Download Empyema: An Uncommon Complication of Common Pneumonia

Heather Hsu, HMS III
Gillian Lieberman, MD
March 2011
Empyema: An Uncommon
Complication of Common Pneumonia
Heather Hsu, HMS III
Gillian Lieberman, MD
Heather Hsu, HMS III
Gillian Lieberman, MD
Overview
• Patient presentation
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History of present illness and other relevant information
Menu of appropriate radiologic tests and their indications
Review of lung anatomy on chest x-ray
Overview of our patient’s radiographic findings
Differential diagnosis
• A complication of the diagnosis
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Definition and epidemiology
Appearance on imaging
Companion patient images
Management overview
• Update on our patient’s clinical course
• Summary
1
Heather Hsu, HMS III
Gillian Lieberman, MD
Our Patient: History of Present
Illness at First Presentation
• CC: left-sided chest/shoulder pain and
dyspnea
• HPI: 70-year-old woman presents with 2 days
of increasing, constant, non-radiating leftsided chest and shoulder pain and 1 day of
increasing dyspnea and productive cough.
• PMH: type 2 DM, HTN, hypothyroid, chronic
pain, hyperlipidemia, breast CA (1989, s/p
mastectomy), thyroid CA (2005, s/p
thyroidectomy and I-125)
2
Heather Hsu, HMS III
Gillian Lieberman, MD
Our Patient: First Presentation
Vital Signs, Physical Exam, and Labs
• Vitals: T 99.6, HR 127, BP 134/70, RR 16,
O2sat 98% RA
• Physical Exam: crackles in left lung base,
pain with movement of left shoulder
• Labs: WBC 13 (90% PMNs)
3
Heather Hsu, HMS III
Gillian Lieberman, MD
At this point, acute respiratory illness is a likely
etiology for our patient’s presentation.
However, the differential diagnosis remains broad.
We will now consider the use of imaging
to narrow this differential.
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Heather Hsu, HMS III
Gillian Lieberman, MD
Menu of Radiologic Tests for Adults
with Acute Respiratory Illness
• Chest X-ray (CXR)
• CT chest
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www.acr.org; Mandell, et al., Clin Infect Dis 2007
Heather Hsu, HMS III
Gillian Lieberman, MD
Indications for Imaging in Adults with
Acute Respiratory Illness: Chest X-Ray
• Chest X-ray
– Indicated for evaluation of acute respiratory illness
in patients with the following characteristics:
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Age >40 years
Hemoptysis
Dementia
Comorbidities (e.g., CAD, CHF, etc.)
Associated abnormalities (e.g., hypoxia, leukocytosis)
Clinical suspicion of pneumonia
• Chest CT
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www.acr.org; Mandell, et al., Clin Infect Dis 2007
Heather Hsu, HMS III
Gillian Lieberman, MD
Indications for Imaging in Adults with
Acute Respiratory Illness: Chest CT
• Chest X-ray
• Chest CT
– Indicated for evaluation of:
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Abnormalities seen on plain x-ray
Recurrent or persistent pneumonia
Suspected pleural abnormality
Suspected lung abscess
Pulmonary embolism
Airway patency
Guidance for thoracentesis when u/s is not sufficient
– Depending on the goal of the study, it may be
performed with and/or without contrast
www.acr.org; Mandell, et al., Clin Infect Dis 2007
7
Heather Hsu, HMS III
Gillian Lieberman, MD
Given this menu of potential tests, their
indications, and our patient’s clinical
presentation, a chest x-ray was obtained.
Before we examine our patient’s current chest
x-ray, we will review some basic anatomy
using prior films.
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Heather Hsu, HMS III
Gillian Lieberman, MD
Review of Lung Anatomy on CXR
Our patient: Prior PA CXR
Prior lateral CXR
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BIDMC, PACS
Heather Hsu, HMS III
Gillian Lieberman, MD
Anatomy Review: Right Lung Fissures
Minor fissure
Minor fissure
Right
major
fissure
Prior PA CXR
Prior lateral CXR
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BIDMC, PACS
Heather Hsu, HMS III
Gillian Lieberman, MD
Anatomy Review: Right Upper Lobe
RUL
Prior PA CXR
RUL
Prior lateral CXR
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BIDMC, PACS
Heather Hsu, HMS III
Gillian Lieberman, MD
Anatomy Review: Right Middle Lobe
RML
Prior PA CXR
RML
Prior lateral CXR
“Silhouette sign”: On the PA film, an opacity in the right middle lobe may
obscure the right heart border ( )
BIDMC, PACS
12
Heather Hsu, HMS III
Gillian Lieberman, MD
Anatomy Review: Right Lower Lobe
RLL
RLL
BIDMC, PACS
Prior PA CXR
Prior lateral CXR
“Silhouette sign”: On a PA film, an
opacity in the RLL may obscure the
right hemidiaphragm ( )
“Spine sign”: On lateral, a RLL opacity
may interrupt the normal progressive
increase in lucency of the thoracic
vertebral bodies ( )
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Heather Hsu, HMS III
Gillian Lieberman, MD
Anatomy Review: Left Major Fissure
Left major
fissure
Left major
fissure
Prior PA CXR
Prior lateral CXR
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BIDMC, PACS
Heather Hsu, HMS III
Gillian Lieberman, MD
Anatomy Review: Left Upper Lobe
LUL
Prior PA CXR
LUL
Prior lateral CXR
“Silhouette sign”: On the PA film, an opacity in the lingular portion of the left
upper lobe may obscure the left heart border ( )
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BIDMC, PACS
Heather Hsu, HMS III
Gillian Lieberman, MD
Anatomy Review: Left Lower Lobe
LLL
LLL
BIDMC, PACS
Prior PA CXR
Prior lateral CXR
“Silhouette sign”: On the PA film, an
opacity in the left lower lobe may obscure
the left hemidiaphragm ( )
“Spine sign”: On lateral, a LLL opacity
may interrupt the normal progressive
increase in lucency of the thoracic
vertebral bodies ( )
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Heather Hsu, HMS III
Gillian Lieberman, MD
Our Patient: Prior PA and Lateral CXR
Prior PA CXR
Prior lateral CXR
Please pause to review our patient’s prior films
and give your general impression.
BIDMC, PACS
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Heather Hsu, HMS III
Gillian Lieberman, MD
Our Patient: Prior CXR Findings
Prior PA CXR
BIDMC, PACS
Prior lateral CXR
General impression: Normal chest X-ray, note the absence
of the left breast shadow ( ) s/p mastectomy
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Heather Hsu, HMS III
Gillian Lieberman, MD
Now back to our patient’s current presentation with
left-sided chest pain and dyspnea…
ECG is unchanged from prior.
A portable AP chest X-ray is obtained.
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Heather Hsu, HMS III
Gillian Lieberman, MD
Our Patient: Current AP CXR
Reminder - Systematic
Approach to CXR:
-Acknowledge major
abnormalities
First admission AP CXR
Prior PA CXR
Please pause to compare our patient’s new
CXR with the prior film.
BIDMC, PACS; Lieberman’s E-Radiology
-Quality control
-Lines + hardware
-Heart + mediastinum
-Lungs + diaphragm
-Pleura
-Bones
-Soft tissues
-Checkpoints
-Apices
-Aortic knob
-Hila
-Retrocardiac regions
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Heather Hsu, HMS III
Gillian Lieberman, MD
Our Patient: Current AP CXR Findings
Note that we are comparing
a current AP CXR with a
prior PA film, so changes in
heart size cannot be
adequately assessed.
Opacity in left mid + lower
lung fields with air
bronchograms, partially
obscuring L hemidiaphragm
Prior PA CXR
Small left pleural
effusion ( ) obscuring
costophrenic angle
Absence of left breast
shadow ( ) s/p
mastectomy
First admission AP CXR
Given these findings, what is the differential diagnosis?
BIDMC, PACS
21
Heather Hsu, HMS III
Gillian Lieberman, MD
Our Patient:
Differential Diagnosis at First Presentation
• Pneumonia
• Malignancy
– Primary
– Metastasis
• Pleural effusion
– Parapneumonic
– Malignant
• Atelectasis
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Heather Hsu, HMS III
Gillian Lieberman, MD
Given our patient’s clinical presentation and CXR
findings, she is diagnosed with a left lower lobe
community-acquired pneumonia, admitted to the
hospital, and started on levofloxacin.
Over the next two days, her white blood cell count,
dyspnea, cough, and chest pain improve
and she is discharged.
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Heather Hsu, HMS III
Gillian Lieberman, MD
Our Patient: Second Presentation
After discharge, our patient returns home.
The next morning, she presents again with
severe, pleuritic, left-sided chest pain.
She is afebrile, tachycardic, and tachypneic.
Another chest X-ray is obtained.
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Heather Hsu, HMS III
Gillian Lieberman, MD
Our Patient:
CXR at Second Presentation
Current AP and lateral CXR
Please pause to compare our
patient’s current CXR with the film
from her prior admission.
BIDMC, PACS
First admission AP CXR
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Heather Hsu, HMS III
Gillian Lieberman, MD
Our Patient: Findings from CXR at
Second Presentation
New Findings:
More prominent opacity in left
mid and lower lung fields,
silhouetting out the left heart
border and hemidiaphragm.
The left costophrenic angle
( ) is obscured.
Spine sign ( )
Second admission AP and lateral CXR
Quality control:
Mediastinum appears wide (
) due to the patient’s rotated position.
Poor arm positioning ( ) obscures upper lung fields.
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BIDMC, PACS
Heather Hsu, HMS III
Gillian Lieberman, MD
Our Patient: Differential Diagnosis at
Second Presentation
• Inadequately treated pneumonia
• Complicated pneumonia
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Simple parapneumonic effusion
Complicated parapneumonic effusion
Empyema
Necrotizing pneumonia
Lung collapse/atelectasis
Mucus plug
Lung malignancy
Malignant effusion
Pulmonary embolism
Given this differential diagnosis, what should the next step be?
Do we need further imaging?
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Heather Hsu, HMS III
Gillian Lieberman, MD
Based on the findings from the chest X-ray and
the patient’s worsening clinical condition, the
decision is made to order a CTA to rule out
pulmonary embolus and further characterize
the abnormalities seen on CXR.
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Heather Hsu, HMS III
Gillian Lieberman, MD
Our Patient: Chest CTA from
Second Presentation
Cross-sectional views, C+ Chest CT, soft tissue window
Not depicted: Contrast opacification of pulmonary arteries is complete to
segmental level and the central airways are patent.
Please pause to evaluate the images.
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BIDMC, PACS
Heather Hsu, HMS III
Gillian Lieberman, MD
Our Patient: Chest CTA Findings
Left lower lobe collapse with
worsening consolidation ( )
Non-hemorrhagic pleural
effusion ( ), with pleural
fluid measuring ~27
Hounsfield units
Septation within pleural
effusion ( ) and nondependent layering ( )
indicating loculation
Cross-sectional view, C+ Chest CT, soft tissue window
Reminder re: Hounsfield units (HU):
Air: -1000 HU
Fat: -30 HU
Water: 0 HU
Soft tissue: +30 HU
Blood: +40 HU Bone: +1000 HU
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BIDMC, PACS
Heather Hsu, HMS III
Gillian Lieberman, MD
Our Patient: Revised Differential
Diagnosis Following Chest CTA
• Complicated pneumonia
– Simple parapneumonic effusion
– Complicated parapneumonic effusion
– Empyema
• Lung collapse/atelectasis
• Lung malignancy
• Malignant effusion
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Heather Hsu, HMS III
Gillian Lieberman, MD
Based on the findings from the chest CTA and the
patient’s clinical presentation, she is diagnosed
with a probable empyema and transferred to the
ICU for further management.
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Heather Hsu, HMS III
Gillian Lieberman, MD
Empyema:
Definition, Phases, and Epidemiology
• Definition: The presence of pus and/or gram
stain/culture-positive fluid in the pleural space
• Three phases:
– Exudative: inflammation of visceral pleura results in
exudative effusion and thickening of pleural surfaces
– Fibropurulent: inflammatory cells and neutrophils invade the
pleural space, fibrin is deposited on inflamed pleural
surfaces
– Organizing: recruitment of fibroblasts and capillaries results
in deposition of collagen and granulation tissue on pleural
surfaces leading to pleural fibrosis
• Epidemiology: <2% of patients with communityacquired pneumonia develop empyema
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Ahmed, et al. Am J Med 2006; Kulman and Singha, Radiographics 1997
Heather Hsu, HMS III
Gillian Lieberman, MD
Empyema:
Appearance on Imaging
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CXR: may see a pleural-based opacity that has an abnormal contour
or does not flow freely on lateral decubitus views
Ultrasonography: may see loculated effusion
C+ CT chest:
– Classic appearance: oblong fluid collection with smooth inner margins
that compresses and displaces surrounding lung and airway
– Important to distinguish empyema from lung abscess
• CT findings favoring abscess include a thick-walled, spherical cavity that
destroys lung rather than displacing it
– “Split pleura” sign on C+ CT:
• Contrast-enhanced thickened visceral and parietal pleura separated by fluid
• May be seen in the fibropurulent phase
• Indicates exudative effusion (not specific to empyema)
– “Pleural microbubbles”
• Small air bubbles within fluid collection
• May indicate resistance of the effusion to chest tube drainage
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Kulman and Singha, Radiographics 1997; Smolikov, et al. Clin Radiol 2006
Heather Hsu, HMS III
Gillian Lieberman, MD
Empyema: Companion Patient Images
Middle-aged man with right-sided chest discomfort and shortness of breath
Cross-sectional views, C+ Chest CTA, soft tissue window
Fluid trapped in the minor fissure ( )
Loculated right pleural effusion ( )
that is layering non-dependently
Atelectasis ( )
Liver dome ( )
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BIDMC, PACS
Heather Hsu, HMS III
Gillian Lieberman, MD
Empyema: Management Overview
• Thoracentesis
– Pleural fluid analysis, gram stain, and culture
• Appropriate antibiotics
– Sterilization of empyema cavity with systemic
antibiotics (minimum 4-6 weeks)
• Drainage
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Tube thoracostomy
Video-assisted thoracoscopic surgery (VATS)
Open decortication
Open thoracostomy
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Colice, et al. Chest 2000
Heather Hsu, HMS III
Gillian Lieberman, MD
Our Patient:
Management of Her Clinical Course
• Pleural fluid analysis
– Culture-negative, non-malignant exudative effusion with low pH
and positive gram stain
– Consistent with empyema
• Antibiotics
– Broad spectrum coverage with vancomycin, cefepime, and
azithromycin
• Drainage
– VATS and decortication procedures were attempted without
success due to difficulty ventilating the right lung during the
procedures.
– Ultimately, a chest tube was placed and the effusion drained
successfully.
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Heather Hsu, HMS III
Gillian Lieberman, MD
Our Patient:
ICU Course and Outcome
• ICU course
– Complicated by NSTEMI, serotonin syndrome, blood
transfusion, and benzodiazepine withdrawal
• Outcome
– Discharged after ~2 weeks in the ICU
– Currently living at home and doing well
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Heather Hsu, HMS III
Gillian Lieberman, MD
Summary
• Patient presentation
–
–
–
–
–
History of present illness and other relevant information
Menu of appropriate radiologic tests and their indications
Review of lung anatomy on CXR
Overview of our patient’s radiographic findings
Differential diagnosis
• Empyema
–
–
–
–
Definition, phases, and epidemiology
Appearance on imaging
Companion patient images
Management overview
• Update on our patient’s clinical course
39
Heather Hsu, HMS III
Gillian Lieberman, MD
Bibliography
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Ahmed RA, Marrie TJ, Huang JQ. Thoracic empyema in patients with communityacquired pneumonia. Am J Med. 2006;119(10):877-83.
Colice GL, Curtis A, Deslauriers J, et al. Medical and surgical treatment of
parapneumonic effusions : an evidence-based guideline. Chest. 2000;118(4):115871.
Kuhlman JE, Singha NK. Complex disease of the pleural space: radiographic and
CT evaluation. Radiographics. 1997;17:63-79.
Lieberman G. A systematic approach to evaluating chest X-rays. Lieberman’s ERadiology. http://eradiology.bidmc.harvard.edu/interactivetutorials/. Accessed
March 15, 2011.
Mandell LA, Wunderink RG, Anzueto A, et al. Infectious Diseases Society of
America/American Thoracic Society consensus guidelines on the management of
community-acquired pneumonia in adults. Clin Infect Dis. 2007;44 Suppl 2:S27-72.
Smolikov A, Smolyakov R, Riesenberg K, et al. Prevalence and clinical significance
of pleural microbubbles in computed tomography of thoracic empyema. Clin Radiol.
2006;61(6):513-9.
Washington L, Kahn A, Mohammed T. American College of Radiology
Appropriateness Criteria: Acute respiratory illness.
http://www.acr.org/secondarymainmenucategories/quality_safety/app_criteria.aspx.
Accessed March 15, 2011.
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Heather Hsu, HMS III
Gillian Lieberman, MD
Acknowledgements
• Gillian Lieberman, MD – for her teaching and
guidance
• Veronica Fernandes, MD – for her feedback
on the presentation
• Emily Hanson – for technical support and
guidance
• Douglas Hsu, MD – for assistance in finding
companion patient images
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