Examining the subjective, psychomotor and reinforcing effects of nitrous oxide in healthy volunteers: a dose-response analysis.
The present study examined the subjective, psychomotor and reinforcing effects of 10%, 20%, 30% and 40% nitrous oxide in oxygen in 16 healthy volunteers using a choice procedure in which sampling (e.g. 20% nitrous oxide and oxygen-placebo) and choice trials (e.g. 20% nitrous oxide vs. oxygen placebo) were within the same session. Across the four-session study, nitrous oxide dose was varied. Nitrous oxide in a dose-related manner altered subjective effects (e.g. increased visual analog scale ratings of "high", "stimulated" and "tingling") and decreased performance on the Digit Symbol Substitution Test. 10%, 20%, 30% and 40% nitrous oxide were chosen over oxygen by 6, 7, 7 and 8 subjects, respectively. We conclude that nitrous oxide across a range of subanesthetic doses did not function as reinforcer in the majority of subjects tested.
Department of Anesthesia and Critical Care MC 4028, and Department of Psychiatry, University of Chicago, 5841 S Maryland Avenue, Chicago, IL 60637, USA.
J.P.
JP
Zacny
J.L.
JL
Lichtor
D.W.
DW
Coalson
R.
R
Alessi
G.
G
Goldsher
C.J.
CJ
Young
J.L.
JL
Apfelbaum
K.M.
KM
Conley