Nitrous oxide for monitoring fluid absorption in volunteers†

Presentation on theme: "Nitrous oxide for monitoring fluid absorption in volunteers†"— Presentation transcript:

1 Nitrous oxide for monitoring fluid absorption in volunteers†
D. Piros, D. Drobin, R.G. Hahn  British Journal of Anaesthesia  Volume 98, Issue 1, Pages (January 2007) DOI: /bja/ael311 Copyright © 2007 British Journal of Anaesthesia Terms and Conditions

2 Fig 1 CO2-adjusted area under the curve (AUC) for N2O concentration per infused fluid volume at the end of a 5 min infusion of 1 ml kg−1 of lactated Ringer’s solution containing 40 ml litre−1 of N2O. Each bar represents the mean (sd) for 12 volunteers. British Journal of Anaesthesia  , 53-59DOI: ( /bja/ael311) Copyright © 2007 British Journal of Anaesthesia Terms and Conditions

3 Fig 2 Breath N2O concentration over time during a continuous and an intermittent infusion of an irrigating fluid containing 40 ml litre−1 of N2O. Continuous infusion concentrations increase towards a steady-state while intermittent infusions yield a pattern with bursts and plateaus (a). Intervals and duration of the intermittent infusions (b). British Journal of Anaesthesia  , 53-59DOI: ( /bja/ael311) Copyright © 2007 British Journal of Anaesthesia Terms and Conditions

4 Fig 3 Coefficient of variation (CV, no unit) over time for N2O concentration in expired air during continuous (closed circles) and intermittent (open symbols) infusions. Each point is the mean of 12 (closed) and 4 experiments (open symbols). Different shapes of open symbols show whether the infusion was given at a low, intermediate, or high rate over 45, 24 and 16 min, respectively. British Journal of Anaesthesia  , 53-59DOI: ( /bja/ael311) Copyright © 2007 British Journal of Anaesthesia Terms and Conditions

5 Fig 4 CO2-adjusted area under the curve (AUC) for N2O concentration vs volume of infused fluid in 12 volunteers receiving continuous and intermittent i.v. infusions of N2O-containing irrigating solution. Best fit and the 95% prediction interval for all observations at the end of each 5 min period is indicated. British Journal of Anaesthesia  , 53-59DOI: ( /bja/ael311) Copyright © 2007 British Journal of Anaesthesia Terms and Conditions

6 Fig 5 Residuals obtained when fitting a linear regression equation to the relationship between N2O and infused volume, as shown in Figure 4, at the end of each 5 min period during continuous and intermittent infusions together and separately. British Journal of Anaesthesia  , 53-59DOI: ( /bja/ael311) Copyright © 2007 British Journal of Anaesthesia Terms and Conditions

7 Fig 6 The end-expiratory ethanol concentration [mean (sd)] during continuous and intermittent infusions of irrigating fluid containing mannitol 3% and ethanol 1% (a). Volume of infused fluid calculated using a regression equation based on the pattern of breath ethanol levels vs the actual infused volume (b). British Journal of Anaesthesia  , 53-59DOI: ( /bja/ael311) Copyright © 2007 British Journal of Anaesthesia Terms and Conditions