Complicated pneumonia in children has been increasing in developed countries since the introduction of routine immunization with heptavalent pneumococcal conjugate vaccine (PCV7), as reported in numerous articles published in peer-review journals. Parapneumonic effusion, a transudative pleural effusion associated with pneumonia, and empyema, purulent fluid in the pleural space, are common complications of pediatric pneumonia.
These two conditions are generally treated with antibiotics, but frequent chest drainage may be required for large or complex effusions.The options for pediatric patients are video-assisted thorascopic surgery or chest tube drainage with intrapleural fibrinolytics. Physicians at the Children’s Hospital for Wales in Cardiff, UK, who have been using real-time ultrasound-guided small bone pigtail catheter chest drainage with installation of urokinase since 2001, describe their technique and outcomes of their patients in a June 27th online article in Pediatric Radiology.
At the Children’s Hospital for Wales, the procedure and timing to insert a chest tube drain are jointly determined by pediatric respiratory and radiology specialists after imaging with chest X-rays and/or ultrasound to assess the severity of pneumonia, size and appearance of the effusion, and any complications such as abscess formation or bronchopleural fistula. Their decisions to insert a drain are based on effusion size, evidence of complicated parapneumonic effusion/empyema, worsening of clinical parameters, and/or failure to respond to antibiotic treatment within 48 hours.
Lead author Megan R. Lewis, of Cardiff University’s Department of Postgraduate Medical and Dental Education, and colleagues said that ultrasound reliably estimates the effusion size and echogenicity, and whether fluid is free or loculated. It can assess pleural thickening. “The lack of body fat in children and generally low echogenicity of the pleural collection results in excellent visualization of the drain system during insertion, even if there is significant loculation,” wrote the authors.
After conscious sedation, children over age four have drains are inserted in the radiology department. The procedure is performed in an operating room for younger children who receive general anesthesia. After receiving local anesthesia, a small-bore pigtail catheter is inserted using a single-step trocar method under direct ultrasound guidance by a pediatric radiologist. Ultrasound determines the optimum position for the drain site.The authors explain that while “drains should be inserted in the triangle of safety, direct ultrasound guidance identifies the optimal site for insertion, which may be outside the recognized safety area.”
7-Fr. drains for children under 24 months of age and 8.5 Fr drains for children over two are inserted. Pleural fluid is aspirated immediately following drain insertion to allow for expansion of the underlying lung, followed by urokinase instillation. On average, six cycles of installation and drainage are performed, according to the authors.
The authors state that ultrasound guidance in real-time offers the advantage of constant monitoring with complete visualization of the needle tip. This minimizes the risk of drain malplacement or visceral or lung damage. It rapidly identifies bleeding and pneumothorax, which facilitates adjustment of the drain position. The only disadvantage is that clinicians performing the procedure need to be available on-site or on-call nights and weekends.
During a 16-year period, 285 pediatric patients had 303 drains placed. Treatment was successful in 93% of patients after a single drain, and in 98% after two or three drain placements. A total of five patients had minor peri-insertion complications. Since 2012, all children have been successfully treated with single-tube drainage only. The authors attribute their high rate of successful outcomes and low rate of complications to their use of small-bore pigtail catheters and direct real-time ultrasound guidance.
They commented that the Children’s Hospital of Wales has had a significantly increased frequency of bronchopleural fistulae with resultant increased length of stay. They postulated that “changes in the epidemiology of causative pathogens with the introduction of pneumoncoccal conjugate vaccines have resulted in increased necrotising or cavitating pneumonias with abscess formation and bronchopleural fistulae.”
Using real-time US-guided radiologically placed chest drains for complicated pneumonia in children . Appl Radiol.