Tierärztliche Hochschule Hannover Vergleichende Studie zur

Publikation 2
water. Daily clinical examination commencing two weeks prior to the start of the study
ensured calves were acclimatised to handling.
Study design and drug application
All 30 calves were randomly assigned to one of three anesthetic protocols:
Inhalation- (INH), injection- (INJ) and epidural- (EPI) anaesthesia, before undergoing
a standardised surgical procedure (Baird 2008), whereby the umbilical stalk was
removed. Food was withheld for 12 hours prior to induction of anaesthesia to prevent
intraoperative regurgitation and excessive bloating.
Calves of the Group INH were initially sedated by intramuscular (IM) injection of
0.1 mg kg -1 2% xylazine (Rompun, Bayer Vital GmbH, Leverkusen, Germany),
followed by slow intravenous (IV) administration of 2.0 mg kg -1 ketamine (Ketamin
10%, Selectavet GmbH, Weyarn-Holzolling, Germany) (Tadmor et al. 1979).
Following endotracheal intubation (Tubus, blue line, ID 8.5, Smith Portex Critical
Care GmbH, Grasbrun, Germany) anaesthesia was maintained with isoflurane to
effect with vaporizer settings between 1.5 and 2 Vol.-% (CuraMED Pharma GmbH,
Karlsruhe, Germany) and an oxygen flow rate of 1-2 L min -1 using a circle breathing
system operated in a semi-closed mode (Sulla 808, Dräger, Lübeck, Germany).
Group INJ was treated with IM injection of xylazine at a dose of 0.2 mg kg -1 . After ten
minutes, 5.0 mg kg -1
ketamine IV was slowly injected (Waterman 1981; Carroll &
Hartsfield 1996). Anaesthesia was maintained with intermittent redoses of 2.5 mg kg -
1 ketamine IV at preset 15 min intervals. However, if the depth of anaesthesia
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