title: Effects of thoracic epidural anesthesia on hemodynamics and global oxygen transport in ovine endotoxemia.
abstract: Besides providing effective analgesia, thoracic epidural anesthesia (TEA) has been shown to decrease perioperative morbidity and mortality. Because of its vasodilatory properties in association with the sympathetic blockade, however, TEA may potentially aggravate cardiovascular dysfunctions resulting from sepsis and systemic inflammatory response syndrome. The objective of the present study was to assess the effects of TEA on hemodynamics, global oxygen transport, and renal function in ovine endotoxemia. After a baseline measurement in healthy sheep (n = 18), Salmonella typhosa endotoxin was centrally infused at incremental doses to induce and maintain a hypotensive-hypodynamic circulation using an established protocol. The animals were then randomly assigned to one of two groups. In the treatment group, continuous TEA was initiated with 0.1 mL.kg of 0.125% bupivacaine at the onset of endotoxemia and maintained with 0.1 mL.kg.h. In the control group, the same amount of isotonic sodium chloride solution was injected through the epidural catheter. In the animals surviving the entire experiment (n = 7 per group), cardiac index and mean arterial pressure decreased in a dose-dependent manner during endotoxin infusion. In the TEA group, neither systemic hemodynamics nor global oxygen transport were impaired beyond the changes caused by endotoxemia itself. Urinary output was increased in the TEA group as compared with the control group (P < 0.05). In this model of endotoxic shock, TEA improved renal perfusion without affecting cardiopulmonary hemodynamics and global oxygen transport.
authors.affiliation: Department of Intensive Care Medicine, University Hospital Bern, Freiburgstrasse, 3010 Bern, Switzerland. fritz.daudel@insel.ch
authors.forename: Fritz
authors.initials: F
authors.lastname: Daudel
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Bone
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Traber
authors.forename: Henning D
authors.initials: HD
authors.lastname: Stubbe
authors.forename: Martin
authors.initials: M
authors.lastname: Lettau
authors.forename: Matthias
authors.initials: M
authors.lastname: Lange
authors.forename: Marion
authors.initials: M
authors.lastname: Scharte
authors.forename: Hugo
authors.initials: H
authors.lastname: Van Aken
authors.forename: Martin
authors.initials: M
authors.lastname: Westphal
mesh_terms: D000767:Anesthesia, Epidural; D000818:Animals; D001692:Biological Transport; D004305:Dose-Response Relationship, Drug; D019446:Endotoxemia / Q000188:drug therapy* / Q000378:metabolism; D004731:Endotoxins / Q000378:metabolism; D015233:Models, Statistical; D010100:Oxygen / Q000378:metabolism*; D015657:Respiratory Transport; D012485:Salmonella typhi / Q000378:metabolism; D018805:Sepsis; D034561:Sheep, Domestic; D012772:Shock, Septic / Q000188:drug therapy* / Q000473:pathology
chemical_list: D004731:Endotoxins; D010100:Oxygen