Bronchoscopy with bronchoalveolar lavage in the evaluation of pulmonary complications of bone marrow transplantation in children

Detection of Bronchiolitis Obliterans Syndrome after Pediatric Hematopoietic Stem Cell Transplantation: An Official American Thoracic Society Clinical Practice Guideline

Background: Many children undergo allogeneic hematopoietic stem cell transplantation (HSCT) for the treatment of malignant and nonmalignant conditions. Unfortunately, pulmonary complications occur frequently post-HSCT, with bronchiolitis obliterans syndrome (BOS) being the most common noninfectious pulmonary complication. Current international guidelines contain conflicting recommendations regarding post-HSCT surveillance for BOS, and a recent NIH workshop highlighted the need for a standardized approach to post-HSCT monitoring. As such, this guideline provides an evidence-based approach to detection of post-HSCT BOS in children. Methods: A multinational, multidisciplinary panel of experts identified six questions regarding surveillance for, and evaluation of, post-HSCT BOS in children. A systematic review of the literature was undertaken to answer each question. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to rate the quality of evidence and the strength of recommendations. Results: The panel members considered the strength of each recommendation and evaluated the benefits and risks of applying the intervention. In formulating the recommendations, the panel considered patient and caregiver values, the cost of care, and feasibility. Recommendations addressing the role of screening pulmonary function testing and diagnostic tests in children with suspected post-HSCT BOS were made. Following a Delphi process, new diagnostic criteria for pediatric post-HSCT BOS were also proposed. Conclusions: This document provides an evidence-based approach to the detection of post-HSCT BOS in children while also highlighting considerations for the implementation of each recommendation. Further, the document describes important areas for future research.

Diagnostic yield of bronchoalveolar lavage in immunocompromised children with malignant and non-malignant disorders

BACKGROUND

The diagnostic yield of bronchoalveolar lavage (BAL) in the Immunocompromised pediatric population has ranged from 28% to 68%. We hypothesized that the diagnostic yield of BALs would be higher in more recent years due to new diagnostic assays.

METHODS

A retrospective case series was performed among immunocompromised children ≤18 years old who underwent BALs from 2001 to 2012, to assess the yield of microbiologic diagnostic studies and to determine the impact of BAL findings on antimicrobial management.

RESULTS

In all, 123 subjects underwent 174 BALs (mean age 9.9 years). Underlying diagnoses included both malignant (n = 79) and non-malignant (n = 44) disorders, and 75 (61.0%) subjects were hematopoietic stem cell transplant (HSCT) recipients. Fifty-four (31.0%) of 174 BAL were positive for ≥1 potential pathogen (n = 58 microorganisms). The diagnostic yield of BALs performed from 2001 to 2006 versus2007-2012 was similar (40.5% vs. 26.6%, respectively, P = 0.07). Most subjects (86.2%) were on ≥1 antimicrobial at the time of BAL. Most (65.8%) negative BALs were associated with narrowing antimicrobial therapy, while most (74.1%) positive BALs were associated with continuing or changing to targeted antimicrobial therapy.

CONCLUSIONS

In this study population, the diagnostic yield of BAL was similar to that previously described and unchanged in more recent years. Both negative and positive BALs were associated with changes in antimicrobial management.

SUMMARY

A 10-year retrospective review of bronchoalveolar lavage in 123 immunocompromised children determined that the rate of isolation of potential pathogens was 31% in this population. The majority of BAL was associated with a change in antimicrobial therapy. Pediatr Pulmonol. 2017;52:820-826. © 2017 Wiley Periodicals, Inc.

Bronchoalveolar lavage and lung biopsy in patients with cancer and hematopoietic stem-cell transplantation recipients: a systematic review and meta-analysis

PURPOSE

The objective of this study was to describe the diagnostic yield and complication rate of bronchoalveolar lavage (BAL) and lung biopsy in the evaluation of pulmonary lesions in patients with cancer and recipients of hematopoietic stem-cell transplantation (HSCT).

METHODS

We conducted a systematic literature review and performed electronic searches of Ovid MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials. Studies were included if patients had cancer or were recipients of HSCT, and if they underwent BAL or lung biopsy for the evaluation of pulmonary lesions. Only English language publications were included.

RESULTS

In all, 14,148 studies were screened; 72 studies of BAL and 31 of lung biopsy were included. The proportion of procedures leading to any diagnosis was similar by procedure type (0.53 v 0.54; P = .94) but an infectious diagnosis was more common with BAL compared with lung biopsy (0.49 v 0.34; P < .001). Lung biopsy more commonly led to a noninfectious diagnosis (0.43 v 0.07; P < .001) and was more likely to change how the patient was managed (0.48 v 0.31; P = .002) compared with BAL. However, complications were more common with lung biopsy (0.15 v 0.08; P = .006), and procedure-related mortality was four-fold higher for lung biopsy (0.0078) compared with BAL (0.0018).

CONCLUSION

BAL may be the preferred diagnostic modality for the evaluation of potentially infectious pulmonary lesions because of lower complication and mortality rates; thus, choice of procedure depends on clinical suspicion of infection. Guidelines to promote consistency in the approach to the evaluation of lung infiltrates may improve clinical care of patients.

Severe lung injury and lung biopsy in children post-hematopoietic stem cell transplantation: The differences between allogeneic and autologous transplantation

To review outcome of children post-allogeneic (allo) and autologous (auto) SCT with severe lung injury who had lung biopsy and to determine whether the diagnoses provided by lung biopsy had an impact on outcome. Retrospective study was carried out from January 2000 to June 2010. Nine hundred and eighteen children (0-18 yr) received SCT (allo 476, auto 442), and 59 biopsies were performed in 48 patients. Most common result of lung biopsy was non-infectious inflammation and recurrent disease in allo- and autorecipients, respectively. In a multivariate analysis, survival of allorecipients who had management change was inferior (p = 0.002; HR: 3.12). These patients were extremely sick, and management change was the last attempt to stabilize their respiratory status. There was a trend toward superior survival for children who had biopsy after 100 days following SCT (p = 0.09; HR: 0.55) and a trend toward inferior survival for those with proven infections within two wk of biopsy (p = 0.07; HR: 2.14). Only 31% of allorecipients and 25% of autorecipients survived. There were no biopsy-related complications. Lung biopsy itself appears to be well tolerated, although requiring a biopsy seems to carry a poor prognosis; this seems to be due to different causes, auto (relapse), allo (non-infectious inflammation).

Acute kidney injury in pediatric stem cell transplant recipients

Because respiratory dysfunction after hematopoietic stem cell transplantation is a manifestation of a continuum of dysfunction temporarily induced by the transplant process, a proactive rather than reactive approach might prevent or attenuate its progression to acute respiratory distress syndrome. Organ dysfunction in this population results from cytokine-driven processes, of which the first manifestation includes fluid accumulation. We describe a multistep protocol that first targets fluid balance control, both through restriction of intake and through augmentation of output using dopamine and furosemide infusions. If these steps fail to stem the tide of water accumulation, we advocate the relatively early use of continuous renal replacement therapy, its use triggered by a continued increase in body weight (>10% above baseline), an increasing c-reactive protein level, and an increasing oxygen need. Renal function parameters do not figure in this protocol. We recommend continuous renal replacement therapy at 35 mL/kg/h (2,000 mL/1.73 m(2)/h), a dose that allows adequate flexibility in fluid management and that may provide effective clearance of proinflammatory (and anti-inflammatory) mediators that drive the evolving dysfunction. Proactive intervention improves the clinical status such that the transition to mechanical ventilation may proceed smoothly or in some cases even may be avoided altogether.

Pulmonary dysfunction in pediatric hematopoietic stem cell transplant patients: overview, diagnostic considerations, and infectious complications

Pulmonary complications are among the most common and serious sequelae seen in hematopoietic stem cell transplantation (HSCT) recipients. This two-part review addresses the incidence and impact of pulmonary complications in pediatric HSCT patients. In this first part we review the available data for the use of diagnostic modalities in this population, including flexible bronchoscopy with bronchoalveolar lavage (BAL) and open lung biopsy (OLB). We also review the many infectious pulmonary complications that may occur in pediatric HSCT recipients, utilizing the traditional chronologic divisions of neutropenic phase (0-30 days following HSCT), early phase (30-100 days), and late phase (>100 days).

Fiberoptic bronchoscopy and bronchoalveolar lavage for the evaluation of pulmonary disease in children with primary immunodeficiency and cancer

BACKGROUND

Patients with childhood cancer or primary immunodeficiencies (PID) are at high risk for developing pulmonary infections and non-infectious complications. The broad differential diagnoses and the critical condition of these patients often drive physicians to start broad-spectrum antibiotic therapy before a definite diagnostic procedure is performed. A definite diagnosis may be achieved in these situations by fiberoptic bronchoscopy (FOB) and bronchoalveolar lavage (BAL).

PATIENTS AND METHODS

The records of 58 PIDs and cancer (immunocompromised group) pediatric patients who underwent 62 fiberoptic bronchoscopies between 2000 and 2004 were retrospectively reviewed and compared to 158 non-cancer patients who underwent 182 fiberoptic bronchoscopies during the same period.

RESULTS

The overall diagnostic rate achieved by macroscopic inspection of purulent secretions or hemorrhage, abnormal cell count, and infectious agent isolation in the immunocompromised patients was 84%. A definite organism was recovered in 53.2% of the patients. Probable infection defined as purulent secretions or abnormal cell count without infectious agent isolation was diagnosed in another 21% of the patients. The rate of complications was 30.6%. In the control group, the overall diagnostic rate was 76.9% (n.s) and an infectious agent was demonstrated in 12.1% (P < 0.001). Probable infection was diagnosed in 24.2% (n.s) while the rate of complications was lower (15%) (P < 0.01).

CONCLUSIONS

Rapid and accurate diagnoses were achieved in most procedures performed on immunocompromised patients. Although the rate of complications was higher in the immunocompromised group, they were usually very mild with no mortality. Based on these results, broncoalveolar lavage should be considered as an initial diagnostic tool in pediatric immunocompromised patients with pulmonary complications.

Retrospective evaluation of a paediatric intensivist-led flexible bronchoscopy service

OBJECTIVE

To demonstrate the diagnostic yield, therapeutic role and safety of flexible bronchoscopy via an intensivist-led service in critically ill children.

DESIGN

Retrospective chart review.

SETTING

Regional paediatric intensive care unit.

MEASUREMENTS AND RESULTS

One hundred forty-eight flexible bronchoscopies were performed by two intensivists on 134 patients (median age 16.5 months) over a 2.5-year period. Eighty-eight percent of patients required mechanical ventilation, and 22% were receiving inotropes. Case mix included general (n = 77), cardiac surgery (n = 18), cardiology (n = 13), ear-nose-and-throat surgery (n = 17), oncology (n = 8) and renal (n = 1). The indication for bronchoscopy was defined a priori according to one of four categories: suspected upper airway disease (n = 32); lower airway disease (n = 70); investigation of pulmonary disease (n = 25); and extubation failure (n = 21). Bronchoscopy was generally performed soon after PICU admission, at a median time of 1.5 days for the former three categories, and 4 days for extubation failure group. A positive yield from bronchoscopy (diagnosis that explained the clinical condition or influenced patient management) was present in 113 of 148 (76%) procedures, varying within groups from 44% (pulmonary disease) to 90% (extubation failure). Ten percent of patients developed a fall in oxygen saturations > 20% during the procedure and 17% required a bolus of at least 10 ml/kg of 0.9% saline for hypotension.

CONCLUSIONS

Critically ill patients with respiratory problems may benefit from a PICU-led bronchoscopy service as the yield for positive bronchoscopic finding is high, particularly for upper airway problems or extubation failure.

Serious and lethal respiratory tract infections of viral etiology in children

Viruses may lead to serious and lethal pulmonary infections in immunocompetent and immunocompromised children. Series of children with acute respiratory distress syndrome and series of children requiring extracorporeal membrane oxygenation, as well as reported series of nosocomial viral illness, offer an insight into the extent of serious viral disease documented in the medical literature. Series of children with specific viral respiratory illness also will be reviewed, as will the means of diagnosis in these groups of patients. Copyright © 2000 by W.B. Saunders Company

Pulmonary complications following hematopoietic stem cell transplantation: diagnostic approaches

Pulmonary complications are a significant cause of morbidity and mortality in hematopoietic stem cell transplant recipients. Pulmonary infiltrates in such patients pose a major challenge for clinicians because of the wide differential diagnosis of infectious and noninfectious conditions. It is rare for the diagnosis to be made by chest radiograph, and commonly these patients will need further invasive and noninvasive studies to confirm the etiology of the pulmonary infiltrates. This review describes the role of the different diagnostic tools available to reach a diagnosis in a timely manner in this patient population.

Open lung biopsy in pediatric patients with respiratory failure after abdominal transplantation

To understand the utility of open lung biopsy (OLB) in the evaluation of respiratory failure in pediatric abdominal organ transplant we reviewed the records of nine children in this patient population who underwent an OLB. Eight of nine patients had undergone a previous non-diagnostic bronchoalveolar lavage. Biopsies were performed at the bedside in the pediatric intensive care unit and tissue was processed by the Department of Pathology with special stains for infectious agents. There were no significant complications of OLB. A specific treatable etiology was identified in four patients (respiratory syncytial virus, adenovirus, graft-vs.-host disease and post-transplant lymphoproliferative disease), leading to a change in therapy and survival in two. Overall survival was 44%. Given the low morbidity, OLB as performed in this study appears appropriate in this patient population.

Clinical utility of bronchoalveolar lavage in pediatric cancer patients

BACKGROUND

Pulmonary disease in the pediatric cancer patient continues to pose a difficult clinical dilemma. Bronchoalveolar lavage (BAL) is commonly utilized for the diagnosis of pulmonary complications in the immunocompromised child.

PROCEDURE

We retrospectively reviewed 53 BAL procedures performed in pediatric cancer patients with pulmonary disease between 1988 and 1998 to determine the diagnostic and clinical utility of BAL. Patients who had undergone prior myeloablative therapy were excluded from analysis.

RESULTS

The majority of patients (83%) had an underlying diagnosis of acute leukemia or lymphoma. BAL yielded a specific diagnosis in 16 patients (30%), including 15 infections and 1 malignant infiltration. Medical management was altered in an additional 14 patients (26%) as a consequence of a negative BAL result. Severe but transient complications associated with the BAL procedure occurred in four patients (8%). Minor complications following the BAL occurred in 21 patients (40%) and included transiently increased oxygen requirement and anesthesia-related gastrointestinal complaints. The mortality from lung disease in this patient population was 7.5%.

CONCLUSIONS

Both positive and negative BAL results contribute to the management of pediatric cancer patients with pulmonary disease. The low incidence of significant complications associated with BAL and the high mortality rate in this patient population support the choice of BAL as an initial diagnostic test in pediatric cancer patients with pulmonary disease.

Open lung biopsy in bone marrow transplant recipients has a poor diagnostic yield for a specific diagnosis

The diagnostic yield of open lung biopsy (OLB) in bone marrow transplantation (BMT) recipients having pulmonary infiltrates has not been evaluated recently. Therefore, we reviewed our 2-year experience (1998-99) with such patients at The University of Texas M. D. Anderson Cancer Center. We found 12 BMT recipients who underwent OLB analysis for the evaluation of pulmonary infiltrates. A treatable infectious etiology leading to the initiation or modification of antimicrobial agent administration was found in only two patients having bilateral nodular disease and one having bilateral parenchymal infiltrates. We conclude that OLB in BMT patients having diffuse pulmonary infiltrates has a low diagnostic yield for treatable infectious etiologies.

Flexible bronchoscopy in the diagnosis of pulmonary infiltrates following autologous peripheral stem cell transplantation for advanced breast cancer

Flexible bronchoscopy is an important tool in the diagnosis of pulmonary complications following bone marrow transplantation. However, the value of this procedure in autologous peripheral stem cell transplant (APSCT) recipients with pulmonary complications is not well defined. We retrospectively evaluated the diagnostic yield of 27 consecutive bronchoscopies done on 23 APSCT recipients following high-dose chemotherapy for breast cancer. FB resulted in a positive diagnosis in 16 cases (59%). Broncheoalveolar lavage (BAL) was performed on all patients, and transbronchial biopsies (TBB) were carried out in 14. TBB were diagnostic in 10 (71%), with pulmonary drug toxicity as the most common finding (n = 8), followed by metastatic breast cancer (n = 2). BAL was diagnostic in six (22%): bacterial pneumonia (n = 3), aspergillosis (n = 2), Pneumocystis carinii pneumonia (n = 1) and Influenza B (n = 1). The procedure was well tolerated with no major complications except a small pneumothorax in one patient that did not require chest tube insertion. In conclusion, flexible bronchoscopy is a useful tool in the evaluation of pulmonary complications following APSCT for breast cancer. TBB can be done safely with relatively high diagnostic yield. Pulmonary drug toxicity is the most common pathological finding.

Pediatric bronchoscopy

Diagnostic flexible endoscopy for pediatric respiratory diseases is performed in many centers. Technical advances have resulted in performance of interventional bronchoscopies, and new diagnostic indications are being explored. Indications with documented clinical benefit include congenital or acquired progressive or unexplained airway obstruction. Pulmonary infections in immunodeficient children who do not respond to empirical antibiotic treatment may be diagnosed by bronchoscopy and bronchoalveolar lavage (BAL). The potential usefulness of bronchoscopy and BAL for managing chronic cough, wheeze, or selected cases with asthma or cystic fibrosis requires further study. The use of transbronchial biopsies (TBB) is established in pediatric lung transplantation. The role of TBB in the diagnosis of chronic interstitial lung disease in children remains to be determined. For a number of interventional applications, rigid endoscopy is required, and pediatric bronchoscopists should be trained in its use. Complications in pediatric bronchoscopy are rare, but severe nosocomial infection or overdosing with local anesthetics has occurred. The issues of quality control, video documentation, interobserver variability of findings, and educational standards will have to be addressed in the future as bronchoscopy use becomes less restricted to only large pediatric pulmonary units.

Value of open lung biopsy in immunocompromised children

OBJECTIVES

To determine the value of open lung biopsy (OLB) in terms of diagnosis, morbidity, mortality, and benefits in immunocompromised children with pulmonary involvement.

STUDY DESIGN

We retrospectively reviewed 36 OLBs performed in 32 immunocompromised children between 1985 and 1998. Seventeen biopsies were performed in patients with primary immunodeficiency syndromes and 19 in patients with secondary immunodeficiency syndromes. Twenty-eight biopsies were performed because of a lack of response to ongoing antimicrobial treatments with negative or positive findings on bronchoalveolar lavage (BAL) and a deteriorating clinical or radiologic course, and 8 biopsies were performed because of persistent chest x-ray infiltrates.

RESULTS

Diffuse pulmonary infiltrates were observed on chest x-ray in 28 cases, hyperinflation in 3 cases, and nodular infiltrates in 5 cases. A histopathologic diagnosis was possible for all 36 OLBs. Specific diagnosis was obtained in 22 (61%) (12 infectious agents, 6 tumors, 4 bronchiolitis obliterans) and non-specific diagnosis in 14 (39%). Fungi were the main infectious agents (8 of 12). For the diagnosed infections, BAL provided 4 true-positive, 3 false-positive, and 6 false-negative results. Specific treatment was changed in 77% of cases, providing real benefits in 12 (33%) cases. The morbidity and overall mortality rates were 31% and 33%, respectively. The mortality rate was significantly higher in the first 30 days after OLB in patients receiving ventilatory assistance (58%).

CONCLUSIONS

OLB in immunocompromised children with deteriorating clinical or radiologic course is a sensitive diagnostic tool.

Bronchoalveolar lavage in the diagnosis of pulmonary complications of bone marrow transplant patients

Bronchoalveolar lavage (BAL) has proved valuable in the diagnosis of pulmonary complications in immunosuppressed patients. We evaluated the diagnostic yield of BAL in pulmonary complications in bone marrow transplantation (BMT) recipients. We reviewed sequentially the records of 89 patients during an 18-month period. BAL was diagnostic in 42 patients (47%). The most common pulmonary complication diagnosed by BAL was diffuse alveolar hemorrhage (n = 15); followed by bacterial pneumonia (n = 10), respiratory syncytial virus (n = 8), aspergillosis (n = 6), Pneumocystis carinii pneumonia (n = 5), cytomegalovirus (CMV) (n = 4), and others (n = 4). The final diagnoses in the BAL non-diagnostic group were: bacterial pneumonia (n = 6), CMV (n = 6), idiopathic pneumonia syndrome (n = 5), cancer recurrence (n = 4), cardiogenic pulmonary edema (n = 4), and others (n = 9). We conclude that BAL is a useful diagnostic tool in BMT-related pulmonary complications.

[Pulmonary complications in immunosuppressed children]

Pulmonary complications, which are dominated by opportunistic infections, can be first manifestations of inherited or acquired pediatric immune deficiencies. Prompt diagnosis is essential. The epidemiology and natural history of these complications have changed as a result of major advances in prevention, diagnosis and treatment.

Investigation of the child with interstitial lung disease

Many disorders can affect the pulmonary interstitium in children. Although individual interstitial lung diseases are rare, the range of conditions encountered is wide. Interstitial disease is also seen increasingly as a consequence of the treatment of children having other primary problems including cancer, immunodeficiency and haemotological diseases, as well as in recipients of solid organ and bone marrow transplants. The management and prognosis of individual conditions is highly variable, thus it is essential to search for a precise diagnosis in every patient. High resolution computerised tomography (HRCT) and other less invasive investigations may be helpful in the management of patients. However, it is unusual to be able to make a firm diagnosis without a lung biopsy.

[Usefulness of routine investigation of fungal infections through bronchoscopy in HIV-infected and non-HIV-infected patients in a general hospital, reference to AIDS]

The diagnostic yields and the spectrum of pulmonary fungal-infection obtained in samples collected by fiberoptic bronchoscopy from HIV-positive and HIV-negative patients were evaluated from 1990 to 1995. A total of 1943 bronchoscopies were performed during this period, 47% in the HIV-positive group and 53% in the HIV-negative group. Of 908 HIV-positive patients, 38 (4%) had a fungus isolated from the pulmonary sample whereas of 1035 HIV-negative patients, only 4 (0.2%) had a fungus isolated. Histoplasmosis and Cryptococcosis were more frequently found in HIV-positive than in HIV-negative patients (p < 0.001). Paracoccidioides brasiliensis was found in only 3 patients, all of them immunocompetent. The study demonstrated that, despite the low yields, the HIV-positive group may benefit from routine screening for fungal elements in specimens obtained by fiberoptic bronchoscopy.

Yield from flexible bronchoscopy in children

Flexible fiberoptic (FO) bronchoscopy can now be undertaken readily in children using topical anesthesia and light sedation and has largely supplanted rigid open tube (OT) bronchoscopy for diagnostic purposes. The present study examined the contribution of the FO bronchoscope to clinical management in children presenting with specific types of problems. We examined the first 200 consecutive flexible bronchoscopies performed in 1995 in children under 18 years of age (median age, 2.27 years). Indications for bronchoscopy were noisy breathing (26.5%), recurrent pneumonia (21.0%), suspected pneumonia in an immunocompromised patient (10.5%), atelectasis or bronchial toilet (12.5%), possible foreign body aspiration (13.0%), and miscellaneous other reasons (16.5%). Inspection of the airway was abnormal in 67.0% of all investigations and made a clinically meaningful contribution to management in 67.5%, especially in those with noisy breathing (98.1%), possible foreign body aspiration (100%), and atelectasis (76.0%). Bronchoalveolar lavage (BAL) cytology was abnormal in 80.4% of the 107 lavages, but contributed little to management except in those with recurrent pneumonia (73.8%). Bacteria were isolated in 26.6% of the 109 specimens cultured, but this finding rarely affected management. Fungi were isolated in 47.4% of the 19 lavages in the immunocomprised group. Together, inspection, BAL and microbiology contributed to management in a mean of 90.5% (range, 76.2-100%) of patients in the various groups. We concluded that a high yield of clinically meaningful information can be expected from FO bronchoscopy in children when coupled with BAL and microbiological studies of lavage fluid.

The diagnostic value of bronchoalveolar lavage in immunocompetent children with chronic diffuse pulmonary infiltrates

We have investigated the diagnostic value of (BAL) in 29 immunocompetent children (ages 1 month to 18 years) with chronic diffuse pulmonary infiltrates on chest radiograph who presented for evaluation over a 3-year period. The median age at the time of the BAL was 20 months with a range of 1-210 months. Positive results (1) diagnostic of a primary disorder; (2) consistent with a diagnosis; or (3) diagnostic of a secondary disorder, were obtained in 20/29 patients (13 with a single positive BAL finding and 7 with more than one finding). BAL was diagnostic of a primary disorder in only 5 patients (17%) with aspiration detected in 3 and infection in 2. The differential diagnosis was narrowed in 15 patients by the presence of lymphocytosis, neutrophilia, or eosinophilia. A secondary disorder was uncovered in 8 patients. Negative results were obtained in 9 additional patients. We conclude that BAL provided useful information in children with chronic diffuse infiltrates, but its ability to determine the primary cause was limited.

Comparison of cell profiles in separately evaluated fractions of bronchoalveolar lavage (BAL) fluid in children

BACKGROUND

Bronchoalveolar lavage (BAL) has been widely accepted as a routine procedure in the differential diagnosis of respiratory diseases in adults. However, there is only limited information about the value of BAL in children and there is no standardisation of the procedures.

METHODS

The difference in cellular profiles of sequential BAL fractions from children was analysed to assess the effect of evaluating bronchial and alveolar fractions separately. Twenty five children (mean age 13.4 years) were examined by fibreoptic bronchoscopy under general anaesthesia, combined with local application of lignocaine. The investigation was part of the clinical evaluation of an infective pulmonary problem. Bronchoalveolar lavage was performed from the right middle lobe using four 20 ml aliquots of normal saline and the four fractions of recovered fluid were evaluated separately.

RESULTS

The total cell count was lowest in the first aspirate (1.8 x 10(6)) and increased gradually from fraction 1 to fraction 4. Similarly, the viability of the cells was lowest in fraction 1 and gradually improved from fraction 1 to fraction 4. In the differential count the number of neutrophils decreased from fraction 1 (8.3%) to fraction 4, with fractions 2 (5.4%), 3 (3.4%), and 4 (2.4%) being significantly different from fraction 1. There were no differences in the numbers of eosinophils, lymphocytes, or macrophages between individual fractions.

CONCLUSIONS

These results show that the cell profile of the first "bronchial" fraction is different from subsequent samples. It should be evaluated separately while the second and third aliquots may be pooled.

Differential cytology of bronchoalveolar lavage fluid in immunosuppressed children with pulmonary infiltrates

OBJECTIVE

Bronchoalveolar lavage (BAL) is a well established technique for the detection of pathogens in immunosuppressed children, but its diagnostic yield is variable. The aim of this study was to investigate whether BAL differential cell counts are helpful in the evaluation of pulmonary infiltrates in immunocompromised children.

STUDY DESIGN

BAL was performed 28 times in 27 febrile immunocompromised children with pulmonary infiltrates. All patients were pretreated with broad spectrum antibiotics; 11 children also received amphotericin B. BAL was conducted with a flexible bronchoscope wedged in the area of maximal pathology as suggested by the chest radiograph or in the middle lobe in patients with diffuse interstitial radiographic changes. Differential cell counts were performed from cell smears obtained after centrifugation of BAL fluid.

RESULTS

Bacterial or fungal organisms were detected in BAL fluid of 12 patients. Patients with bacterial or fungal infections (group 1) had a significantly higher percentage of granulocytes in BAL fluid both compared with patients with sterile BAL cultures (group 2) and with a control group of children without pulmonary disease (p < 0.001, Wilcoxon test). The proportion of lymphocytes was not different from the control group in group 1 but significantly increased in group 2 (p < 0.001, Wilcoxon test). Blood differential cell counts were not different in the two patient groups. Lymphocyte subsets of BAL fluid obtained in a subgroup of patients were not significantly different from controls.

CONCLUSION

These data suggest that BAL differential cell counts may be a useful adjunct in the differential diagnosis of pulmonary infection in immunocompromised children.

Fungal pneumonia: the predominant lung infection causing death in children undergoing bone marrow transplantation

The study included 6 children (aged 4-14 years) receiving a conditioning regimen for bone marrow transplantation (BMT) and 14 children (aged 2 14 years) with bone marrow transplants (13 allogeneic, 1 autologous). The children underwent flexible fibre-optic bronchoscopy (FFB) with bronchoalveolar lavage during 6 and 17 episodes of pneumonia, respectively. The aim was to compare the results of the two groups with respect to bronchoscopy findings, pneumonia-causing agents and outcome. During the conditioning regimen, the aetiological agents were recovered by bronchoscopy in 1/6 (17%) episodes and revealed by autopsy in another episode. In three episodes where the aetiology was uncertain, bacterial pneumonia was suspected in two, and Candida pneumonia in one. In episodes after transplantation the aetiological agents were recovered from bronchoscopy material in 14/17 (82%) patients. Autopsy confirmed the premortal diagnosis in the four children who died. In three episodes, bacterial pneumonia was clinically suspected. Based on clinical manifestations, FFB and autopsy findings, bacterial and fungal pneumonia were the most common diagnoses both during conditioning and after BMT. Fungal pneumonia was the most common cause of death in both groups.

Assessment of lung function in the intensive care unit

Tests of pulmonary function have become more accurate and less invasive in recent years. Our ability to monitor patients continuously with pulse oximetry, transcutaneous and end-tidal CO2, and intraarterial blood gas monitors has greatly enhanced ICU care. In intubated patients in the PICU detailed lung function studies can be performed, and in general they can be carried out with minimal disruption of routine management. Much work remains to be done to define the changes seen in various disease processes and the effects of therapeutic interventions on functional parameters. Many of the available techniques have already been developed to a point that allows them to be employed in clinical decision making. We expect that assessment of lung volumes, compliance, and resistance will become a routine part of management in children with life-threatening pulmonary diseases in the near future, and that a more intimate knowledge of the pathophysiology of respiratory disorders treated in PICU will lead to improved outcomes.

Update on pediatric flexible bronchoscopy

Technological advances in flexible bronchoscopy have expanded the clinician's ability to diagnose and treat pulmonary disease in children. During the neonatal period, flexible bronchoscopy has contributed to the understanding of the incidence and factors responsible for acquired airway lesions. The ability to selectively collect lower airway secretions has contributed to the care of immunocompromised patients with new pulmonary infiltrates. New therapies may use the flexible bronchoscope to specifically target lower airway tissues of interest. Because of the breadth of both current and future applications, most pediatricians will require a working familiarity with the benefits of flexible bronchoscopy in their patients.