Effect of different dialysis duration on the prognosis of peritoneal dialysis-associated peritonitis: a single-center, retrospective study

Figures & data

Figure 1. Peritonitis rates by year in our center from 2007 to 2020.

Table 1. General data and the latest biochemical data before peritonitis.

Variable	All peritonitis (n = 267)	SDD group (n = 184)	LDD group (n = 83)	p-value
Female, n (%)	147 (55.1)	88 (47.8)	59 (71.1)	<.001**
Age (years)	63 (56, 72)	64 (56, 72)	63 (56, 73)	.795
PD duration (months)	40 (19, 68)	26 (11, 42)	80 (71, 106)	<.001**
Primary disease (%)
Chronic glomerulonephritis	97 (36.3)	47 (25.5)	50 (60.2)	<.001**
Diabetic nephropathy	90 (33.7)	78 (42.4)	12 (14.5)	<.001**
Hypertensive nephropathy	40 (15.0)	29 (15.8)	11 (13.3)	.595
Chronic tubulointerstitial nephropathy	29 (10.9)	19 (10.3)	10 (12.0)	.676
Obstructive nephropathy	1 (0.4)	1 (0.5)	0 (0)	1.000
Other	10 (3.7)	10 (5.4)	0 (0)	.034*
Diabetes (%)	134 (50.2)	109 (59.2)	25 (30.1)	<.001**
CAPD, n (%)	241 (90.3)	163 (88.6)	78 (94.0)	.169
BMI (kg/m^2)	22.60 (20.62, 24.78)	22.63 (20.81, 24.91)	22.04 (20.43, 24.22)	.446
K (mmol/L)	4.10 (3.68, 4.61)	4.15 (3.68, 4.63)	4.06 (3.67, 4.51)	.164
Alb (g/L)	35.70 (31.80, 38.03)	36.10 (31.60, 38.60)	34.70 (32.00, 37.30)	.118
Hb (g/L)	114 (102, 121)	114 (104, 122)	112 (98, 119)	.024*
P (mmol/L)	1.46 ± 0.46	1.46 ± 0.42	1.47 ± 0.53	.927
Kt/V urea (/week)	1.82 (1.59, 2.11)	1.80 (1.56, 2.13)	1.87 (1.60, 2.06)	.556

SDD: short-dialysis duration; LDD: long-dialysis duration; PD: peritoneal dialysis; CAPD: continuous ambulatory peritoneal dialysis; BMI: body mass index; Alb: serum albumin levels; Hb: hemoglobin; P: phosphate; K: Potassium.

* p < 0.05 **p < 0.01.

Table 2. Comparison of clinical data of the peritonitis in different PD duration groups.

Variable	All peritonitis (n = 267)	SDD group (n = 184)	LDD group (n = 83)	p-value
Cause of peritonitis (%)
Exchange-related contamination	118 (44.2)	84 (45.7)	34 (41.0)	.475
Enteric infection	97 (36.3)	62 (33.7)	35 (42.2)	.183
Systemic infection	20 (7.5)	16 (8.7)	4 (4.8)	.265
Catheter-related infection	2 (0.7)	1 (0.5)	1 (1.2)	.526
Malnutrition	5 (1.9)	3 (1.6)	2 (2.4)	.648
Causes unknown	22 (8.2)	15 (8.2)	7 (8.4)	.938
Recent usage of antibiotics	3 (1.1)	3 (1.6)	0	.555
dWBC on day0[cells/uL, M (1/4, 3/4)]	1790 (600, 4000)	1400 (480, 3598)	2313 (890, 4674)	.043*
dWBC on day3[cells/uL, M (1/4, 3/4)]	79 (10, 458)	58 (9, 261)	180 (33, 1020)	.003**
Patients with delayed treatment (%)	97 (36.3)	69 (37.5)	28 (33.7)	.554
Fever (%)	84 (31.5)	59 (32.1)	25 (30.1)	.751
Abdominal pain (%)	217 (81.3)	154 (83.7)	63 (75.9)	.131
Blood leukocyte count [×10^9/L, M (1/4, 3/4)]	7.58 (6.35, 9.42)	7.52 (6.39, 9.32)	7.59 (6.13, 10.28)	.820
Serum alb (g/L)	33.15 (30.20, 37.15)	33.80 (30.30, 37.70)	32.10 (29.30, 35.50)	.026*
Causative organisms
Gram-positive pathogens, n (%)	127 (47.6)	85 (46.2)	42 (50.6)	.505
Coagulase-negative	60 (22.5)	44 (23.9)	16 (19.3)	.401
Staphylococcus aureus	15 (5.6)	10 (5.4)	5 (6.0)	1.000
Streptococci/Enterococci	40 (15.0)	25 (13.5)	15 (18.0)	.342
Other gram-positive	12 (4.5)	6 (3.3)	6 (7.2)	.259
Gram-negative pathogens, n (%)	61 (22.8)	43 (23.4)	18 (21.7)	.762
Escherichia coli	30 (11.2)	22 (12.0)	8 (9.6)	.579
Pseudomonas aeruginosa	4 (1.5)	3 (1.6)	1 (1.2)	1.000
Other gram-negative	27 (10.1)	18 (9.8)	9 (10.8)	.790
Other pathogens, n (%)	18 (6.7)	13 (7.1)	5 (6.0)	.753
Fungi	4 (1.5)	4 (2.2)	0	.314
Mycobacterium	2 (0.7)	2 (1.1)	0	1.000
Polymicrobial infection	12 (4.5)	7 (3.8)	5 (6.0)	.623
Culture-negative, n (%)	61 (22.8)	43 (23.4)	18 (21.7)	.762

SDD: short-dialysis duration; LDD: long-dialysis duration; PD: peritoneal dialysis; Alb: serum albumin levels; dWBC: dialysate white blood cell counts.

*p < 0.05; **p < 0.01.

Table 3. Comparison of prognosis of peritonitis at different PD duration groups.

Prognosis, n (%)	All peritonitis (n = 267)	SDD group (n = 184)	LDD group (n = 83)	p-value
Hospitalization	70 (26.2)	36 (19.6)	34 (41.0)	.001**
Treatment outcome
Cure	222 (83.1)	163 (88.6)	59 (71.1)	.001**
Transfer to HD	23 (8.6)	11 (6.0)	12 (14.5)	.022*
Death	20 (7.5)	9 (4.9)	11 (13.3)	.016*
Relapse	2 (0.7)	1 (0.5)	1 (1.2)	.526

HD: hemodialysis.

* p < .05 **p < .01.

Table 4. Logistic regression analysis of risk factors associated with treatment failure of PD peritonitis.

Variables	OR	95%CI	p-value
Model 1: no adjustment
PD duration (per 1 year increase)	1.228	1.105 ∼ 1.364	<.001**
Model 2: adjusted for age and sex
Age (per 1 year increase)	1.018	0.989 ∼ 1.048	.230
Sex (female)	0.611	0.302 ∼ 1.238	.172
PD duration (per 1 year increase)	1.258	1.124 ∼ 1.407	<.001**
Model 3: multivariable adjusted model ^a
Age (per 1 year increase)	0.983	0.915 ∼ 1.055	.630
Sex (female)	0.134	0.021 ∼ 0.846	.033*
PD duration (per 1 year increase)	1.449	1.024 ∼ 2.050	.036*
Year of peritonitis^b
2007–2010	referent	referent	–
2011–2015	2.361	0.035 ∼ 158.136	.689
2016–2020	7.304	0.096 ∼ 556.203	.368
Serum Albumin (per 1 g/L increase)(before peritonitis)	0.854	0.689 ∼ 1.060	.153
Phosphate (per 1 mmol/L increase)(before peritonitis)	0.069	0.007 ∼ 0.671	.021*
Serum Albumin (per 1 g/L increase)	1.093	0.912 ∼ 1.310	.335
dWBC on day 3 (per 100cells/uL increase)	1.173	1.063 ∼ 1.295	.002**
Blood leukocyte count (per 10^9/L increase)	1.413	1.119 ∼ 1.785	.004**
Causative organisms^c
Gram-positive peritonitis	referent	referent	–
Gram-negative peritonitis	6.111	0.785 ∼ 47.553	.084
Other pathogens	16.889	1.656 ∼ 172.234	.017*
Culture-negative peritonitis	6.144	0.599 ∼ 63.045	.126

PD: peritoneal dialysis; PDAP: peritoneal dialysis-associated peritonitis; OR: odds ratio; CI: confidence interval; PD: peritoneal dialysis; dWBC: dialysate white blood cell counts.

* p < .05 **p < .01.

^aAdjusted for age, sex, PD duration, year of peritonitis, serum albumin before and after peritonitis, phosphate before peritonitis, dWBC on day 3, blood leukocyte count and causative organisms.

^b Compared to 2007–2010.

^cCompared to gram-positive peritonitis.

Figure 2. ROC curve of using PD duration to predict PD peritonitis treatment failure.