Long-term efficacy and safety of cow's milk anaphylaxis specific immunotherapy: Allergen unresponsiveness via the Tolerance Induction Program.

Background: Tolerance Induction Program (TIP) immunotherapy applies machine learning contextualized on immunologic and food protein data sets. TIP has established efficacy toward peanut allergy. This form of treatment demonstrates equal efficacy toward cow's milk anaphylaxis. TIP maintains remission outcomes defined as a minimum of 7 days of allergen unresponsiveness to high-dose protein exposures. Furthermore, remission patients openly consume unrestricted amounts of dairy protein. Objective: We sought to assess the rate of decline in specific IgE specific whole and component-resolved diagnostics following 1 year of TIP milk immunotherapy. Methods: The study comprised 214 cow milk anaphylactic children who underwent TIP at the Translational Pulmonary & Immunology Research Center/Food Allergy Institute. Postintervention changes in cow milk specific IgE, component-resolved diagnostics, and specific IgG4 were assessed. Results: After 1 year of 10-g dairy protein weekly sustained unresponsiveness, eosinophil count decreased from 558.38 to 409.26 cells/µL, the mean cow milk IgE decreased from 16.91 to 9.10 kU/L, the mean boiled cow milk IgE decreased from 12.89 to 6.03 kU/L, the mean Bos D4 decreased from 7.38 to 3.52 kU/L, the mean Bos D5 decreased from 6.79 to 3.16 kU/L, and the mean Bos D8 decreased from 13.55 to 6.62 kU/L. Adverse events were rare. Conclusions: TIP cow milk immunotherapy significantly reduced cow milk specific IgE and component-resolved diagnostics while increasing specific IgG4 in cow milk anaphylactic children. TIP demonstrates safety and clinical efficacy in cow milk anaphylaxis treatment.

Pediatric Patients with Tracheostomies and Its Multifacet Association with Lower Airway Infections: An 8-Year Retrospective Study in a Large Tertiary Center.

Background: Lower respiratory tract infections frequently complicate the care of children with chronic tracheostomies. Pediatric patients have significantly more risk to have tracheostomy infections than adults. Better understanding of modifiable risk factors for pulmonary exacerbations may improve the care of technology-dependent children. Methods: A retrospective single-center cohort study conducted on children with tracheostomy and chronic home ventilator to determine the incidence of pulmonary exacerbations leading to hospitalizations, emergency room (ER) visits, and antibiotic prescriptions. Oral and nebulized antibiotic prescriptions were collected and correlated to the type of exacerbation. Results: Gram-negative enteric organisms were the most common microbes seen in the lower airways, with Pseudomonas aeruginosa cultured in 86% of the subjects. P. aeruginosa presence predicted a 4-fold increased rate of pulmonary-related hospitalization. In pediatric patients with chronic respiratory failure, 64% of readmissions were pulmonary or tracheostomy related. When compared to standard care subjects on dual agent, alternating monthly nebulized antibiotic therapy (for chronic pseudomonas colonization) experienced 41% fewer hospitalizations [incidence rate ratios (IRR) 0.59 (0.18), P = 0.08], 46% fewer ER visits [IRR 0.56 (0.16), P = 0.04], and 41% fewer pulmonary-related ER visits [IRR 0.59 (0.19), P = 0.94]. Discussion: Children who require artificial airways are at an increased risk for bacterial bronchopulmonary infections. Most notable risk factors for hospitalization in tracheostomized children included neurologic impairment, dysphagia, aspiration, gastrotomy tube dependence, and gastroesophageal reflux disease. Pathogenic microbes such as P. aeruginosa species, certain gram-negative bacteria, candida, and yeast also predicted increased hospitalizations. Use of nebulized antibiotics prophylaxis in a subset of patients predicted lower rates of hospitalization or ER visits. More studies are needed to assess whether there is increased antimicrobial resistance with this strategy, and whether the benefits persist in the long-term nebulized antibiotics utilization.

Food anaphylaxis diagnostic marker compilation in machine learning design and validation.

BACKGROUND: Traditional food allergy assessment of anaphylaxis remains limited in accuracy and accessibility. Current methods of anaphylaxis risk assessment are costly with low predictive accuracy. The Tolerance Induction Program (TIP) for anaphylactic patients undergoing TIP immunotherapy produced large-scale diagnostic data across biosimilar proteins, which was used to develop a machine learning model for patient-specific and allergen-specific anaphylaxis assessment. In explanation of construct, this work describes the algorithm design for assignment of peanut allergen score as a quantitative measure of anaphylaxis risk. Secondarily, it confirms the accuracy of the machine learning model for a specific cohort of food anaphylactic children. METHODS AND RESULTS: Machine learning model design for allergen score prediction utilized 241 individual allergy assays per patient. Accumulation of data across total IgE subdivision served as the basis of data organization. Two regression based Generalized Linear Models (GLM) were utilized to position allergy assessment on a linear scale. The initial model was further tested with sequential patient data over time. A Bayesian method was then used to improve outcomes by calculating the adaptive weights for the results of the two GLMs of peanut allergy score prediction. A linear combination of both provided the final hybrid machine learning prediction algorithm. Specific analysis of peanut anaphylaxis within one endotype model is estimated to predict the severity of possible anaphylactic reaction to peanut with a recall of 95.2% on a dataset of 530 juvenile patients with various food allergies, including but not limited to peanut allergy. Receiver Operating Characteristic analysis yielded over 99% AUC (area under curve) results within peanut allergy prediction. CONCLUSIONS: Machine learning algorithm design established from comprehensive molecular allergy data produces high accuracy and recall in anaphylaxis risk assessment. Subsequent design of additional food protein anaphylaxis algorithms is needed to improve the precision and efficiency of clinical food allergy assessment and immunotherapy treatment.

Isolated abnormal FEF75% detects unsuspected bronchiolar obstruction in CF children.

BACKGROUND: Physiologic detection of bronchiolar obstruction in children with cystic fibrosis (CF) may be clinically unsuspected because of normal routine spirometry despite bronchiectasis on lung CT. METHODS: Children from two accredited CF facilities had spirometry obtained every 3 months when clinically stable. Pre-bronchodilator maximum expiratory flow volume curves were retrospectively analyzed over 16 years to detect an isolated abnormal FEF75%, despite normal routine spirometry. RESULTS: At Miller Children's and Women's Hospital (MCWH), an abnormal FEF75% was initially detected in 26 CF children at age 7.5 ± 4 (SD) years despite normal routine spirometry initially. FEF75% remained an isolated abnormality for 2.5 ± 1.5 years after it was initially detected in these 26 CF children. At Cohen Children's Medical Center (CCMC), despite normal routine spirometry initially, abnormal FEF75% occurred in 13 children at age 11.7 ± 4.5 years, and abnormal FEF25-75% in 10 children at age 11.8 ± 5.3 years. CONCLUSIONS: FEF75% was most sensitive spirometric test for diagnosing both early and isolated progressive bronchiolar obstruction. Data from CCMC in older children demonstrated the simultaneous detection of abnormal FEF75% and FEF25-75% values consistent with greater bronchiolar obstruction when serial spirometry was initiated at an older age. IMPACT: There is very little published spirometric data regarding diagnosis of isolated small airways obstruction in CF children. FEF75% can easily detect unsuspected small airways obstruction in CF children with normal routine spirometry and bronchiectasis on lung CT and optimize targeted modulatory therapies.

Pediatric P-ANCA vasculitis following COVID-19.

BACKGROUND: Perinuclear anti-neutrophil cytoplasmic antibodies (P-ANCA) are associated with a multisystem vasculitis affecting small blood vessels in the body. A handful of adult patients who developed vasculitis post-COVID-19 have been reported. Although SARS-CoV-2 has been shown to drive an exaggerated immune response in the pediatric population, such as in Multisystem Inflammatory Syndrome in Children (MIS-C), only one case of vasculitis following COVID-19 has been reported previously in children. CASE PRESENTATION: Seventeen-year-old male with a past medical history of COVID-19 pneumonia two months prior presented with acute kidney injury and diffuse alveolar hemorrhage. Rheumatologic workup revealed P-ANCA and Myeloperoxidase (MPO) positivity. Kidney biopsy showed necrotizing glomerulonephritis with limited immune complex deposition. Subsequently, he was treated with steroids and plasmapheresis, and ultimately started on cyclophosphamide. CONCLUSIONS: To our knowledge, this report presents the second reported pediatric case of P-ANCA/MPO vasculitis following COVID-19.

Immune Response to SARS-CoV-2 in an Asymptomatic Pediatric Allergic Cohort.

Disease-specific COVID-19 pediatric comorbidity has not been studied effectively to date. Atopy and food anaphylaxis disease states require improved characterization of SARS-CoV-2 infection risk. To provide the first such characterization, we assessed serum samples of a highly atopic, food anaphylactic, asymptomatic pediatric cohort from across the US during the height of the pandemic. From our biobank, 172 pediatric patient serum samples were characterized specific to atopic, food anaphylactic, and immunologic markers in the US at the beginning of the pandemic, from 1 February to 20 April 2020. Clinical and demographic data were further analyzed in addition to sample analysis for SARS-CoV-2 IgM and IgG ELISA. SARS-CoV-2 antibody results were positive in six patients (4%). Nearly half of the pediatric patients had a history of asthma (49%). Total IgE, total IgG, and IgG1-3 were similar in those positive and negative to SARS-CoV-2. Median total IgG4 in the SARS-CoV-2 positive group was nearly three times (p-value = 0.02) that of the negative group. Atopy controller medications did not confer additional benefit. Our data suggest that food anaphylaxis and highly atopic children are not at increased risk for SARS-CoV-2 seropositivity. This specific population appears either at equal or potentially less risk than the general population. Total and specific IgG4 may be a novel predictor of SARS-CoV-2 infection risk specific to the allergic pediatric population.

Cystic fibrosis patients at risk for disease progression marked by decline in FEV1% predicted: development of the cystic fibrosis risk of disease progression score.

BACKGROUND: Cystic fibrosis (CF) is one of the most common recessively inherited disorders diagnosed in early childhood in the United States. Determining the phenotype of CF patients likely to experience a significant drop in FEV1% predicted will help target efforts for mitigating this deleterious disorder. METHODS: This retrospective cohort study evaluated potential risk variables that account for the decline in FEV1% predicted in 81 CF patients treated at Miller Children's and Women's Hospital, CA. Cystic fibrosis risk of disease progression (CF RD-Pro) score was evaluated as a tool to identify high-risk patients for accelerated disease progression (event = drop in FEV1% predicted ≥10 percentage points) based on risk variables identified as significant. RESULTS: ROC analysis determined classification of high versus low-moderate risk of FEV1% decline during year two based on RD-Pro score. Scores ≥2 applied as threshold for high-risk revealed relatively good validity estimates: sensitivity =82.8%, specificity =66.7%, PVP =77.4%, PVN =73.7%, and correct classification =76%. Patients with CF RD-Pro scores suggestive of high (≥2 points) vs. low-moderate (<2 points) risk were nearly 10 times more likely to experience significant disease progression (OR 9.6, 95% CI, 2.6-36.1, P=0.001). CONCLUSIONS: Identification of patients at high risk for significant decline in lung function will enable address of potential therapeutic modalities, environmental exposures, and behavioral variants that may improve outcomes in these patients. The power of the CF RD-Pro Score lies in its simplicity. Our study provides a novel readily available score, which incorporates body mass index (BMI) and Staphylococcus aureus infection, both being alterable targets for slowing CF progression.

Correlation of negative skin-prick test results for tree nuts and successful tree nut challenges among children with peanut allergy.

Background: Children with peanut allergy are regularly instructed to avoid all tree nuts. However, children with peanut allergy are likely not allergic to all tree nuts. Objective: In our cohort of patients with peanut anaphylaxis and who underwent oral immunotherapy, we sought to determine the correlation of skin-prick testing (SPT) results for tree nuts and the likelihood of successfully passing a tree nut challenge. Methods: SPT was performed for peanut and tree nuts (macadamia, pine nut, coconut, hazelnut, brazil nut, cashew, pecan, walnut, pistachio, almond) in 27 patients with known peanut allergy. The probability of a negative SPT result (wheal < 3 mm) for each nut was determined. Results: All the patients demonstrated positive results in peanut allergy diagnostics in SPT, component testing, or food challenge. Only 15.4% of the patients had a positive SPT result to peanut alone. Macadamia, pine nut, and coconut SPT had a probability of negative SPT results of 0.97, 0.97, and 0.91, respectively. The odds ratio for this group having a negative SPT was 46.22. For hazelnut, brazil nut, and cashew, the probability of a negative SPT result was 0.81, 0.77, and 0.73, respectively. Pecan, walnut, and pistachio had odds ratios of 0.68, 0.68, and 0.64, respectively. All the patients with macadamia, pine nut, and coconut negative SPT results subsequently passed 9-g food challenges without oral immunotherapy. Conclusion: Despite current recommendations to avoid all tree nuts for patients with peanut allergy, the majority of patients with peanut allergy had negative SPTs and food challenges to certain tree nuts, especially macadamia, pine nut, and coconut. This pattern was seen despite most patients having multiple nut sensitizations.

Inter- and intra-subject variability of nitric oxide levels in leukocyte subpopulations.

Assessment of nitric oxide (NO) dynamics in immune cells, commonly measured using NO surrogates such as inducible nitric oxide synthase (iNOS) rather than NO itself, has been effective in understanding pathophysiology across a wide range of diseases. Although the intracellular measurement of NO is now feasible, many technical issues remain unresolved. The principle aim of our study was to determine the effect of storage time of whole blood on nitric oxide (NO) level expression in leukocytes. This is important because immune cells remain chemically dynamic even after they are removed from the circulation, and the impact of storage time must be known to optimally quantify the effect of a disease or condition on NO dynamics in circulating leukocytes. We measured NO levels using the fluorescent probe, diaminofluorescein (DAF-2DA), and flow cytometry in monocytes, neutrophils, and natural killer cells from healthy subjects immediately after blood draw (Time 0) and 30, 60, and 120 min following the blood draw. There was no significant difference among the 4 study time points in NO (DAF-2) levels, though there was wide intra-subject variability at all time points. Using LPS stimulation, we compared iNOS (the more traditional surrogate marker of NO dynamics) with NO (by DAF-2) in natural killer cells and monocytes and, we found no difference in the response patterns. In summary, we did find that within a 2-hour interval from blood draw to sample processing, there was a remarkably wide intra-subject variability in expression of intracellular NO (DAF-2) in leukocytes of healthy individuals at baseline and over time. The mechanism(s) for these differences are not known but could clearly confound efforts to detect changes in NO metabolism in white blood cells. We speculate that rapid pulsatility of NO could explain the wide variability seen.

Wiskott-Aldrich Syndrome: Description of a New Gene Mutation With Normal Platelet Volume.

Wiskott-Aldrich syndrome (WAS) is a rare X-linked primary immunodeficiency characterized by an increased incidence of autoimmunity, malignancy, microthrombocytes with thrombocytopenia, eczema, and recurrent infections. In this case report, we present a novel mutation, hemizygous for c.1125_1129delTGGAC mutation in the WAS gene, and a unique clinical presentation. Our patient was initially diagnosed with a milk protein allergy after presenting with a lower gastrointestinal bleed, leukopenia, and thrombocytopenia with normal platelet volume. However, signs of vasculitis and detection of microthrombocytes required additional testing and consideration of WAS. This case report illustrates the importance of retaining a high index of clinical suspicion despite normal platelet volume, as well as adding to the growing number of known mutations associated with WAS.

Quantification of Aerosol Hydrofluoroalkane HFA-134a Elimination in the Exhaled Human Breath Following Inhaled Corticosteroids Administration.

Inhaled corticosteroids (ICS) and ß2-agonists are the primary pharmacotherapies of asthma management. However, suboptimal medication compliance is common in asthmatics and is associated with increased morbidity. We hypothesized that exhaled breath measurements of the aerosol used in the inhaled medications might prove useful as surrogate marker for asthma medication compliance. To explore this, 10 healthy controls were recruited and randomly assigned to ICS (Flovent HFA) or short acting bronchodilators (Proventil HFA). Both inhalers contain HFA-134a as aerosol propellant. Exhaled breath sampling and pulmonary function tests were performed prior to the inhaler medication dispersion, immediately after inhalation, then at 2, 4, 6, 8, 24, and 48 hours postadministration. At baseline, mean (SD) levels of HFA-134a in the breath were 252 (156) pptv. Immediately after inhalation, HFA-134a breath levels increased to 300 × 10(6) pptv and were still well above ambient levels 24 hours postadministration. The calculated ratio of forced expiratory volume in 1 second over forced vital capacity did not change over time following inhaler administration. This study demonstrates, for the first time, that breath HFA-134a levels can be used to assess inhaler medication compliance. It may also be used to evaluate how effectively the medicine is delivered.

Immunoglobulin replacement therapy: a twenty-year review and current update.

OBJECTIVE: The expansion of immunoglobulin replacement to multiple disease entities marks a decade-long advancement in immune therapy. Parallel to its extension, the characteristics and composition of immunoglobulin products have diversified. The aim of this study was to summarize a 20-year comprehensive literature review of currently commercially available immunoglobulin products, particularly examining individual product properties in a comparative format. Data Sources/Study Selections: The literature review was performed using PubMed and Ovid, screening a time span of 2 decades. Both authors reviewed the obtained articles for acceptable quality, and the selection was narrowed down based on criteria for randomized clinical and therapeutic trials. RESULTS: Product-specific characteristics in terms of purification strategy, stabilizers, composition, and viral inactivation were found among the immunoglobulin products investigated. Such differing characteristics manifest in their variable clinical safety and efficacy as assessed by the comparative product analysis. In subgroups of patients, subcutaneous immunoglobulin therapy may be an alternative to intravenous immunoglobulin (IVIG) therapy with an equal efficacy and a lower number of systemic adverse events. CONCLUSION: Only few comprehensive clinical synopses are available to clearly demonstrate the differences in IVIG products despite the widespread clinical use of the therapy. This review defines significant characteristics of individual immunoglobulin products, noting important differences in product development and application and allowing informed clinical decisions to match a product with patients' risk factors and comorbidity. This balanced approach to gammaglobulin replacement therapy is imperative to produce the highest clinical efficacy and lowest number of adverse events.

Progression and prognostic indicators of bronchial disease in children with sickle cell disease.

PURPOSE: The pulmonary complications of sickle cell disease (SCD) are a leading cause of morbidity and mortality (MacLean et al. Am J Respir Crit Care Med 178:1055-1059, 2008; Klings et al. Am J Respir Crit Care Med 173:1264-1269, 2006; National Heart, Lung, and Blood Institute, 2009). Despite this recognition, predictive markers of lung dysfunction progression remain elusive (Klings et al. Am J Respir Crit Care Med 173:1264-1269, 2006; Platt et al. N Engl J Med 330:1639-1644, 1994; Caboot et al. Curr Opin Pediatr 20:279-287, 2008; Field et al. Am J Hematol 83:574-576, 2008; Shirlo et al. Peadiatr Respir Review 12:78-82, 2011). This study was designed describe the longitudinal progression and identify specific markers that influence bronchial disease in SCD. METHODS: A retrospective, chart review of 89 patients with SCD was conducted. All patients underwent spirometry in conjunction with body plethysmography as part of routine care. Eleven lung function variables were assessed, five of which were selected to establish patterns of normal, obstructive, restrictive, or mixed obstructive-restrictive physiology (Klings et al. Am J Respir Crit Care Med 173:1264-1269, 2006; Field et al. Am J Hematol 83:574-576, 2008). RESULTS: In the unadjusted model, forced expiratory volume in one second (FEV1)% of predicted trended downward with age, while total lung capacity (TLC)% of predicted showed a bimodal distribution and carbon monoxide diffusion capacity corrected for hemoglobin (DLCOcor)% of predicted remained stable. Adjusting for acute chest syndrome (ACS) episodes, medication status, and growth velocity (GV), the final model demonstrated that the downward trend between FEV1% of predicted with age was further influenced by the latter two factors. CONCLUSIONS: Initial decline in FEV1% of predicted is associated with worsening pulmonary dysfunction over time. Independent of ACS episodes, the factors most influential on the progression of FEV1% predicted include the introduction of medications as well as the promotion of adequate prepubertal growth. Efforts to ensure normal prepubertal GV and treatment with bronchodilators, such as short-acting beta(2) agonists and inhaled corticosteroids (ICS), should be considered at an early age to delay progression of pulmonary dysfunction.

Clinical control in the dual diagnosis of obstructive sleep apnea syndrome and rhinitis: a prospective analysis.

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) and allergic rhinitis (AR) are common coexisting disorders. Upper airway, specifically nasal resistance, is thought to increase during exacerbations of AR and nonallergic rhinitis (NAR), as well as in OSAS. The study objective was to determine if a correlation exists between clinical control of rhinitis and OSAS. METHODS: This prospective study followed 43 patients with concurrent OSAS and AR or NAR. OSAS was diagnosed by polysomnography, and AR or NAR was diagnosed by history, skin testing, serum-specific IgE, and total IgE levels. Measurements of control of OSAS included the Epworth Sleepiness Scale (ESS) survey and compliance with continuous positive airway pressure (CPAP) device. Measurements of rhinitis control included Assessment of Nasal Symptom Severity and Assessment of Nonnasal Symptom Severity (NSS refers to both) and Global Assessment of Nasal and Nonnasal Symptom Severity surveys (GSS). Higher NSS scores correlate with more rhinitis symptoms, whereas higher GSS scores correlate with less symptoms. RESULTS: All patients completed the study. There was a positive correlation between ESS and NSS scores (p < 0.001), inverse correlation between ESS and GSS scores (p < 0.001), inverse correlation between CPAP compliance and NSS scores (p < 0.001), and positive correlation between CPAP compliance and GSS scores (p < 0.001). There was no statistically significant difference between the AR, NAR, and AR/NAR groups. CONCLUSION: Our study showed a statistically significant positive correlation between clinical control of rhinitis symptoms and clinical control of OSAS. This study emphasizes the importance of achieving concurrent optimal control of both OSAS and AR/NAR.

Diagnosis of cystic fibrosis in the kindred of an infant with CFTR-related metabolic syndrome: importance of follow-up that includes monitoring sweat chloride concentrations over time.

Newly implemented newborn screening (NBS) programs in California have resulted in a large subset of patients in whom at least two cystic fibrosis transmembrane conductance regulator (CFTR) mutations are identified, but subsequent sweat chloride analysis reveals normal or indeterminate values. These patients are diagnosed with CFTR-Related Metabolic Syndrome (CRMS). However, the natural progression and management of these patients are not clearly understood and frequently after the age of 1-year these patients are lost to follow-up with Cystic Fibrosis (CF) Centers. We present the first case of an infant who was referred to Miller Children's Hospital for a NBS positive for CF and subsequent discovery of identical mutations in six of his seven older brothers. Several siblings had positive sweat chloride results on repeat testing after the age of 3 years. We suggest the need for continued follow-up of CRMS in a CF center with diagnostic evaluation including repeat sweat chloride testing, beyond the currently recommended period.

Beta-blocker management of refractory hemoptysis in cystic fibrosis: a novel treatment approach.

BACKGROUND: /objective: Recurrent hemoptysis is a debilitating complication of cystic fibrosis (CF) and likely results from mucosal erosions into abnormal bronchial blood vessels due to chronic respiratory infection. We hypothesize that the use of beta-blockade will decrease mean arterial pressure resulting in lower bronchial artery blood flow and, subsequently, decrease the frequency and severity of hemoptysis, rate of hospitalizations, and usage of intravenous antibiotics. METHODS: Retrospective chart review was performed on 12 CF patients with recurrent hemoptysis, aged 13-40 years old, along with a follow-up telephone survey to assess the effectiveness of beta-blockade for hemoptysis, tolerance of inhaled respiratory medications, activity tolerance, and potential adverse effects. A beta-blocker, specifically atenolol, was initiated in all subjects within 24 hours after experiencing recurrent hemoptysis episodes. RESULTS: A majority of patients (72.7%) had complete cessation of hemoptysis. There were significant decreases in the frequency of hemoptysis (p = 0.02) and the amount of hemoptysis (p = 0.004). The rate of hospitalizations significantly decreased from 1.33 to 0.67 (p = 0.05) after initiation of atenolol. There was a trend toward statistical significance in the reduction of intravenous antibiotics use (p = 0.08). No statistical difference was found when comparing the pre- and post-treatment means of forced expiratory volume in 1-second (p = 0.59). Very minimal adverse effects were observed with only one patient reporting intermittent facial flushing. CONCLUSION: Beta-blockade, particularly with atenolol, appears to successfully treat, if not resolve, recurrent hemoptysis refractory to conservative therapy in CF. Beta-blocker therapy appears to maintain an effective safety profile in CF.

Clinical significance of respiratory isolates for Mycobacterium abscessus complex from pediatric patients.

Mycobacterium abscessus complex is the most virulent of rapidly growing mycobacteria causing invasive lung disease. To better delineate clinical pediatric experience and outcomes with M. abscessus complex, we retrospectively gathered 5-year data on M. abscessus complex infection and outcomes in a large, hospital-based pediatric pulmonary center. Patients were selected from the database of the microbiology department at Miller Children's Hospital in Long Beach, CA. Patients had at least one positive pulmonary isolate for M. abscessus complex from February 2006 to May 2011. Treatment modality data were collected and successful therapy of disease was determined as clearance of M. abscessus complex infection after antibiotics proven by culture negative respiratory isolate within at least 12 months of therapy initiation. Two cystic fibrosis patients with M. abscessus complex were identified, one with failed therapy and the other with stable pulmonary status despite persistent isolation. One primary ciliary dyskinesia patient had successful clearance of M. abscessus complex, however is now growing M. avium intracellulare. A patient with no prior medical history was successfully treated with antimycobacterial therapy. Eleven patients with neuromuscular disorders had tracheal aspirates positive for M. abscessus complex. None were treated due to stable lung status and all but two had spontaneous clearance of the mycobacteria. The two remaining persist with sporadic isolation of M. abscessus complex without clinical significance. We concluded that patients with tracheostomy associated M. abscessus complex infections do not appear to require treatment and often have spontaneous resolution. Cystic fibrosis or primary ciliary dyskinesia patients may have clinical disease warranting treatment, but current antimycobacterial therapy has not proven to be completely successful. As M. abscessus complex gains prevalence, standardized guidelines for diagnosis and therapy are needed in the pediatric population. Multicenter cohort analysis is necessary to achieve such guidelines.

High-frequency oscillatory ventilation in pediatric acute hypoxemic respiratory failure: disease-specific morbidity survival analysis.

BACKGROUND: Multiple ventilatory strategies for acute hypoxemic respiratory failure (AHRF) in children have been advocated, including high-frequency oscillatory ventilation (HFOV). Despite the frequent deployment of HFOV, randomized controlled trials remain elusive and currently there are no pediatric trials looking at its use. Our longitudinal study analyzed the predictive clinical outcome of HFOV in pediatric AHRF given disease-specific morbidity. METHODS: A retrospective 8-year review on pediatric intensive care unit admissions with AHRF ventilated by HFOV was performed. Primary outcomes included survival, morbidity, length of stay (LOS), and factors associated with survival or mortality. RESULTS: A total of 102 patients underwent HFOV with a 66 % overall survival rate. Survivors had a greater LOS than nonsurvivors (p = 0.001). Mortality odds ratio (OR) for patients without bronchiolitis was 8.19 (CI = 1.02, 65.43), and without pneumonia it was 3.07 (CI = 1.12, 8.39). A lower oxygenation index (OI) after HFOV commencement and at subsequent time points analyzed predicted survival. After 24 h, mortality was associated with an OI > 35 [OR = 31.11 (CI = 3.25, 297.98)]. Sepsis-related mortality was associated with a higher baseline FiO(2) (0.88 vs. 0.65), higher OI (42 vs. 22), and augmented metabolic acidosis (pH of 7.25 vs. 7.32) evaluated 4 h on HFOV (p < 0.05). CONCLUSION: High-frequency oscillatory ventilation may be safely utilized. It has a 66 % overall survival rate in pediatric AHRF of various etiologies. Patients with morbidity limited to the respiratory system and optimized oxygenation indices are most likely to survive on HFOV.

Pediatric fiberoptic bronchoscopy as adjunctive therapy in acute asthma with respiratory failure.

BACKGROUND: Status asthmaticus respiratory failure is associated with thickened mucus secretions necessitating aggressive pulmonary clearance. The role of bronchoscopy in pediatric mechanically ventilated asthmatic patients has not been published. METHODS: A chart review was performed on all pediatric intensive care unit (PICU) asthmatics with respiratory failure over 13 years. Forty-four patients were identified. Patients were managed per standardized guidelines for status asthmaticus with mechanical ventilation. Ventilator management prioritized spontaneous breathing with pressure support. Extubation criteria included spontaneous tidal volumes of 5-7 cm(3) /kg on low-pressure support. Standard endotracheal tube pulmonary toilet were implemented. Twenty-nine patients underwent bronchoscopy as an adjunctive therapy. Indications for bronchoscopy included: Pathogen identification via bronchoalveolar ravage, atelectasis, mucus obstruction resulting in severe air trapping, suspected aspiration, and poor response to standard therapy. Clinical outcomes of this intervention were compared to the fifteen patient cohort who did not undergo bronchoscopy. RESULTS: Bronchoscopies revealed thick mucus plugs, secretions, and bronchial casts. The large airways were lavaged for clearance of obstructive secretions with normal saline. All patients tolerated the procedure without any complications. Demonstrable improvement in pulmonary compliance was noted. The median time of intubation for the bronchoscopy group was 10 hr compared to 20.5 hr for the control group (P < 0.0005). The mean intensive care unit length of stay was 3.06 days for the bronchoscopy group versus 3.4 days for the non-bronchoscopy group (P < 0.05). CONCLUSION: Flexible bronchoscopy with bronchial lavage is a safe adjunctive therapy in pediatric asthmatics with respiratory failure resulting in reduced mechanical ventilation and intensive care length of stay. Restoring lung volume in certain asthmatics during respiratory failure may be deemed beneficial. Further validated studies are necessary to recommend bronchoscopy to the present, accepted treatment regimen in pediatric asthmatic respiratory failure.