Effects of epidural anesthesia on cardiovascular response and survival in experimental hemorrhagic shock in dogs.
The purpose of the present study was to assess the effects of epidural anesthesia on cardiovascular responses and survival in experimental hemorrhagic shock in dogs. Thirty mongrel dogs were randomly assigned to one of three groups on the basis of anesthetic technique: the upper-level group (n = 10), receiving general anesthesia plus upper-level (mainly thoracic region) epidural anesthesia; the lower-level group (n = 10), receiving general anesthesia plus lower-level (mainly lumbar region) epidural anesthesia; and the control group (n = 10), receiving general anesthesia alone. After withdrawal of blood, the changes in mean arterial pressure (40 mmHg) and cardiac index were similar in all groups. In the upper-level group, a lower heart rate and systemic vascular resistance than the control group were maintained throughout in the presence of severe hypotension. A significant difference in survival was seen between the upper-level and control groups over the 100-min observation period as a whole (P less than 0.05 by the Generalized Wilcoxon test), since, at the end of the period, only two of the ten animals in the control group survived, whereas nine of ten in the upper-level group survived (P less than 0.001 by the Kaplan-Meier test). This result demonstrates that, in dogs lightly anesthetized with halothane and nitrous oxide, upper thoracic level epidural anesthesia significantly improves survival in experimental hemorrhagic shock (compared with survival in dogs with lumbar epidural or no epidural anesthesia) when the epidural is performed before hemorrhage and when the mean arterial pressure is constant.(ABSTRACT TRUNCATED AT 250 WORDS)
Shibata
K
K
Department of Anesthesiology, School of Medicine, Kanazawa University, Japan.
Yamamoto
Y
Y
Murakami
S
S
D000767:Anesthesia, Epidural; D000818:Animals; D004285:Dogs; D004837:Epinephrine / Q000097:blood; D007773:Lactates / Q000097:blood; D008619:Mepivacaine; D009638:Norepinephrine / Q000097:blood; D011379:Prognosis; D011773:Pyruvates / Q000097:blood; D012771:Shock, Hemorrhagic / Q000097:blood / Q000503:physiopathology*
D007773:Lactates; D011773:Pyruvates; D008619:Mepivacaine; D009638:Norepinephrine; D004837:Epinephrine