Nitrous oxide uptake in man: a new concept of uptake of inhalation anesthetics.
BACKGROUND
With proper recognition of the functional residual capacity (FRC) and the existence of the alveolar membrane in consideration of gas uptake, the uptake of nitrous oxide does not follow the previously described power function of time, 1,000 ml x t(-1/2).


METHODS
By use of a simple subtraction method, nitrous oxide uptake was measured in patients undergoing anesthesia with nitrous oxide in oxygen and a high-dose narcotic for cardiac surgery.


RESULTS
When FRC washin was considered separately, the uptake of nitrous oxide which started from zero, reached its peak value at the end of washin, and then diminished slowly.


CONCLUSIONS
In contrast to previous publications, in which the time course of FA/FI was used to express the uptake of nitrous oxide, in spite of the area under the curve of FA/FI should not be used to express uptake, instead, the area above the curve, (1-FA/FI), fits the results and should be considered as representing uptake.
Lin
Chung-Yuan
CY
Department of Anesthesia and Critical Care, The University of Chicago Hospitals, Chicago, Illinois, USA. licy@airway.bsd.uchicago.edu
D018685:Anesthetics, Inhalation / Q000493:pharmacokinetics*; D005652:Functional Residual Capacity; D006801:Humans; D008297:Male; D009609:Nitrous Oxide / Q000493:pharmacokinetics*
D018685:Anesthetics, Inhalation; D009609:Nitrous Oxide