Consensus-Based Best Practice Guidelines for the Management of Spinal Deformity and Associated Tumors in Pediatric Neurofibromatosis Type 1: Screening and Surveillance, Surgical Intervention, and Medical Therapy.

BACKGROUND: Spinal conditions, such as scoliosis and spinal tumors, are prevalent in neurofibromatosis type 1 (NF1). Despite the recognized importance of their early detection and treatment, there remain knowledge gaps in how to approach these manifestations. The purpose of this study was to utilize the experience of a multidisciplinary committee of experts to establish consensus-based best practice guidelines (BPGs) for spinal screening and surveillance, surgical intervention, and medical therapy in pediatric patients with NF1. METHODS: Using the results of a prior systematic review, 10 key questions that required further assessment were first identified. A committee of 20 experts across medical specialties was then chosen based on their clinical experience with spinal deformity and tumors in NF1. These were 9 orthopaedic surgeons, 4 neuro-oncologists/oncologists, 3 neurosurgeons, 2 neurologists, 1 pulmonologist, and 1 clinical geneticist. An initial online survey on current practices and opinions was conducted, followed by 2 additional surveys via a formal consensus-based modified Delphi method. The final survey involved voting on agreement or disagreement with 35 recommendations. Items reaching consensus (≥70% agreement or disagreement) were included in the final BPGs. RESULTS: Consensus was reached for 30 total recommendations on the management of spinal deformity and tumors in NF1. These were 11 recommendations on screening and surveillance, 16 on surgical intervention, and 3 on medical therapy. Five recommendations did not achieve consensus and were excluded from the BPGs. CONCLUSION: We present a set of consensus-based BPGs comprised of 30 recommendations for spinal screening and surveillance, surgical intervention, and medical therapy in pediatric NF1.

Low Preoperative Lung Functions in Children With Early Onset Scoliosis Predict Postoperative Length of Stay.

INTRODUCTION: Children with early onset scoliosis (EOS) undergoing spine surgery often have significant respiratory disease. Preoperative risk assessments that predict an increased length of hospital stay (LOS) for this group have not been previously evaluated. METHODS: A voluntary protocol using preoperative lung function studies began among participants of a multicenter registry in 2016. Preoperative assessments were standardized to include spirometry, blood hemoglobin levels, serum bicarbonate, albumin and prealbumin; radiographic parameters of the spine, C-EOS classification and need for preoperative pulmonary assistance before initial growth friendly device insertion or "definitive" spine fusion. Primary outcome was LOS postoperatively. Data, including age, diagnosis, and type of surgery, was collected prospectively. Secondary outcomes measured included intensive care unit LOS, requirement for new pulmonary assistance on discharge, and pulmonary complications. Groups were compared using the Fisher exact tests. RESULTS: Of 525 children enrolled, 101 (20%) had preoperative spirometry. Median age was 8.9 years [interquartile range (IQR): 4.27]. Etiologies for EOS included 29 neuromuscular (28%), 33 idiopathic (32%), 19 syndromic (19%), and 22 congenital (21%) scoliosis. Eighty (78%) had growing rod (GR) insertions; 23 (22%) had spine fusion SF. Eighteen subjects (17%) were hospitalized ≥7 days (median=9 d); 83 had a LOS <7 days (median=3 d). Percentage of forced vital capacity (FVC%) predicted was inversely associated with LOS ≥7 days with a median of 75.3% (IQR: 41.7) for LOS <7 days and 51.7% (IQR: 41.6) (P=0.02). There were no detectable differences in LOS for other preoperative values. CONCLUSION: FVC predicted ≤50% preoperatively in children undergoing initial growth friendly rod insertion or definitive fusion after growth friendly treatment is associated with an increased risk of postoperative hospital stays ≥7 days. As demonstrated in previous studies, severe restrictive lung disease (FVC% predicted at or below 50%) is associated with increased risk of poorer outcomes for EOS patients.

Preoperative 6-Minute Walk Performance in Children With Congenital Scoliosis.

BACKGROUND: The 6-minute walk test (6MWT) is used to assess the function of cardiopulmonary and neuromuscular conditions in adults and children. The primary research question was to determine the relationship between 6MWT distance and forced vital capacity (FVC) and the major curve among children with congenital scoliosis with rib anomalies. METHODS: The authors recorded 6MWT distance in meters, FVC as a percentage of predicted normal value using arm span for height (FVC%), and Cobb angle in 20 children (13 girls; average age, 6.7±1.3 y) with congenital scoliosis before outpatient surgical treatment. The 6MWT uses a standardized protocol and measures distance traveled in 6 minutes on a flat surface. The authors then determined the correlation between these measures using linear regression analysis. RESULTS: The Cobb angle of the major curvature was 55.4±20.5 degrees. The type of vertebral anomaly was mixed in 17 cases, formation failure in 2 cases, and segmentation failure in 1 case. The range of rib anomalies was 3.4±3.9 levels; 15 and 5 patients, respectively, had unilateral and bilateral rib anomalies. FVC and FVC% were 0.7±0.2 L and 60%±19%, respectively. The ratio of forced expiratory volume at 1 second to FVC (FEV1/FVC), which indicates obstructive lung disease, was normal at 93%±7%. The 6MWT distance was 386.3±59.4 m, which was ≤10% of the predicted distance for normal children. No child was able to walk the normal distance on the basis of published norms. 6MWT distance was significantly correlated with arm span (ρ=0.46, P=0.04) and major curve (ρ=-0.61, P=0.004), but not with FVC% (ρ=0.17, P=0.49). CONCLUSIONS: The 6MWT distance is a feasible measure of function and is substantially reduced before surgery in children with thoracic congenital scoliosis with rib anomalies. The 6MWT distance was significantly correlated with a major curve but not with FVC%. 6MWT distance is not affected by moderate lung function impairment. LEVEL OF EVIDENCE: Level IV-retrospective cohort study.

Persistence and Progression of Airway Obstruction in Children With Early Onset Scoliosis.

BACKGROUND: Obstructive lung disease occurs in 30% of children with early onset scoliosis (EOS); changes in degree of airway obstruction over time have not been reported. METHODS: Longitudinal patterns of incidental, persistent, and progressive airway obstruction were retrospectively analyzed in a cohort of children with EOS with at least 1 forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) value <85% on serial spirometric assessments over a ≥3-year observation period. The prevalence of clinical features and the severity of coronal and sagittal spine deformities for each group at the beginning and end of the study period were compared. RESULTS: Airway obstruction was incidental in 12 (24%) and persistent in 37 (76%) of 49 children with EOS. Twenty of 37 (54%) of those with persistent obstruction developed progressive airway obstruction. The decline in FEV1/FVC over 6±2 years was insignificant in the incidental group (4%±2%) and the persistent nonprogressive group (7%±4%) but significant in the progressive group (13%±4%, t test; P=0.002). In total, 29% of the 49 children at the onset and 57% at the end of the study had airway obstruction. The incidental, persistent nonprogressive, and progressive groups did not differ with regard to age, diagnosis distribution, or sex. The initial coronal curve size, apex, direction of the curve, and degree of kyphosis were statistically similar among the 3 groups. Coronal curve magnitude inversely correlated with FEV1/FVC at the end but not the beginning of the study (r=-0.19, P=0.002). Six of 19 responded to bronchodilator treatment, suggesting concurrent asthma. Airway obstruction did not relate to restrictive pulmonary abnormalities measured by FVC at first or last timepoints [slope=-0.076 (95% confidence interval, -0.99 to 0.038; P=0.19)]. Changes in degrees of airway obstruction and restrictive lung disease over time did not correlate [slope=-0.125 (95% confidence interval, -0.294 to 0.044; P=0.14)]. CONCLUSIONS: Children with EOS and progressive airway obstruction represent an important subgroup which may require new surgical and nonsurgical treatment strategies to prevent loss of lung function over time.

Best practices in peri-operative management of patients with skeletal dysplasias.

Patients with skeletal dysplasia frequently require surgery. This patient population has an increased risk for peri-operative complications related to the anatomy of their upper airway, abnormalities of tracheal-bronchial morphology and function; deformity of their chest wall; abnormal mobility of their upper cervical spine; and associated issues with general health and body habitus. Utilizing evidence analysis and expert opinion, this study aims to describe best practices regarding the peri-operative management of patients with skeletal dysplasia. A panel of 13 multidisciplinary international experts participated in a Delphi process that included a thorough literature review; a list of 22 possible care recommendations; two rounds of anonymous voting; and a face to face meeting. Those recommendations with more than 80% agreement were considered as consensual. Consensus was reached to support 19 recommendations for best pre-operative management of patients with skeletal dysplasia. These recommendations include pre-operative pulmonary, polysomnography; cardiac, and neurological evaluations; imaging of the cervical spine; and anesthetic management of patients with a difficult airway for intubation and extubation. The goals of this consensus based best practice guideline are to provide a minimum of standardized care, reduce perioperative complications, and improve clinical outcomes for patients with skeletal dysplasia.

Primary thoraco-spinal disorders of childhood.

Primary structural deformities of the spine and thorax were at one time rare and reportable in case series. With the development of new "growth friendly" implantable devices, children with these disorders are living longer and receiving both surgical and pulmonary care. As a result, there has been growing interest in the functional cardiopulmonary consequences of these deformities, the current surgical and non-surgical treatments, and the role of long-term supportive care. This article reviews current literature in this rapidly changing field, where new devices are developed and outcomes are changing. The respiratory consequences of early-onset thoraco-spinal disorders are emphasized and the roles of the pulmonologist and surgeons are discussed. There are more questions than answers as no long-term outcome data yet exists.

An official American Thoracic Society clinical practice guideline: classification, evaluation, and management of childhood interstitial lung disease in infancy.

BACKGROUND: There is growing recognition and understanding of the entities that cause interstitial lung disease (ILD) in infants. These entities are distinct from those that cause ILD in older children and adults. METHODS: A multidisciplinary panel was convened to develop evidence-based guidelines on the classification, diagnosis, and management of ILD in children, focusing on neonates and infants under 2 years of age. Recommendations were formulated using a systematic approach. Outcomes considered important included the accuracy of the diagnostic evaluation, complications of delayed or incorrect diagnosis, psychosocial complications affecting the patient's or family's quality of life, and death. RESULTS: No controlled clinical trials were identified. Therefore, observational evidence and clinical experience informed judgments. These guidelines: (1) describe the clinical characteristics of neonates and infants (<2 yr of age) with diffuse lung disease (DLD); (2) list the common causes of DLD that should be eliminated during the evaluation of neonates and infants with DLD; (3) recommend methods for further clinical investigation of the remaining infants, who are regarded as having "childhood ILD syndrome"; (4) describe a new pathologic classification scheme of DLD in infants; (5) outline supportive and continuing care; and (6) suggest areas for future research. CONCLUSIONS: After common causes of DLD are excluded, neonates and infants with childhood ILD syndrome should be evaluated by a knowledgeable subspecialist. The evaluation may include echocardiography, controlled ventilation high-resolution computed tomography, infant pulmonary function testing, bronchoscopy with bronchoalveolar lavage, genetic testing, and/or lung biopsy. Preventive care, family education, and support are essential.

Chronic respiratory disease in Indigenous peoples: a framework to address inequity and strengthen respiratory health and health care globally.

Indigenous peoples around the world bear a disproportionate burden of chronic respiratory diseases, which are associated with increased risks of morbidity and mortality. Despite the imperative to address global inequity, research focused on strengthening respiratory health in Indigenous peoples is lacking, particularly in low-income and middle-income countries. Drivers of the increased rates and severity of chronic respiratory diseases in Indigenous peoples include a high prevalence of risk factors (eg, prematurity, low birthweight, poor nutrition, air pollution, high burden of infections, and poverty) and poor access to appropriate diagnosis and care, which might be linked to colonisation and historical and current systemic racism. Efforts to tackle this disproportionate burden of chronic respiratory diseases must include both global approaches to address contributing factors, including decolonisation of health care and research, and local approaches, co-designed with Indigenous people, to ensure the provision of culturally strengthened care with more equitable prioritisation of resources. Here, we review evidence on the burden of chronic respiratory diseases in Indigenous peoples globally, summarise factors that underlie health disparities between Indigenous and non-Indigenous people, propose a framework of approaches to improve the respiratory health of Indigenous peoples, and outline future directions for clinical care and research.

Lung function and biomarkers of airway inflammation during and after hospitalization for acute exacerbations of childhood asthma associated with viral respiratory symptoms.

BACKGROUND: There are limited data assessing relationships between biomarkers of inflammation and lung function after hospitalization for asthma exacerbations in children. OBJECTIVE: To assess the associations in asthmatic children among changes in lung function, fraction of exhaled nitric oxide (FENO), and cysteinyl leukotrienes (CysLTs) in exhaled breath condensate (EBC) after hospitalization for acute asthma. METHODS: Spirometry and FENO were measured and EBC collected for CysLT measurement from 40 children during and 1, 2, and 4 weeks after hospitalization for an asthma exacerbation and during a single-study visit for 40 healthy children. RESULTS: Enrollment FENO and EBC CysLT concentrations were higher in the children with asthma than in healthy individuals (mean FENO, 31.6 vs 7 ppb; P < .0001; mean EBC CysLT, 7.9 vs 4.9 ppb; P = .03). Among children with asthma, improvement in lung function reached a plateau within 2 weeks after hospital discharge. The EBC CysLT concentrations were not associated with changes in lung function, use of albuterol, or use of inhaled corticosteroids (ICSs). Among asthmatic children enrollment FENO was not associated with changes in lung function during follow-up. However, among children who had an elevated enrollment FENO (≥25 ppb), patients who did not use ICSs after hospital discharge had lower end-of-study lung function than those who used ICSs. At 2 and 4 weeks after hospital discharge, FENO was higher among patients who reported albuterol use more than twice weekly and among patients who reported no ICS use. CONCLUSION: FENO measured at hospital discharge among children hospitalized with acute asthma may be useful in identifying patients who will respond to ICS therapy.

Update on treatment of childhood bronchiectasis unrelated to cystic-fibrosis.

There are multiple aetiologies for childhood bronchiectasis unrelated to cystic fibrosis. Some of these aetiologies, such as those predisposing to recurrent lung infections, e.g. immunodeficiencies, require treatment of the underlying condition and disease-specific pulmonary pathogens within the airway. Regardless of aetiology, the treatments for bronchiectasis include antibiotics, airway clearance regimens, immunizations to prevent infections, and in some cases asthma therapies. The grade of evidence for specific treatments is low with few randomized controlled trials in children. Extrapolations of care provided to adults with bronchiectasis and patients with cystic fibrosis may not always be justified. Comprehensive care programs for children with bronchiectasis have demonstrated clinically relevant improvements over 2-7 year periods. Multi-center research is needed to rigorously evaluate current treatment practices for children with this disorder.

Failure to recover to baseline pulmonary function after cystic fibrosis pulmonary exacerbation.

RATIONALE: Patients with cystic fibrosis periodically experience pulmonary exacerbations. Previous studies have noted that some patients' lung function (FEV(1)) does not improve with treatment. OBJECTIVES: To determine the proportion of patients treated for a pulmonary exacerbation that does not recover to spirometric baseline, and to identify factors associated with the failure to recover to spirometric baseline. METHODS: Cohort study using the Cystic Fibrosis Foundation Patient Registry from 2003-2006. We randomly selected one pulmonary exacerbation treated with intravenous antibiotics per patient and compared the best FEV(1) in the 3 months after treatment with the best FEV(1) in the 6 months before treatment. Recovery to baseline was defined as any FEV(1) in the 3 months after treatment that was greater than or equal to 90% of the baseline FEV(1). Multivariable logistic regression was used to estimate associations with the failure to recover to baseline FEV(1). MEASUREMENTS AND MAIN RESULTS: Of 8,479 pulmonary exacerbations, 25% failed to recover to baseline FEV(1). A higher risk of failing to recover to baseline was associated with female sex; pancreatic insufficiency; being undernourished; Medicaid insurance; persistent infection with Pseudomonas aeruginosa, Burkholderia cepacia complex, or methicillin-resistant Staphylococcus aureus; allergic bronchopulmonary aspergillosis; a longer time since baseline spirometric assessment; and a larger drop in FEV(1) from baseline to treatment initiation. CONCLUSIONS: For a randomly selected pulmonary exacerbation, 25% of patients' pulmonary function did not recover to baseline after treatment with intravenous antibiotics. We identified factors associated with the failure to recover to baseline, allowing clinicians to identify patients who may benefit from closer monitoring and more aggressive treatment.

Structure-respiration function relationships before and after surgical treatment of early-onset scoliosis.

BACKGROUND: Spine and chest wall deformities in children with early onset scoliosis (EOS) frequently impair respiratory function and postnatal growth of the lung. While a relationship between deformity and such impairment has been reported in children with adolescent idiopathic scoliosis it is not well understood in children with early-onset scoliosis (EOS). QUESTIONS/PURPOSES: We therefore describe (1) the preoperative relation between Cobb angle and forced vital capacity (FVC) in infants with EOS; (2) how changes in Cobb angle before and after surgery relate to changes in lung ventilation and perfusion in the right and left lungs. METHODS: We measured FVC in 10 children with EOS < 3 years old using the raised volume rapid thoracic compression (RVRTC) technique and correlated them with Cobb angles. We then measured right lung contributions to total lung ventilation and perfusion using lung scans before and 4 to 57 months after placement of vertical expandable prosthetic titanium ribs (VEPTRs) in 15 children with EOS and correlated changes in right lung function with postoperative changes in Cobb angles. RESULTS: In children 4 to 57 months of age, preoperative FVC (mean value, 83%; range, 63%-109% of predicted values) did not correlate with Cobb angles (mean value, 56º; range, 14°-120º). In children 1.8 to 11.5 years old, right lung ventilation and perfusion were abnormal in eight and seven children, respectively, but neither ventilation nor perfusion predictably normalized despite reductions in Cobb angle postoperatively. CONCLUSIONS: The data extend the age range of children with EOS whose Cobb angles correlate poorly with FVC preoperatively. The data are also consistent with reports that reduced Cobb angles after VEPTR insertion do not correlate with postoperative changes in respiratory function.

Exhaled nitric oxide, lung function, and exacerbations in wheezy infants and toddlers.

BACKGROUND: There are limited data assessing the relationship between fraction of exhaled nitric oxide and lung function or exacerbations in infants with recurrent wheezing. OBJECTIVES: In a longitudinal pilot study of children less than 2 years old, we assessed whether baseline fraction of exhaled nitric oxide was associated with lung function, bronchodilator responsiveness, changes in lung function, or subsequent exacerbations of wheezing. METHODS: Forced expiratory flows and volumes using the raised-volume rapid thoracic compression method were measured in 44 infants and toddlers (mean age, 15.7 months) with recurrent wheezing. Single-breath exhaled nitric oxide (SB-eNO) was measured at 50 mL/s. Lung function was again measured 6 months after enrollment. RESULTS: At enrollment, forced expiratory volume in 0.5 seconds (FEV(0.5)), forced expiratory flow at 25% to 75% of expiration (FEF(25-75)), and forced expiratory flow at 75% of expiration (FEF(75)) z scores for the cohort were significantly less than zero. There was no correlation between enrollment SB-eNO levels and enrollment lung function measures. SB-eNO levels were higher in infants with bronchodilator responsiveness (46.1 vs 23.6 ppb, P < .001) and was associated with a decrease in FEV(0.5) (r = -0.54, P = .001), FEF(25-75) (r = -0.6, P < .001), and FEF(75) (r = -0.55, P = .001) over 6 months. A 10-ppb increase in SB-eNO level was associated with a 0.4-point z score decrease in FEV(0.5), a 0.4-point z score decrease in FEF(25-75), and a 0.42-point z score decrease in FEF(75). SB-eNO level was superior to lung function and bronchodilator responsiveness in predicting subsequent wheezing treated with systemic steroids. CONCLUSIONS: SB-eNO level might predict changes in lung function and risk of future wheezing and holds promise as a biomarker to predict asthma in wheezy infants and toddlers.

55th Harrington Lecture: The respiratory impact of EOS and its therapies: where are we and where do we go from here?

The following lecture was delivered at the Scoliosis Research Society annual meeting in 2020. It addresses our current knowledge about the respiratory impact of Early Onset Scoliosis, the limitations in the data that have been published, and the opportunity for further clinical research in the field.

Does pulmonary function improve after surgical correction of adult idiopathic scoliosis?

PURPOSE: The aim was to investigate pulmonary function after surgical correction of adult idiopathic scoliosis. METHODS: This study included 146 adult scoliosis patients aged 20-50 years (main curve in thoracic spine). Respiratory function was assessed as predicted forced vital capacity (%FVC) and the ratio of forced expiratory volume in 1 s / FVC (%FEV1) preoperatively and 2 years postoperatively and classified as a normal function (≥ 80%), mild impairment (≥ 65% and < 80%), and moderate impairment (< 65%). RESULTS: Preoperative %FVC and %FEV1 were 85.3% and 85.4%, which were 81.5% and 87.5% at 2 years post-surgery. The preoperative %FVC was mild and moderate in 39 (26.7%) and 12 patients (11.6%), respectively. The %FVC significantly improved (+ 6.2% ± 11.4%, P < 0.001) postoperatively for moderate severity but significantly decreased postoperatively (- 6.4% ± 9.4%, P < 0.001) for normal function. The preoperative %FEV1 was mild and moderate in 27 (18.5%) and 0 patients, respectively. The %FEV1 significantly improved postoperatively (6.3% ± 5.3%, P < 0.001) for mild severity but did not significantly change for normal severity. Twenty-three (15.8%) and 41 (28.1%) patients showed improved ⊿%FVC and ⊿% FEV1 > 5%. Logistic regression analysis showed that preoperative %FVC and %FEV1 severities were independent factors affecting postoperative recovery of %FVC (OR 0.95) and %FEV1 (OR 0.85). CONCLUSION: Pulmonary function improved in patients with preoperative pulmonary impairment of < 65% in %FVC and < 80% in %FEV1, and the real improvement was limited to patients with severe preoperative impairment.

Clinical Issues for Pediatric Pulmonologists Managing Children With Thoracic Insufficiency Syndrome.

Thoracic insufficiency Syndrome (TIS) is a recently coined phrase to describe children with spine and chest wall deformities, inherited and acquired, who have respiratory impairment, and are skeletally immature. This population has both restrictive and less often obstructive lung disease due to changes in spine and rib configuration which reduce lung volume, stiffen the chest wall, and reduce respiratory muscle strength. Although the population is heterogeneous with regard to age of onset, etiology, severity of deformity, and rate of progression of the deformity, there are common issues that arise which can be addressed by pediatric pulmonologists. These are illustrated in this review by using Early Onset Scoliosis as a common form of TIS. The pulmonary issues pertaining to TIS require collaboration with multi-disciplinary teams, particularly spine surgeons, in order to make decisions about non-surgical and surgical strategies, timing of surgery and medical supportive care over time. Pulmonary input about respiratory function should be used in conjunction with structural features of each deformity in order to determine the impact of the deformity and the response to various treatment options. In those patients with residual lung function impairment as young adults, pediatric pulmonologists must also ensure successful transition to adult care.

A decade on: Follow-up findings of indigenous children with bronchiectasis.

OBJECTIVE: The sole prospective longitudinal study of children with either chronic suppurative lung disease (CSLD) or bronchiectasis published in the current era was limited to a single center. We sought to extend this study by evaluating the longer-term clinical and lung function outcomes and their associated risk factors in Indigenous children of adolescents from Australia, Alaska, and New Zealand who participated in our previous CSLD or bronchiectasis studies during 2004-2010. METHODS: Between 2015 and 2018, we evaluated 131 out of 180 (72.8%) children of adolescents from the original studies at a single follow-up visit. We administered standardized questionnaires, reviewed medical records, undertook clinical examinations, performed spirometry, and scored available chest computed tomography scans. RESULTS: Participants were seen at a mean age of 12.3 years (standard deviation: 2.6) and a median of 9.0 years (range: 5.0-13.0) after their original recruitment. With increasing age, rates of acute lower respiratory infections (ALRI) declined, while lung function was mostly within population norms (median forced expiry volume in one-second = 90% predicted, interquartile range [IQR]: 81-105; forced vital capacity [FVC] = 98% predicted, IQR: 85-114). However, 43 out of 111 (38.7%) reported chronic cough episodes. Their overall global rating judged by symptoms, including ALRI frequency, examination findings, and spirometry was well (20.3%), stable (43.9%), or improved (35.8%). Multivariable regression identified household tobacco exposure and age at first ALRI-episode as independent risk factors associated with lower FVC% predicted values. CONCLUSION: Under our clinical care, the respiratory outcomes in late childhood or early adolescence are encouraging for these patient populations at high-risk of premature mortality. Prospective studies to further inform management throughout the life course into adulthood are now needed.

Bronchiectasis in children.

Bronchiectasis is a chronic disease of the conducting airways that produces persistent productive cough, recurrent respiratory infectious exacerbations, and obstructive lung disease in children and adults. This article focuses on the grading and recommendations for chronic therapies of bronchiectasis caused by cystic fibrosis (CF)- and non-CF-related conditions. The scope of this article is to focus on outpatient treatment and not include as-needed treatment for mild or severe pulmonary exacerbations associated with bronchiectasis.

The Spinal Structure and Lung Function Relationship in an Untreated Nonambulatory Myelomeningocele Group of Patients.

INTRODUCTION: The relationship between spinal structure and respiratory function has been coined as thoracic insufficiency syndrome and is defined as the inability of the thorax to support normal respiratory function or lung growth. Little is known about what supports this relationship in untreated nonambulatory myelomeningocele patients. METHODS: A prospective cross-sectional study of nonambulatory myelodysplasia patients was performed. Anatomic, radiographic, and functional parameters were evaluated to validate the respiratory-spinal structure relationship. Thirty-one patients diagnosed with nonambulatory myelomeningocele fulfilled the inclusion criteria. RESULTS: The imaging study confirmed the spinal deformity. Lung functions measured in this patient population describe reduced lung volumes by CT lung volume reconstruction, reduced vital capacity by spirometry, and reduced total lung capacity by the nitrogen washout method. Together, these findings suggest moderate restrictive respiratory disease. The blood count study did not show evidence of anemia or other blood disturbances. Echocardiogram analysis did not show pulmonary hypertension in any patient. CONCLUSION: The data validate the relationship between spinal structure and lung function. However, there is no simple structural feature that could help to diagnose thoracic insufficiency syndrome. Thus, the diagnosis continues to be based on a combination of clinical findings and radiological and respiratory function evaluations. LEVEL OF EVIDENCE: Level III.

The impact of imposed expiratory resistance in neonatal mechanical ventilation: a laboratory evaluation.

BACKGROUND: Small endotracheal tubes (ETTs) and neonatal ventilators can impact gas exchange, work of breathing, and lung-mechanics measurements in infants, by increasing the expiratory resistance (R(E)) to gas flow. METHODS: We tested two each of the Babylog 8000plus, Avea, Carestation, and Servo-i ventilators. In the first phase of the study we evaluated (1) the imposed R(E) of an ETT and ventilator system during simulated passive breathing at various tidal volume (V(T)), positive end-expiratory pressure (PEEP), and frequency settings, and (2) the intrinsic PEEP at various ventilator settings. In the second phase of this study we evaluated the imposed expiratory work of breathing (WOB) of the ETT and ventilator system at various PEEP levels during simulated spontaneous breathing using an infant lung model. Pressure and flow were measured continuously, and we calculated the imposed R(E) of the ETT and each ventilator, and the intrinsic PEEP with various PEEP, V(T), and frequency settings. We measured the imposed expiratory WOB with several PEEP levels during a simulated spontaneous breathing pattern. RESULTS: The ventilator's contribution to the imposed R(E) was greater than that of the ETT with nearly all of the ventilators tested. There were significant differences in ventilator-imposed R(E) between the ventilator brands at various PEEP, V(T), and frequency settings. The Babylog 8000plus consistently had the lowest ventilator-imposed R(E) in the majority of the test conditions. There was no intrinsic PEEP (>1 cm H(2)O) in any of the test conditions with any ventilator brand. There were also no significant differences in the imposed expiratory WOB between ventilator brands during simulated spontaneous breathing. CONCLUSIONS: The major cause of R(E) appears to be the ventilator exhalation valve. Neonatal ventilators that use a set constant flow during inhalation and exhalation appear to have less R(E) than ventilators that use a variable bias flow during exhalation. Clinical studies are needed to determine whether the imposed R(E) of these ventilator designs impacts gas exchange, lung mechanics, or ventilator weaning.