1. Influence of volatile anaesthetics on hypercapnoeic ventilatory responses in mice with blunted respiratory drive† 
Groeben H , Meier S , Tankersley C.G. , Mitzner W , Brown R.H.  
British Journal of Anaesthesia 
Volume 92, Issue 5, Pages (May 2004)
DOI: /bja/aeh124
Copyright © 2004 British Journal of Anaesthesia Terms and Conditions

2. Fig 1
Original recordings of one C3 mouse before and during isoflurane anaesthesia. Six seconds of each step and one carbon dioxide challenge are shown. Carbon dioxide at baseline led to deepening of the breath and an increase in respiratory rate. Increasing concentrations of isoflurane (without additional carbon dioxide) affected respiratory rate dramatically.
British Journal of Anaesthesia  , DOI: ( /bja/aeh124)
Copyright © 2004 British Journal of Anaesthesia Terms and Conditions

3. Fig 2
Respiratory rate (RR) and pressure amplitude (Amp), as an expression of tidal volume, in 11 male C3H/HeJ mice measured at baseline and during isoflurane, sevoflurane or desflurane anaesthesia at 0.5, 1.0 and 1.5 MAC. Data are mean and sd. Four additional measurements were performed during recovery (RI–RIV) at 5, 10, 15 and 20 min for isoflurane and desflurane and 5, 10, 20 and 30 min for isoflurane anaesthesia. During sevoflurane anaesthesia, RR was preserved up to 1.0 MAC but RR was significantly depressed at 1.0 MAC during anaesthesia with either isoflurane (P<0.0001) or desflurane (P<0.0001). The increase in Amp for isoflurane at 1.5 MAC and RI (P<0.0001) could compensate only partly for the decrease in RR, while there were no changes in Amp for sevoflurane and desflurane. *=Significant difference for isoflurane vs sevoflurane; #=significant difference for isoflurane vs desflurane; §=significant difference for sevoflurane vs desflurane (P<0.0167).
British Journal of Anaesthesia  , DOI: ( /bja/aeh124)
Copyright © 2004 British Journal of Anaesthesia Terms and Conditions

4. Fig 3
The product of respiratory rate (RR) and pressure amplitude (Amp), as an equivalent of minute ventilation, of 11 male C3H/HeJ mice measured at baseline and during isoflurane, sevoflurane or desflurane anaesthesia at 0.5, 1.0, and 1.5 MAC. Data are mean and sd. At rest, four additional measurements were performed during recovery (RI–RIV) at 5, 10, 15 and 20 min for isoflurane and desflurane and 5, 10, 20 and 30 min for isoflurane anesthesia (a). The percentage increase in MV in response to exposure to 8% carbon dioxide is presented at baseline, 0.5, 1.0 and 1.5 MAC and at the end of recovery (b). During sevoflurane anaesthesia, MV was preserved up to 1.0 MAC but was significantly depressed at 1.0 MAC during anaesthesia with isoflurane (P=0.0008) or desflurane (P<0.0001). During recovery, MV was higher at the first and second time points during anaesthesia with sevoflurane and desflurane compared with isoflurane. The response to hypercapnoeia was significantly more depressed during desflurane anaesthesia compared with isoflurane and sevoflurane at 0.5 MAC. At the end of recovery the response to hypercapnoeia was completely blocked regardless of the agent used. Overall, sevoflurane preserved spontaneous breathing more than isoflurane and desflurane, but there was no relevant difference between the three agents in the dramatic depression of the response to hypercapnoeia. *=Significant difference for isoflurane vs sevoflurane; #=significant difference for isoflurane vs desflurane; §=significant difference for sevoflurane vs desflurane (P<0.0167).
British Journal of Anaesthesia  , DOI: ( /bja/aeh124)
Copyright © 2004 British Journal of Anaesthesia Terms and Conditions

5. Fig 4
Changes in respiratory rate (RR) and pressure amplitude (Amp), as an expression of tidal volume, to 8% carbon dioxide in 11 male C3H/HeJ mice measured at baseline and during isoflurane, sevoflurane or desflurane anaesthesia at 0.5, 1.0 and 1.5 MAC and at the end of recovery. Data are mean and sd. Even at the lowest concentrations of all three anaesthetics, RR was significantly decreased (P<0.0001). The decrease with 0.5 MAC desflurane was only partly compensated for by an increase in Amp (P=0.0029). In recovery, the response to carbon dioxide was significantly suppressed for all three anaesthetics and did not differ from the blockade during deep anaesthesia at 1.5 MAC (P<0.0001). *=Significant difference for isoflurane vs sevoflurane; #=significant difference for isoflurane vs desflurane; §=significant difference for sevoflurane vs desflurane (P<0.0167).
British Journal of Anaesthesia  , DOI: ( /bja/aeh124)
Copyright © 2004 British Journal of Anaesthesia Terms and Conditions