Table 1.
Characteristics at baseline and on day one of intensive care unit admission.
| Culture-negative patients (n = 415) | Culture-positive patients (n = 586) | P value | |
|---|---|---|---|
| Demographics | |||
| Age, years | 62.0 (50.0-74.0) | 64.0 (50.1-74.0) | 0.62 |
| Men | 236 (56.9) | 375 (64.0) | 0.02 |
| Race | 0.09 | ||
| Chinese | 229 (55.2) | 358 (61.1) | |
| Malay | 106 (25.5) | 120 (20.5) | |
| Indian | 56 (13.5) | 64 (10.9) | |
| Others | 24 (5.8) | 44 (7.5) | |
| Source of admission | 0.49 | ||
| Emergency department | 195 (47.0) | 257 (43.9) | |
| Hospital floor | 195 (47.0) | 293 (50.0) | |
| Other ICU | 25 (6.0) | 34 (5.8) | |
| Operating room/recovery | 0 (0) | 2 (0.3) | |
| Time of ICU admission | |||
| Day of hospital admission | 0 (0-2.00) | 0 (0-2.00) | 0.38 |
| Office hour admission | 166 (40.0) | 260 (44.4) | 0.17 |
| Comorbid conditions | |||
| Diabetes mellitus | 141 (34.0) | 234 (39.9) | 0.06 |
| Chronic heart failure | 22 (5.3) | 40 (6.8) | 0.32 |
| Chronic kidney disease | 48 (11.6) | 96 (16.4) | 0.03 |
| COPD | 24 (5.8) | 38 (6.5) | 0.65 |
| Cancer | 29 (7.0) | 55 (9.4) | 0.18 |
| Hematological malignancy | 9 (2.2) | 24 (4.1) | 0.09 |
| No. of comorbid conditionsa | 0.004 | ||
| 0 | 214 (51.6) | 241 (41.1) | |
| 1 | 136 (32.8) | 225 (38.4) | |
| 2 | 59 (14.2) | 98 (16.7) | |
| ≥3 | 6 (1.4) | 22 (3.8) | |
| Vital signs upon ICU admission | |||
| Temperature, °C | 37.0 (36.0-38.0) | 37 (36.2-38.0) | 0.29 |
| Heart rate, /min | 107.3 ± 27.5 | 113.4 ± 25.9 | <0.001 |
| Mean blood pressure, mm Hg | 78.0 (64.0-96.0) | 75.0 (62.0-91.0) | 0.01 |
| Respiratory rate, /min | 24.0 (20.0-31.0) | 25.0 (20.0-31.0) | 0.84 |
| Investigationsb | |||
| White blood cell, 109/L | 13.27 (9.18-19.47) | 13.44 (6.58-19.65) | 0.19 |
| Procalcitonin, ng/mL | 3.95 (0.90-17.28) | 16.40 (2.74-47.03) | <0.001 |
| C-reactive protein, mg/L | 47.50 (14.05-191.50) | 51.50 (11.63-181.50) | 0.53 |
| Severity scores | |||
| APACHE II | 25.0 (19.0-32.0) | 27.0 (21.0-33.0) | 0.001 |
| Acute Physiology Score | 20.0 (14.0-26.0) | 22.0 (16.8-28.3) | <0.001 |
| SOFA | 9.0 (6.0-12.0) | 10.0 (8.0-13.0) | <0.001 |
| Organ failurec | |||
| Renal | 88 (21.2) | 127 (21.7) | 0.86 |
| Respiratory | 239 (57.6) | 344 (58.7) | 0.73 |
| Cardiovascular | 205 (49.4) | 360 (61.4) | <0.001 |
| Central nervous system | 142 (34.2) | 241 (41.1) | 0.03 |
| Coagulation | 31 (7.5) | 66 (11.3) | 0.046 |
| Hepatic | 15 (3.6) | 37 (6.3) | 0.06 |
| Treatment on day one in the ICU | |||
| Vasoactive agents | 247 (59.5) | 432 (73.7) | <0.001 |
| Mechanical ventilation | 315 (75.9) | 469 (80.0) | 0.12 |
| Renal replacement therapy | 37 (8.9) | 51 (8.7) | 0.91 |
| Glucocorticoids for septic shock | 104 (25.1) | 143 (24.4) | 0.81 |
aCulture-negative patients were more likely to have no comorbidities than culture-positive patients (P = 0.001, significant after Bonferroni correction); bwhite blood cell values available for all patients; procalcitonin values available for 266 culture-negative and 359 culture-positive patients; C-reactive protein values available for 120 culture-negative patients and 174 culture-positive patients; corgan failure defined as SOFA score >2 for the specified organ. ICU, intensive care unit; COPD, chronic obstructive pulmonary disease; APACHE, Acute Physiology and Chronic Health Evaluation; SOFA, Sequential Organ Failure Assessment.