Management of necrotizing pneumonia in children: Time for a patient-oriented approach

Early predictors of lung necrosis severity in children with community-acquired necrotizing pneumonia

OBJECTIVE

To analyze baseline clinical and laboratory characteristics and explore the possible predictors of lung necrosis severity in children with community-acquired necrotizing pneumonia (NP).

METHODOLOGY

This retrospective observational study was performed in a tertiary referral center. A total of 104 patients aged <15 years with community-acquired pneumonia and radiologically confirmed NP by computed tomography (CT) were included. Patients were classified into the mild, moderate, or massive necrosis groups.

RESULTS

Among them, 29, 41, and 34 patients had mild, moderate, and massive necrosis, respectively. Moreover, 34.6% of the patients were admitted to pediatric intensive care unit. Massive necrosis was more likely to occur during winter (p < 0.05) and was associated with more severe clinical outcomes, such as longer duration of fever, longer hospitalization, increased mortality, and a higher risk of subsequent surgical intervention (p < 0.05). Multivariate analysis demonstrated that the following were independent risk factors for massive necrosis in this study: C-reactive protein (CRP) (p = 0.036), serum albumin (p = 0.009), and immunoglobulin M (IgM) (p = 0.022). Receiver operating characteristic analysis showed that when the cut-off value for CRP, serum albumin, and IgM were set at 122 mg/L, 30.8 g/L, and 95.7 mg/dl, respectively, they showed good diagnostic performance for differentiating patients with massive necrosis from all patients with NP.

CONCLUSION

NP is a potentially severe complication of pediatric community-acquired pneumonia. Different severities of lung necrosis can lead to different clinical outcomes. CRP, serum albumin, and IgM levels are independent predictors of the degree of lung necrosis.

Necrotizing pneumonia due to Streptococcus pneumoniae in children during the period of non-systematic use of PCV13 in Catalonia, Spain

BACKGROUND

Some studies have observed an increased incidence of necrotizing pneumonia (NP) in recent years. This might be related to the emergence of non-vaccine S. pneumoniae serotypes after PCV7 introduction although it is suggested that evolutionary factors may have modified the virulence and the interactions of pneumococci. The aim of this study was to clinically and microbiologically define NP in the population served by the three major paediatric hospitals in Barcelona (Catalonia, Spain).

METHODS

A prospective observational study was conducted in patients <18 years hospitalized due to invasive pneumococcal disease (January 2012-June 2016). Data of confirmed cases of pneumococcal NP (diagnosed by culture or DNA detection and serotyped) were collected. PCV13 was not systematically administered in Catalonia during the study period, but was available in the private market so the vaccination coverage in children increased from 48.2% to 74.5%.

RESULTS

35 cases of NP were identified. 77.1% of cases were associated with empyema. In the first 4 years, a trend to a decrease in NP incidence was observed (p=0.021), especially in children <5 years (p=0.006). Serotype 3 was responsible for 48.6% of NP cases. Five patients with NP due to serotype 3 were fully vaccinated for their age with PCV13.

CONCLUSIONS

Serotype 3 has a preeminent role in pneumococcal NP and was associated with all PCV13 vaccination failures. Although in our series the incidence does not seem to be increasing, evolution of pneumococcal NP rates should be monitored after inclusion of PCV13 in the systematic calendar.

Comparison of pediatric empyema secondary to tuberculosis or non-tuberculosis community-acquired pneumonia in those who underwent surgery in high TB burden areas

INTRODUCTION

Tuberculous empyema (TE) in children is common in high-TB burden and medical resource-limited areas. However, studies that evaluate the characteristics of TE in children are sparse. This study aimed to analyze the clinical features of pediatric TE receiving surgical intervention.

METHODS

We performed a retrospective study of children with empyema secondary to community-acquired pneumonia who underwent surgery in our institution. The clinical characteristics were compared between TE and empyema secondary non-tuberculosis infection (non-tuberculosis empyema, NTE).

RESULTS

One hundred patients were included (27 with TE and 73 with NTE). Stage 3 empyema occupied 81.5% and 45.2% of TE and NTE in this study. The TE children had older age, longer duration of illness, and milder symptoms. Pleural fluid culture was positive for Mycobacterium tuberculosis in 7.4% of patients with TE. Lymph node enlargement, lymph node calcification, and pleural nodules presented in TE with high specificity (93.2%, 98.6%, and 98.5%) but low sensitivity (33.3%, 14.8%, and 29.6%) on CT scan. Thoracoscopy surgery was performed in 14 (51.9%) in TE and 39 (53.4%) in NTE. Postoperative chest-tube indwelling time was longer (7.85 ± 5.00 vs. 4.89 ± 1.81 days, p < .001), and more patients had incomplete lung expansion after 3 months in TE.

CONCLUSION

Tuberculosis infection should be screened in management of children with empyema in high-TB burden areas. Pediatric TE usually presented at older age and with milder respiratory symptoms. Pleural biopsy during surgery is often necessary to confirm the cause of infection. Thoracotomy is still required in some pediatric TE or NTE with delayed treatment in medical resource-limited area.

Early recognition of necrotizing pneumonia in children based on non-contrast-enhanced computed tomography radiomics signatures

BACKGROUND

Necrotizing pneumonia (NP) is an infrequent but severe complication of pneumonia in children. In the early stages of NP, CT imaging shows lung consolidation, which cannot be detected in time. This study aimed to explore the ability of non-contrast-enhanced CT radiomics features to recognize NP in early stage.

METHODS

This was a retrospective study, and 250 patients who presented with lung consolidation on initial CT images were included in this study. After a follow-up period of 1-3 weeks, 116 patients developed NP, whose CT or X-ray shows cavitation or liquefied necrosis. Manual segmentation of lesion sites in the initial non-contrast-enhanced CT scans was performed with RadCloud (Huiying Medical Technology Co., Ltd., China), and 1,409 radiomics features were extracted. We used Variance threshold (0.8), SelectKBest, and the least absolute shrinkage and selection operator (LASSO) methods for feature dimension reduction. Three machine learning algorithms, k-nearest neighbor (KNN), support vector machine (SVM), and logistic regression (LR) models, were established to recognize NP early. To assess the recognition performance, the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and other indicators were used in the validation cohort.

RESULTS

Radiomics features helped to recognize NP in early stage in both the training and validation cohorts. The AUC (sensitivity, specificity) for the training and validation cohorts were 0.81 (0.73, 0.68) and 0.71 (0.61, 0.65) for KNN, respectively; 0.81 (0.72, 0.70) and 0.77 (0.66, 0.65) for SVM, respectively; and 0.82 (0.73, 0.73) and 0.76 (0.63, 0.70) for LR, respectively. Recall and F1-scores determined that LR performed better at diagnosing early NP, with the values of the above two indexes being 0.70 and 0.67, respectively.

CONCLUSIONS

Non-contrast-enhanced CT-based radiomics models may be helpful for recognizing NP in early stage.

Necrotizing pneumonia among Italian children in the pneumococcal conjugate vaccine era

BACKGROUND

Necrotizing pneumonia (NP) is a severe complication of community-acquired pneumonia. The impact of 13-valent pneumococcal conjugate vaccine (PCV13) on the epidemiology of NP in children has not been assessed.

PATIENTS AND METHODS

Medical records of children less than 18 years admitted with NP to two pediatric hospitals in Italy between 2005 and 2019 were reviewed. The following four periods were defined: 2005-2010 (pre-PCV13), 2011-2013 (early post-PCV13), 2014-2016 (intermediate post-PCV13), and 2017-2019 (late post-PCV13).

RESULTS

Forty-three children (median age, 44 months) were included. Most of them (93%) were previously healthy. No differences in age, sex, season of admission, comorbidity, clinical presentation, or hospital course were identified between pre-PCV13 and post-PCV13 periods. A significant decrease in the rate of NP-associated hospitalizations was found between the early (1.5/1000 admissions/year) and the intermediate (0.35/1000 admissions/year) post-PCV13 period (p = .001). An increased trend in admissions was found thereafter. Streptococcus pneumoniae was the most common agent detected in both periods (pre-PCV13: 11/18, 61%; post-PCV13: 13/25, 52%). Serotype 3 was the most common strain in both periods (pre-PCV13: 3/11, 27%; post-PCV13; 4/13, 31%). There were no changes in the etiology over time, but most patients with Streptococcus pyogenes or Staphylococcus aureus infection were admitted during the post-PCV13 period.

CONCLUSIONS

The hospitalization rate for NP in children decreased a few years after the implementation of PCV13 immunization in Italy. However, an increased trend in admissions was found thereafter. S. pneumoniae was the most frequent causal agent in both pre- and post-PCV13 periods. Pneumococcal serotypes were mainly represented by Strain 3.

Necrotizing pneumonia due to Streptococcus pneumoniae in children during the period of non-systematic use of PCV13 in Catalonia, Spain

BACKGROUND

Some studies have observed an increased incidence of necrotizing pneumonia (NP) in recent years. This might be related to the emergence of non-vaccine S. pneumoniae serotypes after PCV7 introduction although it is suggested that evolutionary factors may have modified the virulence and the interactions of pneumococci. The aim of this study was to clinically and microbiologically define NP in the population served by the three major paediatric hospitals in Barcelona (Catalonia, Spain).

METHODS

A prospective observational study was conducted in patients <18 years hospitalized due to invasive pneumococcal disease (January 2012-June 2016). Data of confirmed cases of pneumococcal NP (diagnosed by culture or DNA detection and serotyped) were collected. PCV13 was not systematically administered in Catalonia during the study period, but was available in the private market so the vaccination coverage in children increased from 48.2% to 74.5%.

RESULTS

35 cases of NP were identified. 77.1% of cases were associated with empyema. In the first 4 years, a trend to a decrease in NP incidence was observed (p=0.021), especially in children <5 years (p=0.006). Serotype 3 was responsible for 48.6% of NP cases. Five patients with NP due to serotype 3 were fully vaccinated for their age with PCV13.

CONCLUSIONS

Serotype 3 has a preeminent role in pneumococcal NP and was associated with all PCV13 vaccination failures. Although in our series the incidence does not seem to be increasing, evolution of pneumococcal NP rates should be monitored after inclusion of PCV13 in the systematic calendar.

Lung ultrasound findings in pediatric community-acquired pneumonia requiring surgical procedures: a two-center prospective study

BACKGROUND

Lung ultrasound (US) in the evaluation of suspected pediatric pneumonia is increasingly used and has a recognized role in evaluating pleural effusions, although there are no detailed studies specifically addressing its use in the pediatric population.

OBJECTIVES

To define lung US findings of severe pediatric community-acquired pneumonia that required surgical procedures during admission.

MATERIALS AND METHODS

Our prospective case-control study compared lung US findings in patients ages 1 month to 17 years admitted with community-acquired pneumonia that required surgical procedures from findings those who did not. Lung US was performed at admission and always before surgical procedures. Medical treatment, laboratory and microbiological findings, chest X-ray, computed tomography scan and surgical procedures are described.

RESULTS

One hundred twenty-one children with community-acquired pneumonia were included; of these, 23 underwent surgical intervention. Compared with the control group, children requiring a surgical procedure had a significantly higher rate of large consolidations (52.2%; 95% confidence interval [CI]: 30.6% to 73.2%), larger and complicated pleural effusions (100%; 95% CI: 85.2% to 100%), and both liquid and air bronchograms (73.9%; 95% CI: 51.6% to 89.8%).

CONCLUSION

Larger consolidations, larger and more complicated pleural effusions, and liquid and air bronchograms were associated with surgical treatment.

Complicated pneumonia in children

Complicated community-acquired pneumonia in a previously well child is a severe illness characterised by combinations of local complications (eg, parapneumonic effusion, empyema, necrotising pneumonia, and lung abscess) and systemic complications (eg, bacteraemia, metastatic infection, multiorgan failure, acute respiratory distress syndrome, disseminated intravascular coagulation, and, rarely, death). Complicated community-acquired pneumonia should be suspected in any child with pneumonia not responding to appropriate antibiotic treatment within 48-72 h. Common causative organisms are Streptococcus pneumoniae and Staphylococcus aureus. Patients have initial imaging with chest radiography and ultrasound, which can also be used to assess the lung parenchyma, to identify pleural fluid; CT scanning is not usually indicated. Complicated pneumonia is treated with a prolonged course of intravenous antibiotics, and then oral antibiotics. The initial choice of antibiotic is guided by local microbiological knowledge and by subsequent positive cultures and molecular testing, including on pleural fluid if a drainage procedure is done. Information from pleural space imaging and drainage should guide the decision on whether to administer intrapleural fibrinolytics. Most patients are treated by drainage and more extensive surgery is rarely needed; in any event, in low-income and middle-income countries, resources for extensive surgeries are scarce. The clinical course of complicated community-acquired pneumonia can be prolonged, especially when patients have necrotising pneumonia, but complete recovery is the usual outcome.