Table 1.
Baseline characteristics and study population
| Overall (N = 45) | No bacterial superinfection (n = 26) | Bacterial superinfection (n = 19) | p value | |
|---|---|---|---|---|
| Baseline characteristics | ||||
| Age (years) | 60 (54–69) | 61.5 (54–71) | 59 (54–69) | 0.654 |
| Male sex (n/%) | 35 (77.8%) | 19 (73.1%) | 16 (84.2%) | 0.375 |
| Weight (kg) | 83 (75–99) | 80 (72.5–90) | 92 (78–100) | 0.049 |
| Height (cm) | 175 (165–182) | 172 (160–180) | 176 (169–185) | 0.112 |
| Body mass index (kg/m2) | 27.8 (25.7–31.6) | 27.5 (25.6–30.6) | 27.8 (26.8–35) | 0.346 |
| Comorbidity and other clinical conditions | ||||
| Myocardial infarction/ischemic heart disease | 6 (13.3%) | 5 (19.2%) | 1 (5.3%) | 0.222 |
| Arterial hypertension | 26 (57.8%) | 16 (61.5%) | 10 (52.6%) | 0.550 |
| Chronic kidney disease | 12 (26.7%) | 10 (38.5%) | 2 (10.5%) | 0.047 |
| Dialysis | 1 (2.2%) | 1 (3.8%) | 0 (0%) | 0.999 |
| Diabetes, no insulin therapy | 5 (11.1%) | 3 (11.5%) | 2 (10.5%) | 0.999 |
| Diabetes, insulin therapy | 14 (31.1%) | 7 (26.9%) | 7 (36.8%) | 0.528 |
| Asthma | 1 (2.2%) | 1 (3.8%) | 0 (0%) | 0.999 |
| Chronic obstructive pulmonary disease (COPD) | 5 (11.1%) | 4 (15.4%) | 1 (5.3%) | 0.378 |
| Renal or liver transplantation | 5 (11.1%) | 4 (15.4%) | 1 (5.3%) | 0.378 |
| Immunosuppression | 7 (15.6%) | 5 (19.2%) | 2 (10.5%) | 0.222 |
| Cancer | 4 (8.9%) | 2 (7.7%) | 2 (10.5%) | 0.999 |
| Smoking | 14 (31.1%) | 7 (26.9%) | 7 (36.8%) | 0.625 |
| Alcohol abuse | 1 (2.2%) | 0 (0%) | 1 (5.3%) | 0.999 |
| Drug abuse | 0 (0%) | 0 (0%) | 0 (0%) | 1.000 |
| Medical therapy before admission | ||||
| Statin | 10 (22.7%) | 6 (24%) | 4 (21.1%) | 0.999 |
| Angiotensin-converting enzyme (ACE) inhibitor | 7 (15.9%) | 4 (16%) | 3 (15.8%) | 0.999 |
| Scores/index | ||||
| Sepsis-related organ failure assessment score (SOFA) | 8 (5–10) | 8 (3–10) | 9 (7–10) | 0.480 |
| Simplified acute physiology score (SAPS) II | 36 (25–50) | 32.5 (24–50) | 42 (28–51) | 0.275 |
| Lowest PaO2/FiO2 ratio at admission | 122 (94–177) | 129 (97–200) | 108 (85–163.5) | 0.228 |
| Organ failure during ICU stay | ||||
| Acute kidney injury | 27 (60%) | 15 (57.7%) | 12 (63.2%) | 0.712 |
| Dialysis | 18 (40%) | 9 (34.6%) | 9 (47.4%) | 0.388 |
| Invasive mechanical ventilation | 40 (88.9%) | 21 (80.8%) | 19 (100%) | 0.043 |
| Extracorporeal life support (ECLS) | 8 (17.8%) | 3 (11.5%) | 5 (26.3%) | 0.253 |
| Rescue therapies | ||||
| Prone position | 28 (62.2%) | 11 (42.3%) | 17 (89.5%) | 0.001 |
| Inhaled nitric oxide (iNO) | 11 (24.4%) | 5 (19.2%) | 6 (31.6%) | 0.341 |
| Tracheotomy | 20 (44.4%) | 6 (23.1%) | 14 (73.7%) | 0.001 |
| Timing (days) | ||||
| Time to ICU admission | 2 (1–6) | 2 (1–6) | 3 (1–6) | 0.636 |
| Duration prone position | 6 (1–10) | 1.5 (1–7) | 6 (4–10) | 0.022 |
| Duration iNO therapy | 3 (1–6) | 1 (1–3) | 4.5 (1–22) | 0.349 |
| Duration intubation to tracheotomy | 20 (10–33) | 10.5 (9–21) | 27 (15–33) | 0.114 |
| Laboratory values at admission | ||||
| White blood cell (WBC) count (G/L) | 7.7 (5.7–10.7) | 7.5 (5.7–10) | 8 (5.3–13.4) | 0.515 |
| Hemoglobin (gr/L) | 118.5 (101.5–133) | 117 (107–132) | 126 (98–134) | 0.896 |
| Hematocrit (%) | 0.4 (0.3–0.4) | 0.4 (0.3–0.4) | 0.4 (0.3–0.4) | 0.619 |
| Platelet count (G/L) | 199 (169.5–272) | 200 (177–271) | 190 (154–297) | 0.776 |
| Alanine transaminase (ALT) (U/L) | 42.5 (25.5–65.5) | 31 (24–60) | 56 (33–72) | 0.008 |
| Lactate dehydrogenase (LDH) (U/L) | 676 (527–842.5) | 619 (471–742) | 772 (626–876) | 0.144 |
| Alkaline phosphatase (U/L) | 74.5 (53.5–103.5) | 77.5 (56–108) | 61 (53–98) | 0.308 |
| Urea (mmol/L) | 6 (4.3–10.3) | 6.2 (4.1–7.9) | 6 (4.4–12.2) | 0.651 |
| Creatinine (μmol/L) | 92.5 (67–138.5) | 95 (70–128) | 91 (57–149) | 0.387 |
| Serum sodium (mmol/L) | 138 (134–141) | 137 (135–140) | 141 (134–146) | 0.203 |
| Serum potassium (mmol/L) | 3.9 (3.7–4.5) | 4.1 (3.7–4.4) | 3.8 (3.5–4.7) | 0.601 |
| C-reactive protein (CRP) (mg/L) | 168.5 (83.5–276.5) | 124 (62–238) | 255 (102–301) | 0.034 |
| Procalcitonin (PCT) (mcg/L) | 0.3 (0.2–1.2) | 0.2 (0.1–1.7) | 0.4 (0.2–1.2) | 0.060 |
| Interleukin-6 (IL-6) (ng/L) | 127 (71.2–454) | 122 (84–697) | 127 (62.7–263) | 0.554 |
| COVID-19 targeted drug therapy and antimicrobials | ||||
| Steroids | 21 (46.7%) | 8 (30.8%) | 13 (68.4%) | 0.012 |
| Hydroxychloroquine | 27 (61.4%) | 13 (52%) | 14 (73.7%) | 0.143 |
| Lopinavir/ritonavir | 7 (15.9%) | 4 (16%) | 3 (15.8%) | 0.999 |
| Remdesivir | 8 (18.2%) | 4 (16%) | 4 (21.1%) | 0.704 |
| Tocilizumab | 2 (4.7%) | 2 (8.3%) | 0 (0%) | 0.501 |
| Empiric antimicrobial therapy | 40 (8,839%) | 22 (88%) | 18 (94.7%) | 0.441 |
| Sample size overall | ||||
| TBS | 433 | 114 | 319 | |
| BAL | 35 | 12 | 23 | |
| Blood cultures | 455 | 152 | 303 | |
Demographic and clinical characteristics as well as risk factors of COVID-19 patients stratified according to presence or absence of pulmonary relevant pathogens in tracheobronchial secretions (TBSs) and bronchioalveolar lavages (BALs) reflecting superinfection. The data are presented as median (interquartile range (IQR)) or number and percentage (%). The two groups were compared using chi-square test/Fisher exact or the Mann-Whitney test as appropriate.