Paediatric complicated pneumonia: Diagnosis and management of empyema
Posted: Sep 1 2011 | Updated: Dec 18 2018
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TK Chibuk, E Cohen, JL Robinson, S Mahant, DS Hartfield; Canadian Paediatric Society. Updated by Jennifer Walton, Hospital Paediatrics Section
Pneumonia can be complicated by an empyema, progressing from an exudative effusion, to a fibrinopurulent stage with loculations, and then organized with a thick fibrinous peel. The predominant causative organisms are Streptococcus pneumoniae, Staphyloccocus aureus (including methicillin-resistant S aureus) and Streptococcus pyogenes. For diagnostic imaging, a chest radiograph followed by a chest ultrasound is preferred. Computed tomography chest scans, with associated radiation, should not be routinely used. Antibiotic coverage should treat the most common causative organisms. Additional invasive or surgical management is recommended to reduce the duration of illness in cases not promptly responding to antibiotics or with significant respiratory compromise. Choice of management should be guided by best evidence and local expertise. Video-assisted thorascopic surgery or insertion of a small-bore percutaneous chest tube with instillation of fibrinolytics are the best current options.
Key Words: Chest tube; Complicated pneumonia; Empyema; Fibrinolytics; Paediatric
Pneumonia is one of the most common reasons for hospitalization in childhood. Although most bacterial pneumonia will resolve with treatment of the underlying infection, some cases will be complicated by the development of an empyema, defined as intrapleural pus or a moderate to large exudative parapneumonic effusion (stage 1), which can progress to being loculated (stage 2) with further development of a fibrinous peel (stage 3). Small parapneumonic effusions are common and do not require drainage. Although other complications of pneumonia occur (eg, pulmonary abscess or necrotizing lung), those topics are beyond the scope of the present document. The most common pathogens in this setting, in an immunocompetent host, are Streptococcus pneumoniae, Staphylococcus aureus and Streptococcus pyogenes (group A streptococcus). Methicillin-resistant S aureus (MRSA) can occur, particularly in the setting of post-influenza pneumonia . Initial studies after the introduction of heptavalent pneumococcal conjugate vaccine (PCV7) have reported an increased incidence of paediatric complicated pneumonia -, caused in part by the emergence of non-vaccine pneumococcus serotypes. Recent evidence has suggested that the incidence of complicated pneumonia from particularly virulent serotypes (such as 19A) may be in decline with the replacement of PCV7 with the 13-valent conjugate vaccine (PCV13) .
Children with complicated pneumonia will present with many of the symptoms and signs of uncomplicated pneumonia including tachypnea, fever, cough and respiratory distress. The patient may present with complicated pneumonia or an initially uncomplicated pneumonia that is poorly responsive to antibiotics (persistent fever after 48 h to 72 h of antibiotics without clinical improvement, persistent or worsening respiratory distress and/or hypoxia, or new clinical findings of a pleural effusion). Findings on examination that are consistent with a pleural effusion include decreased breath sounds, decreased chest expansion and dullness to percussion of the affected side.
A chest radiograph (CXR) should always be the initial imaging modality. Ultrasound provides a noninvasive, radiation-free modality to confirm the presence of a pleural effusion suspected on CXR. As well, ultrasound can estimate the size of the effusion, and differentiate free-flowing effusions from those that are loculated . Chest computed tomography is associated with significant radiation exposure, and generally does not alter management or predict outcomes; therefore, it should not be performed routinely . However, chest computed tomography should be considered if an alternative diagnosis, such as malignancy, is suspected. Repeat CXRs are not necessary unless clinical deterioration is evident. When drainage of fluid is clinically indicated, the fluid should be sent for bacterial culture. The yield from pleural fluid cultures is low because most children have already received antibiotics; however, molecular tests, such as pneumococcal polymerase chain reaction, may increase yield if available . Blood cultures are positive in only a minority of cases (approximately 10%), but they should be collected before antibiotics are administered to potentially guide the choice of antibiotics for children who are sufficiently ill to be hospitalized for pneumonia . Sputum culture is occasionally helpful if available, but is usually difficult to obtain. Molecular diagnostic testing of pleural fluid is not universally available, however, and when performed does commonly confirm S. pneumonia .
Management of empyemas is a controversial area. In addition to antibiotics, procedural interventions to drain the pleural space are often warranted to expedite resolution of complicated pneumonias. Conservative management with antibiotics alone may prolong hospitalization. Early procedural intervention is recommended if the patient is in moderate to severe respiratory distress  (worsening tachypnea, work of breathing and/or hypoxia) because the pleural fluid often occupies most of the hemithorax and may even cause mediastinal shift. Early consultation with a paediatric surgeon or interventional radiologist is recommended.
Choice of antibiotics
Antibiotics remain a key component in the medical management of empyema, with initial parenteral therapy to cover the most common pathogens, usually followed by oral therapy. Antibiotic coverage for likely causative organisms is essential. There are no randomized trials pertaining to the choice of antibiotics, specifically in empyema, so the potential choice of agents should be guided by clinical appearance and local prevalence of penicillin-resistant S. pneumoniae and MRSA risk factors. One suggested initial empirical antibiotic choice, in the absence of a confirmed organism, would be ampicillin or cefotaxime/ceftriaxone, depending on local guidelines or antibiograms. The addition of vancomycin (or linezolid) is usually reserved for culture-proven or severe suspected MRSA pneumonia. Although no evidence exists for optimal treatment length for empyemas, a total of three to four weeks’ duration is reasonable if there is adequate drainage and no evidence of additional complications. Transition to oral antibiotics is appropriate when drainage has been completed, and the patient is clinically improving and off oxygen (ie, at or just before discharge). Appropriate oral antibiotics vary depending on local resistance patterns. If the cultures are negative, amoxicillin is the recommended antimicrobial. Penicillin resistance to S. pneumonia is very low and therefore, amoxicillin given in appropriate doses should be reasonable. In cases where methicillin-resistant S. s aureus or Haemophilus influenzae is proven or suspected, amoxicillin-clavulanate or another appropriate pathogen-targeted agent should be chosen. Refer to the Canadian Paediatric Society’s practice point “Uncomplicated pneumonia in healthy Canadian children and youth” for antibiotic dosages .
It is not uncommon for children with empyemas to have fevers that persist for more than 72 h on appropriate therapy; if the child is otherwise improving clinically, it is usually not a sign of treatment failure.
Choice of procedural intervention
A variety of procedural interventions are used in Canada for the management of empyema. These include chest tube placement with or without fibrinolytics, repeated thoracentesis, video-assisted thorascopic surgery (VATS) and open thoracotomy with decortication. Although there is still ongoing controversy and a need for additional randomized trials, the best evidence suggests that either VATS, early thoracotomy or small-bore percutaneous chest tube placement with instillation of fibrinolytics (CTWF) results in the best outcomes as measured by hospital length of stay -. CTWF may be the most cost-effective choice . Clinicians should consider local expertise in interventions (eg, a surgeon experienced in performing VATS or an interventional radiologist able to insert a small-bore pigtail catheter), and parental and patient preference when deciding on a treatment. Although most studies have used urokinase as a fibrinolytic agent in CTWF, this agent is not currently available in Canada. Therefore, an alternative agent is tissue plasminogen activator (at a dose of 4 mg in 30 mL to 50 mL of normal saline daily for up to three days) .
Complete recovery of pulmonary lung function with normalization of the CXR is expected in the majority of children with complicated pneumonias. In a small number of patients, lung function testing has revealed minor abnormalities of both a mild restrictive  and mild obstructive  nature, although even these patients demonstrated normal exercise tolerance. Children should be followed after discharge until they have clinically recovered and their CXRs have returned to near normal, recognizing that the latter may take several months . Repeating the CXR at two to three months is reasonable.
HOSPITAL PAEDIATRICS SECTION EXECUTIVE
Members: Sanjay Mahant MD (president); Isabelle M Chevalier MD (president-elect); Dawn S Hartfield MD (past-president); Eyal Cohen MD; Jeret Keith McLeod MD; Jennifer Walton MD
Liaison: Nirej Mistry MD, Residents Section, Canadian Paediatric Society
Principal authors: Thea K Chibuk MD; Eyal Cohen MD; Joan L Robinson MD; Sanjay Mahant MD; Dawn S Hartfield MD
Updated by: Jennifer Walton, MD
- Buckingham SC, King MD, Miller ML. Incidence and etiologies of complicated parapneumonic effusions in children, 1996 to 2001. Pediatr Infect Dis J 2003;22:499-504.
- Schultz KD, Fan LL, Pinsky J, et al. The changing face of pleural empyemas in children: Epidemiology and management. Pediatrics 2004;113:1735-40.
- Byington CL, LaShonda YS, Johnson TA, et al. An epidemiological investigation of a sustained high rate of pediatric parapneumonic empyema: Risk factors and microbiological associations. Clin Infect Dis 2002;34:434-40.
- Finley C, Clifton J, FitzGerald JM, Yee J. Empyema: An increasing concern in Canada. Can Respir J 2008;15:85-92.
- Byington CL, Korgenski K, Daly J, et al. Impact of the pneumococcal conjugate vaccine on pneumococcal parapneumonic empyema. Pediatr Infect Dis J 2006;25:250-4.
- Hicks LA, Harrison LH, Flannery B, et al. Incidence of pneumococcal disease due to non-pneumococcal conjugate vaccine (PCV7) serotypes in the United States during the era of widespread PCV7 vaccination, 1998-2004. J Infect Dis 2007;196:1346-54.
- Balsells E, Guillot L, Nair H, Kyaw MH. Serotype distribution of Streptococcus pneumoniae causing invasive disease in children in the post-PCV era: A systematic review and meta-analysis. PLoS One 2017;12(5):e0177113.
- Iroh Tam PY, Madoff LC, Coombes B, Pelton SI. Invasive pneumococcal disease after implementation of a 13-valent conjugate vaccine. Pediatrics 2014;134(2):210–7.
- Ramnath RR, Heller RM, Ben-Ami T, et al. Implications of early sonographic evaluation of parapneumonic effusions in children with pneumonia. Pediatrics 1998;101:68-71.
- Jaffe A, Calder AD, Owens CM, et al. Role of routine computed tomography in paediatric empyema. Thorax 2008;63:897-902.
- Tarrago D, Fenoll A, Sanchez-Tatay D, et al. Identification of pneumococcal serotypes from culture-negative clinical specimens by novel real-time PCR. Clin Microbiol Infect 2008;14:828-34.
- Blaschke A, Heyrend C, Byington CL, et al. Molecular analysis improves pathogen identification and epidemiologic study of pediatric parapneumonic empyema. Pediatr Infect Dis J 2011;30(4):289–94.
- World Health Organization. The Management of Acute Respiratory Infections in Children: Practical Guidelines for Outpatient Care. Geneva: World Health Organization, 1995.
- Le Saux N, Robinson JL; Canadian Pediatric Society, Infectious Diseases and Immunization Committee. Uncomplicated pneumonia in healthy Canadian children and youth: Practice points for management. Paediatr Child Health 2015;20(8):441-5.
- Avansino JR, Goldman B, Sawin RS, et al. Primary operative versus nonoperative therapy for pediatric empyema: A meta-analysis. Pediatrics 2005;115:1652-9.
- Gates RL, Caniano DA, Hayes JR, et al. Does VATS provide optimal treatment of empyema in children? A systematic review. J Pediat Surg 2004;39:381-6.
- Li ST, Gates RL. Primary operative management for pediatric empyema: Decreases in hospital length of stay and charges in a national sample. Arch Pediatr Adolesc Med 2008;162:44-8.
- Mahant S, Cohen E, Weinstein M, et al. Video-assisted thorascopic surgery vs chest drain with fibrinolytics for the treatment of pleural empyema in children: A systematic review of randomized controlled trials. Arch Pediatr Adolesc Med 2010;164:201-3.
- Sonnappa S, Cohen G, Owens CM, et al. Comparison of urokinase and video-assisted thorascopic surgery for treatment of childhood empyema. Am J Resp Crit Care Med 2006;15:221-7.
- Thomson AH, Hull J, Kumar MR, et al. Randomised trial of intrapleural urokinase in the treatment of childhood empyema. Thorax 2002;57:343-7.
- Cohen E, Weinstein M, Fisman DN. Cost-effectiveness of competing strategies for the treatment of pediatric empyema. Pediatrics 2008;21:e1250-7.
- Weinstein M, Restrepo R, Chait PG, et al. Effectiveness and safety of tissue plasminogen activator in the management of complicated parapneumonic effusions. Pediatrics 2004;113:e182-5.
- McLaughlin FJ, Goldmann DA, Rosenbaum DM, et al. Empyema in children: Clinical course and long-term follow-up. Pediatrics 1984;73:587-93.
- Redding GJ, Walund L, Walund D, et al. Lung function in children following empyema. Am J Dis Child 1990;144:1337-42.
- Balfour-Lynn IM, Abrahamson E, Cohen G, et al. BTS guidelines for the management of pleural effusions in children. Thorax 2005;60(Suppl I):i1-21.
- Satish B, Bunker M, Seddon P. Management of thoracic empyema in childhood: Does the pleural thickening matter? Arch Dis Child 2003;88:918-21.
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