RESULTS	The mean decrease in systolic blood pressure after propofol was 28 mmHg when no fentanyl was given , 53 mmHg after 2 microgram.kg-1 of fentanyl ( P < 0.05 vs. no fentanyl ) , and 50 mmHg after 4 micrograms.kg-1 ( P < 0.05 vs. no fentanyl ; no statistically significant difference 4 vs. 2 micrograms.kg-1 ) .\