Pediatric emergency medicine trisk 4089 4089
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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
