Background
Methods
Design, setting and patients
Data collection
Sampling and laboratory techniques
Viral
Bacterial sampling
Bacterial cultures
Other diagnostics
Definitions
Bacterial counts
-
No bacterial growth: no growth or growth of commensal bacteria only.
-
Low bacterial growth: Presence of pathogens in the BAL <104 CFU/ml or trachea aspirates <105 CFU/ml.
-
Bacterial co-infection: Presence of pathogens in the BAL ≥104 CFU/ml or trachea aspirates ≥105 CFU/ml.
Timing
Statistical analysis
Results
Patient characteristics
N = 189 | |
---|---|
Demographic characteristics | |
Boys | 108 (57.1%) |
Age (months) | 2.91 ± 3.52 |
< 6 months of age | 168/189 (88.9%) |
Admission weight (kg) | 4.91 ± 2.0 |
Born Prematurea | 53/171b (31.0%) |
Gestational age (weeks) | 37.1 ± 4.05 |
Deathsc | 1 (0.5%) |
Underlying conditions | |
Any underlying condition | 25/188b (13.3%) |
Congenital Heart diseases | 11/25b (44.0%) |
Down Syndrome | 5 (20.0%) |
Viral characteristics | |
RSV | 126/162b(77.8%) |
2 or more viral infection | 24/97b (24.7%) |
Clinical characteristics | |
CRP max (mg/l) | 85.0 ± 62.2 |
CRP 0–40 mg/l | 55/188b (29.3%) |
40–100 mg/l | 67/188b (35.6%) |
> 100 mg/l | 66/188b (35.1%) |
Leukocytes highest value (× 109 /l) | 13.6 ± 6.4 |
Fever (> 38,5 °C) | 4/149b (2.7%) |
Antimicrobial drug treatment | |
Antibiotics started prior to PICU admission | 51/101b (50.5%) |
Treatment started during PICU admission | 159 (84.1%) |
Cultures | |
Cultured (BAL or TA) | 167 (88.4%) |
Bacterial co-infection
Cultured (N = 167) | |
---|---|
Co-infection | 63 (37.7%) |
Early co-infection
|
52 (82.5%)
|
Late co-infection
|
11 (17.5%)
|
Low bacterial growth | 67 (40.1%) |
No growth | 37 (22.2%) |
Types of pathogens
Co-infection (N = 85) | Early co-infection (N = 69) | Late co-infection (N = 16) | p-value | |
---|---|---|---|---|
Haemophilus influenza
| 34 (40.0%) | 29 (42.0%) | 5 (31.3%) | 0,533 |
Streptococcus pneumoniae
| 23 (27.1%) | 19 (27.5%) | 4 (25.0%) | 0,637 |
Moraxella catarrhalis
| 19 (22.4%) | 17 (24.6%) | 2 (12.5%) | 0,286 |
Staphylococcus aureus
| 6 (7.1%) | 4 (5.8%) | 2 (12.5%) | 0,280 |
Enterobacteriaceae
a
| 3 (3.5%) | – | 3 (18.8%) | 0,004 |
Duration of ventilation and PICU stay
Duration of ventilation (days) | p-value Uni−/multivariate | PICU stay | p-value Uni−/multivariate | |
---|---|---|---|---|
(days) | ||||
Negative | 6.5 ± 3,20 | 7.7 ± 3.55 | ||
Co-infection | 8.1 ± 3,47 | 0.021/0.016* | 9.1 ± 3.45 | 0.044/0.054* |
Low Bacterial Growth | 7.3 ± 3,40 | 0.260/0.200* | 8.7 ± 3.74 | 0.167/0.104* |
Predictors of a bacterial co-infection
Negative (N = 37) | Co-infection (N = 63) | Low Bacterial Growth (N = 67) | P Value** univariate | P Value** Multivariate | |
---|---|---|---|---|---|
Age (months) | 4.1 ± 5.2 | 2.3 ± 2.6 | 3.0 ± 3.4 | 0.053 | 0.088 |
Fever (> 38,5 °C) | 0 (0.0%) | 3 (4.8%) | 1 (1.5%) | 0.394 | |
CRP (mg/l)* | 57.6 ± 53.8 | 97.7 ± 51.8 | 102.6 ± 69.5 | < 0.001 | 0.001 |
CRP 0–40 mg/l | 21 (56.8%) | 9 (14.3%) | 12 (17.9%) | < 0.001 | |
40–100 mg/l | 9 (24.3%) | 28 (44.4%) | 23 (34.3%) | ||
> 100 mg/l | 7 (18.9%) | 26 (41.3%) | 32 (47.8%) | ||
Leukocytes* (10e9/ml)* | 12.58 ± 4,72 | 14.67 ± 7.25 | 14.16 ± 6.79 | 0.085 | – |
Neutrophils* (10e9/ml)* | 6.38 ± 4,45 | 8.93 ± 6.50 | 8.40 ± 6.41 | 0.048 | – |
Two viral infections | 4/21 (19.0%) | 6/23 (26.1%) | 12/43 (27.9%) | 0.578 | |
CXR*** Consolidation | 15/36 (19.0%) | 25/62 (40.3%) | 33/66 (50.0%) | 0.896 | |
Antibiotics before 1st culture | 9/34 (75.0%) | 21/59 (35.6%) | 39/63 (61.9%) | < 0.001 | 0.000 |