Risk factors for mortality in postoperative peritonitis in critically ill patients

Table 1 Baseline characteristics, severity scores and initial surgery n (%)

	All patients (n = 201)	Non-survivors (n = 63)	Survivors (n = 138)	P
Age (yr)	63 ± 15	69 ± 12	61 ± 16	< 0.001
Sex, male	133 (66)	46 (73)	87 (63)	0.199
Origin of patients
Rennes University Hospital	132 (66)	44 (70)	88 (64)	0.4
Other hospitals	69 (34)	19 (30)	50 (36)
Hospitalization in the previous 3 mo, yes	78 (39)	24 (38)	54 (39)	1
Immunosuppression, yes	33 (16)	9 (14)	24 (17)	0.581
Antimicrobial therapy in the past 3 mo, yes	54 (26)	16 (25)	38 (28)	0.751
MacCabe score
Class A	57 (28)	11 (18)	46 (34)	0.036
Class B	107 (53)	36 (57)	71 (51)
Class C	37 (19)	16 (25)	21 (15)
SAPS II	48 ± 19	60 ± 25	43 ± 14	< 0.001
APACHE II	20 ± 8	24 ± 11	18 ± 6	< 0.001
SOFA	7 ± 4	8 ± 5	6 ± 4	< 0.001
Urgent initial surgery	69 (34)	22	47	0.905
Site of the initial surgery
Colorectal	82 (41)	25 (40)	57 (41)	0.363
Liver - biliary - pancreas	48 (24)	15 (24)	33 (24)
Oesophagus - gastro-duodenal - small bowel	60 (30)	22 (35)	38 (28)
Others	11 (5)	1 (1)	10 (7)

Data are expressed as the mean ± SD or as the number of patients (percentages). SAPS II: Simplified acute physiological score II; APACHE II: Acute physiology and chronic health evaluation II; SOFA: Sequential organ failure assessment.

Table 2 Surgical considerations n (%)

	Total (n = 201)	Non-survivors (n = 63)	Survivors (n = 138)	P
Delay between first operation and surgical reintervention (d)	9.9 ± 7.5	10.4 ± 9.6	9.9 ± 6.2	0.718
Complete surgical source control	140 (69)	45 (71)	95 (69)	0.743
Large way of laparotomy	181 (90)	56 (89)	125 (91)	0.71
Per-operative management of lesions1	184 (92)	57 (89)	127 (92)	0.713
Peritoneal washing (at least 6 L) and clear peritoneal cavity	175 (87)	55 (89)	120 (87)	0.946
Reoperation after the first episode of postoperative peritonitis (number)	59 (29)	23 (37)	36 (29)	0.132
No. of reoperations after the first episode of postoperative peritonitis	1.3 ± 0.6	1.4 ± 0.7	1.2 ± 0.5	0.121
Surgical complications
Parietal abscess	23 (11)	11 (17)	12 (10)	0.095
Intra-abdominal abscess	36 (18)	11 (17)	25 (20)	0.875
Computed tomography-scan guided drainage	30 (15)	7 (11)	23 (19)	0.287

¹The per-operative management of lesions was defined as the realization of ileostomy or colostomy in cases of injured/perforated infra-mesocolic bowel injury or drainage in cases of supra-mesocolic bowel injury. Data are expressed as the mean ± SD or as the number of patients (percentages).

Table 3 Antimicrobial therapies and medical complications n (%)

	Total (n = 201)	Non-survivors (n = 63)	Survivors (n = 138)	P
Antibiotic prophylaxis for the first surgery	165 (82)	53 (84)	112 (81)	0.38
Antimicrobial treatment prior to the first reintervention	132 (66)	40 (63)	93 (67)	0.564
Empirical antibiotic therapy for POP effective against Enterococcus spp.	104 (52)	35 (56)	69 (50)	0.466
Change in empirical antimicrobial POP treatment	130 (65)	33 (52)	97 (70)	0.005
Escalation	60 (46)	20 (32)	40 (29)
De-escalation	70 (54)	13 (21)	57 (41)
Medical complications				0.001
Septic shock	125 (62)	58 (92)	67 (49)
Acute renal failure	79 (39)	39 (62)	40 (29)
ARDS	54 (27)	28 (44)	26 (19)
Lengths of stay, d
ICU	17 ± 17	17 ± 18	17 ± 17	0.2
Hospital	48 ± 44	31 ± 27	57 ± 48	< 0.001

Data are expressed as the mean ± SD or as the number of patients (percentages). POP: Postoperative peritonitis; ARDS: Acute respiratory distress syndrome; ICU: Intensive care unit.

Table 4 Microorganisms recovered from the peritoneal liquid and number per patients in which they were found

	Total1 (n = 440)	Non-survivors1 (n = 63)	Survivors1 (n = 138)	P
Gram-negative bacilli	206	62	144	0.959
Escherichia coli	97	26	71	0.213
Enterobacter spp.	32	13	19	0.079
Pseudomonas aeruginosa	24	7	17	0.700
Klebsiella spp.	15	3	12	0.066
Proteus spp.	9	3	6	1.000
Citrobacter spp.	8	4	4	0.255
Other gram-negative bacilli	21	6	15	1.000
Gram-positive cocci	161	48	113	0.989
Enterococcus spp.	107	35	72	0.429
E. faecalis	70	25	45	0.328
E. faecium	18	2	16	0.053
Other enterococci	19	8	11	0.279
Streptococcus spp.	23	6	17	0.504
Staphylococcus aureus
Methicillin sensitive	7	1	6	0.580
Other gram-positive cocci	24	6	18	0.625
Anaerobes	47	17	30	0.979
Bacteroides spp.	39	13	26	0.889
Clostridium spp.	4	2	2	1.000
Other anaerobes	3	2	1	1.000
Fungi	26	12	14	0.938
Candida albicans	17	7	10	0.715
Other fungi	8	4	4	0.317
Number of microorganism types recovered per patient	2.2 ± 1.2	2.2 ± 1.2	2.2 ± 1.2	0.998

¹Methicillin resistant Staphylococcus aureus was not recovered. Data are expressed as the number of microorganisms (percentage) and the mean ± SD until otherwise.

Table 5 Multivariate analysis for the risk factors for mortality

	Odds ratio	95%CI	P
Simplified acute physiological score II	1.03	1.02-1.05	< 0.0001
Medical postoperative complications	6.02	1.95-18.55	< 0.0001
Number of subsequent reoperations	2.45	1.16-5.17	0.0154