Pediatric emergency medicine trisk 1023

result from nontraumatic conditions. Necrotizing pulmonary infections,
tuberculosis, pulmonary arteriovenous (AV) malformations, torn pleural
adhesions, hemophilia, thrombocytopenia, systemic anticoagulation, and pleural
tumors have all been reported to cause hemothoraces. Chylothorax, or the
accumulation of lymphatic fluid in the pleural space, has increased in frequency
as thoracic, especially complex cardiac, surgical operations have become more
common in children.
Clinical Recognition
Small, sterile collections, as well as large, chronic collections, may be
asymptomatic. Symptomatic children often present with nonspecific symptoms
such as fever, cough, malaise, and anorexia. Additionally, acute collections
produce symptoms by compressive effects on the lung, with resultant atelectasis,
and right-to-left shunting, with resultant hypoxia and hypercapnia. Respiratory
distress may follow, marked by dyspnea, tachypnea, increased use of accessory
muscles of respiration, and even cyanosis. Small to moderate effusions may not
be evident on physical examination, with most effusions detected by chest
radiograph. Larger effusions will cause dullness to percussion and decreased
breath sounds.
Small effusions can be quite subtle and may manifest as slight blunting of the
costophrenic angle on chest x-ray. Larger effusions may cause significant
opacification of a hemithorax and may layer out on an upright view of the chest,
creating the so-called “meninscus sign.” Chest radiographs may also demonstrate
the likely etiology of the effusion since cardiomegaly, mediastinal masses, and
hilar lymphadenopathy may all be appreciated. Moderate to large effusions on
chest x-ray merit further evaluation by ultrasound to further characterize the
effusion and determine whether it is comprised of free fluid or a loculated
collection. In skilled hands, ultrasound provides more information than either
decubitus radiographs or CT and has the obvious advantages of not requiring
sedation or exposing the child to radiation.
Management
Children with pleural effusions should have peripheral blood counts and blood

cultures obtained since parapneumonic collections are the most likely culprit.
Many small effusions can be managed conservatively with treatment of the
underlying disease. For moderate or large effusions, drainage of pleural fluid, or
thoracentesis (see Chapter 130 Procedures ), may be necessary. Thoracentesis
may be therapeutically indicated for significant respiratory distress or


diagnostically indicated when there is concern for a noninfectious cause of the
collection. Gram stain and culture should always be sent when pleural fluid is
available. Nucleic acid amplification testing through polymerase chain reaction
(PCR) or specific antigen testing of pleural fluid may increase the likelihood of
pathogen detection, particularly in patients who have been partially treated with
antibiotics. Fluid should be sent for a cell count with differential since this can
help distinguish between various infectious pathogens and malignancy. Cytology
should be sent as well when malignancy is suspected. Analysis of other pleural
fluid parameters that have historically been assessed such as pH, LDH, glucose,
and protein have been used to predict the need for further interventions, but are
not routinely required as they rarely alter management.
Thin, free-flowing pleural fluid may sometimes be managed by simple
thoracentesis (which may be repeated as needed) or the effusion may resolve as
the underlying condition is treated. Alternatively, a small-diameter tube, such as
an 8F to 12F pigtail percutaneous tube, can be placed in the anterior or
midaxillary line. Early and continued administration of fibrinolytics into the
catheter can be helpful in fostering resorption and preventing fibrin and other
products from obstructing tube drainage. Thick fluid, such as blood, pus, and
sometimes chyle, often requires the placement of a larger diameter tube. Either
tube must be attached to a pleural drainage system. When the drainage decreases
significantly, to approximately 1 mL/lb of body weight per day, the drain may be
removed. The drain should not be removed in the presence of an accompanying
“air leak” caused by a bronchopleural connection. See section below on empyema

for discussion of further drainage modalities.
Disposition
Pleural effusions that require drainage or further diagnostic evaluation clearly
warrant inpatient admission. There is a role for outpatient antibiotic therapy in the
setting of very small effusion in the well-appearing child who has close followup. Please refer to the pneumonia clinical pathway for suggested empiric
antibiotic
therapy
( ). This should be tailored, however, to
local sensitivities for common pathogens.

Empyema
Goals of Treatment
The goals of treatment for empyema include the provision of adequate antibiotic
treatment for the underlying infection and evacuation of significant pleural


collections to allow for lung reexpansion. Patients who develop small
parapneumonic effusions will frequently improve clinically with appropriate
antibiotic therapy, and small- to moderate-sized simple effusions may resorb as
the underlying intraparenchymal infection resolves. Large effusions that compress
the lung or complex, loculated effusions are best treated with drainage. Simple
layering effusions may be effectively evacuated with tube thoracostomy alone,
while large or complex, loculated effusions and simple effusions not effectively
managed with tube thoracostomy may require chemical fibrinolysis or surgical
drainage and debridement. Surgical drainage and debridement, which can
typically be done via a minimally invasive thoracoscopic approach, serves to
relieve acute lung compression and to prevent a complex parapneumonic effusion
from organizing and establishing a thick pleural peel, which could entrap the lung
and result in chronic restriction on the affected side.
CLINICAL PEARLS AND PITFALLS

Utilize ultrasound for moderate to large pleural effusions to better
characterize the fluid collection and identify loculations.
For patients with empyema, early consultation with surgical consultants
can facilitate more rapid intervention and resolution in appropriate
patients.
Current Evidence
An empyema is the presence of infected fluid within the pleural cavity and is
typically a sequela of an underlying pneumonia. The incidence of empyema has
varied over recent decades, largely due to variation in invasive pneumoccoal
disease with widespread vaccination. Empyemas seem to have seasonal variation,
being more common in the winter and spring months. While chronic medical
problems do predispose children to having more complicated pneumonias and
empyemas, they also occur in previously healthy children. The predominant
organisms implicated in empyemas have varied over time with vaccination and
resistance patterns but they generally include Streptococcus pneumoniae ,
Staphylococcus aureus , group A streptococci, and Haemophilus influenza among
others. When empyema follows trauma or surgery, other bacterial organisms may
be involved. Viruses and Mycoplasma pneumoniae infections can also cause
parapneumonic effusions but these rarely require intervention and patients are
generally less severely ill than with traditional bacterial collections.


Clinical Considerations
Clinical Recognition. Empyema is most common in children 2 to 9 years of age,
though children under 2 years tend to have the highest mortality. The clinical
presentation varies based on when in the disease course the child is evaluated.
Presentation with a pneumonia that fails to improve after about 48 hours of
appropriate antibiotic treatment should lead to the consideration of a complication
like empyema. High fever is common, as are the symptoms of pneumonia: cough,
pleuritic chest pain, malaise, and shortness of breath. Children are typically ill

appearing and may demonstrate tachypnea, respiratory distress, and hypoxia.
Examination findings may include rales, decreased breath sounds on the affected
side, and dullness to percussion.
Please refer to the Community Acquired Pneumonia Clinical Pathway at
. Plain radiographs of the chest should be obtained. Different guidelines
in the United States and the United Kingdom propose either decubitus films or
ultrasound to delineate if the fluid in the pleural space layers. Children with a
moderate (i.e., opacification of more than ¼ of the thorax) to large (i.e.,
opacification of more than ½ of the thorax) effusion should undergo ultrasound to
better characterize the fluid. Ultrasound has several advantages over CT including
lack of radiation, no need for sedation, earlier detection of septae and loculations,
as well as superior ability to describe the nature of the fluid collection.
Furthermore, it can be a helpful therapeutic adjunct to help with chest tube
placement when necessary.
Management. Unlike in uncomplicated pneumonias, children with empyemas are
more likely to be bacteremic and they should all have a blood culture drawn in
order to help direct antimicrobial therapy. Empyema in healthy children may
respond to prolonged IV antibiotic therapy and chest tube drainage, if the fluid is
thin and not loculated. Initial antibiotics should be broad spectrum and based on
local resistance patterns and can be narrowed later if a pathogen is identified.
Coverage for MRSA is often included in initial antibiotic selection. If a patient
fails to respond to this management, loculation of thick purulent material should
be suspected. In such cases, both thoracostomy drainage with the addition of
fibrinolytic agents and VATS have been shown to be effective in hastening
recovery and reducing morbidity. Choice of therapy is often dictated by regional
expertise. Regardless of treatment modality, early surgical consultation is
warranted for significant empyemas.