Table 1.
Demographics, severity of disease, clinical, laboratory, radiological findings on admission, microbiology and empiric antibiotic therapy of the study population, according to the three study groups
| Characteristic | Group A | Group B | Group C | p (Among 3 groups) | p (Group B vs. Group C) |
|---|---|---|---|---|---|
| n. (%) |
954 (100) |
771 (100) |
420 (100) |
|
|
|
Demographics |
|
|
|
|
|
| Male, n. (%) |
451 (47) |
368 (48) |
186 (44) |
0.492 |
0.255 |
| Age, median (IQR) years |
67 (47–81) |
75 (61–83) |
75 (61–84) |
<0.001 |
0.868 |
|
Comorbidities, n. (%) |
|
|
|
|
|
| Congestive heart failure |
148 (16) |
170 (22) |
103 (25) |
<0.001 |
0.332 |
| Chronic obstructive pulmonary disease |
139 (15) |
237 (31) |
115 (27) |
<0.001 |
0.225 |
| Diabetes mellitus |
111 (12) |
118 (15) |
61 (15) |
0.069 |
0.731 |
| Cerebrovascular disease |
83 (9) |
93 (12) |
70 (17) |
<0.001 |
0.027 |
| Chronic renal failure |
63 (7) |
63 (8) |
68 (16) |
<0.001 |
<0.001 |
| Liver disease |
52 (6) |
27 (4) |
32 (8) |
0.008 |
0.002 |
| Residency in a nursing home |
46 (5) |
63 (8) |
54 (13) |
<0.001 |
0.009 |
|
Severity on admission, n. (%) |
|
|
|
|
|
| PSI Risk Class IV and V |
332 (35) |
464 (60) |
343 (82) |
<0.001 |
<0.001 |
| CURB-65 score 3, 4 and 5 |
127 (13) |
198 (26) |
231 (55) |
<0.001 |
<0.001 |
| Admission to ICU |
6 (0.6) |
54 (7) |
90 (21) |
<0.001 |
<0.001 |
|
Physical findings on admission, median (IQR) |
|
|
|
|
|
| Systolic blood pressure, mmHg |
127 (112–145) |
130 (115–150) |
108 (85–133) |
<0.001 |
<0.001 |
| Diastolic blood pressure, mmHg |
70 (64–80) |
71 (62–80) |
60 (50–72) |
<0.001 |
<0.001 |
| Heart rate, beats/minute |
95 (83–107) |
100 (85–114) |
110 (100–120) |
<0.001 |
<0.001 |
| Respiratory rate, breaths/minute |
20 (18–26) |
24 (20–30) |
30 (24–34) |
<0.001 |
<0.001 |
| SpO2,% |
96 (95–97) |
92 (89–95) |
90 (85–93) |
<0.001 |
<0.001 |
|
Laboratory values, median (IQR) |
|
|
|
|
|
| Arterial pH |
7.45 (7.42-7.48) |
7.44 (7.40-7.48) |
7.39 (7.31-7.46) |
<0.001 |
<0.001 |
| PaO2/FiO2 ratio |
339 (318–378) |
256 (216–279) |
229 (182–276) |
<0.001 |
<0.001 |
| PaCO2, mmHg |
33 (29–38) |
36 (31–42) |
36 (30–48) |
<0.001 |
0.164 |
| Respiratory acidosis, n. (%) |
0 (0) |
59 (8) |
47 (13) |
<0.001 |
0.014 |
| White blood cells, cell/L−1 |
11900 (8238–16300) |
12790 (9100–17000) |
144000 (9993–19000) |
<0.001 |
0.001 |
| Platelet, cell/L−1 |
232000 (182000–300500) |
237000 (186500–317000) |
233000 (166750–307250) |
0.054 |
0.028 |
| Hemoglobin, g/dL |
13 (12–14) |
13 (12–14) |
13 (11–14) |
0.010 |
0.021 |
| Hematocrit,% |
39 (36–42) |
40 (37–44) |
39 (34–43) |
<0.001 |
0.001 |
| Urea, mg/dL |
37 (27–54) |
45 (31–64) |
63 (42–103) |
<0.001 |
<0.001 |
| Creatinine, mg/dL |
0.9 (0.8-1.2) |
1.0 (0.8-1.2) |
1.2 (0.9-1.9) |
<0.001 |
<0.001 |
| Sodium, mEq/L |
137 (134–139) |
137 (134–139) |
136 (133–140) |
0.650 |
0.409 |
| Glucose, mg/dL |
105 (73–128) |
113 (74–148) |
101 (65–149) |
0.002 |
0.035 |
|
Radiology findings on CXR, n. (%) |
|
|
|
|
|
| Multilobar involvement |
161 (18) |
195 (28) |
141 (36) |
<0.001 |
0.003 |
| Pleural effusion |
204 (22) |
150 (20) |
100 (24) |
0.209 |
0.078 |
|
Microbiological findings, n. (%) |
|
|
|
|
|
| Patients with isolated bacteria |
184 (19) |
198 (26) |
141 (34) |
<0.001 |
0.004 |
| Polymicrobial infection |
3 (2) |
8 (4) |
4 (3) |
0.369 |
0.547 |
| Patients with > = one MDR pathogen |
17 (4) |
20 (5) |
22 (8) |
0.015 |
0.060 |
| S. pneumoniae |
90 (49) |
114 (58) |
64 (45) |
0.064 |
0.027 |
| S. aureus |
15 (8) |
19 (10) |
23 (16) |
0.049 |
0.064 |
| Legionella pneumophila |
16 (9) |
16 (8) |
5 (4) |
0.156 |
0.088 |
| Respiratory viruses |
11 (6) |
12 (6) |
13 (9) |
0.439 |
0.273 |
| Atypicals |
31 (17) |
22 (11) |
9 (6) |
0.014 |
0.137 |
| H. influenzae |
17 (9) |
14 (7) |
7 (5) |
0.328 |
0.419 |
|
Empiric antibiotic therapy, n. (%) |
|
|
|
|
|
| Levofloxacin |
287 (30) |
234 (30) |
106 (25) |
0.133 |
|
| Ceftriaxone |
348 (37) |
324 (42) |
145 (35) |
0.015 |
|
| Amoxicillin (clavulanate) |
295 (31) |
218 (28) |
148 (35) |
0.045 |
|
| Azithromycin |
230 (24) |
189 (25) |
72 (17) |
0.007 |
|
| Clarithromycin |
198 (21) |
211 (27) |
152 (36) |
<0.001 |
|
| Piperacillin/tazobactam |
34 (3.6) |
44 (5.7) |
43 (10) |
<0.001 |
|
| Antibiotics compliant with local guidelines |
731 (81) |
595 (79) |
328 (79) |
0.606 |
0.933 |
|
Outcomes |
|
|
|
|
|
| Length of hospital stay, median (IQR) days |
6 (3–11) |
9 (6–14) |
12 (7–21) |
<0.001 |
0.004 |
| In-hospital mortality, n. (%) | 43 (4.2) | 72 (9.3) | 108 (26) | <0.001 | <0.001 |
n: number; IQR: 25–75 interquartile range; COPD: chronic obstructive pulmonary disease; CAP: community-acquired pneumonia; PSI: pneumonia severity index; ICU: intensive care unit; CXR: chest radiograph; ESBL: extended-spectrum beta-lactamase; MDR: multidrug resistant (including methicillin-resistant S. aureus, Pseudomonas aeruginosa resistant to antipseudomonal penicillins, cephalosporins, carbapenems, and quinolones, Stenotrophomonas maltophilia, vancomycin-resistant Enterococcus, Acinetobacter baumanii, extended spectrum b-lactamase producing Enterobacteriaceae, and other non-fermenting Gram-negative bacilli); SpO2: oxygen saturation; PaO2: partial pressure of oxygen in arterial blood; PaCO2: partial pressure of carbon dioxide in arterial blood. +Hypotension defined as Systolic blood pressure <90 mm Hg or diastolic blood pressure < 60 mm Hg. Differences in continuous variables were monitored with Kruskal-Wallis test (three groups) and Mann–Whitney U Test differences (two groups); differences in proportions were monitored with ANOVA (three groups) and the chi square test (two groups).
Group A: Community-acquired pneumonia (CAP) patients with neither acute respiratory failure (ARF) nor severe sepsis (SS) on admission. Group B: CAP patients with only ARF on admission. Group C: CAP patients with both ARF and SS on admission.