The aim of this study was to investigate pain perception during thiope
ntone or propofol infusions for sedation. Thirty ASA 1 or 2 patients r
eceived a two step infusion of either thiopentone (step 1: 1.25mg.kg(-
1) followed by 2.5mg.kg(-1).h(-1); step 2: 1.25mg.kg(-1) and 12.5mg.kg
(-1).h(-1); n=15) or propofol (step 1: 0.5mg.kg(-1), 1mg.kg(-1).h(-1);
step 2: 0.5mg.kg(-1), 5mg.kg(-1).h(-1); n = 15) for sedation. At cont
rol and 10 min after the start of each infusion dosage, reaction times
and thermal pain detection thresholds were determined. We found no cl
inically or statistically significant depression of thermal pain detec
tion thresholds during propofol or thiopentone infusions and these are
, therefore, unlikely to be associated with clinically relevant hypera
lgesia.