Application of Suctioning Ureteral Access Sheath during Flexible Ureteroscopy for Renal Stones Decreases the Risk of Postoperative Systemic Inflammatory Response Syndrome

Table 3

DAG-guided multivariable logistic regression model analysis of causal effect of suctioning UAS on postoperative SIRS.

Variables	Multivariate
	OR (95%CI)	value
Sex
Female	Reference
Men	0.58 (0.28–1.21)	0.145
Age (years)	0.98 (0.95–1.01)	0.152
Diabetes mellitus
No	Reference
Yes	2.41 (0.81–6.55)	0.095
Urine WBC
−	Reference
+	1.22 (0.52–2.99)	0.651
Urine culture
−	Reference
+	3.6 (1.39–9.09)	0.007
Urine nitrate
−	Reference
+	1.07 (0.14–5.14)	0.941
Preoperative fever
No	Reference
Yes	1.18 (0.49–2.75)	0.703
Preoperative ureteral stenting
Absent	Reference
Present	5.72 (2.09–20.56)	0.002
Number of stones
1	Reference
≥2	0.96 (0.4–2.27)	0.918
Stone size (mm)	1.07 (1–1.15)	0.049
Location
Upper/middle pole	Reference
Lower pole	0.65 (0.29–1.39)	0.275
Surgery
Suctioning UAS	Reference
Nonsuctioning UAS	5.28 (1.38–35.07)	0.034

A two-sided P< 0.05 was considered statistically significant.