Journal of anesthesia
-
Journal of anesthesia · Jun 1994
An analysis of CO2 elimination curves during artificial ventilation.
We have developed some indices to evaluate the phase III slope in CO2 elimination curves. The indices were applied to 12 mechanically ventilated patients in ICU to determine their stability under various ventilator settings. Fco2-sl[30-90] and[Formula: see text] expressed the mean incline of phase III slope in Fco2-volume curves and[Formula: see text]-volume curves, respectively. ⋯ In the first study, Fco2-sl[30-90] and[Formula: see text][30-90] correlated with ETco2, Vd/Vt and the volume of CO2 expired, but Fco2-SR and[Formula: see text]-SR were independent of these parameters.[Formula: see text]-SR did not show any significant changes under various ventilator settings except for application of PEEP. In the second study, those with impaired preoperative respiratory function had significantly larger values for[Formula: see text].[Formula: see text] was as sensitive as parameters such as VD/VT, arterial to end-tidal CO2 tension difference (a-ET·Dco2), and volume pressure index (VPI) in prediting poor respiratory functions. We concluded that[Formula: see text] is a useful index for evaluating the phase III slope in CO2 elimination curves.
-
Journal of anesthesia · Jun 1994
Estimation of cerebrospinal fluid pressure via lumbar epidural space by equilibration method.
By introducing water into the lumbar epidural space from a vertically held tube under gravity, we measured lumbar epidural pressure (EDP) when the water meniscus no longer declined. In principle, the pressure of either side of dura mater had become equal at this time which is referred to as the equilibrium point. ⋯ Both EDP and CSFP responded sensitively to the manipulations of CSFP during this period. We suggest that this method may provide a means to continuously monitor CSFP by EDP.