Table 2. Operative characteristics of patients who underwent multivertebral microendoscopic laminectomy.

*per decompression level 

n: number of patients; x±y: mean±standard deviation

	POSEH group	Non-POSEH group	P
	(n=41)	(n=272)
Number of decompressed levels	2.5±0.6	2.2±0.5	0.002
Blood loss volume (g)*	17.0±2.61	12.3±1.01	0.10
Operating time (minutes)*	75.6±17.5	80.4±20.4	0.15
Blood pressure after extubation (mmHg)	138.3±25.4	139.5±21.4	0.73
Postoperative blood pressure (mmHg)	144.4±23.3	137.3±23.2	0.07