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Aortic surgery: effect of clonidine on intraoperative catecholaminergic and circulatory stability

1990; Wiley; Volume: 34; Issue: 2 Linguagem: Inglês

10.1111/j.1399-6576.1990.tb03057.x

1399-6576

Luc Quintin, Françis Bonnet, I. Macquin, Barbara Székély, J.-P. Becquemin, M. Ghignone,

Hemodynamic Monitoring and Therapy

Twenty‐eight patients presenting for aortic surgery were randomly assigned in a double‐blind, placebo‐controlled protocol to receive placebo (n=14) or clonidine (4.7 ± 1.2 μg · kg ‐1 po; n=14), in addition to flunitrazepam 120 min before induction of anesthesia. Plasma catecholamines (CA) and hemodynamic variables were determined at 7 stages during surgery. In the placebo group, plasma epinephrine (E) and norepinephrine (NE) had risen twofold at skin closure compared to baseline (E: from 109 ± 51 pg p ml ‐1 to 294 ± 161 pg · ml ‐1 ; NE: from 658 ± 226 to 1150 ± 494 pg · ml ‐1 ). Plasma CA were significantly lower in the clonidine group ( P <0.001 and 0.01 vs placebo for NE and E respectively). In both groups, similar directional changes were observed for the circulatory variables, upon aortic clamping and declamping. In the clonidine group, however, mean arterial pressure was lower at most stages ( P <0.05 vs placebo); moreover, stroke volume index was greater in the clonidine group ( P >0.05) upon declamping. This improved stability in the clonidine group was achieved with a halving in the number of anesthetic/circulatory interventions ( P >0.05 vs placebo). Provided intravascular volume is adequate, clonidine suppresses the increase in plasma catecholamines induced by aortic surgery and improves circulatory stability, with a reduced number of anesthetic/ circulatory adjustments.