Complicated pneumonia: current concepts and state of the art

Imaging of Acute Complications of Community-Acquired Pneumonia in the Paediatric Population-From Chest Radiography to MRI

The most common acute infection and leading cause of death in children worldwide is pneumonia. Clinical and laboratory tests essentially diagnose community-acquired pneumonia (CAP). CAP can be caused by bacteria, viruses, or atypical microorganisms. Imaging is usually reserved for children who do not respond to treatment, need hospitalisation, or have hospital-acquired pneumonia. This review discusses the imaging findings for acute CAP complications and the diagnostic role of each imaging modality. Pleural effusion, empyema, necrotizing pneumonia, abscess, pneumatocele, pleural fistulas, and paediatric acute respiratory distress syndrome (PARDS) are acute CAP complications. When evaluating complicated CAP patients, chest radiography, lung ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI) can be used, with each having their own pros and cons. Imaging is usually not needed for CAP diagnosis, but it is essential for complicated cases and follow-ups. Lung ultrasound can supplement chest radiography (CR), which starts the diagnostic algorithm. Contrast-enhanced computed tomography (CECT) is used for complex cases. Advances in MRI protocols make it a viable alternative for diagnosing CAP and its complications.

Increased susceptibility to complicated pneumonia among egyptian children with FokI (rs2228570), not TaqI (rs731236), vitamin D receptor gene polymorphism in association with vitamin D deficiency: a case-control study

BACKGROUND

Determining a genetic contribution to the development of complicated community-acquired pneumonia in children may help understand underlying pathogenesis. We aimed to investigate the association between two vitamin D receptor (VDR) gene polymorphisms, FokI and TaqI, and susceptibility to complicated pneumonia in Egyptian children compared to uncomplicated pneumonia. Associations with 25 hydroxy-vitamin D serum level were studied.

METHODS

This was a case-control study that included 320 participants divided into 2 groups: patients and controls. The patients' group included 100 children hospitalized with complicated pneumonia and 100 with uncomplicated pneumonia. 120 age and sex-matched apparently healthy children served as controls. The VDR FokI and TaqI polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. 25 hydroxy-vitamin D level was estimated in serum using ELISA.

RESULTS

Regarding FokI, homozygous CC genotype was more common in complicated (52%) than uncomplicated pneumonia (28%) and controls (10%) (OR = 65; 95%CI (5.13-822.63), p < 0.001) and (OR = 4.3; 95%CI (0.7-27.16), p = 0.003), respectively. Children carrying C allele possessed 3 higher odds for complicated than uncomplicated pneumonia (OR = 3.08; 95%CI (1.33-7.14), p < 0.001). Heterozygous CT genotype increased susceptibility to complicated pneumonia (OR = 13.7; 95%CI (4.6-40.1), p < 0.001), not uncomplicated pneumonia (OR = 1.56; 95%CI (0.86-2.85), p = 0.145). Among complicated pneumonia, vitamin D level was lower in CC (6.92 ± 2.6ng/ml) than CT (9.55 ± 3.2 ng/ml) and TT genotype carriers (13.13 ± 3.6ng/ml) (p < 0.001). There was no significant difference between patients and controls as regards TaqI genotypes and alleles.

CONCLUSION

In association with vitamin D deficiency, VDR gene FokI polymorphism, not TaqI, is a genetic risk factor for complicated pneumonia in Egyptian children.

Risk of Pleural Empyema in Adult Patients With Asthma: A Nationwide Retrospective Cohort Study

Background

Respiratory system infections commonly occur among individuals with asthma. However, whether asthma patients have a higher risk of pleural empyema development remains unclear.

Methods

This is a retrospective cohort study based on data from the National Health Insurance Research Database of Taiwan. The asthma cohort consisted of 48,360 newly diagnosed adult individuals from 2000 to 2012. The comparison cohort consisted of the same number of adults who did not have asthma and was matched for age, gender, comorbidity, and the year of diagnosis. The development of pleural empyema was followed up to 2013.

Results

Pleural empyema incidence was 2.03-fold higher in the asthma cohort compared to the comparison cohort (8.65 vs. 4.25 per 10,000 person-years), with an adjusted hazard ratio (HR) of 2.12 [95% confidence interval (CI) = 1.76–2.56]. Stratified analyses by age, gender, comorbidity, and corticosteroid use revealed that the crude and adjusted HRs of pleural empyema associated with asthma were all significant. Among patients with asthma, the risk of pleural empyema elevated with increased frequency of annual asthma-related emergency room visits and hospital admissions (≥1 vs. &lt;1, aHR = 8.07, 95% CI = 4.31–15.1 and aHR = 9.31, 95% CI = 5.56–15.6).

Conclusion

An increased risk of pleural empyema occurrence was observed in adult patients with asthma than those without asthma. Furthermore, the risk of pleural empyema may increase with poor control of asthma.

Pediatric Lower Respiratory Tract Infections: Imaging Guidelines and Recommendations

Lower respiratory tract infection (LRTI) remains a major cause of morbidity and mortality in children. Various organisms cause LRTI, including viruses, bacteria, fungi, and parasites, among others. Infections caused by 2 or more organisms also occur, sometimes enhancing the severity of the infection. Medical imaging helps confirm a diagnosis but also plays a role in the evaluation of acute and chronic sequelae. Medical imaging tests help evaluate underlying pathology in pediatric patients with recurrent or long-standing symptoms as well as the immunocompromised.

Contrast-enhanced ultrasound in pediatric interventional radiology

There is growing interest in the use of contrast-enhanced ultrasound (CEUS) in diagnostic and interventional radiology. CEUS applications in interventional radiology are performed with intravascular or intracavitary administration of microbubble-based US contrast agents to allow for real-time evaluation of their distribution within the vascular bed or in body cavities, respectively, providing additional information beyond gray-scale US alone. The most common interventional-radiology-related CEUS applications in children have been extrapolated from those in adults, and they include the use of CEUS to guide lesion biopsy and to confirm drain placement in pleural effusions and intra-abdominal fluid collections. Other applications are emerging in interventional radiology for use in adults and children, including CEUS to optimize sclerotherapy of vascular malformations, to guide arthrography, and for lymphatic interventions. In this review article we present a wide range of interventional-radiology-related CEUS applications, emphasizing the current and potential uses in children. We highlight the technical parameters of the CEUS examination and discuss the main imaging findings.

Variation in Management and Outcomes of Children With Complicated Pneumonia

OBJECTIVES

To assess the characteristics of children hospitalized with complicated pneumonia at US children's hospitals and compare these characteristics with those of children hospitalized with community-acquired pneumonia (CAP).

METHODS

We identified children hospitalized with complicated pneumonia (parapneumonic effusion, empyema, necrotizing pneumonia, or lung abscess) or CAP across 34 hospitals between 2011 and 2019. We evaluated differences in patient characteristics, antibiotic selection, and outcomes between children with complicated pneumonia and CAP. We, also, assessed seasonal variability in the frequency of these 2 conditions and evaluated the prevalence of complicated pneumonia over the 9-year study period.

RESULTS

Compared with children hospitalized with CAP (n = 75 702), children hospitalized with complicated pneumonia (n = 6402) were older (a median age of 6.1 vs 3.4 years; P < .001), with 59.4% and 35.2% of patients ≥5 years of age, respectively. Patients with complicated pneumonia had higher rates of antibiotic therapy targeted against methicillin-resistant Staphylococcus aureus (46.3% vs 12.2%; P < .001) and Pseudomonas (8.6% vs 6.7%; P < .001), whereas differences in rates of coverage against mycoplasma were not clinically significant. Children with complicated pneumonia had a longer median hospital length of stay and higher rates of ICU admissions, mechanical ventilation, 30-day readmissions, and costs. Seasonal variation existed in both complicated pneumonia and CAP, with 42.7% and 46.0% of hospitalizations occurring during influenza season. The proportion of pneumonia hospitalizations due to complicated pneumonia increased over the study period (odds ratio 1.04, 95% confidence interval: 1.02-1.06).

CONCLUSIONS

Complicated pneumonia more frequently occurs in older children and accounts for higher rates of resource use, compared to CAP.

Contrast-enhanced ultrasound of pediatric lungs

In addition to radiography, ultrasound (US) has long proved to be a valuable imaging modality to evaluate the pediatric lung and pleural cavity. Its many inherent advantages, including real-time performance, high spatial resolution, lack of ionizing radiation and lack of need for sedation make it preferable over other imaging modalities such as CT. Since the introduction of ultrasound contrast agents (UCAs), contrast-enhanced ultrasound (CEUS) has become a valuable complementary US technique, with many well-established uses in adults and evolving uses in children. Lung CEUS applications are still not licensed and are performed off-label, although the added value of CEUS in certain clinical scenarios is increasingly reported. The limited evidence of CEUS in the evaluation of pediatric lungs focuses primarily on community-acquired pneumonia and its complications. In this clinical setting, CEUS is used to confidently and accurately diagnose necrotizing pneumonia and to delineate pleural effusions and empyema. In addition to intravenous use, UCAs can be administered directly into the pleural cavity through chest catheters to improve visualization of loculations within a complex pleural effusion, which might necessitate fibrinolytic therapy. The purpose of this paper is to present the current experience on pediatric lung CEUS and to suggest potential additional uses that can be derived from adult studies.

Diagnosis of Community-acquired Pneumonia in Hospitalized Children: A Multicenter Experience in Bolivia

BACKGROUND

Community-acquired pneumonia (CAP) represents a major cause of hospitalization, especially among young children. In the third world countries, information about CAP etiology is scarce. Therefore, rapid and highly sensitive diagnostic methods are crucial to determine etiologic agents.

METHODS

Between March 2016 and March 2017, we have prospectively studied the clinical, radiologic, laboratory, and molecular aspects of patients with CAP at 2 tertiary-level hospitals in Santa Cruz de la Sierra, using a multiplex real-time polymerase chain reaction (RT-PCR).

RESULTS

A total of 274 children were evaluated, with a median age of 13 months. An etiologic agent was identified in 187 patients (68.2%): 54% (n = 148) were viruses and 14.2% (n = 39) were bacteria. CAP prevalence was highest among children under 2 years (71%; 195/274); respiratory syncytial virus (RSV) was the most frequent cause in 22% (60/274), especially among infants, followed by influenza (14.5%; 40/274). Streptococcus pneumoniae accounted for 7% of the total (19/274), followed by Staphylococcus aureus (3%;8/274) and Haemophilus influenzae (1.4%;4/274). Together, these cases accounted for 79.5% (31/39) of all bacterial CAP. Pleural effusion (PE) complicated CAP in 13.8% (38/274), of which 29 were of bacterial etiology. RT-PCR increased the detection rate of pneumococcus by 47%. Coinfection occurred in 28 patients (10%); 26 (9.5%) required intensive care and 9 patients (3%) died.

CONCLUSIONS

RT-PCR provided additional diagnostic value to conventional, clinical, and laboratory methods. The higher prevalence of RSV, influenza, and Streptococcus pneumoniae reveals the need for preventive measures with better vaccine uptake and future research for RSV vaccines.

Consensus Document on Community-Acquired Pneumonia in Children. SENP-SEPAR-SEIP

Community-acquired pneumonia (CAP) is a prevalent disease among children and is frequently associated with both diagnostic and therapeutic uncertainties. Consensus has been reached between SEPAR, SENP and SEIP, and their conclusions are as follows.

Tetrahydropyrimidines, ZL-5015 Alleviated Lipopolysaccharide (LPS)-Induced Acute Pneumonia in Rats by Activating the NRF-2/HO-1 Pathway

BACKGROUND Acute pneumonia is a severe inflammatory disease of the respiratory system. Drugs used to treat acute pneumonia often have strong side effects. Recent studies have shown that tetrahydropyrimidines, ZL-5015 has anti-inflammatory and antitumor effects. However, whether ZL-5015 can relieve symptoms of acute pneumonia is unclear. MATERIAL AND METHODS In this study, we used lipo-polysaccharide (LPS) to stimulate SD rats to simulate conditions of acute pneumonia. Diverse doses of ZL-5015 were used for treatment of these rats. After the rates were sacrificed, serum, lung tissue, and bronchoalveolar lavage fluid were collected for the next study. Hematoxylin-eosin (H&E) staining then was used to detect pathologic changes in lung tissues. Enzyme-linked immunosorbent assay was performed to assess levels of inflammatory factors in serum. Commercial kits were used to assess levels of reactive oxygen species (ROS) in bronchoalveolar lavage fluid. RESULTS Treatment of ZL-5015 relieved stenosis of the alveolar space and pulmonary edema. Furthermore, levels of inflammatory factors (TNF-alpha, IL-1ß and IL-18) in the lung tissues and serum were downregulated after treatment with ZL-5015. Production of ROS also was suppressed after application of ZL-5015. Moreover, inhibition of expression of NRF-2 and HO-1 was relieved after treatment with ZL-5015. The therapeutic effect of ZL-5015 showed a dose-response relationship. CONCLUSIONS ZL-5015 alleviated LPS-induced inflammatory injury and oxidative damage by activating the NRF-2/HO-1 pathway.

Long non-coding RNA SNHG16 promotes lipopolysaccharides-induced acute pneumonia in A549 cells via targeting miR-370-3p/IGF2 axis

BACKGROUND

Pneumonia is an infectious lung inflammation in children with high mortality and morbidity rates. Small nucleolar RNA host gene 16 (SNHG16) has been verified to accelerate the progression of acute pneumonia. However, the role of SNHG16 in acute pneumonia has not yet been fully elucidated. The study was aimed to explore the regulatory mechanism of SNHG16 in LPS-induced acute pneumonia in A549 cells.

METHODS

The levels of SNHG16, miR-370-3p and IGF2 in serum samples and LPS-induced A549 cells were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The cell viability and apoptosis of A549 cells were examined by Cell Counting Kit-8 (CCK-8) assay and flow cytometer, respectively. The levels of interleukin 1β (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) were determined by enzyme-linked immunosorbent assay (ELISA). The binding relationships among SNHG16, miR-370-3p and IGF2 were predicted by online database and verified by Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. The protein levels of IGF2 were tested by Western blot.

RESULTS

SNHG16 and IGF2 were upregulated while miR-370-3p was downregulated in serum of acute pneumonia patients and LPS-induced A549 cells. SNHG16 regulated proliferation, apoptosis and inflammatory cytokines by inhibiting miR-370-3p in LPS-induced A549 cells. MiR-370-3p targeted IGF2 and inhibited LPS-induced inflammatory injury via IGF2 in A549 cells. Furthermore, SNHG16 was verified to promote IGF2 expression by sponging miR-370-3p in A549 cells.

CONCLUSION

SNHG16 impeded cell viability and promoted apoptosis, inflammatory injury by targeting IGF2 mediated by miR-370-3p in LPS-induced A549 cells.

American Thoracic Society 2019 Pediatric Core Curriculum

The American Thoracic Society Pediatric Core Curriculum updates clinicians annually in pediatric pulmonary disease in a 3 to 4 year recurring cycle of topics. The 2019 course was presented in May during the Annual International Conference. An American Board of Pediatrics Maintenance of Certification module and a continuing medical education exercise covering the contents of the Core Curriculum can be accessed online at www.thoracic.org.

Radiologic Diagnosis and Hospitalization among Children with Severe Community Acquired Pneumonia: A Prospective Cohort Study

Objectives

This study was designed to assess the role of chest radiography for the diagnosis of pneumonia and assess the association of clinical characteristics with radiologic findings and predictors of hospitalization among children with severe community acquired pneumonia.

Methods

A prospective study was conducted on 122 children between ages of 3 month and 14 years admitted to pediatric emergency unit with diagnosis of severe pneumonia from September 1^st to November 30^th, 2017. Eligible children were subjected to chest radiography which was read by two senior radiologists independently (R1 and R2). Disagreements between R1 and R2 were resolved by a third senior radiologist (R3). Level of agreement between radiologists was assessed using Cohen's kappa coefficient. Clinical and laboratory parameters which could explain the variability in the duration of hospital stay were assessed using a linear regression mode. Independent predictors were assessed using multiple linear regression.

Results

The median age of the cohort was 10.0 months (interquartile range (IQR): 6.75-24.0); 76 (62.3%) were male. Nearly half, 63 (51.6%) did not have radiologic evidence of pneumonia. There was low level of agreement between R1 and R2 in reporting consolidation (kappa=0.435, p-value≤0.001), haziness (kappa=0.375, p-value≤0.001), and infiltration (kappa=0.267, p-value=0.008). Children with higher recorded temperature were more likely to have radiologic abnormalities suggesting pneumonia (p-value=0.033). The median duration of hospitalization was 3 days (IQR: 1-4 days); 118 (96.7%) were discharged with improvement. Height-for-age z-score (Coef.=0.203, R²=0.041, p-value=0.027); and hemoglobin level (Coef.=-0.249, R²=0.062, p-value=0.006) explained 4.1% and 6.2% of the variability in the duration of hospital stay, respectively.

Conclusion

Radiologic evidence of pneumonia was absent in half of the children with severe pneumonia. There was low agreement between senior radiologists in reporting chest radiographic findings, potentially necessitating harmonization activities to uniformly implement the WHO guidelines in reading chest radiographs.