODS: This observational, prospective,

before-after clinical study constitutes phase II of the Cardiac Arrest and

Resuscitation Epidemiology project. Included were all patients who are older

than 8 years, with nontraumatic out-of-hospital cardiac arrest conveyed by

the national emergency ambulance service. The comparison between the 2

intervention groups for survival to discharge was made with logistic

regression and expressed in terms of the odds ratio (OR) and the

corresponding 95% confidence interval (CI). RESULTS: From October 1, 2002,

to October 14, 2004, 1,296 patients were enrolled into the study, with 615

in the pre-epinephrine and 681 in the epinephrine phase. Demographic and EMS

characteristics were similar in both groups. Forty-four percent of patients

received intravenous epinephrine in the epinephrine phase. There was no

significant difference in survival to discharge (pre-epinephrine 1.0%;

epinephrine 1.6%; OR 1.7 [95% CI 0.6 to 4.5]; adjusted for rhythm OR 2.0

[95% CI 0.7 to 5.5]); return of circulation (pre-epinephrine 17.9%;

epinephrine 15.7%; OR 0.9 [95% CI 0.6 to 1.2]), or survival to admission

(pre-epinephrine 7.5%; epinephrine 7.5%; OR 1.0 [95% CI 0.7 to 1.5]). There

was a minimal increase in scene time in the epinephrine phase (10.3 minutes

versus 10.7 minutes; 95% CI of difference 0.02 to 0.94 minutes). CONCLUSION:

We were unable to establish a significant survival benefit with the

introduction of intravenous epinephrine to an EMS system. More research is

needed to determine the effectiveness of drugs such as epinephrine in

resuscitation.

E. Bledsoe, DO, FACEP

Midlothian, Texas

[Guest guest]

>>> Call be a heretic, but, I'll bet 2-3 years from now we will be

giving NO medications for cardiac arrest: <<<

It'll make the ACLS class much shorter!

See you in Virginia.

Kenny Navarro

Dallas

[Guest guest]

Then what will happen to all of those poor ACLS, PALS, XYZLS etc.

instructors. They wont have any classes to teach. Will this be the

begining of the end of scout patch medicine as we know it?

AJL

On Nov 6, 2007 11:05 PM, Kenny Navarro

wrote:

>

>

>

>

> >>> Call be a heretic, but, I'll bet 2-3 years from now we will be

> giving NO medications for cardiac arrest: <<<

>

> It'll make the ACLS class much shorter!

>

> See you in Virginia.

>

> Kenny Navarro

> Dallas

>

>

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>