Community-Acquired Acinetobacter baumannii Pneumonia: Initial Chest Radiographic Findings and Follow-up CT Findings in Helping Predict Patient Outcome Jeong Joo Woo, Dong Hyun Lee, Jin Kyung An Department of Radiology, Eulji Hospital, Eulji University College of Medicine, Seoul, Korea
No relevant financial disclosure for all authors
INTRODUCTION Acinetobacter baumannii (AB) - Gram-negative coccobacillus - Common nosocomial pathogen, affecting patients receiving treatment in the ICU, especially requiring mechanical ventilation and having wound or burn injuries - Important cause of hospital-acquired pneumonia(hap) - High resistance to all available antibiotics
INTRODUCTION Community-acquired AB pneumonia (CAP-AB) - CAP-AB has been reported sporadically in Asian- Pacific countries, especially during the warmer and more humid seasons - CAP-AB cause bacteremia, meningitis, soft- tissue infection, ocular infection, and native valve endocarditis - Uncommon but important cause of community acquired pneumonia
INTRODUCTION Community-acquired AB pneumonia(cap-ab) - Fulminant course, that rapidly progress to respiratory failure and shock - High mortality rate (40 to 64%) (higher than the overall mortality rate resulting from severe CAP (24%), higher than hospital-acquired AB pneumonia) The purpose of this study was to evaluate whether initial radiographic findings and follow-up thin-section CT findings of CPA-AB patients can help predict clinical outcome.
MATERIALS AND METHODS We identified 98 patients with culture-proven AB pneumonia over a 5-year period through the computerized infectious disease database. Hospital acquired AB pneumonia (n=78) Sex: Male-Female ratio 58:20 Age : 31-94 years, median age 72.2 years Community acquired AB pneumonia (n=20) Sex: Male-Female ratio 10:10 Age : 42-88 years, median age 78.9 years
MATERIALS AND METHODS CAP-AB with grave outcome(n=10) Sex: Male-Female ratio 5:5 Age : 71-86 years, median age 78.3 years Intubation : 9 ( grave outcome measures were the need for mechanical ventilation and death ) CAP-AB with recovery(n=10) Sex: Male-Female ratio 5:5 Age : 42-88 years, median age 67.8 years Intubation : 0
MATERIALS AND METHODS We retrospectively reviewed clinical history, initial chest radiographs and CT findings including type, pattern and extent of opacities Patterns at radiograph, CT - focal consolidation - patchy unilateral consolidation - bilateral consolidation - bronchopneumonia - ground-glass opacity - pleural effusion - lymphadenopathy
RESULT Recovery (n=10) Grave outcome (n=10) Recovery (n=10) Grave outcome (n=10) Cough 6 1 Sputum 4 1 Dyspnea 3 5 Fever 3 1 Chest wall pain 3 0 General weakness 1 2 Hemoptysis 1 0 Mental change 1 2 HTN 3 6 DM 2 6 CKD 1 4 CHF 1 0 CVA 1 3 Asthma 1 1 Atrial fibrillation 1 0 TB 1 0 COPD 1 2 Table 1. Symptoms of patients Table 2. Underlying disease of patients CKD: Chronic Kidney Disease, CHF: Congestive Heart Failure, DM: Diabetes Mellitus, HTN: Hypertension, CVA: Cerebrovascular Accident, COPD: Chronic Obstructive Pulmonary Disease
RESULT Recovery (n=10) Grave outcome (n=10) P-value Age 67.8 78.3 0.03 Focal consolidation Patchy unilateral consolidation Bilateral consolidation Broncho Pneumonia Recovery (n=10) Grave outcome (n=10) P-value 4 3 0.13 2 1-2 4 0.16 2 3 0.13 Effusion 3 1 0.16 GGO 2 4 0.15 Table 3. Initial chest radiograph findings
RESULT Recovery (n=10) Grave outcome (n=10) P-value Focal consolidation 4 1 0.15 Patchy unilateral consolidation Bilateral consolidation Broncho Pneumonia 3 3-2 6 0.01 5 4 0.32 Effusion 5 3 0.27 GGO 4 6 0.66 Lymphadenopathy 3 3 - Table 4. Follow up CT findings
RESULT Focal consolidation in recovery group(4/10) and bilateral consolidation with GGO in grave outcome group (4/10) were the most common initial chest radiographic findings of CAP-AB No statistically significant findings at initial chest radiographs in grave outcome group of CAP-AB compared with recovery group On follow-up CT findings taken 1-7 days later, bilateral consolidation with extensive ground-glass opacities were significantly more often seen with grave outcome group compared with recovery group (P=.01)
RESULT Patients with grave outcome were significantly older(p=0.03) than recovery group of CAP-AB Patients with grave outcome had more underlying disease such as DM, HTN, COPD than recovery group of CAP-AB
Recovery CASE 1 F/58 Cough, Fever DM Figure 1-1. Initial chest radiograph shows consolidation in the right lower lobe.
Recovery CASE 1 A B Figure 1-2. (A) and (B). Axial chest CT obtained 1 day after initial radiograph shows multifocal consolidations in the right lower lobe.
Recovery CASE 1 A B Figure 1-3. (A) Chest radiograph shows minimal resolution of RLL pneumonia after using antibiotics for 2 weeks. (B) Three months after A, consolidation in right lung has almost resolved.
Recovery CASE 2 F/62 Dyspnea, cough, sputum Adrenal insufficiency, CKD, CHF Figure 2-1. Initial Chest AP shows patchy consolidation and peribronchial small nodular opacities in both lung fields. (Hickman catheter in place in CKD patient)
Recovery CASE 2 A B B Figure 2-2. (A) 2 days after initial chest PA, patchy consolidations and branching small nodular opacities are noted in both lung fields on lungwindow CT. (B) Multiple reactive lymph nodes are noted in the mediastinum.
Recovery CASE 2 A B Figure 2-3. (A) Follow-up chest AP obtained 4 days after antibiotics treatment shows improvement of pneumonia. (B) Further resolution of pneumonic infiltrates is observed on the13 th hospital day. Left pleural effusion due to chronic kidney disease.
Recovery CASE 3 M/78 General weakness, poor oral intake Figure 3-1. Initial Chest PA shows patchy peribronchial nodular opacities in both lung fields.
Recovery CASE 3 A B Figure 3-2. (A) 4 days after initial chest PA, patchy consolidations with GGO are noted in both lung fields on lung-window CT. (B) Diffuse centrilobular nodular opacities are noted on lung-window CT.
Recovery CASE 3 A B Figure 3-3. (A) Follow-up chest PA obtained 4 days after antibiotics treatment shows partial improvement of pneumonia. (B) Further resolution of pneumonic infiltrates is observed after 2 months from discharge.
Grave outcome CASE 1 M/86 Fever, Mental change Complete AV block, DM, CKD Figure 4-1. Initial chest radiograph shows focal consolidation in right upper lobe and pacemaker for first degree AV block.
Grave outcome CASE 1 A B Figure 4-2. Four days later, axial chest CT shows consolidation with ground glass opacity in right upper and lower lobes (A). Axial enhanced chest CT (B) shows focal consolidation in the RUL, right paratracheal node and small pleural effusion.
Grave outcome CASE 1 Figure 4-3. Follow-up chest radiograph obtained 20 days later with antibiotics treatment shows persistent consolidation in the right upper lobe. The patient expired due to multi-organ failure 10 days later.
Grave outcome CASE 2 M/79 Cough, Sputum CKD, DM, HTN, CVA Figure 5-1. Chest radiograph shows focal increased opacity in left retrocardiac area (arrow) and tuberculosis sequelae in bilateral upper lobes.
Grave outcome CASE 2 A B Figure 5-2. Axial chest CT shows round pneumonia in left lower lobe. Bronchiectasis in the both lower lobes are noted.
Grave outcome CASE 2 Figure 5-3. Follow-up chest radiograph obtained 10 days later with antibiotics treatment shows progressive diffuse haziness in both lung fields and persistent consolidation in retrocardiac area. The patient expired due to septic shock.
Grave outcome CASE 3 F/70 Dyspnea COPD, HTN Figure 6-1. Chest radiograph shows multifocal consolidation with ill-defined nodular infiltrates in both lung fields.
Grave outcome CASE 3 A B Figure 6-2. (A) and (B), axial chest CT 2 days later shows patchy ground glass opacities and consolidation with intralobular interstitial thickening in bilateral lung fields. Mild bronchial dilatation(arrow) within the consolidation representing acute lung injury is noted.
Grave outcome CASE 3 Figure 6-3. One month after admission, despite sustained antibiotics therapy, chest AP shows extensive opacification in both lung fields indicating ARDS. The patient died of ARDS on the 40th hospital day.
CONCLUSION CAP-AB is uncommon, but it is a clinically unique entity, with a high mortality rate. (45% in our study) There was no significant difference at initial chest radiographic findi ngs between community-acquired AB pneumonia patients with recovery and grave outcome. Rapid progress with extensive involvement of both lungs revealed as bilateral consolidation with patchy GGA on follow-up CT was significantly associated with grave prognosis. Older age is significantly associated with grave outcome Patients with CAP-AB pneumonia should be treated carefully and intensively in elderly patients with underlying disease such as DM, COPD, hypertension to lower the mortality rate.
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