Table 1. Demographic data .

-	Group C (n=30)	Group D (n=30)	Group M (n=30)	P Value
Mean age (yrs)	46.57 ±8.73	45.93±9.19	48.30±7.70	0.543
Weight (Kg)	62.27±10.19	60.37 ±7.20	64.70 ±8.12	0.153
Male/Female	16/14	18/12	17/13	0.873
Spine surgery Cervical/Lumbar	10/20	8/22	11/19	0.713
Duration of surgery (hrs)	2.73±0.62	2.62±0.59	2.41±0.48	0.087

Data are presented as either mean values ± SD or by absolute numbers