Eficacia da epinefrina, norepinefrina e angiotensina II ana ressuscitação cardiopulmonar : estudo experimental na fibrilação ventricular

AUTOR(ES)
DATA DE PUBLICAÇÃO

1996

RESUMO

The augmentation of peripheral vascular tone, by using alpha-adrenergic drugs, is vital for elevation of coronary perfusion pressure (CorPP) and for restoration of spontaneous circulation (ROSC) during cardiopulmonary resuscitation (CPR). We studied, comparatively to a placebo group, the efficacy of Epinephrine (the standard alpha-adrenergic drug), Norepinephrine (an altemative alpha-adrenergic drug) and Angiotensin-1I (a non-adrenergic vasopressor drug) for increasing CorPP and ROSC rates, in a canine model of closed-chest CPR (CC-CPR) from ventricular fibrillation (VF). Forty mongrel dogs, both sexes, weighing 12.0 :t 3.7 Kg, preanaesthetized with inoval (2 00) and anaesthetized with thiopental (20 mg/Kg), were orotracheally "intubated and ventilated wi~h air (TV: 20 m1/Kg; RR: 15/min). Thoracic aortic pressure (AoP), right atrial pressure (RAP) and the electrocardiogram (EKG) were continuously recorded. VF was induced by passing a low voltage electrical current (4 V, 60 Hz, 500 mA) through a pacing wire transvenously positioned into the right ventricle cavity. Manual closed-chest CPR (1 ventilationl 5 chest compressions) was initiated 10 min after the beginning of the VF. The animaIs were then divided into four equal groups and they received by a central IV line, in bolus, at the end !of the second minute of basic CC-CPR: Saline, 10 00 (group A); Angiotensin lI, 0.1 mg/Kg (group B); Epinephrine, 0.2 mg/Kg (group C) and Norepinephrine, 0.2 mg/Kg (group D). Defibrillation attempts were initiated 2 minutes after drugs injections by delivering sequential DC shocks at 15 seconds intervals, until a viable electrocardiographic rythm had been obtained or a maximum of 6 DC shocks had been delivered. CorPP values measured at the control period in groups A, B, C and D were, respectively: 113.5 :t 21.3; 109.8 :t 14.0; 117.5 :t 19.9 and 108.8 :t 19.7 mmHg (p = NS). At the end of the 10th minute of VF, CorPP was virtually zero in all four animal groups. At the end of the 2nd minute of basic CC-CPR, the measured vaIues of CorPP in the same groups were, respectively: 7.6 :!: 9.8; 6.4 :!: 2.9; 8.0 :!: 6.2 and 10.2 :!: 4.7 mmHg (p = NS). At the end ofthe 4th minute of CC-CPR (2 min afier drugs administration), the measured vaIues of CorPP in groups A, B, C and D were, respectively: 11.2 :!: 14.2; 36.2 :!: 9.9; 14.0:!: 7.6 and 27.0 :!: 13.2 mmHg (p =0.0003, group B and D in relation to groups A and C). ROSC was obtained in 1/10 (10%) animaIs in group A; 8/10 (80%) in group B; 1/10 (10%) in group C and 7/10 (70%) animaIs in group D. StatisticaIly significant differences were observed by comparing groups B and D to A and C (p = 0.0004 and 0.002, respectively). Angiotensin II (0.1 mg/Kg) and Norepinephrine (0.2 mg/Kg) were highly effective for increasing CorPP and for ROSC, whereas EPI (0.2 mg/Kg) was not superior to placebo, in this canine model of CPR from VF. These data indicate the need of further investigations about the role of altemative vasopressor drugs to EPI for using during CPR, especiaIly non-adrenergic ones, like Angiotensin II

ASSUNTO(S)

ressuscitação cardiopulmonar (primeiros socorros) fibrilação ventricular angiotensina

ACESSO AO ARTIGO

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