Table 1.
Baseline characteristics and outcomes of sepsis stratified according to the development or not of ICU-acquired infection.
| Patients | All patients | No ICU-acquired infection | ICU-acquired infection | p-value |
|---|---|---|---|---|
| (N = 16,808) (100%) |
(N = 13,937) (82.9%) |
(N = 2,871) (17.1%) |
||
| Demographics | ||||
| Age, years (mean, SD) | 64.65 (16.27) | 65.09 (16.17) | 62.49 (16.62) | <0.001 |
| Age <60 years (%) | 5,734 (34.1%) | 4,629 (33.2%) | 1,105 (38.5%) | <0.001 |
| Gender, men (%) | 9,609 (57.2%) | 7,975 (57.2%) | 1,634 (56.9%) | 0.761 |
| BMI, kg/m2 (mean, SD) | 29.09 (7.92) | 28.99 (7.82) | 29.49 (8.30) | 0.008 |
| BMI, >25 kg/m2 | 7,512 (68.1%) | 5,948 (67.8%) | 1,564 (69.1%) | 0.238 |
| Admission | ||||
| Admission ICU unit (%) | ||||
| Medical | 8,584 (51.1%) | 7,416 (53.2%) | 1,168 (40.7%) | <0.001 |
| Surgical | 8,224 (48.9%) | 6,521 (46.8%) | 1,703 (59.3%) | <0.001 |
| Severity of disease | ||||
| SOFA (mean, SD) | 3.76 (2.13) | 3.70 (2.07) | 4.05 (2.39) | <0.001 |
| SIRS (mean, SD) | 2.83 (0.89) | 2.81 (0.89) | 2.90 (0.91) | <0.001 |
| LODS (mean, SD) | 6.40 (3.40) | 6.07 (3.28) | 8.00 (3.51) | <0.001 |
| SAPS II (mean, SD) | 40.92 (13.90) | 40.63 (13.63) | 42.31 (15.04) | <0.001 |
| APS III (mean, SD) | 59.28 (25.58) | 56.83 (24.51) | 71.17 (27.28) | <0.001 |
| OASIS (mean, SD) | 36.47 (9.02) | 35.74 (8.88) | 40.02 (8.89) | <0.001 |
| CCI (mean, SD) | 6.01 (2.97) | 6.05 (2.96) | 5.82 (2.99) | <0.001 |
| Chronic comorbidity (%) | ||||
| Cerebrovascular insufficiency | 884 (5.3%) | 632 (4.5%) | 252 (8.8%) | <0.001 |
| Cardiovascular insufficiency | 3,811 (22.7%) | 3,320 (23.8%) | 491 (17.1%) | <0.001 |
| Respiratory insufficiency | 480 (2.9%) | 413 (3.0%) | 67 (2.3%) | 0.065 |
| Liver insufficiency | 1,472 (8.8%) | 1,214 (8.7%) | 258 (9.0%) | 0.634 |
| Renal insufficiency | 403 (2.4%) | 337 (2.4%) | 66 (2.3%) | 0.704 |
| Cardiovascular shock | 1,144 (6.8%) | 888 (6.4%) | 256 (8.9%) | <0.001 |
| Sepsis shock | 3,887 (23.1%) | 3,064 (22.0%) | 823 (28.7%) | <0.001 |
| Trauma shock | 117 (0.7%) | 70 (0.5%) | 47 (1.6%) | <0.001 |
| Treatment interventions before ICU-acquired infections events (%) | ||||
| Any hydrocortisone use | 15,293 (91.0%) | 12,834 (92.1%) | 2,459 (85.6%) | <0.001 |
| Hydrocortisone >200 mg (2d) a | 2,001 (11.9%) | 1,573 (11.3%) | 428 (14.9%) | <0.001 |
| Norepinephrine, median (IQR), mg | 0.0 (0.0, 2,576.7) | 0.0 (0.0, 1,891.7) | 0.0 (0.0, 7,276.3) | <0.001 |
| Anticoagulant | 10,311 (61.3%) | 8,167 (58.6%) | 2,144 (74.7%) | <0.001 |
| Any norepinephrine use (2d) b | 15,873 (94.4%) | 13,427 (96.3%) | 2,446 (85.2%) | <0.001 |
| RBC | 6,641 (39.5%) | 5,157 (37.0%) | 1,484 (51.7%) | <0.001 |
| Cell Saver Intake | 1,950 (11.6%) | 1,670 (13.0%) | 280 (7.1%) | <0.001 |
| Cryoprecipitate | 639 (3.8%) | 450 (3.2%) | 189 (6.6%) | <0.001 |
| Central venous catheter | 9,684 (57.6%) | 7,682 (55.1%) | 2,002 (69.7%) | <0.001 |
| Mechanical ventilation | 9,851 (58.6%) | 7,697 (55.2%) | 2,154 (75.0%) | <0.001 |
| Urinary catheter | 4,421 (26.3%) | 3,240 (25.2%) | 1,181 (29.7%) | <0.001 |
| Tracheostomy | 76 (0.5%) | 46 (0.3%) | 30 (1.0%) | <0.001 |
| Renal replacement therapy | 612 (3.6%) | 431 (3.1%) | 181 (6.3%) | <0.001 |
| Primary infection of sepsis (%) c | ||||
| Primary infection | 6,151 (36.6%) | 4,924 (35.3%) | 1,227 (42.7%) | <0.001 |
| Causative Pathogen, No. (%) | ||||
| Gram-positive bacteria | 3,573 (21.3%) | 2,887 (20.7%) | 686 (23.9%) | <0.001 |
| Staphylococcus aureus | 712 (4.2%) | 572 (4.1%) | 140 (4.9%) | 0.061 |
| MRSA | 498 (3.0%) | 395 (2.8%) | 103 (3.6%) | 0.030 |
| Streptococcus pneumoniae | 521 (3.1%) | 418 (3.0%) | 103 (3.6%) | 0.098 |
| Gram-negative bacteria | 2,360 (14.0%) | 1,839 (13.2%) | 521 (18.1%) | <0.001 |
| Escherichia coli | 330 (2.0%) | 274 (2.0%) | 56 (2.0%) | 0.957 |
| Pseudomonas species | 102 (0.6%) | 67 (0.5%) | 35 (1.2%) | <0.001 |
| Klebsiella species | 128 (0.8%) | 98 (0.7%) | 30 (1.0%) | 0.055 |
| VRE | 151 (0.9%) | 125 (0.9%) | 26 (0.9%) | 0.964 |
| Notrophomonas maltophilia | 23 (0.1%) | 15 (0.1%) | 8 (0.3%) | 0.024 |
| Acinetobacter baumannii | 11 (0.1%) | 6 (0.0%) | 5 (0.2%) | 0.012 |
| Virus | 113 (0.7%) | 87 (0.6%) | 26 (0.9%) | 0.093 |
| Fungi | 1,731 (10.3%) | 1,357 (9.7%) | 374 (13.0%) | <0.001 |
| Candida | 55 (0.3%) | 47 (0.3%) | 8 (0.3%) | 0.617 |
| Aspergillus | 25 (0.1%) | 21 (0.2%) | 4 (0.1%) | 0.886 |
| Source of Infection, No. (%) | ||||
| Skin | 687 (4.1%) | 546 (3.9%) | 141 (4.9%) | 0.014 |
| Tissue | 923 (5.8%) | 743 (5.6%) | 180 (6.9%) | 0.009 |
| Pulmonary tract | 2,852 (17.0%) | 2,193 (15.7%) | 659 (23.0%) | <0.001 |
| Bloodstream infection | 3,441 (20.5%) | 2,833 (20.3%) | 608 (21.2%) | 0.304 |
| Abdomen | 137 (0.8%) | 110 (0.8%) | 27 (0.9%) | 0.412 |
| Neurological | 108 (0.6%) | 91 (0.7%) | 17 (0.6%) | 0.710 |
| Urinary tract | 4,012 (23.9%) | 3,400 (24.4%) | 612 (21.3%) | <0.001 |
| Stool | 340 (2.0%) | 291 (2.1%) | 49 (1.7%) | 0.186 |
| Pleura | 88 (0.5%) | 72 (0.5%) | 16 (0.6%) | 0.783 |
| Bile | 75 (0.4%) | 61 (0.4%) | 14 (0.5%) | 0.715 |
| Other c | 11 (0.1%) | 6 (0.0%) | 5 (0.2%) | 0.012 |
| Outcome | ||||
| Length of stay, median (IQR), d | ||||
| Hospital | 9.9 (6.3, 16.7) | 8.9 (6.0, 14.5) | 17.6 (11.2, 26.2) | <0.001 |
| ICU | 4.8 (3.0, 8.9) | 4.1 (2.8, 6.9) | 12.1 (7.6, 18.5) | <0.001 |
| Mortality (%) | ||||
| Hospital | 3,512 (20.9%) | 2,600 (18.7%) | 912 (31.8%) | <0.001 |
| ICU | 1,543 (9.2%) | 1,036 (7.4%) | 507 (17.7%) | <0.001 |
| Discharge location | <0.001 | |||
| Clinical ward | 8,681 (51.6%) | 7,024 (50.4%) | 1,657 (57.7%) | <0.001 |
| Home | 5,162 (30.7%) | 4,792 (34.4%) | 370 (12.9%) | <0.001 |
| Other/Unknown | 138 (0.8%) | 123 (0.9%) | 15 (0.5%) | 0.052 |
| Died | 2,796 (16.6%) | 1,970 (14.1%) | 826 (28.8%) | <0.001 |
| Laboratory parameter | ||||
| WBC, 10⁹/L, median (IQR) | 11.8 (8.3, 16.4) | 11.7 (8.2, 16.3) | 12.0 (8.5, 16.8) | 0.106 |
| Lymphocytes, 10⁹/L, median (IQR) | 45.5 (1.3, 123.0) | 45.1 (1.3, 123.4) | 47.3 (1.3, 118.3) | 0.616 |
| Lymphocytes <0.7 × 10⁹/L | 1,736 (10.3%) | 1,436 (10.3%) | 300 (10.4%) | 0.815 |
| Neutrophils, 10⁹/L, median (IQR) | 389.8 (10.6, 1,013.0) | 440.8 (11.4, 1,101.7) | 495.1 (12.4, 1,165.1) | 0.129 |
| Neutropenia (<0.5 × 10⁹/L) | 79 (0.5%) | 68 (0.5%) | 11 (0.4%) | 0.455 |
| Monocytes, 10⁹/L | 19.2 (0.9, 54.0) | 18.6 (0.9, 53.8) | 23.1 (0.9, 54.3) | 0.792 |
| Platelets, 10⁹/L, median (IQR) | 187.0 (130.0, 258.0) | 185.0 (129.0, 256.0) | 197.0 (131.0, 267.5) | <0.001 |
| Platelets <50 × 10⁹/L | 889 (5.3%) | 719 (5.2%) | 170 (5.9%) | 0.097 |
| AST, U/L, median (IQR) | 40.0 (24.0, 86.0) | 40.0 (24.0, 83.0) | 37.0 (24.0, 78.5) | 0.824 |
| ALT, U/L, median (IQR) | 27.0 (16.0, 57.0) | 27.0 (16.0, 52.0) | 26.0 (15.0, 54.0) | 0.344 |
| ALT, <40 U/L | 6,773 (40.3%) | 5,519 (39.6%) | 1,254 (43.7%) | <0.001 |
| AST, <40 U/L | 5,207 (31.0%) | 4,301 (30.9%) | 906 (31.6%) | 0.462 |
| PaO2/FiO2, mmHg, median (IQR) | 302.0 (204.0, 403.3) | 299.0 (202.0, 400.0) | 310.0 (210.0, 420.0) | <0.001 |
| PaO2/FiO2 <300 mmHg | 12,169 (72.4%) | 10,235 (73.4%) | 1,934 (67.4%) | <0.001 |
| PaO2/FiO2 <200 mmHg | 3,243 (19.3%) | 2,592 (18.6%) | 651 (22.7%) | <0.001 |
| INR | 1.3 (1.2, 1.6) | 1.3 (1.2, 1.6) | 1.3 (1.1, 1.6) | 0.578 |
| PT, s, median (IQR) | 14.6 (12.8, 17.5) | 14.6 (12.8, 17.5) | 14.3 (12.6, 17.6) | 0.316 |
| APTT, s, median (IQR) | 31.3 (27.4, 38.8) | 31.4 (27.4, 38.5) | 31.3 (27.2, 41.1) | 0.05 |
| BUN, mg/dl, median (IQR) | 21.0 (14.0, 35.0) | 21.0 (14.0, 35.0) | 21.0 (14.0, 35.0) | 0.719 |
| Calcium, mg/dl, median (IQR) | 8.2 (7.7, 8.8) | 8.2 (7.7, 8.7) | 8.2 (7.7, 8.8) | 0.982 |
| Creatinine, mg/dl, median (IQR) | 1.0 (0.7, 1.6) | 1.0 (0.7, 1.6) | 1.0 (0.7, 1.6) | 0.232 |
ICU, intensive care unit; SD, standard deviation; IQR, interquartile range; BMI, body mass index; LODS, Logistic Organ Dysfunction System; APS III, Acute Physiology Score III; OASIS, Oxford Acute Severity of Illness; SIRS, Systemic Inflammatory Response Syndrome Score; SAPS II, Simplified Acute Physiology Score II; SAPS II, Simplified Acute Physiology Score II; SOFA, Sequential Organ Failure Assessment; CCI, Charlson Comorbidity Index; RBC, red blood cell; VRE, vancomycin-resistant enterococci; MRSA, methicillin-resistant Staphylococcus aureus; LOS, length of stay; WBC, white blood cell; SpO2, peripheral blood oxygen saturation; ALT, alanine aminotransferase; AST, aspartate transaminase; BUN, blood urea nitrogen; PT, partial thromboplastin time; APTT, activated partial thromboplastin time.
a
The use of any hydrocortisone or its equivalent (hydrocortisone dose = 4× prednisolone dose, 5× methylprednisolone dose, 25× dexamethasone dose).
b
The use of noradrenaline for >24 h at a dose of >0.1 µg/kg/min in the first 48 h in the ICU.
c
The site of infection and pathogenic microorganisms of all sepsis patients recorded within 48 h of ICU admission.
d
Other infection indicates unspecified sites other than those listed.