Fulminant Community-Acquired Acinetobacter baumannii Pneumonia as a Distinct Clinical Syndrome: Baseline Characteristics

In the 19 CAP-AB cases, 16 patients were male (84%) and 3 patients were female (16%). The mean age was 72.6 years (SD, 9.6 years). Almost all of the patients (18 of 19 patients; 95%) had some underlying chronic illness, including COPD, diabetes melli-tus, hypertension, heart disease, and carcinoma.
Compared to the HAP-AB group, the CAP-AB group had more ever-smokers, more COPD patients, fewer patients with other non-COPD chronic lung diseases, and a lower number of hospitalization in the previous year. There was no significant difference in the number of other nonpulmonary comorbidities in both groups (Table 1).
The majority of CAP-AB patients presented with acute onset of fever, shortness of breath, and cough. The initial presentation was characterized by severe respiratory distress. When compared with patients in the HAP-AB group, more CAP-AB patients had shortness of breath, cough, and pleuritic chest pain on presentation, while sputum production was less common. In a subgroup analysis excluding patients who were intubated and mechanically ventilated, shortness of breath was more common in CAP-AB patients (p = 0.036), while sputum production was less common (p = 0.005; data not shown). The APACHE II score was not significantly different in both groups. In terms of hematologic parameters, the CAP-AB group had higher mean hemoglobin levels, lower total WBC count, absolute neutrophil count, platelet count, and more prolonged activated partial thromboplastin time than the HAP-AB group. For radiographic features, lobar consolidation was more common in the CAP-AB group, while pleural effusion and cavitatory changes were not present in this group (Table 2). Pleural effusions developed in nine patients in the HAP-AB group (12.1%); however, the amounts of fluid were considered too small to warrant thoracocentesis. generic zyrtec

A significant proportion (32%) of CAP-AB patients had bacteremia on presentation. Four patients in the CAP-AB group had other organisms cultured in the sputum sample (Streptococcus pneumoniae, 2 patients; Pseudomonas aeruginosa, 2 patients). However, AB was considered as the pathogen as it was also cultured in the blood culture of these four patients.

Table 1—Comparison of Baseline Characteristics of CAP-AB and HAP-AB

Parameters CAP-AB Group (n = 19) HAP-AB Group (n = 74) p Value
Sex 0.15
Male 16 50
Female 3 24
Mean (SD) age, yr 72.6 (9.6) 68.8(14.1) 0.26
Ever smokers 16 (84.2) 41 (55.4) 0.031
Alcoholism 3(15.8) 10(13.5) 0.73
COPD 12 (63.2) 22 (29.7) 0.014
Non-COPD chronic lung disease 0(0) 15 (20.3) 0.035
Charlson comorbidity score, median (range) 1 (0-7) 1 (0-7) 0.54
Hospitalization in previous 1 yr, d median (range) 0 (0-0) 0(0-32) 0.049
Previous use of antibiotic within 2 mo 0(0) 7 (9.5) 0.34
Previous use of systemic steroid within 2 mo 0 (0) 8 (10.8) 0.20

Table 2—Comparison of Clinical Presentation of CAP-AB and HAP-AB

Parameters CAP-AB Group (n = 19) HAP-AB Group (n = 74) p Value
Clinical features, No. %
Fever 17 (89.5) 59 (79.7) 0.51
Shortness of breath 17 (89.5) 37 (50) 0.002
Cough 16 (84.2) 36 (48.6) 0.008
Sputum production 13 (68.4) 69 (93.2) 0.008
Hemoptysis 1 (5.3) 5 (6.8) 0.81
Pleuritic chest pain 2 (10.5) 0(0) 0.04
Laboratory parameters, mean (SD)
Hemoglobin, g/dL 12.3 (2.4) 10.2 (2.4) 0.001
Total WBC count, X109 cells/L 10.6 (7.6) 15.6 (6.2) 0.003
Absolute neutrophil count, X109 cells/L 8.2 (7.5) 12.9 (5.4) 0.005
Platelet count, X109 cells/L 135.1 (67.5) 258.7 (139.0) > 0.001
APACHE II score 14.1 (4.8) 15.5 (7.5) 0.46
Microbiological features, No. (%)
Bacteremia 6 (31.6) 0(0) > 0.001
Positive pleural fluid culture 0(0) 0 (0)
Positive sputum or tracheal aspirate culture 18 (94.7) 74 (100) 0.20
Radiological features, No. (%)
Lobar consolidation 13 (68.4) 12 (16.2) 0.013
Cavitation 0 (0) 0(0)
Pleural effusion 0 (0) 9 (12.1) 0.20
This entry was posted in Pulmonary Function and tagged Acinetobacter baumannii, community-acquired pneumonia, hospital-acquired pneumonia.