Recommended management of pediatric parapneumonic effusions
The treatment of choice for parapneumonic effusion in children remains a matter of controversy in the literature and in clinical practice, and the management of this disease remains largely center dependent14.
All children with parapneumonic effusion should be admitted to the hospital 8. The majority of the children included in our study were hospitalized in PICU / middle care. However, contrary to adult empyema, parapneumonic effusions in childhood are associated with a low mortality and the vast majority of children recover completely15. The high admission rate to PICU in our cohort is explained by our admission policies rather than by the severity of the disease.
Although it has been reported than approximately 20 to 50% of the parapneumonic effusions can be treated with intravenous antibiotics alone, there is some evidence that early evacuation of the pleural effusion may be beneficial 16,17. The role of needle thoracocentesis in the management of pediatric parapneumonic effusions remains unclear, and some advocate that it should be reserved for cases where non-infective causes of parapneumonic effusions are being considered 15. However, needle aspirations have advantages: it less invasive than a chest tube, it is relatively easy and safe to perform in older children who can tolerate the procedure with a local anesthetic and sedation, and the sample collected via this minimally invasive procedure can be analyzed for diagnostic clarifications. Therefore, a single simple needle thoracocentesis may be considered for the management of some free-flowing parapneumonic effusion. However, repeated taps are not recommended, and a drain should be inserted once it is clear a second tap is required; moreover, chest tube is recommended over simple thoracocentesis for loculated and/or purulent effusions 8,9. In our cohort, one fifth (21.6%) of the children were successfully managed with simple needle thoracocentesis, confirming that this less-invasive strategy may be appropriate for selected cases.
In a large cohort study including 14225 pediatric empyema-related hospital discharges aiming to describe trends in the number and type of empyema-related procedures in the United States between 2008 and 2014, there was an increase in the proportions of patients coded for chest tube placement as the only procedure (from 14.6% to 20.9%), for 2 chest tube procedures (from 0.9% to 3.5%), and for chest tube placement as part of their management along with other therapeutic strategies (from 24.8% to 30.6%) 18. In another cohort of 192 Australian children with a diagnosis of empyema, 174 (90.6%) were managed by primary chest drainage, among which 49 (28.1%) required subsequent VATS. In this study, the authors failed to identify risk markers of VATS at the time of insertion of the primary chest tube, which highlights the difficulties in identifying patients at risk of drainage failure. They observed, however, that each day of fever after the chest tube insertion was associated with an increased risk of VATS19. Our results are within the range suggested by these 2 recent studies: 70.1% of the children included in our study were managed with a chest tube. Such discrepancies between the reported proportion of primary chest drainage may be explained by differences in patient characteristics, as well as differences in management strategies since the priority of the available therapeutic interventions is not clearly defined.
Pediatric data on intrapleural fibrinolysis are scarce, but indicate that instillation of a fibrinolytic agent through the chest tube may be of interest by reducing the hospital length of stay20. Therefore, intrapleural fibrinolysis is recommended for parapneumonic effusions of thick fluid with loculations and/or empyema (overt pus) 8. The agent, dosage, concentration, dwell time, interval and total doses have not been proven with comparative data and are subject for future investigation9. In our cohort, only 32/68 (47.1%) of the children with a chest tube received intrapleural fibrinolysis, while fibrin was found in the pleural ultrasound of 77.7% of the children and while the median leucocyte count (IQR) of 6.8 (1.5-21.1) x 103/mm3 indicates that most of the effusions were purulent. Our practice is thus not totally in accordance with the aforementioned recommendation, maybe because the level of evidence for this recommendation is weak.
Primary VATS is associated with good clinical outcomes and low rates of reintervention 19. A recent meta-analysis suggested that VATS may be associated with a lower reintervention rate and shorter post-procedural length of stay than primary chest tube and fibrinolysis7. However, the level of evidence is low, and the authors of this meta-analysis acknowledge that chest drainage with fibrinolysis may be effective in more than 75% of cases. Furthermore, VATS require minimally invasive surgery expertise which is not routinely available. The place of VATS in the management of parapneumonic effusions in children is thus not clearly defined. In our cohort, only 1 child (1% of the whole cohort) was treated with VATS. This only VATS was required because insertion of a chest tube at the bedside was technically challenging (morbid obesity). No child received VATS because of a failure of non-surgical management. This proportion of children requiring surgery is remarkably low, considering that others have reported that the need for surgical rescue interventions for parapneumonic empyema in children remained as high as 20%21. Our finding is probably explained by the use of corticosteroids if chest drainage was deemed not possible (multiloculated effusion not drainable) or as soon as chest drainage was considered a failure (persisting fever).