Table 2.

Changes in pupil characteristics before and after opioid administration

Parameter	No opioid	After opioid	p value**
Baseline pupil diameter (mm)	3.57 ± 1.09	2.17 ± 0.38	< 0.0001
Stimulation intensity (mA)	30.79 ± 10.24	45.26 ± 14.66	0.000016
Pupil variation (mm)	1.09 ± 0.53	0.35 ± 0.21	< 0.0001
Pupil variation (%)	31.39 ± 14.81	15.97 ± 7.01	< 0.0001
PPI score*	7.68 ± 1.17	5.21 ± 2.16	0.000001

Data are expressed mean ± SD

^*PPI = pupillary pain index;

^**stat. sign. for p < 0.05