Ellen Cheang, MS4
Radiology student conference
July 1st, 2011
Overview

Case Presentation
- HPI , clinical exams and ddx
- Review of our patient’s radiographic findings
- Further lab tests

Management of empyema
- Definition and epidemiology
- Discussion of appropriate radiologic test and their
indications
- Current management guidelines
- Literature review and future directions
Case presentation
HPI: 70 y.o. male presents with 1-week history of
dyspnea, dry cough and constant, non-radiating,
progressively worsening right-sided chest pain. Denies
any fever, chills or weight loss.
PMH:
1 mo ago, hospitalized for CAP. Completed 1-wk of abx
- Emphysema
- Hypertension
-
Objectives:



Vitals: T 99, HR 100, BP 125/80, RR 22, O2 95% RA
PE: Crackles , decreased breath sound and dullness to
percussion in LLL
Labs: WBC 12 (87% PMNs)
What’s your differential?
Inadequately treated pneumonia
- Complicated pneumonia
-
- Simple/complicated parapneumonic effusion
- empyema
- necrotizing pneumonia
- Primary lung malignancy
- Malignant effusion
What is your next step of management?
What’s the next step?

Diagnostic thoracentesis (NEJM 2006;335:e16)
Indications:
all effusion >1cm in decubitus view
Any asymmetry, fever, pleuritic chest pain. Cannot exclude
infection clinically
If suspect d/t CHF, diurese first and see if effusion resolves in
48-72 hours
Diagnostic studies:
pH, total protein, LDH, glucose, cell count with diff, gram stain &
culture
Additional studies should be ordered based on clinical
suspicision (e.g. suspected malignancy -> cytology)
Transudate vs exudate
Light’s criteria (Annals 1972;77:507)
-
TP eff/ TP serum > 0.5 or
LDH eff/LDH serum >0.6 or
LDH eff > 2/3 upper normal limit of LDH serum
Our patient:
pH= 7.01, glucose= 35, LDH = 2100, WBC = 50000
Gram stain positive, culture pending

Common causes of transudates
Etiology
appear
WBC diff
RBC
pH
glucose
others
CHF
clear
<1000 lymph
<5000
normal
~serum
bilateral
Cirrhosis
clear
<1000
<5000
normal
~serum
R-sided

Common causes of exudate
Etiology
appear
WBC diff
RBC
pH
glucos
e
others
Uncomplicated
parapneumonic
Turbid
5-40,000
polys
<5000
>7.2
>40
Abx ok
Complicated
parapneumonic
Turbidpurulent
5-40,000
polys
<5000
<7.2
<40
Need
drainage
Empyema
purulent
25-100,000
polys
<5000
<7.2
<40
Need
drainage
Malignancy
bloody
1-10,000 ly
<100,000
Sl ↓
Sl ↓
+cytology
What is your diagnosis?
Empyema
(Ahmed, et al. Am J Med 2006; Kulman and Singha, Radiographics 1997)

Def: The presence of inflammatory debris (pus) in the pleural space
due to untreated/undertreated infection (most common cause:
bacterial pneumonia)

Epi: About 20-60% of pneumonia are associated with
parapneumonic effusion, which usually resolve with antibiotic
treatment. However, ~1% do not resolve, causing infection and
loculated pus in the pleural space.

Three phases
1.
2.
3.
Exudative: inflammation of the visceral pleura results in weeping of
fluid into pleural space
Fibinopurulent: inflammatory cells and fibrin accumulate in the
pleural space (At this stage, CT may show a “split pleura” sign)
Organizing: deposition of collagen and granulation tissue along the
visceral & pleural results in pleural fibrosis
Empyema: Imaging features
Chest radiograph
(Study of choice of initial assessment!)
-
Pleural-based opacity that has an abnormal
contour
-
Does not flow freely on lateral decubitus views
-
When parapneumonic effusion is suspected, a
diagnostic thoracentesis will be the next step
-
CXR can generally differentiate empyema from
lung abscess, CT is not usually indicated!
Empyema
-Right/obtuse angle with chest wall
-Lenticular in shape
-Much larger on 1 of 2 right angle
projections
Lung Abscess
-Form an acute angle with chest wall
-Spherical in shape
-More similar in size on right angle
projection
What are the indications for
Chest CT/ultrasound?
Indications for ultrasound
-
To guide thoracentesis/chest tube placement
To assess anatomy in the pediatric population
Indications for chest CT
To evaluate complex anatomy which cannot be fully
assessed by CXR
- Differentiate lung abscess and empyema
- Suspected pleural masses (e.g. mesothelioma)
- Guidance for thoracentesis/chest tube placement when
ultrasound is not sufficient
-
Could CT or ultrasound
predict outcomes?
Study 1: CT and ultrasound in
parapneumonic effusion and empyema
(Kearney et al. Clin Radiol. 2000 Jul;55(7):542-7)
Aim: To determine if CT and US correlated with the severity of infection
and to see if they could predict clinical outcomes
Result:
There was a trend for mean pleural thickness to increase with an
increasing stage of pleural infection but this was not significantly
related to the stage of pleural effusion or to the requirement for
surgery.
No relationship between US appearance, effusion stage or the
need of surgical treatment.
Conclusion: Neither technique reliably identifies the stage of pleural
effusion or predict clinical outcomes
Would CT change our
management?
Study 2: Role of Routune CT in pediatric pleural
empyema
Jaffe et al. Thorax 2008;63:897-902
Aim: To assess the utility of routine CT scanning and develop a radiologic
scoring system for pediatric empyema.
Results:
- Of the 25 CXRs showing simple opacification of the underlying
parenchyma only, CT demonstrated simple consolidation (n = 14),
necrotising pneumonia (n = 7), cavitary necrosis (n = 3) and
pneumatoceles (n = 1).
- No abnormality was detected on CT scanning which directly altered
clinical management.
- Routine CT was not able to predict length of hospital stay.
Conclusion: Chest CT detects more parenchymal abnormalitis than CXR.
However, the additional information does not alter management and is
unable to predict clinical outcome.
Treatment options
Systemic antibiotics for at least 4-6 wks
 Therapeutic thoracentesis
 Tube thoracostomy
 Tube thoracostomy + fibrinolytics
 Video-assisted thoracoscopic surgery
(VATS)
 Surgical decortications

Management of parapneumonic effusion
AACP guidelines
Category Risk of poor
outcome
Drainage
Pleural Space anatomy
Pleural Fluid
Bacteriology
pH
1
very low
no
Minimal, free flowing
effusion (<10mm on LD)
unknown
unknown
2
low
no
Small-moderate free
flowing effusion
(>10mm on LD and <1/2
hemithorax)
Negative
Gram stain
and culture
> 7.2
3
moderate
yes
- Large effusion
(>1/2 hemithorax)
- Loculated effusion
- Thickened parietal
pleura
Positive gram
stain and
culture
< 7.2
4
high
yes
Current management guidelines for
parapneumonic effusion from ACCP

Drainage is recommended for category 3 or 4

Based on the pooled data, therapeutic thoracentesis
and chest tube alone appear to be insufficient
treatment for category 3 or 4 PPE. However, the panel
recognizes individual patient may show complete
respond. Careful evaluation is essential in these cases.
If resolution occurs, no further intervention is necessary

VATS and surgery are acceptable approaches. Data
indicates they are associated with lower mortality and
need for 2nd interventions.
Are large-bore chest tubes
better than the small pigtail
catheters for drainage?
Large vs small chest tubes
-
Large chest tube have been recommended due to the
assumption that smaller tubes would become obstructed
with thick fluids
-
A recent prospective study showed no difference in
mortality or the need for 2nd interventions in patients
receiving chest tube of different sizes.
However, pain scores were higher in patients receiving
larger tubes.
-
Rahman et al. Chest 2010;137;536-543
Large vs small chest tubes
-
2 recent studies: 103 and 141 patients with
empyema were treated with small-bore catheter
inserted under ultrasound or CT guidance.
-
They showed small tubes served as definitive
treatment in 78% and 63% respectively, which
were as good as results with using much larger
tubes from previous studies .
-
This suggests correct positioning of the chest tube
is more important than its size
Shankar et al. Eur Radiol 2000;10:495-499
Chen et al. Ultrasound Med Bio 2009;35:1468-74
In case of complicated
PPE/empyema, would fibrinolytics
offer better outcomes?
Intrapleural fibrinolytics?
-
Indicated for loculated parapneumonic effusion/empyema
Several studies have been done
study
Size
Study groups
Results
References
1
52 pts
Steptokinase vs no tx
No difference in the need for 2nd
intervention and mortality
Chin et.al Chest
1997;111:275-279
3d steptokinase (SK)
vs placebo
SK group – significant reduction in
the size of pleural fluid collection and
greater improvement in the CXR
Davies et al. Thorax
1997;111:275-279
3d urokinase (UK) vs
placebo
UK group- 86% showed complete
drainage. However, when UK given
to pt with incomplete drainage , only
50% showed complete drainage
Bouros et al. Am J
Resp Crit Care Med
1999;159:37-42
5d urokinase vs
placebo
UK group- lower need for
decortication (29 vs 60%), shorter
hospitalization (14d vs 21 d)
Tuncozgur et. al. Int
J Clin Pract 2001;55:
658-660
Not
randomized
2
24
randomized
3
31
randomized
4
49
randomized
The results seem promising. What are
the problems in the above studies?
Small sample size
 Surrogate endpoint not necessarily correlate
with actual clinical endpoint

Most recent multicenter, double
blind study
Maskell N Engl J Med 2005;352: 865-874
- 427 patients were randomized to receive
steptokinase vs placebo
- No significant differences in between 2 groups in
term of mortality, rate of surgery, radiographic
outcomes or length of hospital stay
-
Based on this study, fibrinolytics are not effective in treating
loculated (complicated) parapneumonic effusion.
The use of fibrinolytics should be reserved for pts in centers
without VATS or for pts who are not surgical candidates
Drainage alone is unlikely to be the definitive
treatment for complicated PPE/empyema.
Can VATS potentially be the first line of
treatment?
Video-assisted thoracic surgery (VATS)

A recent review article summarized 14 studies
Chambers et al. Int Card and Thor surg 2010;11:171-177
For Stage 2 empyema
- VATS vs chest tube+ streptokinase
Higher success rate of 91% vs 44%, shorter hospital stay 8.7d vs 12.8 d
For stage 3 empyema
VATS vs tube thoracostomy
Cure rate 88% vs 62%, mortality rate 1.3% vs 11%, hospital stay 14d vs
17d
Conclusion:
Current guidelines do not recommend VATS as the1st line of tx
Studies have consistently shown VATS offers superior outcomes
compared to chest tube drainage +/- fibrinolytics
Consider VATS as the first step of management in empyema
Summary

Chest Radiograph remains the most important work-up for the initial dx of
pleural effusion

Diagnostic thoracentesis gives us the most information about the etiology of
the effusion

No data suggests Chest CT could predict clinical outcomes or change our
management. (expensive + radiation exposure)

Large chest tubes are not superior to small chest tubes for drainage
Large chest tubes cause more pain to the patients

Fibinolytics are not effective in the management of loculated PPE/empyema

VATS offers better outcomes compared to tube thoracostomy +/- fibinolytics
in complicated PPE/empyema
Questions?
The proportion of patients dying within each individual cohort (○) and pooled across all
studies (♦) is shown for each primary management approach.
Colice G L et al. Chest 2000;118:1158-1171
©2000 by American College of Chest Physicians
The proportion of patients requiring a second intervention to manage the PPE within each
individual cohort (○) and pooled across all studies (♦) is shown for each primary management
approach.
Colice G L et al. Chest 2000;118:1158-1171
©2000 by American College of Chest Physicians