Surgical Parameters Related to Excessive Intrarenal Pressure during Minimally Invasive Percutaneous Nephrolithotomy in the Supine Position: A Prospective Observational Clinical Study

Table 2

The multiple regression analysis of surgical parameters related to  cmH₂O.

	Beta	SE	std. beta	value	value
Stone burden, maximal diameter (mm)	-0.01	0.01	-0.31	-1.575	0.128
Hounsfield unit	0	0	0.24	1.229	0.231
Number of calyces with stones	0.15	0.07	0.42	2.252	0.034
Number of stones	0.01	0.01	0.12	0.604	0.552
Hydronephrosis	0.18	0.16	0.22	1.107	0.279
Previous cortical defect	-0.18	0.19	-0.2	-0.979	0.337
Number of percutaneous tract	-0.26	0.2	-0.26	-1.304	0.205
Laser energy setting (J)	-0.73	0.34	-0.4	-2.163	0.041
Laser energy setting (Hz)	0.05	0.02	0.41	2.201	0.038
Laser using time (min)	0	0	-0.13	-0.656	0.518
Initial intrarenal pressure (cmH2O)	0.03	0	0.83	7.192	<0.001

p <0.05.