Jeong Joo Woo, Dong Hyun Lee, Jin Kyung AnDepartment of Radiology,

Eulji Hospital, Eulji University College of Medicine, Seoul, Korea

Community-Acquired Acinetobacter baumannii Pneumonia: Initial Chest Radiographic Findings and Follow-up CT Findings in Helping Predict Patient Outcome

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

Table 1. Symptoms of patients

CKD: Chronic Kidney Disease, CHF: Congestive Heart Failure, DM: Diabetes Mellitus, HTN: Hypertension, CVA: Cerebrovascular Accident, COPD: Chronic Obstructive Pulmonary Disease

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

Recovery (n=10)

Grave outcome (n=10)

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 2. Underlying disease of patients

RESULT

Table 3. Initial chest radiograph findings

Recovery (n=10)

Grave outcome (n=10) P-value

Focal consolidation 4 3 0.13

Patchy unilateralconsolidation

2 1 -

Bilateral consolidation 2 4 0.16

BronchoPneumonia 2 3 0.13

Effusion 3 1 0.16

GGO 2 4 0.15

RESULTRecovery

(n=10)Grave outcome

(n=10) P-value

Age 67.8 78.3 0.03

Table 4. Follow up CT findings

Recovery (n=10)

Grave outcome (n=10) P-value

Focal consolidation 4 1 0.15

Patchy unilateralconsolidation 3 3 -

Bilateral consolidation 2 6 0.01

BronchoPneumonia 5 4 0.32

Effusion 5 3 0.27

GGO 4 6 0.66

Lymphadenopathy 3 3 -

RESULT

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)

▣ 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

RESULT

Figure 1-1. Initial chest radiograph shows consolidation in the right lower lobe.

▣ F/58▣ Cough, Fever▣ DM

Recovery CASE 1

Figure 1-2. (A) and (B). Axial chest CT obtained 1 day after initial radiograph shows multifocal consolidations in the right lower lobe.

A B

Recovery CASE 1

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.

A B

Recovery CASE 1

▣ F/62▣ Dyspnea, cough, sputum▣ Adrenal insufficiency,

CKD, CHF

Figure 2-1. Initial Chest AP shows patchy consolidation and peribronchialsmall nodular opacities in both lung fields. (Hickman catheter in place in CKD patient)

Recovery CASE 2

Figure 2-2. (A) 2 days after initial chest PA, patchy consolidations and branching small nodular opacities are noted in both lung fields on lung-window CT. (B) Multiple reactive lymph nodes are noted in the mediastinum .

A BB

Recovery CASE 2

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 the13th hospital day. Left pleural effusion due to chronic kidney disease.

A B

Recovery CASE 2

▣ 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

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 centrilobularnodular opacities are noted on lung-window CT.

A B

Recovery CASE 3

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.

A B

Recovery CASE 3

Figure 4-1. Initial chest radiograph shows focal consolidation in right upper lobe and pacemaker for first degree AV block.

Grave outcome CASE 1

▣ M/86▣ Fever, Mental change▣ Complete AV block,

DM, CKD

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.

BA B

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 1

Figure 5-1. Chest radiograph shows focal increased opacity in left retrocardiac area (arrow) and tuberculosis sequelae in bilateral upper lobes.

▣ M/79▣ Cough, Sputum▣ CKD, DM, HTN, CVA

Grave outcome CASE 2

Figure 5-2. Axial chest CT shows round pneumonia in left lower lobe. Bronchiectasis in the both lower lobes are noted.

A B

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 retrocardiacarea . The patient expired due to septic shock.

Grave outcome CASE 2

Figure 6-1. Chest radiograph shows multifocal consolidation with ill-defined nodular infiltrates in both lung fields.

▣ F/70▣ Dyspnea▣ COPD, HTN

Grave outcome CASE 3

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.

A B

Grave outcome CASE 3

Figure 6-3. One month after admission, despite sustained antibiotics therapy, chest AP shows extensive opacificationin both lung fields indicating ARDS. The patient died of ARDS on the 40th hospital day.

Grave outcome CASE 3

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 findings 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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▣ Thank you for your interest

▣ Please contact jjblue@eulji.ac.kr , if you have any questions or comments.