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Background: General anaesthesia in pigs maintained with intravenous drugs such as propofol may cause respiratory depression. Alfaxalone gives less respiratory depression than propofol in some species. The aim of the investigation was to compare respiratory effects of propofol-ketamine-dexmedetomidine and alfaxalone-ketamine-dexmedetomidine in pigs. Sixteen pigs premedicated with ketamine 15 mg/kg and midazolam 1 mg/kg intramuscularly were anaesthetised with propofol or alfaxalone to allow endotracheal intubation, followed by propofol 8 mg/kg/h or alfaxalone 5 mg/kg/h in combination with ketamine 5 mg/kg/h and dexmedetomidine 4 µg/kg/h given as a continuous infusion for 60 min. The pigs breathed spontaneously with an FIO 2 of 0.21. Oxygen saturation (SpO 2), end-tidal CO 2 concentration (PE′CO 2), respiratory rate (f R) and inspired tidal volume (V T) were measured, and statistically compared between treatments. If the SpO 2 dropped below 80% or if PE′CO 2 increased above 10.0 kPa, the pigs were recorded as failing to complete the study, and time to failure was statistically compared between treatments. Results: Alfaxalone treated pigs had significantly higher respiratory rates and lower PE′CO 2 than propofol treated pigs, with a f R being 7.3 /min higher (P = 0.01) and PE′CO 2 0.8 kPa lower (P = 0.05). SpO 2 decreased by 0.6% and f R by 1.0 /min per kg increase in body weight in both treatment groups. Three of eight propofol treated and two of eight alfaxalone treated pigs failed to complete the study, and times to failure were not significantly different between treatments (P = 0.75). Conclusions: No major differences in respiratory variables were found when comparing treatments. Respiratory supportive measures must be available when using both protocols.

Background: Pigs are anesthetized when used for emergency procedures live tissue training (LTT) of civilian and military medical personnel or for experimental purposes, but there is a paucity in the literature regarding anesthesia of pigs for this purpose.Objective(s): The main goals of the study were to compare oxygen debt, macrocirculatory parameters, and time to cardiac arrest between pigs in hemorrhagic shock and anesthetized with propofol-ketamine-dexmedetomidine or alfaxalone-ketamine-dexmedetomidine.Design: A prospective, non-blinded randomized study design was used. Sixteen pigs were randomized in blocks of four to be anesthetized with either propofol-ketamine-dexmedetomidine (n = 8) or alfaxalone-ketamine-dexmedetomidine (n = 8) as a continuous infusion.Interventions: Premedication with ketamine 15 mg kg−1 and midazolam 1 mg kg−1 was given i.m. Anesthesia was maintained with propofol 8 mg kg−1 h−1 or alfaxalone 5 mg kg−1 h−1 combined with ketamine 5 mg kg−1 h−1 and dexmedetomidine 4 μg kg−1 h−1 i.v. A stepwise, volume-controlled model for hemorrhage was created by exsanguination.Main Outcome Measures: Indices of oxygen debt (lactate, base excess, and oxygen extraction), macrocirculatory (PR, SAP, DAP, MAP, and CI, SVI, and TPR) variables, and time to death was compared between groups.Results: Pigs in the alfaxalone group had significantly higher SAP than pigs given propofol. No difference in other macrocirculatory variables or indices of oxygen debt could be found. A blood loss of 50% of the total blood volume or more was possible in most pigs with both anesthetic regimes.Conclusions: Pigs anesthetized with propofol or alfaxalone combined with ketamine and dexmedetomidine tolerated substantial blood loss.

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