Diagnoses unveiled by early bronchoscopy in children with leukemia and pulmonary infiltrates

Diagnostic yield of bronchoscopy in children with leukemia or post hematopoietic stem cell transplant

BACKGROUND

The utility of bronchoscopy with bronchoalveolar lavage (BAL) in immunocompromised children is not well understood. We aim to describe the bronchoscopy diagnostic yield and complications and to investigate factors associated with diagnostic yield.

METHODS

This is a single-center, retrospective cohort study of 60 children with leukemia or post-hematopoietic stem cell transplant who had a bronchoscopy with BAL between 2017 and 2021. Comparisons were done with regression analysis.

RESULTS

Of the 60 bronchoscopies performed, 46 (77%) revealed diagnostic information: 39 (65%) identified a pathogen, 14 (23.3%) found secretions/mucus plugging, and 6 (10%) found pulmonary hemorrhage. BAL results changed antimicrobial therapy in 27 (45%) cases. Bronchoscopies were performed in the intensive care unit (27/60) or operating room (33/60), with the former having a higher diagnostic yield (96% vs. 60%, p = 0.001). Half (50%) of bronchoscopies found a new infectious diagnosis. Respiratory symptoms (n = 58, 97%), supplemental oxygen use (n = 39, 65%), and antibiotic use (n = 56, 93%) before bronchoscopy were all common. The median volume of fluid instilled during bronchoscopy was 1.3 mL/kg (interquatile range [IQR]: 0.7, 2.6). None of these factors were associated with the diagnostic yield. Complications were rare and minor with only one child having self-resolved bleeding and four children, previously in room air requiring a nasal cannula. For the 27 (45%) children on mechanical ventilation when the bronchoscopy was performed, there was no difference in ventilator settings pre- and post-bronchoscopy.

CONCLUSION

Bronchoscopies with BAL are useful, safe, and important in the diagnostic management of pulmonary complications in this cohort of children.

The Challenge of Diagnosing Invasive Pulmonary Aspergillosis in Children: A Review of Existing and Emerging Tools

Invasive pulmonary aspergillosis remains a major cause of morbidity and mortality for immunocompromised children, particularly for patients with acute leukaemia and those undergoing haematopoietic stem cell transplantation. Timely diagnosis, using a combination of computed tomography (CT) imaging and microbiological testing, is key to improve prognosis, yet there are inherent challenges in this process. For CT imaging, changes in children are generally less specific than those reported in adults and recent data are limited. Respiratory sampling by either bronchoalveolar lavage or lung biopsy is recommended but is not always feasible in children, and serum biomarkers, including galactomannan, have important limitations. In this review we summarise the current paediatric data on available diagnostic tests for IPA and highlight key emerging diagnostic modalities with potential for future use.

Clinical Utility of Bronchoalveolar Lavage in Pediatric Oncology Patients

BACKGROUND

Lower airway sampling is important in the assessment of lower respiratory tract infection in children with cancer or posthematopoietic stem cell transplant and can be done via bronchoalveolar lavage (BAL). Clinicians can struggle with balancing the benefits of BAL against the risks. This study aimed to define the diagnostic and clinical utility of BAL in this population.

METHODS

A single-center retrospective review of BAL performed in children with cancer or posthematopoietic stem cell transplant. Data extracted included demographics, BAL method and results and antimicrobial treatment. Variables significantly associated with diagnostic yield, diagnostic impact (confirmation or exclusion of infection), and clinical impact (any change in antimicrobial or nonantimicrobial therapy) were assessed in both univariate and multivariate analysis.

RESULTS

Seventy-three BAL episodes were included. In 26 (35.6%) episodes, a pathogen was identified on BAL. Forty-nine (67%) BAL episodes had a diagnostic impact and 15 (21%) had a clinical impact. Late BAL (>72 hours) compared with early BAL (odds ratio 3.27; 95% CI: 1.03-10.86), and flexible bronchoscopy compared with nonbronchoscopic lavage (odds ratio 6.10; 95% CI: 1.90-24.0), were more likely to have a diagnostic impact on multivariate analysis. No associations were found for clinical impact.

CONCLUSIONS

One-third of BAL episodes identified a pathogen, two-thirds had a diagnostic impact, and almost a quarter of episodes impacted antimicrobial prescribing. The method and timing of BAL may be important, with flexible bronchoscopy 6-fold more likely and late BAL 3-fold more likely to have a diagnostic impact.

Metagenomic Next-Generation Sequencing Successfully Detects Pulmonary Infectious Pathogens in Children With Hematologic Malignancy

Background

Pulmonary infection is a leading cause of mortality in pediatric patients with hematologic malignancy (HM). In clinical settings, pulmonary pathogens are frequently undetectable, and empiric therapies may be costly, ineffective and lead to poor outcomes in this vulnerable population. Metagenomic next-generation sequencing (mNGS) enhances pathogen detection, but data on its application in pediatric patients with HM and pulmonary infections are scarce.

Methods

We retrospectively reviewed 55 pediatric patients with HM and pulmonary infection who were performed mNGS on bronchoalveolar lavage fluid from January 2020 to October 2021. The performances of mNGS methods and conventional microbiological methods in pathogenic diagnosis and subsequently antibiotic adjustment were investigated.

Results

A definite or probable microbial etiology of pulmonary infection was established for 50 of the 55 patients (90.9%) when mNGS was combined with conventional microbiological tests. The positive rate was 87.3% (48 of 55 patients) for mNGS versus 34.5% (19 of 55 patients) with conventional microbiological methods (P < 0.001). Bacteria, viruses and fungi were detected in 17/55 (30.9%), 25/55 (45.5%) and 19/55 (34.5%) cases using mNGS, respectively. Furthermore, 17 patients (30.9%) were identified as pulmonary mixed infections. Among the 50 pathogen-positive cases, 38% (19/50) were not completely pathogen-covered by empirical antibiotics and all of them were accordingly made an antibiotic adjustment. In the present study, the 30-day mortality rate was 7.3%.

Conclusion

mNGS is a valuable diagnostic tool to determine the etiology and appropriate treatment in pediatric patients with HM and pulmonary infection. In these vulnerable children with HM, pulmonary infections are life-threatening, so we recommend that mNGS should be considered as a front-line diagnostic test.

Retrospective Review of Flexible Bronchoscopy in Pediatric Cancer Patients

The use of flexible bronchoscopy (FB) with bronchoalveolar lavage (BAL) to diagnose and manage pulmonary complications has been shown to be safe in adult cancer patients, but whether its use is safe in pediatric cancer patients remains unclear. Thus, to describe the landscape of FB outcomes in pediatric cancer patients and to help define the populations most likely to benefit from the procedure, we undertook a retrospective review of FBs performed in patients younger than 21 years treated at our institution from 2002 to 2017. We found that a greater volume of total fluid instilled during BAL was significantly associated with increased probabilities of positive BAL culture (p=0.042), positive bacterial BAL culture (p=0.037), and positive viral BAL culture (p=0.0496). In more than half of the FB cases, findings resulted in alterations in antimicrobial treatment. Our study suggests that for pediatric cancer patients, FB is safe, likely provides diagnostic and/or therapeutic benefits, and has implications for treatment decisions.

Case Report: Sudden Fatal Hemorrhage in Ulcerative Fungal Laryngotracheitis-A Pediatric Case Report

In this report, we describe an autopsy case of a child affected by acute lymphoblastic leukemia and opportunistic pulmonary aspergillosis. The patient died because of a full-thickness tracheal wall ulceration with right inferior thyroid artery lesion and sudden hemorrhage, likely ascribable to undiagnosed invasive Aspergillus laryngotracheitis. Aspergillus infection, particularly in immunocompromised patients, should be considered an urgent risk factor to manage as it may lead to sudden fatal events in absence of evident critical symptoms.

Pulmonary Infectious Complications in Children with Hematologic Malignancies and Chemotherapy-Induced Neutropenia

Infections frequently complicate the treatment course in children with hematologic malignancies undergoing chemotherapy. Febrile neutropenia (FN) remains a major cause of hospital admissions in this population, and respiratory tract is often proven to be the site of infection even without respiratory signs and symptoms. Clinical presentation may be subtle due to impaired inflammatory response. Common respiratory viruses and bacteria are widely identified in these patients, while fungi and, less commonly, bacteria are the causative agents in more severe cases. A detailed history, thorough clinical and basic laboratory examination along with a chest radiograph are the first steps in the evaluation of a child presenting signs of a pulmonary infection. After stratifying patient’s risk, prompt initiation of the appropriate empirical antimicrobial treatment is crucial and efficient for the majority of the patients. High-risk children should be treated with an intravenous antipseudomonal beta lactam agent, unless there is suspicion of multi-drug resistance when an antibiotic combination should be used. In unresponsive cases, more invasive procedures, including bronchoalveolar lavage (BAL), computed tomography (CT)-guided fine-needle aspiration or open lung biopsy (OLB), are recommended. Overall mortality rate can reach 20% with higher rates seen in cases unresponsive to initial therapy and those under mechanical ventilation.

Utility of bronchoscopy in immunocompromised paediatric patients: Systematic review

PURPOSE

The objective of this study was to describe the diagnostic yield and safety of bronchoalveolar lavage (BAL) in the evaluation of pulmonary lesions in immunocompromised children.

METHODS

We conducted a systematic review of literature published during the past 20 years, searching Medline, Medline EPub, EMBASE, and Scopus. Studies included involved paediatric patients (<18 years) on treatment for an oncological diagnosis or other immune compromise who underwent BAL for evaluation of pulmonary lesions. Only English language publications were included.

RESULTS

In all, 272 studies were screened and 19 included. All were observational studies with moderate (11/19) or serious (8/19) risk of bias. BAL yielded a potential pathogen in 43% of cases (496/1156). Two papers reported improved diagnostic yield with early BAL (less than 3 days of presentation). A change in patient management after BAL was reported in 53% of cases (275/519). Adverse events were reported in 19% of cases following BAL (193/993) but were generally mild with no procedure-related mortality reported.

CONCLUSION

BAL appears to be useful for evaluation of pulmonary lesions in immunocompromised children with generally acceptable safety, though included studies had at least moderate risk of bias. Future prospective studies may provide more definitive estimates of benefit, timing and risk of BAL in this population.

Case Report of a Child after Hematopoietic Cell Transplantation with Acute Aspergillus Tracheobronchitis as a Cause for Respiratory Failure

Rapid respiratory failure due to invasive mycosis of the airways is an uncommon presentation of Aspergillus infection, even in immunocompromised patients, and very few pediatric cases have been reported. Patients with Aspergillus tracheobronchitis present with nonspecific symptoms, and radiologic studies are often noninformative, leading to a delay in diagnosis. Prompt initiation of adequate antifungal therapies is of utmost importance to improve outcome. We report the case of a 9-year-old girl with chronic myelogenous leukemia who developed respiratory distress 41 days after hematopoietic cell transplantation and rapidly deteriorated despite multiple interventions and treatment modalities.

Safety and Benefits of Bronchoalveolar Lavage and Lung Biopsy in the Management of Pulmonary Infiltrates in Children With Leukemia

BACKGROUND

Children with leukemia are at risk of developing life-threatening opportunistic pulmonary infections. The role of bronchoalveolar lavage (BAL) and lung biopsy (BX) in the management of these patients is controversial. In this study, we evaluate the yield and safety of BAL and BX in children with leukemia.

PROCEDURE

We reviewed the records of all children with leukemia who underwent either BAL or BX between 1997 and 2007 at the St Jude Children's Research Hospital.

RESULTS

A total of 64 patients were included, of whom 35 (55%) had BX and 29 (45%) had BAL. Positive results were obtained in 69% of BAL cohort and in 46% of BX cohort. Both procedures resulted in change in antimicrobial coverage (77% in BX, 83% in BAL). Pulmonary hemorrhage occurred in 2 patients, and transient hypoxia was the most frequent complication. All resolved without negatively impacting the clinical course.

CONCLUSIONS

Both BAL and BX are safe and useful in the management of children with leukemia and pulmonary disease.