SIMULTANEOUS RADIAL, FEMORAL, AND AORTIC ARTERIAL PRESSURES DURING HUMAN CARDIOPULMONARY-RESUSCITATION

Objective: To examine the validity of interchanging arterial sites and their responses to graded doses of epinephrine during human cardiopul monary resuscitation (CPR). Design: Consecutive case series. Setting: Large, urban Emergency Department. Patients: Adult, normothermic, nonh emorrhagic cardiac arrest patients. Interventions: While receiving adv anced cardiac life support, patients received right atrial (n = 40), a ortic (n = 40), radial (n = 40), and femoral (n = 17) artery catheters . Pressures were measured simultaneously at baseline, after 0.01 mg/kg and 0.2 mg/kg of epinephrine. Measurements and Main Results: The mean aortic compression-phase pressure was 9.3 +/- 10 (sD), 8.1 +/- 11, an d 4.4 +/- 9.5 mm Hg higher than radial artery pressure at baseline, af ter 0.01 mg/kg, and 0.2 mg/kg of epinephrine, respectively (all statis tically significant). When compared with the femoral artery at the sam e time points, the mean aortic compression-phase pressure was also 3.0 +/- 6.8, 1.9 +/- 8, and 0.6 +/- 7.7 mm Hg higher, respectively (none statistically significant). The aortic relaxation-phase pressure was 1 .3 +/- 3.6, 1.1 +/- 3.8, and 1.6 +/- 2.5 mm Hg lower than the radial a rtery at baseline, after 0.01 mg/kg and 0.2 mg(kg of epinephrine, resp ectively (all statistically significant). When compared with the femor al artery at the same time points, the aortic relaxation-phase pressur e was 0.6 +/- 2.0, 0.3 +/- 3.3, and 0.3 +/- 2.4 mm Hg lower, respectiv ely (none statistically significant). Conclusions: Radial artery relax ation-phase pressure, although statistically higher, correlated with a ortic relaxation-phase pressure. Femoral artery relaxation-phase press ure was not statistically different from aortic relaxation-phase press ure. Aortic pressure was statistically higher and had a lower correlat ion with radial artery pressures during compression phase. The aortic to radial artery and aortic to femoral artery compression-phase gradie nts abated with increasing doses of epinephrine therapy. Caution must be used when substituting compression-phase pressure obtained at radia l or femoral artery sites for aortic pressure during human CPR. Corona ry artery perfusion pressures obtained with radial and femoral arterie s correlate with aortic pressure when measuring the response to vasopr essor therapy during CPR when an interpretable waveform exists.