Early prediction of postoperative infection using inflammatory markers after cytoreductive surgery for peritoneal carcinomatosis

Table 1 Baseline and surgical characteristics according to morbidity of all 111 patients in the study, n (%)

Characteristic	All patients (n = 111)	Overall postoperative infection			Intra-abdominal infection
		No (n = 92)	Yes (n = 19)	P value	No (n = 103)	Yes (n = 8)	P value
Age (years), mean ± SD	60.7 ± 10.3	60.7 ± 10.5	60.8 ± 9.6	0.957	60.7 ± 10.3	60.0 ± 11.9	0.849
Sex
Men	29 (26.1)	24 (82.8)	5 (17.2)	0.984	26 (89.7)	3 (10.3)	-
Women	82 (73.9)	68 (82.9)	14 (17.1)	-	77 (93.9)	5 (6.1)	0.447
ASA score, mean ± SD	2.2 ± 0.6	2.2 ± 0.6	2.4 ± 0.6	0.262	2.2 ± 0.6	2.4 ± 0.7	0.473
Neoadjuvant chemotherapy
No	51 (45.0)	45 (88.2)	6 (11.8)	0.167	48 (94.1)	3 (5.9)	0.619
Yes	60 (54.1)	47 (78.3)	13 (21.7)	-	55 (91.7)	5 (8.3)	-
Immunonutrition
No	62 (55.9)	53 (85.5)	9 (14.5)	0.413	59 (95.2)	3 (4.8)	0.278
Yes	49 (44.1)	39 (79.6)	10 (20.4)	-	44 (89.8)	5 (10.2)	-
Carcinomatosis origin
Ovarian	55 (49.5)	48 (87.3)	7 (12.7)	-	54 (98.2)	1 (1.8)	-
Colorectal	34 (30.6)	24 (70.6)	10 (29.4)	-	28 (82.4)	6 (17.7)	-
Pseudomyxoma	13 (11.7)	13 (100.0)	0 (0.0)	-	13 (100.0)	0 (0.0)	-
Gastric	2 (1.8)	1 (50.0)	1 (50.0)	1	2 (100.0)	0 (0.0)	1
Endometrial	2 (1.8)	2 (100.0)	0 (0.0)	-	2 (100.0)	0 (0.0)	-
Mesothelioma	1 (0.9)	1 (100.0)	0 (0.0)	-	1 (100.0)	0 (0.0)	-
Primary	1 (0.9)	1 (100.0)	0 (0.0)	-	1 (100.0)	0 (0.0)	-
Neuroendocrinal	1 (0.9)	1 (100.0)	0 (0.0)	-	1 (100.0)	0 (0.0)	-
Others	2 (1.8)	1 (50.0)	1 (50.0)	-	1 (50.0)	1 (50.0)	-
PCI, median ± SD	10.4 ± 6.5	10.5 ± 6.7	9.5 ± 5.4	0.520	10.4 ± 6.6	10.0 ± 5.3	0.874
Complete cytoreduction	97 (87.4)	78 (80.4)	19 (19.6)	0.069	89 (91.8)	8 (8.3)	0.265
Number of visceral resections, mean ± SD	1.6 ± 1.2	1.5 ± 1.2	2.0 ± 1.2	0.161	1.6 ± 1.2	2.0 ± 1.1	0.324
Number of digestive anastomoses, mean ± SD	0.6 ± 0.6	0.5 ± 0.7	1.0 ± 0.7	0.053	0.6 ± 0.6	1.2 ± 0.5	0.049
HIPEC
No	23 (20.7)	17 (73.9)	6 (26.1)	0.200	20 (87.0)	3 (13.0)	0.224
Yes	88 (79.3)	75 (85.2)	13 (14.8)	-	83 (94.3)	5 (5.7)	-
In hospital stay, median ± SD	15.6 ± 7.2	14.9 ± 7.1	19.0 ± 6.6	0.022	15.1 ± 7.0	22.3 ± 6.3	0.006
Reintervention	11 (9.9)	5 (45.5)	6 (54.5)	0.000	7 (63.6)	4 (36.4)	0.000
Mortality	2 (1.8)	1 (50.0)	1 (50.0)	0.213	2 (100.0)	0 (0.0)	0.691

¹The test has been omitted due to the small number of cases in the categories.

ASA: American Society of Anaesthesiologists; HIPEC: Hyperthermic intraperitoneal chemotherapy; PCI: Peritoneal carcinomatosis index; SD: Standard deviation.

Table 2 Daily levels of C-reactive protein and neutrophil-to-lymphocyte ratio in all patients according to the presence or absence of overall postoperative infection and in the presence or absence of intra-abdominal infection

Characteristic	All patients (n = 111)	Overall postoperative infection			Intra-abdominal infection
		No (n = 92)	Yes (n = 19)	P value	No (n = 103)	Yes (n = 8)	P value
Day 1
CRP (mg/L)	79.5 (58.0-102.0)	77.0 (58.0-101.0)	91.0 (51.0-119.0)	0.390	77.5 (58.0-101.3)	89.5 (73.0-165.5)	0.114
NLR (mg/L)	10.4 (6.2-16.2)	10.2 (6.1-15.8)	10.4 (6.6-23.4)	0.682	9.9 (6.2-15.2)	15.9 (4.0-28.0)	0.228
Day 2
CRP (mg/L)	91.5 (65.3-147.0)	87.0 (60.0-127.0)	145.0 (81.0-187.0)	0.013	88.1 (62.3-143.5)	143.0 (76.5-195.5)	0.195
NLR (mg/L)	10.4 (7.2-14.5)	10.4 (7.1-14.3)	9.6 (7.2-15.6)	0.377	10.3 (7.2-14.3)	13.3 (5.9-17.7)	0.707
Day 3
CRP (mg/L)	75.0 (47.0-140.0)	70.4 (44.5-120.5)	153.5 (100.3-240.3)	0.001	73.0 (47.0-136.0)	119.0 (38.0-167.8)	0.442
NLR (mg/L)	10.0 (7.0-12.2)	10.5 (7.1-12.1)	8.4 (6.1-17.1)	0.674	10.0 (7.0-12.1)	9.9 (4.9-33.4)	0.783
Day 4
CRP (mg/L)	99.5 (48.5-155.3)	80.5 (46.5-128.0)	151.5 (90.8-204.6)	0.047	96.5 (49.3-156.8)	123.5 (40.1-163.5)	0.918
NLR (mg/L)	8.4 (6.2-11.1)	8.1 (6.0-10.4)	9.3 (6.7-18.5)	0.120	8.2 (6.2-10.6)	8.73 (6.4-24.2)	0.294

Results are presented as medians and interquartile ranges. CRP: C-reactive protein; NLR: Neutrophil-to-lymphocyte ratio.

Table 3 Daily area under the receiver operating characteristic curve of C-reactive protein and neutrophil-to-lymphocyte ratio in patients with overall postoperative infection and with intra-abdominal infection

Characteristic	AUC for OPI (95%CI)	P value	AUC for IAI (95%CI)	P value
Day 1
CRP (mg/L)	0.6 (0.4-0.7)	0.453	0.6 (0.5-0.8)	0.201
NLR (mg/L)	0.5 (0.4-0.7)	0.716	0.6 (0.3-0.8)	0.448
Day 2
CRP (mg/L)	0.7 (0.5-0.8)	0.019	0.7 (0.5-0.9)	0.129
NLR (mg/L)	0.5 (0.4-0.7)	0.946	0.6 (0.3-0.8)	0.557
Day 3
CRP (mg/L)	0.7 (0.6-0.9)	0.005	0.6 (0.3-0.8)	0.550
NLR (mg/L)	0.5 (0.3-0.6)	0.674	0.5 (0.3-0.8)	0.783
Day 4
CRP (mg/L)	0.7 (0.5-0.9)	0.038	0.5 (0.3-0.8)	0.831
NLR (mg/L)	0.6 (0.5-0.8)	0.120	0.6 (0.4-0.9)	0.294

Results are presented as medians and interquartile ranges. AUC: Area under the receiver operating characteristic curve; CI: Confidence interval; CRP: C-reactive protein; IAI: Intra-abdominal infection; NLR: Neutrophil-to-lymphocyte ratio; OPI: Overall postoperative infection.

Table 4 Overall postoperative infection: Daily levels of C-reactive protein depending on immunonutrition intake

Characteristic	Immunonutrition
	No (n = 62)	Yes (n = 49)	P value
CRP day 1
Overall postoperative infection	60.0 (39.0-121.0)	96.4 (82.3-126.0)	0.282
No overall postoperative infection	77.0 (54.5-95.0)	80.0 (63.0-106.7)	0.346
CRP day 2
Overall postoperative infection	88.0 (61.5-204.0)	163.0 (117.0-186.3)	0.535
No overall postoperative infection	84.0 (52.8-109.0)	103.0 (76.7-158.8)	0.005
CRP day 3
Overall postoperative infection	165.0 (72.5-268.0)	125.0 (88.0-167.5)	0.313
No overall postoperative infection	64.0 (40.5-96.5)	102.0 (65.3-143.8)	0.008
CRP day 4
Overall postoperative infection	154.5 (45.3-187.0)	146.0 (108.3-205.7)	0.811
No overall postoperative infection	65.3 (36.5-122.3)	97.0 (62.0-130.0)	0.243

Results are presented as medians and interquartile ranges. CRP: C-reactive protein.

Table 5 Intra-abdominal infection: Daily levels of C-reactive protein depending on immunonutrition intake

Characteristic	Immunonutrition
	No (n = 62)	Yes (n = 49)	P value
CRP day 1
Intra-abdominal infection	113.0	86.0 (61.0-138.5)	0.487
No intra-abdominal infection	67.0 (50.0–95.0)	81.0 (65.0-113.0)	0.112
CRP day 2
Intra-abdominal infection	199.0	120.0 (78.5-175.5)	0.510
No intra-abdominal infection	84.0 (53.5-111.0)	118.0 (77.0-170.0)	0.002
CRP day 3
Intra-abdominal infection	114.0	124.0 (41.5-167.5)	0.642
No intra-abdominal infection	67.0 (41.0-114.0)	114.4 (65.0-172.0)	0.047
CRP day 4
Intra-abdominal infection	48.0	142.0 (60.8-177.0)	0.377
No intra-abdominal infection	76.0 (38.0-156.0)	102.0 (65.0-172.0)	0.278

Results are presented as medians and interquartile ranges. CRP: C-reactive protein.