Investigation of the potentiation of the analgesic effects of fentanyl by ketamine in humans: a double-blinded, randomised, placebo controlled, crossover study of experimental pain[ISRCTN83088383]

Table 3 Origins of the Significant Differences between the Study Drugs with Respect to the Profile of the Dose Response Curves (P ≤ 0.05)

Outcome Variable	Origins of Difference in Profile by Drug
Nociception Tests
Electrical pain threshold	fentanyl & ketamine versus ketamine, fentanyl versus saline
Pressure pain threshold	fentanyl & ketamine, fentanyl, versus ketamine, saline
Sedation Score
Sedation visual analogue	ketamine, fentanyl, propofol, fentanyl & ketamine versus saline
OASS	propofol versus ketamine, fentanyl, fentanyl & ketamine, versus saline
Psychometric Tests
SDMT	propofol versus ketamine, fentanyl, fentanyl & ketamine versus saline
Reaction time	propofol versus ketamine, fentanyl, fentanyl & ketamine, saline
Finger tapping test	propofol versus ketamine, fentanyl, fentanyl & ketamine, saline

SDMT denotes symbol digit modalities test; OASS, observer assessment of alertness/sedation scale.

ISSN: 1471-2253