Hemodynamic effects of thoracic epidural analgesia in ovine hyperdynamic endotoxemia.
OBJECTIVE
Thoracic epidural analgesia (TEA) is increasingly used for perioperative analgesia. If patients with TEA develop sepsis or systemic inflammatory response subsequent to extended surgery the question arises if it would be safe to continue TEA with its beneficial effects of improving gastrointestinal perfusion and augmenting tissue oxygenation. A major concern in this regard is hemodynamic instability that might ensue from TEA-induced vasodilation. The objective of the present study was to assess the effects of TEA on systemic and pulmonary hemodynamics in a sepsis model of hyperdynamic endotoxemia.


METHODS
After a baseline measurement in healthy sheep (n = 14), Salmonella thyphosa endotoxin was continuously infused at a rate of 10 ngxkg(-1)xmin(-1) over 16 hours. The surviving animals (n = 12) were then randomly assigned to 1 of 2 study groups. In the treatment group (n = 6), continuous TEA was initiated with 0.1 mLxkg(-1) bupivacaine 0.125% and maintained with 0.1 mLxkg(-1)xh(-1). In the control group (n = 6) the same amount of isotonic sodium saline solution was injected at the same rate through the epidural catheter.


RESULTS
In both experimental groups cardiac index increased and systemic vascular resistance decreased concurrently (each P < .05). Functional epidural blockade in the TEA group was confirmed by sustained suppression of the cutaneous (or panniculus) reflex. During the observational period of 6 hours neither systemic nor pulmonary circulatory variables were impaired by TEA.


CONCLUSIONS
From a hemodynamic point of view, TEA presents as a safe treatment option in sepsis or systemic inflammatory response syndrome.
Daudel
Fritz
F
Department of Intensive Care Medicine, University Hospital of Bern, Bern, Switzerland. fritz.daudel@insel.ch
Ertmer
Christian
C
Stubbe
Henning D
HD
Lange
Matthias
M
Pulina
Rafael
R
Bone
Hans-Georg
HG
Sielenkämper
Andreas W
AW
Van Aken
Hugo
H
Westphal
Martin
M
D015360:Analgesia, Epidural / Q000379:methods*; D000818:Animals; D002302:Cardiac Output / Q000502:physiology; D000075202:Contraindications; D004195:Disease Models, Animal; D019446:Endotoxemia / Q000503:physiopathology*; D011897:Random Allocation; D012485:Salmonella typhi; D012756:Sheep; D013904:Thoracic Vertebrae / Q000294:innervation; D014655:Vascular Resistance / Q000502:physiology; D014664:Vasodilation / Q000502:physiology*