Urological and nursing-related predictors of unplanned hospital readmission after percutaneous nephrolithotomy: A prospective cohort study

Table 4 Comparison of the operative and postoperative variables between the readmitted and non-readmitted groups of patients (n = 161), n (%)/mean ± SD

Variables	Readmitted (n = 36)	Non-readmitted (n = 125)	P value1
Operative variables
Approach
Infracostal	31 (86.1)	112 (89.6)	0.555
Supracostal	5 (13.9)	13 (10.4)
Number of punctures
Single	6 (16.7)	63 (50.40	< 0.001
Multiples	30 (83.3)	62 (49.6)
Target calyx of puncture
Upper calyx	4 (11.1)	12 (9.6)	0.671
Middle calyx	9 (25)	41 (32.8)
Lower calyx	23 (63.9)	72 (57.6)
Type of disintegrators
Ultrasonic	2 (5.6)	4 (3.2)	0.403
Pneumatic	34 (94.4)	121 (96.8)
Academic qualification of the main operator
Professor	16 (44.4)	51 (40.8)	0.665
Assistant professor	0 (0)	2 (1.6)
Lecturer	19 (52.8)	63 (50.4)
Assistant lecturer	1 (2.8)	9 (7.2)
Patient position
Supine	2 (5.6)	20 (16)	0.167
Prone	34 (94.4)	105 (84)
Operative time
Total operation time (minute)	182.5 ± 34.7	150.72 ± 31.3	0.001
PNL procedural time (minute)	158 ± 27.3	130 ± 29	< 0.001
Ureteral JJ
Number of patients	12 (33.3)	21 (16.8)	0.033
Duration	43.3 ± 19	59.6 ± 25.5	0.062
Indications
For residual stone	10 (27.8)	16 (12.8)	0.082
For other causes	2 (5.6)	5 (4)
Nephrostomy tube
Number of patients	33 (82.4)	103 (82.4)	0.136
Removal before discharge	33 (91.7)	92 (73.6)	0.146
Removal after discharge (within 3 days)	1 (2.8)	10 (8)
Postoperative Variables
UOP at the 1st postoperative 24 hours (mL)	925 ± 210.95	956.80 ± 267.48	0.512
Pain degree
No pain	20 (55.6)	75 (60)	0.172
Mild	1 (2.8)	15 (12)
Moderate	8 (22.2)	23 (18.4)
Sever	7 (19.4)	12 (9.6)
Discharge with urethral catheter and its duration (day)
Discharge with urinary catheter	24 (66.7)	54 (43.2)	0.011
2-7	18 (50)	85 (68)	0.014
8-13	10 (27.8)	32 (25.6)
14-20	8 (22.2)	8 (6.4)
Mean duration with catheter	9.5 ± 6	6.4 ± 3.7	< 0.001
Complications
Pneumothorax	5 (13.9)	7 (5.6)	0.100
Intraperitoneal fluid collection	10 (27.8)	6 (4.8)	< 0.001
Postoperative urinary tract infection	13 (36.1)	20 (16)	0.011
Received pre-discharge instructions
Instructions about wound care	16 (44.4)	70 (56)	0.150
Instructions about medications	25 (69.4)	81 (64.8)	0.379
Activity daily living instructions	12 (33.3)	65 (52)	0.048
Instructions about urethral catheter care	7 (19.4)	55 (44)	0.005
Diet instructions	8 (22.2)	27 (21.6)	0.550
Follow-up appointment	19 (68.2)	63 (50.4)	0.475
Education on warning signs	18 (50)	57 (45.6)	0.390
Hospital stay (day)	5.1 ± 3.8	4.6 ± 2.9	0.370

¹χ² test used for qualitative data between the two groups and independent t-test used for quantitative data between the two groups.

JJ: Double-J stent; UOP: Urine output; PNL: Percutaneous nephrolithotomy.