Catecholamines during cardiopulmonary resuscitation for cardiac arrest

Serum catecholamines were measured during continued prolonged cardiopulmonary resuscitation and after 10 mg increments of intravenous epinephrine. This was part of an ongoing trial of 10 mg epinephrine versus placebo. Eight patients were in the placebo arm and seven in the epinephrine arm and the rhythms were two ventricular fibrillation, nine asystole and four electromechanical dissociation. Data were analysed by time from onset of the cardiac arrest and samples were analysed for levels of DHPG (dihydroxyphenylglycol) nor-epinephrine, epinephrine, DOPA (dihydroxyphenylalanine) and DOPAC (dihydroxyphenyl acetic acid). There was a significant (P < 0.001) difference between arterial and venous samples of epinephrine but not the other catecholamines. High levels of catecholamines were maintained in all time phases except for nor-epinephrine where significant (P < 0.0003) reduction occurred progressively after 20 min. Non-steady state kinetics were suggested between epinephrine and nor-epinephrine and DHPG and nor-epinephrine for the first 20 min. Very large increases in epinephrine were achieved with administered 10 mg epinephrine and this resulted in high DHPG levels supporting the experimental belief that exogenously administered epinephrine induces myocardial release of nor-epinephrine. This data supports the known effects of CPR on catecholamine release. It provides data on the other neurotransmitter hormones and supports the relationships shown in other animal and human data. It is suggested that supplementation with epinephrine during CPR may be unnecessary and the levels reached may be deleterious. Nor-adrenaline supplementation may be necessary after prolonged CPR.