[Hemodynamic effects of aortic occlusion during inhalational anesthesia with isoflurane and sevoflurane: experimental study in dogs].
OBJECTIVE
Aortic flow suppression and release during aortic procedures promote major hemodynamic disorders. This study aimed at evaluating these disorders in dogs anesthetized with isoflurane or sevoflurane.


METHODS
This study involved 41 dogs divided in two groups according to the anesthetic agent used for maintenance with 1 MAC: GI (n = 21) isoflurane; GS (n = 20) sevoflurane. Aorta was occluded by intra-arterial infra-diafragmatic cuff inflation for 30 minutes. Hemodynamic parameters were observed in moments M1 (control), M2 and M3, 15 and 30 minutes after aortic occlusion, M4 and M5, 15 and 30 minutes after cuff deflation.


RESULTS
During aortic occlusion there has been increased mean blood pressure (MBP), central venous pressure (CVP), pulmonary artery pressure (PAP), pulmonary capillary wedge pressure (PCWP) and systemic vascular resistance (SVR), without increase in pulmonary vascular resistance (PVR) and cardiac output (CO). CO was more stable with isoflurane as compared to sevoflurane where it has decreased after occlusion. Heart rate has initially decreased followed by increase during occlusion, being more expressive in GS as compared to GI, however without statistically significant difference between groups. Systolic volume was not importantly changed; left and right ventricular function have similarly increased after occlusion for both groups. With flow release, MBP, CVP, PAP, PCWP and SVR have decreased, and PVR has increased for both groups; ventricular function has abruptly decreased.


CONCLUSIONS
This study has shown that isoflurane is a better indication for such interventions for promoting less hemodynamic changes.
Udelsmann
Artur
A
Departamento de Anestesiologia, FCM, UNICAMP, Brazil. artur@fcm.unicamp.br
Munhoz
Derli Conceição
DC
Cintra
Alvaro Edmundo Simões Ulhoa
AE
Santos
José Eduardo Tanus dos
JE