[Comparative study of circulatory response to tracheal intubation with atracurium and succinylcholine]. / Estudo comparativo das respostas circulatórias à intubação traqueal com atracúrio ou succinilcolina.

Changes in some circulatory parameters after orotracheal intubation (OTI) were investigated in 40 patients anesthetized with thiopental 5.0 mg.kg-1 and fentanyl 100 micrograms, receiving either atracurium 0.5 mg.kg-1 (n = 20) or succinylcholine 1.0 mg.kg-1 (n = 20) to facilitate intubation. In the succinylcholine group (SC), mean values of SAP, DAP, MAP, and HR rose significantly in relation to control at 30 sec and 2 min after OTI. In the atracurium group (A), mean values of SAP, DAP, and MAP rose significantly at 30 sec after OTI, however, contrary to the SC group, mean values of HR did not rise significantly after OTI. Mean values of the double product HR x SAP rose significantly at 30 sec, 2 min, and 5 min after OTI in the SC group, but only at 30 sec and 2 min after OTI in the A group. The magnitude of elevation of those circulatory parameters studied was always greater in the SC group than in the A group. The authors conclude that atracurium does not modify the nature of circulatory changes after OTI but is associated to such changes in a lesser degree when compared to succinylcholine in a standard induction technique with thiopental/fentanyl.