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 2 Differences between the Profiles of the Study Drug Dose Response Curves

Outcome Variable	P value
Nociception Tests
Electrical pain threshold	<0.01	*
Pressure pain threshold	<0.01	*
Heat pain threshold	0.99
Skin temperature	0.59
Sedation Score
Subjective sedation visual analogue score	0.01	*
OASS	<0.01	*
Psychometric Tests
SDMT	0.03	*
SDMT errors	0.17
SDMT recall	0.99
Reaction time	<0.01	*
Finger tapping test	<0.01	*
Physiological Tests
Systolic blood pressure	0.34
Diastolic blood pressure	0.99
Heart rate	0.99
Respiratory rate	0.99
Tidal volume	0.73
Pulse oximetry	0.99
End tidal carbon dioxide	0.99
Minute volume	0.99

SDMT denotes symbol digit modalities test; OASS, observer assessment of alertness/sedation scale; *, P ≤ 0.05

ISSN: 1471-2253