title: Influence of a preload of hydroxyethylstarch 6% on the cardiovascular effects of epidural administration of ropivacaine 0.75% in anaesthetized dogs.
abstract: OBJECTIVE
  To evaluate the cardiovascular effects of a preload of hydroxyethylstarch 6% (HES), preceding an epidural administration of ropivacaine 0.75% in isoflurane anaesthetized dogs.
  
  
  METHODS
  Six female, neutered Beagle dogs (mean 13.3 ± SD 1.0 kg; 3.6 ± 0.1 years).
  
  
  METHODS
  Randomized experimental cross-over study (washout of 1 month).
  
  
  METHODS
  Anaesthesia was induced with propofol and maintained with isoflurane in oxygen/air. All dogs were anaesthetized twice to receive either treatment HESR (continuous rate infusion [CRI] of 7 mL kg(-1) HES started 30 minutes [T-30] prior to epidural administration of ropivacaine 0.75% 1.65 mg kg(-1) at T0) or treatment R (no HES preload and similar dose and timing of epidural ropivacaine administration). Baseline measurements were obtained at T-5. Heart rate (HR), mean (MAP), diastolic (DAP) and systolic (SAP) invasive arterial pressures, cardiac output (Lithium dilution and pulse contour analysis) and derived parameters were recorded every 5 minutes for 60 minutes. Statistical analysis was performed on five dogs, due to the death of one dog.
  
  
  RESULTS
  Clinically relevant decreases in MAP (<60 mmHg) were observed for 20 and 40 minutes following epidural administration in treatments HESR and R respectively. Significant decreases in MAP and DAP were present after treatment HESR for up to 20 minutes following epidural administration. No significant within-treatment and overall differences were observed for other cardiovascular parameters. A transient unilateral Horner's syndrome occurred in two dogs (one in each treatment). One dog died after severe hypotension, associated with epidural anaesthesia.
  
  
  CONCLUSIONS
  A CRI of 7 mL kg(-1) HES administered over 30 minutes before epidural treatment did not prevent hypotension induced by epidural ropivacaine 0.75%. Epidural administration of ropivacaine 0.75% in isoflurane anaesthetized dogs was associated with a high incidence of adverse effects in this study.
authors.affiliation: Department of Medicine and Clinical Biology of Small Animals, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, Belgium. Tim.Bosmans@Ugent.be
authors.forename: Tim
authors.initials: T
authors.lastname: Bosmans
authors.forename: Stijn
authors.initials: S
authors.lastname: Schauvliege
authors.forename: Frank
authors.initials: F
authors.lastname: Gasthuys
authors.forename: Luc
authors.initials: L
authors.lastname: Duchateau
authors.forename: Barbara
authors.initials: B
authors.lastname: Steblaj
authors.forename: Caroline
authors.initials: C
authors.lastname: Gadeyne
authors.forename: Ingeborgh
authors.initials: I
authors.lastname: Polis
mesh_terms: D000577:Amides / Q000009:adverse effects; D000767:Anesthesia, Epidural / Q000009:adverse effects / Q000379:methods / Q000662:veterinary*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D004285:Dogs; D005260:Female; D006895:Hydroxyethyl Starch Derivatives / Q000494:pharmacology*; D007022:Hypotension / Q000139:chemically induced / Q000517:prevention & control / Q000662:veterinary*; D007268:Injections, Epidural / Q000662:veterinary; D007530:Isoflurane; D016343:Monitoring, Intraoperative / Q000662:veterinary; D000077212:Ropivacaine; D013318:Stroke Volume / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D000577:Amides; D006895:Hydroxyethyl Starch Derivatives; D000077212:Ropivacaine; D007530:Isoflurane