Influence of the Mode of Ventilation on Ketamine/Xylazine Requirements in Rabbits
Abstract
Objective To evaluate the effect of the mode of mechanical ventilation (MV) on the dose of intravenous anesthetic during 3 hours of ketamine/ xylazine anesthesia. Study design Prospective laboratory study. Animals Sixty-one adult male New Zealand White rabbits. Methods Rabbits were anesthetized (ketamine/xylazine 35 + 5 mg kg -1 , IM), the trachea was intubated and randomized to four groups (1) CMV-1 (n = 14), ventilated with traditional conventional volume-cycled MV [VT = 12 mL kg-1 , RR = 20, positive end-expiratory pressure (PEEP) = 0 cm- H2O]; (2) CMV-2 (n = 13), ventilated with a modern lung-protective regimen of volume-cycled MV (VT = 6 mLkg-1 ,RR = 40, PEEP = 5 cmH2O); (3) HFPV (n = 17) ventilated with high-frequency percussive ventilation [high-frequency oscillations (450 minute -1) superimposed on 40 minute -1 low-frequency respiratory cycles, I:E ratio 1:1], oscillatory continuous positive airway pressure (CPAP) of 7 - 10 cmH2O, and demand CPAP of 8-10 cmH2O. (4) A fourth group, spontaneously ventilating (SV, n = 17), was anesthetized, intubated, but not ventilated mechanically. FiO2 in all groups was 0.5. Anesthesia was maintained at a surgical plane by IV administration of a ketamine/ xylazine mixture (10 + 2 mg kg-1 , as necessary) for 3 hours after intubation. Total dose of xylazine/ ketamine administered and the need for yohimbine to facilitate recovery were quantitated. Results The total dose of xylazine/ketamine was significantly higher in the HFPV and SV groups compared with CMV-1 ( p less than 0.01). Fewer animals required yohimbine to reverse anesthesia in the HFPV than CMV-1 group ( p less than 0.05). Conclusions The HFPV mode of MV led to higher doses of ketamine/xylazine being used than the other modes of MV.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2007
- Accession Number
- ADA627826
Entities
People
- Andrey L. Yershov
- Bryan S. Jordan
- James M. Fudge
- Michael A. Dubick
Organizations
- United States Army Institute of Surgical Research