British Thoracic Society guideline for respiratory management of children with neuromuscular weakness

Definition of diaphragmatic sleep disordered breathing and clinical meaning in Duchenne muscular dystrophy

BACKGROUND

Diaphragmatic sleep disordered breathing (dSDB) has been recently identified as sleep dysfunction secondary to diaphragmatic weakness in Duchenne muscular dystrophy (DMD). However, scoring criteria for the identification of dSDB are missing.This study aimed to define and validate dSDB scoring criteria and to evaluate whether dSDB severity correlates with respiratory progression in DMD.

METHODS

Scoring criteria for diaphragmatic apnoea (dA) and hypopnoeas (dH) have been defined by the authors considering the pattern observed on cardiorespiratory polygraphy (CR) and the dSDB pathophysiology.10 sleep professionals (physiologists, consultants) blinded to each other were involved in a two-round Delphi survey to rate each item of the proposed dSDB criteria (Likert scale 1-5) and to recognise dSDB among other SDB. The scorers' accuracy was tested against the authors' panel.Finally, CR previously conducted in DMD in clinical setting were rescored and diaphragmatic Apnoea-Hypopnoea Index (dAHI) was derived. Pulmonary function (forced vital capacity per cent of predicted, FVC%pred), overnight oxygen saturation (SpO2) and transcutaneous carbon dioxide (tcCO2) were correlated with dAHI.

RESULTS

After the second round of Delphi, raters deemed each item of dA and dH criteria as relevant as 4 or 5. The agreement with the panel in recognising dSDB was 81%, kappa 0.71, sensitivity 77% and specificity 85%.32 CRs from DMD patients were reviewed. dSDB was previously scored as obstructive. The dAHI negatively correlated with FVC%pred (r=-0.4; p<0.05). The total number of dA correlated with mean overnight tcCO2 (r 0.4; p<0.05).

CONCLUSIONS

dSDB is a newly defined sleep disorder that correlates with DMD progression. A prospective study to evaluate dSDB as a respiratory measure for DMD in clinical and research settings is planned.

Development of respiratory care guidelines for Duchenne muscular dystrophy in the UK: key recommendations for clinical practice

Significant inconsistencies in respiratory care provision for Duchenne muscular dystrophy (DMD) are reported across different specialist neuromuscular centres in the UK. The absence of robust clinical evidence and expert consensus is a barrier to the implementation of care recommendations in public healthcare systems as is the need to increase awareness of key aspects of care for those living with DMD. Here, we provide evidenced-based and/or consensus-based best practice for the respiratory care of children and adults living with DMD in the UK, both as part of routine care and in an emergency.

METHODOLOGY

Initiated by an expert working group of UK-based respiratory physicians (including British Thoracic Society (BTS) representatives), neuromuscular clinicians, physiotherapist and patient representatives, draft guidelines were created based on published evidence, current practice and expert opinion. After wider consultation with UK respiratory teams and neuromuscular services, consensus was achieved on these best practice recommendations for respiratory care in DMD.

RESULT

The resulting recommendations are presented in the form of a flow chart for assessment and monitoring, with additional guidance and a separate chart setting out key considerations for emergency management. The recommendations have been endorsed by the BTS.

CONCLUSIONS

These guidelines provide practical, reasoned recommendations for all those managing day-to-day and acute respiratory care in children and adults with DMD. The hope is that this will support patients and healthcare professionals in accessing high standards of care across the UK.

Can postural changes in spirometry in children with Duchenne muscular dystrophy predict sleep hypoventilation?

AIM

To explore the relationship between postural changes in lung function and polysomnography (PSG) in children with Duchenne muscular dystrophy (DMD).

METHODS

In this prospective cross-sectional study, children with DMD performed spirometry in sitting and supine positions. A control group of age and gender matched healthy children also underwent postural lung function testing. PSG was performed within six months of spirometry.

RESULTS

Seventeen children with DMD, aged 12.3 ± 3 years performed sitting spirometry. 14 (84%) performed acceptable spirometry in the supine position. Mean FEV1sit and FVCsit were 77% (SD ± 22) and 74% (SD ± 20.4) respectively, with mean% ΔFVC(sit-sup) 9% (SD ± 11) (range 2% to 20%), and was significantly greater than healthy controls 4% (n = 30, SD ± 3, P < 0.001). PSG data on the 14 DMD children with acceptable supine spirometry showed total AHI 6.9 ± 5.9/hour (0.3 to 29), obstructive AHI 5.2 ± 4.0/hour (0.2 to 10), and REM AHI 14.1 ± -5.3/hour (0.1 to 34.7). ΔFVC(sit-sup) had poor correlation with hypoventilation on polysomnography.

CONCLUSION

Children with DMD and mild restrictive lung disease showed greater postural changes in spirometry than healthy controls but lower supine spirometry was not predictive of sleep hypoventilation.

Supplementary Respiratory Therapy Improves Pulmonary Function in Pediatric Patients with Cerebral Palsy: A Systematic Review and Meta-Analysis

BACKGROUND

Despite medical advances, individuals with cerebral palsy (CP) face significant respiratory challenges, leading to heightened hospitalization rates and early mortality among this population. We hypothesize that integrating supplementary respiratory therapy into standard rehabilitation will result in significant improvements in pulmonary function, enhanced respiratory muscle strength, and an overall increase in the quality of life among pediatric patients with CP.

METHODS

A systematic search of literature across five databases was conducted, and random-effects meta-analyses were performed to assess the impact of supplementary respiratory therapy on (a) pulmonary function: forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FVC/FEV1 ratio, peak expiratory flow (PEF), and (b) respiratory muscle strength: maximal inspiratory and expiratory pressure (MIP, MEP), and (c) quality of life. Certainty of evidence was determined by the GRADE assessment.

RESULTS

Analysis of data from 11 eligible randomized controlled trials revealed clinically meaningful changes in pulmonary function. We found a relevant mean difference (MD) in absolute PEF of 0.50 L/s (95% confidence interval (CI): 0.19; 0.82 p = 0.0107). The certainty of the evidence ranged from moderate to high.

CONCLUSIONS

This study presents current evidence on the impact of various supplementary respiratory therapies for CP patients classified under gross motor function classification level I-IV, demonstrating clinically meaningful improvements in pulmonary function and respiratory muscle strength. These improvements suggest the potential for an enhanced quality of life. Our findings hold the promise of serving as a foundational reference for potential revisions to conventional rehabilitation care, incorporating supplementary respiratory therapy.

Best practice recommendations for speech-language pathology in children with neuromuscular disorders: A Delphi-based consensus study

PURPOSE

Speech-language pathology (SLP) is considered an essential intervention due to the high prevalence of dysphagia and dysarthria in paediatric neuromuscular disorders (pNMD). Evidence-based guidelines for SLP in pNMD are missing and children could be deprived the best of care. This study aimed to achieve consensus and present best practice recommendations on SLP intervention in pNMD.

METHOD

A modified Delphi technique was used with a panel of experienced Dutch speech-language pathologists. In two online survey rounds and a face-to-face consensus meeting, the SLP experts proposed intervention items for cases of four types of pNMD (congenital myopathy, Duchenne muscular dystrophy, myotonic dystrophy type 1, and spinal muscular atrophy type 2), covering symptoms of dysphagia, dysarthria, drooling, and oral hygiene problems. They rated the level of agreement.

RESULT

Intervention items that achieved consensus were incorporated into best practice recommendations. These recommendations cover six core intervention components (wait and see, explanation and advice, training and treatment, aids and adjustments, referral to other disciplines, and monitoring) suitable for the described symptoms.

CONCLUSION

Insight into treatment options is essential to facilitate speech-language pathologists in clinical decision-making. The current study led to best practice recommendations for speech-language pathologists working within the field of pNMD.

Diagnosis and Orthodontic Treatment of Obstructive Sleep Apnea Syndrome Children-A Systematic Review

Obstructive sleep apnea syndrome (OSAS) is a respiratory illness that is associated with recurrent episodes of either partial or full obstruction of the upper airways, or apnea, among other sleep disorders. This study aims to analyze, through a literature review, whether orthodontic treatment can be a good treatment strategy for this type of disorder. We performed a database search on Scopus, Web of Science, and Pubmed with the keywords OSA(S) and orthodontics to select the papers under evaluation. The criteria for inclusion were articles related to OSA(S) children undergoing an orthodontic treatment and clinical studies or case series, excluding systematic reviews, narrative reviews, meta-analyses, adult studies, animal models, and in vitro studies. The screening phase ended with the selection of 16 publications for this work. RME, or rapid maxillary expansion, turned out to be the preferred orthodontic treatment in cases of pediatric OSAS. The goal of this orthodontic procedure is to increase the hard palate's transverse diameter by reopening the mid-palatal suture. Children with maxillary contraction and dental malocclusion typically undergo such a procedure and have excellent results. However, OSAS is a multifactorial disorder; it does not seem related to the morphology of the oral cavity, and therefore, it is not always possible to cope with this problem exclusively through orthodontic treatment.

Indications and practice of home invasive mechanical ventilation in children

BACKGROUND

Developments and technological advances in neonatal and pediatric intensive care units have led to a prolonged life expectancy of pediatric patients with chronic respiratory failure. Therefore, the number of hemodynamically stable pediatric patients with chronic respiratory failure who need mechanical ventilator assistance throughout the day has significantly increased.

AIMS

Numerous conditions, including parenchymal lung diseases, airway disorders, neuromotor disorders, or respiratory defects, can lead to chronic respiratory failure. For individuals who cannot tolerate non-invasive mechanical ventilation (NIMV), invasive mechanical ventilation (IMV) is the only suitable choice. Due to increasing need, mechanical ventilator technology is continuously evolving.

RESULTS

As a result of this process, home-type mechanical ventilators have been produced for patients requiring long-term IMV. Patients with chronic respiratory failure can be safely monitored at home with these ventilators.

DISCUSSION

Home follow-up of these patients has many benefits such as an increase in general quality of life and a positive contribution to their emotional and cognitive development.

CONCLUSION

In this compilation, indications for home-based IMV, features of home invasive mechanical ventilators (HMVs), patient monitoring, and the detailed advantages of using IMV at home will be elucidated.

A history of home mechanical ventilation: The past, present and future

This state-of-the-art review provides an overview of the history of home mechanical ventilation (HMV), including early descriptions of mechanical ventilation from ancient and Renaissance perspectives and the mass development of ventilators designed for long-term use during the poliomyelitis epidemic. Seminal data from key clinical trials supports the application of HMV in certain patients with chronic obstructive pulmonary disease, neuromuscular disease and obesity-related respiratory failure. Innovative engineering coupled with refined physiological understanding now permits widespread delivery of home mechanical ventilation to a global population, using portable devices with advanced ventilatory modes and telemonitoring capabilities. Exponential growth in digital technology continues, and ongoing research is needed to understand how to harness clinical and physiological data to benefit patients and healthcare services in a clinically- and cost-effective manner.

Mechanically assisted cough strategies: user perspectives and cough flows in children with neurodisability

Background

Mechanical insufflation-exsufflation (MI-E) is used to augment cough in children with neurodisability. We aimed to determine the user comfort and cough flows during three MI-E strategies, and to predict factors associated with improved comfort and cough flows.

Methods

This multicentre, crossover trial was done at four regional hospitals in Norway. Children with neurodisability using MI-E long term via mask were enrolled. In randomised order, they tested three MI-E setting strategies (in-/exsufflation pressure (cmH2O)/in (In)- versus exsufflation (Ex) time): 1) "A-symmetric" (±50/In=Ex); 2) "B-asymmetric" (+25- +30)/-40, In>Ex); and 3) "C-personalised", as set by their therapist. The primary outcomes were user-reported comfort on a visual analogue scale (VAS) (0=maximum comfort) and peak cough flows (PCF) (L·min-1) measured by a pneumotachograph in the MI-E circuit.

Results

We recruited 74 children median (IQR) age 8.1 (4.4-13.8) years, range 0.6-17.9, and analysed 218 MI-E sequences. The mean±sd VAS comfort scores were 4.7±2.96, 2.9±2.44 and 3.2±2.46 for strategies A, B and C, respectively (A versus B and C, p<0.001). The mean±sd PCF registered during strategies A, B and C were 203±46.87, 166±46.05 and 171±49.74 L·min-1, respectively (A versus B and C, p<0.001). Using low inspiratory flow predicted improved comfort. Age and unassisted cough flows increased exsufflation flows.

Conclusions

An asymmetric or personalised MI-E strategy resulted in better comfort scores, but lower PCF than a symmetric approach utilising high pressures. All three strategies generated cough flows above therapeutic thresholds and were rated as slightly to moderately uncomfortable.

Predictors of NIV-related adverse events in children using long-term noninvasive ventilation

BACKGROUND AND OBJECTIVES

An increasing number of children with diverse medical conditions are using long-term noninvasive ventilation (NIV). This study examined the impact of demographic, clinical, and technology-related factors on long-term NIV adverse events in a large cohort of children using long-term NIV.

METHODS

This was a multicenter retrospective review of all children who initiated long-term NIV in the province of Alberta, Canada, from January 2005 to September 2014, and followed until December 2015. Inclusion criteria were children who had used NIV for 3 months or more and had at least one follow-up visit with the NIV programs.

RESULTS

We identified 507 children who initiated NIV at a median age of 7.5 (interquartile range: 8.6) years and 93% of them reported at least one NIV-related adverse event during the initial follow-up visit. Skin injury (20%) and unintentional air leaks (19%) were reported more frequently at the initial visit. Gastrointestinal symptoms, midface hypoplasia, increased drooling, aspiration and pneumothorax were rarely reported (<5%). Younger age and underlying conditions such as Down syndrome, achondroplasia, and Duchenne muscular dystrophy were early predictors of unintentional air leak. Younger age also predicted child sleep disruption in the short term and ongoing parental sleep disruption. Obesity was a risk factor for persistent nasal symptoms. Mask type was not a significant predictor for NIV-related short- or long-term complications.

CONCLUSIONS

This study demonstrates that NIV-related complications are frequent. Appropriate mask-fitting and headgear adaptation, and a proactive approach to early detection may help to reduce adverse events.

Peri-partum respiratory management of pregnant women with neuro-muscular disorders: a prospective observational study (IT-NEUMA-Pregn study)

BACKGROUND

Pregnant women with neuromuscular diseases (NMDs) often display respiratory muscle impairment which increases the risk for pulmonary complications (PCs). The aim of this study was to identify pregnant NMDs patients with pulmonary risk factors and to apply in these women non-invasive ventilation (NIV) combined with mechanical insufflation-exsufflation (MI-E) in the peri-partum period.

METHODS

We conducted a multicenter observational study on women with NMDs undergoing cesarean section or spontaneous labor in a network of 7 national hospitals. In these subjects we applied a protocol for screening and preventing PCs, and we evaluated PCs rate, maternal and neonatal outcome.

RESULTS

Twenty-four patients out of the 94 enrolled pregnant women were at risk for PCs and were trained or retrained to use NIV and/or MI-E before delivery. After delivery, 17 patients required NIV with or without MI-E. Despite nine out of the 24 women at pulmonary risk developed postpartum PCs, none of them needed reintubation nor tracheostomy. In addition, the average birth weight and Apgar score were normal. Only one patient without pulmonary risk factors developed postpartum PCs.

CONCLUSION

This study showed the feasibility of applying a protocol for screening and treating pregnant NMDs women with pulmonary risk. Despite a PCs rate of 37% was observed in these patients, maternal and neonatal outcome were favorable.

Respiratory Management of Patients With Neuromuscular Weakness: An American College of Chest Physicians Clinical Practice Guideline and Expert Panel Report

BACKGROUND

Respiratory failure is a significant concern in neuromuscular diseases (NMDs). This CHEST guideline examines the literature on the respiratory management of patients with NMD to provide evidence-based recommendations.

STUDY DESIGN AND METHODS

An expert panel conducted a systematic review addressing the respiratory management of NMD and applied the Grading of Recommendations, Assessment, Development, and Evaluations approach for assessing the certainty of the evidence and formulating and grading recommendations. A modified Delphi technique was used to reach a consensus on the recommendations.

RESULTS

Based on 128 studies, the panel generated 15 graded recommendations, one good practice statement, and one consensus-based statement.

INTERPRETATION

Evidence of best practices for respiratory management in NMD is limited and is based primarily on observational data in amyotrophic lateral sclerosis. The panel found that pulmonary function testing every 6 months may be beneficial and may be used to initiate noninvasive ventilation (NIV) when clinically indicated. An individualized approach to NIV settings may benefit patients with chronic respiratory failure and sleep-disordered breathing related to NMD. When resources allow, polysomnography or overnight oximetry can help to guide the initiation of NIV. The panel provided guidelines for mouthpiece ventilation, transition to home mechanical ventilation, salivary secretion management, and airway clearance therapies. The guideline panel emphasizes that NMD pathologic characteristics represent a diverse group of disorders with differing rates of decline in lung function. The clinician's role is to add evaluation at the bedside to shared decision-making with patients and families, including respect for patient preferences and treatment goals, considerations of quality of life, and appropriate use of available resources in decision-making.

Longitudinal Analysis of Respiratory Function of Different Types of Limb Girdle Muscular Dystrophies Reveals Independent Trajectories

Background and Objectives

The prevalence and progression of respiratory muscle dysfunction in patients with limb girdle muscular dystrophies (LGMDs) has been only partially described to date. Most reports include cross-sectional data on a limited number of patients making it difficult to gain a wider perspective on respiratory involvement throughout the course of the disease and to compare the most prevalent LGMD subtypes.

Methods

We reviewed the results of spirometry studies collected longitudinally in our cohort of patients in routine clinical visits from 2002 to 2020 along with additional clinical and genetic data. A linear mixed model was used to investigate the factors associated with the progression of respiratory dysfunction.

Results

We followed up 156 patients with 5 different forms of LGMDs for a median of 8 years (range 1-25 years). Of them, 53 patients had pathogenic variants in the Capn3 gene, 47 patients in the Dysf gene, 24 patients in the Fkrp gene, 19 in the Ano5 gene, and 13 in one of the sarcoglycan genes (SCG). At baseline, 58 patients (37.1%) had a forced vital capacity percentage predicted (FVCpp) below 80%, while 14 patients (8.9%) had peak cough flow (PCF) values below 270 L/min. As a subgroup, FKRP was the group with a higher number of patients having FVC <80% and/or PCF <270 L/min at initial assessment (66%). We observed a progressive decline in FVCpp and PCF measurements over time, being age, use of wheelchair, and LGMD subtype independent factors associated with this decline. Fkrp and sarcoglycan patients had a quicker decline in their FVC (Kaplan-Meier curve, F test, p < 0.001 and p = 0.02, respectively). Only 7 of the 58 patients with low FVCpp values reported symptoms of respiratory dysfunction, which are commonly reported by patients with FVCpp below 50%-60%. The number of patients ventilated increased from 2 to 8 during follow-up.

Discussion

Respiratory dysfunction is a frequent complication of patients with LGMDs that needs to be carefully studied and has direct implications in the care offered in daily clinics. Respiratory dysfunction is associated with disease progression because it is especially seen in patients who are full-time wheelchair users, being more frequent in patients with mutations in the Fkrp and sarcoglycan genes.

The role of lung volume recruitment therapy in neuromuscular disease: a narrative review

Respiratory muscle weakness results in substantial discomfort, disability, and ultimately death in many neuromuscular diseases. Respiratory system impairment manifests as shallow breathing, poor cough and associated difficulty clearing mucus, respiratory tract infections, hypoventilation, sleep-disordered breathing, and chronic ventilatory failure. Ventilatory support (i.e., non-invasive ventilation) is an established and key treatment for the latter. As survival outcomes improve for people living with many neuromuscular diseases, there is a shift towards more proactive and preventative chronic disease multidisciplinary care models that aim to manage symptoms, improve morbidity, and reduce mortality. Clinical care guidelines typically recommend therapies to improve cough effectiveness and mobilise mucus, with the aim of averting acute respiratory compromise or respiratory tract infections. Moreover, preventing recurrent infective episodes may prevent secondary parenchymal pathology and further lung function decline. Regular use of techniques that augment lung volume has similarly been recommended (volume recruitment). It has been speculated that enhancing lung inflation in people with respiratory muscle weakness when well may improve respiratory system "flexibility", mitigate restrictive chest wall disease, and slow lung volume decline. Unfortunately, clinical care guidelines are based largely on clinical rationale and consensus opinion rather than level A evidence. This narrative review outlines the physiological changes that occur in people with neuromuscular disease and how these changes impact on breathing, cough, and respiratory tract infections. The biological rationale for lung volume recruitment is provided, and the clinical trials that examine the immediate, short-term, and longer-term outcomes of lung volume recruitment in paediatric and adult neuromuscular diseases are presented and the results synthesised.

Limitations of the apnea-hypopnea index in children and young adults with neuromuscular disorders

There are no validated criteria to initiate noninvasive ventilation (NIV) in children and young adults with neuromuscular disease (NMD). In order to analyze NIV initiation criteria, we reviewed the polysomnography (PSG) criteria that led to the initiation of NIV in 61 consecutive patients with NMD, median age 4.1 (0.8-21) years, who had a PSG during their routine care. NIV was initiated on abnormal PSG data (apnea-hypopnea index (AHI) > 10 events/h and/or a transcutaneous carbon dioxide pressure > 50 mmHg and/or a pulse oximetry 〈 90%, both during at least 2% sleep time or 〉 5 consecutive minutes) in 11 (18%) patients. Six of these 11 patients had an AHI ≤ 10 events/h and would not have been ventilated if only AHI was retained. However, one of these 6 patients had isolated nocturnal hypoxemia, 3 isolated nocturnal hypercapnia and 2 abnormal respiratory events. Six (10%) patients with a normal PSG were started on NIV on clinical criteria. Our results show the limitation of the AHI when taken as the unique PSG criterion for NIV initiation in young patients with NMD and underline the need to include also abnormalities of overnight gas exchange into the NIV decision-making process.

ATS Core Curriculum 2022. Pediatric Pulmonary Medicine: Updates in pediatric neuromuscular disease

The American Thoracic Society Core Curriculum updates clinicians annually in pediatric pulmonary disease. This is a concise review of the Pediatric Pulmonary Medicine Core Curriculum presented at the 2022 American Thoracic Society International Conference. Neuromuscular diseases (NMD) comprise a variety of conditions that commonly affect the respiratory system and cause significant morbidity including dysphagia, chronic respiratory failure, and sleep disordered breathing. Respiratory failure is the most common cause of mortality in this population. Substantial progress has been made in diagnosis, monitoring and treatment for NMD over the last decade. Pulmonary function testing (PFT) is utilized to objectively measure respiratory pump function and PFT milestones are utilized in NMD-specific pulmonary care guidelines. New disease modifying therapies are approved for the treatment of patients with Duchenne muscular dystrophy and spinal muscular atrophy (SMA), including the first ever approved systemic gene therapy, in the case of SMA. Despite extraordinary progress in the medical management of NMD, little is known regarding the respiratory implications and long-term outcomes for patients in the era of advanced therapeutics and precision medicine. The combination of technological and biomedical advancements has increased the complexity of the medical decision-making process for patients and families, thus emphasizing the importance of balancing respect for autonomy with the other foundational principles of medical ethics. This review features an overview of PFT, noninvasive ventilation strategies, novel and developing therapies, as well as the ethical considerations specific to the management of patients with pediatric NMD.

The influence of viral respiratory season on perioperative outcomes in patients undergoing spinal fusion for neuromuscular scoliosis

PURPOSE

Respiratory complications are common following neuromuscular scoliosis (NMS) spinal fusion. Concern exists regarding the safety to perform complicated procedures in winter months when viral respiratory illness is common. The purpose of this study was to compare perioperative outcomes in children with NMS undergoing spinal fusion during peak (November-March) or non-peak (April-October) viral season.

METHODS

The Health Care and Utilization Project (HCUP) Kids' inpatient database (KID) from 2006 to 2012 was reviewed. Children 20 years or younger who underwent spinal fusion for NMS were included. Patients were grouped by date of surgery during peak or non-peak viral season. Continuous variables were compared using t tests and categorical variables were compared using the Rao-Scott Chi-square test. Weighted logistic regression models were performed.

RESULTS

This study identified 5082 records, including 1711 and 3371 patients who had surgery in peak and non-peak viral seasons, respectively. Patients who had spinal fusion during peak viral season were less likely to experience respiratory failure (p = 0.0008) and did not demonstrate an increased incidence of aspiration pneumonia (p = 0.26), respiratory complication (p = 0.43), or mortality (p = 0.68). Respiratory failure was associated with younger age (p = 0.0031), the presence of a tracheostomy (p < 0.0001), and the number of chronic conditions (p < 0.0001). Higher number of chronic medical conditions (mean of 5.0) was associated with an increased risk of in-hospital mortality (p < 0.0001), aspiration pneumonia (p = 0.0009), and respiratory failure (p < 0.0001).

CONCLUSION

Spinal fusion for NMS during peak viral season has a lower risk of respiratory failure without an increase in mortality or other complications compared to during non-peak viral season.

Highlights from the Respiratory Failure and Mechanical Ventilation 2022 Conference

The Respiratory Intensive Care Assembly of the European Respiratory Society gathered in Berlin to organise the second Respiratory Failure and Mechanical Ventilation Conference in June 2022. The conference covered several key points of acute and chronic respiratory failure in adults. During the 3-day conference, ventilatory strategies, patient selection, diagnostic approaches, treatment and health-related quality of life topics were addressed by a panel of international experts. Lectures delivered during the event have been summarised by Early Career Members of the Assembly and take-home messages highlighted.

Lung function decline preceding chronic respiratory failure in spinal muscular atrophy: a national prospective cohort study

BACKGROUND

Progressive lung function decline, resulting in respiratory failure, is an important complication of spinal muscular atrophy (SMA). The ability to predict the need for mechanical ventilation is important. We assessed longitudinal patterns of lung function prior to chronic respiratory failure in a national cohort of treatment-naïve children and adults with SMA, hypothesizing an accelerated decline prior to chronic respiratory failure.

METHODS

We included treatment-naïve SMA patients participating in a prospective national cohort study if they required mechanical ventilation because of chronic respiratory failure and if lung function test results were available from the years prior to initiation of ventilation. We analyzed Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 s (FEV₁), Peak Expiratory Flow (PEF) and Maximum Expiratory Pressure (PE_max). We studied the longitudinal course using linear mixed-effects models. We compared patients who electively started mechanical ventilation compared to patients who could not be weaned after acute respiratory failure.

RESULTS

We analyzed 385 lung function tests from 38 patients with SMA types 1c-3a. At initiation of ventilation median age was 18.8 years (IQR: 13.2-30.1) and median standardized FVC, FEV₁ and PEF were 28.8% (95% CI: 23.5; 34.2), 28.8% (95% CI: 24.0; 33.7) and 30.0% (95% CI: 23.4; 36.7), with an average annual decline of 1.75% (95% CI: 0.86; 2.66), 1.72% (95% CI: 1.04; 2.40) and 1.65% (95% CI: 0.71; 2.59), respectively. Our data did not support the hypothesis of an accelerated decline prior to initiation of mechanical ventilation. Median PE_max was 35.3 cmH₂O (95% CI: 29.4; 41.2) at initiation of mechanical ventilation and relatively stable in the years preceding ventilation. Median FVC, FEV_1, PEF and PE_max were lower in patients who electively started mechanical ventilation (p < 0.001).

CONCLUSIONS

Patterns of lung function decline cannot predict impending respiratory failure: SMA is characterized by a gradual decline of lung function. We found no evidence for an accelerated deterioration. In addition, PE_max remains low and stable in the years preceding initiation of ventilation. Patients who electively started mechanical ventilation had more restrictive lung function at initiation of ventilation, compared to patients who could not be weaned after surgery or a respiratory tract infection.

User-perceived impact of long-term mechanical assisted cough in paediatric neurodisability

AIM

To (1) compare the perceived benefit of long-term mechanical insufflation-exsufflation (MI-E) of children with neuromuscular disorders (NMDs) and central nervous system (CNS) disorders, including health care needs and treatment routines and (2) describe the children's health-related quality of life (HRQoL).

METHOD

This cross-sectional study used a questionnaire and memory card data to assess the perceived benefit of MI-E via the Visual Analogue Scale (VAS; 10 maximum), willingness to pause treatment, level of health care needs before and after MI-E initiation, and the children's treatment routines. A DISABKIDS questionnaire assessed HRQoL (100 maximum).

RESULTS

Seventy-three children using MI-E participated (42 males, median [interquartile range {IQR}] age 10 years 2 months [6 years 3 months-14 years 1 month]), 47 with NMDs (such as spinal muscular atrophy and Duchenne muscular dystrophy) and 26 with CNS disorders (such as cerebral palsy, encephalitis, neurometabolic and other diseases). The median (IQR) VAS score for the perceived benefit of MI-E therapy at stable state and respiratory tract infection were 9 (6-10) and 10 (8.5-10) respectively. Sixty-two per cent were reluctant or unwilling to pause MI-E therapy, with no NMD versus CNS disorder group difference. After MI-E initiation, fewer physician consultations and hospitalizations were reported by the group with NMDs. The MI-E routine was similar in both groups. The mean (SD) HRQoL score for 26 of 51 eligible children was 71 (16.7).

INTERPRETATION

MI-E treatment was generally perceived as beneficial and performed equally in both diagnostic groups. HRQoL was in line with children with a moderate-to-severe chronic condition.

Going home: Clinician perspectives on decision-making in paediatric home mechanical ventilation

AIM

Despite a recent increase in the use of ventilators in the home setting for children with chronic respiratory failure, there is currently no unified approach for clinical decision-making for children requiring long-term mechanical ventilation. The purpose of this study is to understand the clinician's perspective on decision-making around home ventilation for children, and how home-based care contributes to successful outcomes in this population.

METHODS

We recruited physicians and home ventilation nurses with at least 2 years' experience working in an Australian paediatric tertiary home ventilation service using professional networks and snowball sampling. Semi-structured interviews were conducted by two researchers between February 2019 and June 2020. Interviews were audio-recorded, transcribed, and analysed using inductive content analysis.

RESULTS

Twenty-five individuals participated (17 physicians and 8 home ventilation nurses). Participants viewed themselves as impartial medical advocates in the decision-making process, believing the decision to initiate or cease ventilation belonged to the child's family. While participants held the child's quality of life as the cornerstone of decision-making, quality of life was subjective and family specific.

CONCLUSION

These findings provide insight into how clinicians working with children with chronic respiratory insufficiency approach the decision to introduce home-based ventilation. By understanding their role, strategies can be developed to assist them, leading to better outcomes for patients and families. Further research is needed to compare the perspectives of clinicians with the experience of ventilator-assisted children and families in Australia.

Respiratory phenotypes of neuromuscular diseases: A challenging issue for pediatricians

Neuromuscular disease (NMDs) encompass a heterogeneous group of genetic disorders, with respiratory problems of variable intensity and progression described at any pediatric age, from infancy to adolescence, and they are largely associated with significant lifelong morbidity and high mortality. Restriction of breathing, impaired gas exchange, decline of lung function and sleep disordered breathing progressively develop because of muscular weakness and culminate in respiratory failure. Depending on the disease progression, airways manifestations can take weeks to months or even years to evolve, thus depicting two major respiratory phenotypes, characterized by rapid or slow progression to respiratory failure. Assessing type and age at onset of airways problems and their evolution over time can support pediatricians in the diagnostic assessment of NMD. In addition, knowing the characteristics of patients' respiratory phenotype can increase the level of awareness among neonatologists, geneticists, neurologists, pulmonologists, nutritionists, and chest therapists, supporting them in the challenging task of the multidisciplinary medical care of patients. In this review we examine the issues related to the pediatric respiratory phenotypes of NMD and present a novel algorithm that can act as a guide for the diagnostic agenda and the key preventive or therapeutic interventions of airways manifestations. With prolonged survival of children with NMD, the advent of neuromuscular respiratory medicine, including accurate assessment of the respiratory phenotype, will help physicians to determine patients' prognoses and to design studies for the evaluation of new therapies.

Understanding the experiences of lung volume recruitment among boys with Duchenne muscular dystrophy: A multicenter qualitative study

BACKGROUND

Despite recommendations for regular lung volume recruitment (LVR) use in clinical practice guidelines for children with neuromuscular disease, adherence to LVR is poor. We aimed to describe the experience of LVR by boys with Duchenne muscular dystrophy (DMD), their families, and healthcare providers (HCPs), as well as to identify the barriers and facilitators to LVR use.

METHODS

This multicenter, qualitative study evaluated boys with DMD (n = 11) who used twice-daily LVR as part of a randomized controlled trial, as well as their parents (n = 11), and HCPs involved in the clinical use of LVR (n = 9). Semistructured interviews were conducted to identify participants' understanding of LVR therapy and their beliefs, barriers and facilitators to its use. Thematic analysis was conducted using an inductive approach. A subanalysis compared adherent and nonadherent children.

RESULTS

Seven themes were identified related to participants' beliefs and experiences with LVR: emotional impact, adaptation to LVR, perceived benefits of LVR, routine, family engagement, clinical resources, and equipment-related factors. Strategies to improve adherence were also identified, including education, reinforcement and demonstration of LVR benefit, as well as clinician support. There were no thematic differences between adherent and nonadherent children.

DISCUSSION

Despite the benefits of LVR and positive experiences with it by many families, there remain barriers to adherence to treatment. HCPs need to balance the need for early introduction to give families time to adapt to LVR while ensuring that the benefit of LVR outweighs the burden. Clinician support is important for family engagement.

Ambulatory transcutaneous carbon dioxide monitoring for children with neuromuscular disease

OBJECTIVE

Early screening and diagnosis of nocturnal hypoventilation can slow progression to diurnal hypercapnia and mortality in children with neuromuscular disease (NMD). However, gold standard, laboratory-based polysomnography (PSG) testing is a limited resource. Therefore, we evaluated the diagnostic accuracy of ambulatory transcutaneous carbon dioxide (tcCO₂) monitoring used in the home compared to PSG in children with NMD.

METHODS

Prospective, cross-sectional study in children 0-18 years old with a confirmed diagnosis of NMD and a clinically indicated need for PSG. Ambulatory tcCO₂ was assessed by a respiratory therapist in participant's homes. Demographics, and PSG (including tcCO₂).

RESULTS

We enrolled 39 children with NMD; 3 had unusable ambulatory tcCO₂ data because of failure of drift correction on the machine (n = 2) or an air bubble (n = 1). The remaining 36 patients aged 11 months to 16 years (median (IQR) 12.5 years (6.0-15.8)) had ambulatory tcCO₂ and outpatient level 1 PSG data. Ambulatory tcCO₂ monitoring had a sensitivity of 20.0% (95% confidence interval [CI] 0.5-71.6%) and a specificity of 93.5% (95% CI 78.6-99.2%). Almost all children and/or parents (34/36, 94%) preferred ambulatory monitoring over in-hospital PSG.

CONCLUSIONS

Ambulatory transcutaneous carbon dioxide monitoring was not sufficiently accurate as a clinical tool for the diagnosis of nocturnal hypoventilation our cohort of children with neuromuscular disease despite being preferred over PSG by both children and parents.

Rapidly and slowly progressive neuromuscular disease: differences in pulmonary function, respiratory tract infections and response to lung volume recruitment therapy (LVR)

INTRODUCTION

Reduced lung volumes are a hallmark of respiratory muscle weakness in neuromuscular disease (NMD). Low respiratory system compliance (C_rs) may contribute to restriction and be amenable to lung volume recruitment (LVR) therapy. This study evaluated respiratory function and the immediate impact of LVR in rapidly progressive compared to slowly progressive NMD.

METHODS

We compared vital capacity (VC), static lung volumes, maximal inspiratory and expiratory pressures (MIP, MEP), C_rs and peak cough flow (PCF) in 80 adult participants with motor neuron disease ('MND'=27) and more slowly progressive NMDs ('other NMD'=53), pre and post a single session of LVR. Relationships between respiratory markers and a history of respiratory tract infections (RTI) were examined.

RESULTS

Participants with other NMD had lower lung volumes and C_rs but similar reduction in respiratory muscle strength compared with participants with MND (VC=1.30±0.77 vs 2.12±0.75 L, p<0.001; C_rs=0.0331±0.0245 vs 0.0473±0.0241 L/cmH₂O, p=0.024; MIP=39.8±21.3 vs 37.8±19.5 cmH₂O). More participants with other NMD reported an RTI in the previous year (53% vs 22%, p=0.01). The likelihood of having a prior RTI was associated with baseline VC (%predicted) (OR=1.03 (95% CI 1.00 to 1.06), p=0.029). Published thresholds (VC<1.1 L or PCF<270 L/min) were, however, not associated with prior RTI.A single session of LVR improved C_rs (mean (95% CI) increase = 0.0038 (0.0001 to 0.0075) L/cmH₂O, p=0.047) but not VC.

CONCLUSION

These findings corroborate the hypothesis that ventilatory restriction in NMD is related to weakness initially with respiratory system stiffness potentiating lung volume loss in slowly progressive disease. A single session of LVR can improve C_rs. A randomised controlled trial of regular LVR is needed to assess longer-term effects.

Pulmonological issues

Pediatric leukodystrophies are rare neurodegenerative diseases involving multiple systems. Each form has unique neurologic features but are characterized by encephalopathy with accompanying impairments evidenced in reflexes, muscle tone and movement control. Weakness of expiratory, inspiratory, and upper airway muscles may lead to impaired airway secretion clearance resulting in recurrent respiratory infections, dysphagia, sleep-disordered breathing, restrictive lung disease, and ultimately chronic respiratory insufficiency.

Clinical Challenges in Pediatric Ventilation Liberation: A Meta-Narrative Review

OBJECTIVES

To map the evidence for ventilation liberation practices in pediatric respiratory failure using the Realist And MEta-narrative Evidence Syntheses: Evolving Standards publication standards.

DATA SOURCES

CINAHL, MEDLINE, COCHRANE, and EMBASE. Trial registers included the following: ClinicalTrials.gov, European Union clinical trials register, International Standardized Randomized Controlled Trial Number register.

STUDY SELECTION

Abstracts were screened followed by review of full text. Articles published in English language incorporating a heterogeneous population of both infants and older children were assessed.

DATA EXTRACTION

None.

DATA SYNTHESIS

Weaning can be considered as the process by which positive pressure is decreased and the patient becomes increasingly responsible for generating the energy necessary for effective gas exchange. With the growing use of noninvasive respiratory support, extubation can lie in the middle of the weaning process if some additional positive pressure is used after extubation, while for some extubation may constitute the end of weaning. Testing for extubation readiness is a key component of the weaning process as it allows the critical care practitioner to assess the capability and endurance of the patient's respiratory system to resume unassisted ventilation. Spontaneous breathing trials (SBTs) are often seen as extubation readiness testing (ERT), but the SBT is used to determine if the patient can maintain adequate spontaneous ventilation with minimal ventilatory support, whereas ERT implies the patient is ready for extubation.

CONCLUSIONS

Current literature suggests using a structured approach that includes a daily assessment of patient's readiness to extubate may reduce total ventilation time. Increasing evidence indicates that such daily assessments needs to include SBTs without added pressure support. Measures of elevated load as well as measures of impaired respiratory muscle capacity are independently associated with extubation failure in children, indicating that these should also be assessed as part of ERT.

Long-Term Ventilation in Children with Medical Complexity: A Challenging Issue

Children with medical complexity (CMCs) represent a subgroup of children who may have congenital or acquired multisystemic disease. CMCs are frequently predisposed to respiratory problems and often require long-term mechanical ventilation (LTMV). The indications for LTMV in CMCs are increasing, but gathering evidence about indications, titration, and monitoring is currently the most difficult challenge due to the absence of validated data. The aim of this review was to examine the clinical indications and ethical considerations for the initiation, continuation, or withdrawal of LTMV among CMCs. The decision to initiate long-term ventilation should always be based on clinical and ethical considerations and should be shared with the parents.

Predictors of postoperative systemic inflammatory response syndrome after scoliosis surgery in adolescents with cerebral palsy: A retrospective analysis

Background

Systemic inflammatory response syndrome (SIRS) is known to complicate postsurgical intensive care patients. We noticed that roughly half children with cerebral palsy who undergo posterior spinal fusion (PSF) for neuromuscular scoliosis developed SIRS in the intensive care unit. There is a paucity of literature detailing the impact of intraoperative causes of postoperative SIRS and downstream consequences in these patients. Study purpose was to understand the factors associated with SIRS in children who undergo PSF for neuromuscular scoliosis.

Methods

This retrospective, case control study included children who underwent PSF for neuromuscular scoliosis. Patients with idiopathic scoliosis, osteogenesis imperfecta, and tracheotomy were excluded. Subjects were divided into two study groups based on the diagnosis of SIRS in the intensive care unit. Descriptive statistical analysis was used to identify factors associated with SIRS; a regression analysis was used to further evaluate the independent and significant influence of these factors.

Results

There was no significant difference in the demographic and other preoperative variables. However, total blood products (ml/kg) administered was significantly higher among the SIRS group compared with the non-SIRS group (54.4±41.0 vs 34.1±21.5 P <0.034). Percent of patients remaining intubated was greater in the SIRS group compared with the non-SIRS group (44.1% vs 7.0%, P < 0.001). The regression model revealed that the odds to develop SIRS in patients who were not extubated were 7.467-fold higher (CI: 1.534-36.347) compared with those who were extubated (p=0.013).

Conclusions

The incidence of SIRS is significantly higher among the patients who were not extubated at the end of PSF surgery. Further prospective studies are needed to look at the factors that impede the ability to extubate these patients at the end of surgery.

Prediction of height using ulna length in African-Caribbean children

Standing height is an essential anthropometric measurement in pediatrics. In children unable to stand upright, measurement of ulna to predict standing height is recommended, but height prediction equations based on the ulna have not been established in children of African ancestry. We hypothesized that such equations would result in lower predicted height compared to using equations derived from non-African children. We measured prospectively standing height and both ulna in 358 African-Caribbean children without bone deformity or muscle disease, referred to two pulmonary function test laboratories. Interobserver variability was low for standing height (n = 54) and ulna measurement (n = 51) (mean biases [95%CI]: -0.02 [-0.99; 0.95] and 0.05 [-0.91; 1.01] cm, respectively), as well as inter-ulna variability (n = 352; mean bias 0.03 95%CI [-0.66; 0.73] cm). We used the mean value of 247 bilateral ulna measurements to calculate prediction equations using a generalized linear model including age, sex, ulna length, and geographic origin group, the latter showing no influence on the model. In the validation population of 107 children, the median difference [inter-quartile range] between standing height and ulna-predicted height was -0.4 [-2.7; 1.0] cm. Of 260 reliable baseline spirometry, there was a strong concordance between bronchial obstruction diagnosis established using standing height or ulna-predicted height (kappa coefficient: 0.85 [0.77; 0.94]) with only 11 (4.3%) children misclassified. The ulna predicted height calculated from African-Caribbean prediction equations resulted in a smaller height than the height calculated using equations derived from non-African children.

Changes in Ventilatory Support Requirements of Spinal Muscular Atrophy (SMA) Patients Post Gene-Based Therapies

Spinal muscular atrophy (SMA) is a genetic neuromuscular disease resulting in global muscular weakness and, frequently, in respiratory failure and premature death. Gene-based therapies like Nusinersen are now available for patients with SMA. The aim of this review was to assess in "real world" studies, whether novel treatments would have a positive impact on the mechanical ventilatory support requirements of SMA patients, already initiated on ventilatory support prior to treatment administration. A literature search was performed in Pubmed using multiple combinations of MESH terms and the snowball procedure. A total of 14 publications were discussed in this review. Considering all patients included in the published studies who were on ventilatory support and were treated with Nusinersen, 13/172 (7.5%) had reduced needs for ventilatory support, 1/172 (0.6%) did not need ventilation post-treatment, and 122/172 (70.9%) were maintained on the same ventilator settings. Moreover, 2/41 (4.9%) children who were offered gene therapy had no need for further ventilatory support and 12/41 (29.2%) had reduced requirements. In conclusion, available evidence suggests that among children with SMA, who are on mechanical respiratory support either noninvasively or via tracheostomy at the time of gene-based treatment, only a few will be weaned off the ventilator or have reduced ventilator needs per 24 h. Children will usually require the same level of support as before treatment.

Congenital or Early Developing Neuromuscular Diseases Affecting Feeding, Swallowing and Speech – A Review of the Literature from January 1998 to August 2021

Background:

The knowledge about the impact of oral motor impairment in neuromuscular diseases (NMDs) is limited but increasing.

Objective:

The aim of this review was to collect and compile knowledge on how muscle weakness in congenital or early developing NMDs directly or indirectly affects feeding, swallowing, speech and saliva control.

Methods:

A literature search was performed in PubMed from January 1, 1998, to August 31, 2021. The keywords “feeding”, “dysphagia”, “swallowing”, “dysarthria”, “speech”, “drooling” and “sialorrhea” were used in combination with “paediatric neuromuscular disease” or specific diagnoses.

Results:

Sixty-five studies were selected for the review, 33 focused on feeding and swallowing, 11 on speech, four on a combination of feeding, swallowing, saliva control or speech and 17 general descriptions. Most of the studies reported on patients with a disorder affecting muscles. These studies show that muscle weakness and impaired motility affecting the muscles innervated by the cranial nerves may influence feeding, swallowing, and speech, and that respiratory function, general health and neurodevelopmental delay also influence these functions. Feeding impairment and breathing difficulties are common in NMDs. Lifesaving interventions such as tube feeding and ventilatory support are common in severe cases.

Conclusions:

Feeding impairment, dysphagia and dysarthria are prevalent in NMDs with congenital or early age of onset. Feeding and swallowing has been studied more than speech and saliva control. More children with NMD survive thanks to new treatment options and it is therefore urgent to follow up how these therapies may impact the development of feeding, swallowing, and speech.

Oscillometry: A substitute of spirometry in children with neuromuscular diseases?

INTRODUCTION

Spirometry plays an important role in the assessment of possible respiratory failure in children with neuromuscular diseases (NMDs). However, obtaining reliable spirometry results is a major challenge. We studied the relation between oscillometry and spirometry results. Oscillometry is an easy, noninvasive method to measure respiratory resistance R and reactance X. We hypothesized an increased R and reduced X in patients with more reduced lung function.

METHODS

In this prospective single-center study, we included all children with NMDs able to perform spirometry. We consecutively measured R and X at 5, 11, and 19 Hz and (forced) vital capacity, peak expiratory flow. Spearman correlation coefficients and positive and negative predictive values were calculated. Regression curves were estimated.

RESULTS

We included 148 patients, median age 13 years (interquartile range: 8-16). A negative correlation was found between R and spirometry outcomes (Spearman correlation coefficient [ρ]: -0.5 to -0.6, p < 0.001). A positive correlation was found between X (i.e., less negative outcomes) and spirometry outcomes (ρ: 0.4-0.6, p < 0.001). Highest correlation was found at lower frequencies. Regression analysis showed a nonlinear relation. Measurement of inspiratory and expiratory R and X did not provide added value. Positive predictive values of 80%-85% were found for z-scores of R measured at 5 Hz versus (F)VC ≤ 60%.

CONCLUSION

We found a nonlinear relation between oscillometry and spirometry results with increased R and reduced X in patients with more restrictive lung function decline. Given the difficulties with performing spirometry, oscillometry may be a promising substitute.

[Respiratory physiotherapy in pediatric practice]

Congestion of the upper (URT) and lower respiratory tracts (LRT) is a common symptom in several acute and chronic respiratory diseases that occur in childhood. To eliminate these secretions, airway clearance techniques (ACT) directed to the URT and LRT are frequently prescribed. The rationale for the application of these techniques is the same as in adults, but they need to be adapted to be transposed to children. The physiotherapist will be able to choose among a wide range of techniques, of which the most adequate will depend not only on the age of the child and the indication, but also on the basis of his preferences or habits, as well as those of the child. Upper airway clearance, including nasal irrigation, is now recommended for acute and chronic rhinosinusitis in children. It is also one of the symptomatic treatments recommended for infants with acute bronchiolitis. For LRT clearance, several indications, such as cystic fibrosis, primary ciliary dyskinesia and neuromuscular disease, are now widely advocated. Conversely, other indications, such as for infants with acute viral bronchiolitis, are highly controversial. Thoughtful application of these techniques is lacking in robust and precise tools to objectively assess the presence of bronchial congestion, and to treat it accordingly. Similarly, no precise and reliable evaluation of the effectiveness of these ACTs is available to date. This review is designed to explore the ACTs used by physiotherapists, to provide an overview of their current indications, and to consider complementary approaches.

[Pneumatic instrumental airway clearance techniques: Description, settings and indications]

Airway clearance techniques aim to eliminate excess of bronchopulmonary secretions. Common airway clearance methods involve manual techniques or the use of (oscillatory) positive expiratory pressure systems. In some clinical situations, these techniques may be ineffective, and the physiotherapist will require pneumatic instrumental support. Unfortunately, these devices are expensive and burdensome. Moreover, as their utilization requires specialized expertise, they are seldom used by practitioners. This article describes the pneumatic instrumental supports mainly used in France for airway clearance techniques currently available. We explain their key characteristics, how they function, and their basic settings according to different indications.

The effect of scoliosis surgery on pulmonary function in spinal muscular atrophy patients: review of the literature and a meta-analysis

PURPOSE

To determine the effect of surgical instrumentation on pulmonary function after surgery.

METHODS

A literature review was performed to identify articles reporting on the effect of scoliosis surgery on the pulmonary function in patients with spinal muscular atrophy (SMA). Data for each patient were extracted from included studies, and a meta-analysis was performed using the values of forced vital capacity (FVC) before and after surgery.

RESULTS

A total of 127 articles were reviewed, and ten articles were selected for data extraction according to inclusion criteria. The results of the meta-analysis showed no difference in respiratory function pre-operatively and at last follow-up. Four out of ten studies demonstrated similar results and five studies reported a decrease in pulmonary function after surgery. Only one study showed improvement in lung function.

CONCLUSION

At the moment, there is insufficient evidence in the literature to support that spinal surgery can improve respiratory function. According to our meta-analysis study, vital capacity remains either unchanged or the rate of deterioration is decreased after surgery. Nevertheless, these are both considered favorable outcomes taking into account the natural course of the disease with progressive deterioration of pulmonary function over time.

The effects of inspiratory muscle training in adults with muscular dystrophy

Background/Aims Patients with muscular dystrophy usually have impaired lung function and respiratory muscle strength, leading to pneumonia and respiratory failure, which are significant causes of morbidity and mortality. Inspiratory muscle training might be a safe adjunct treatment to increase the strength and endurance of weakened respiratory muscles. The researchers have developed a new protocol for inspiratory muscle training and evaluated its effect on inspiratory muscle strength and coughing capacity.

Methods A total of 12 participants diagnosed with muscle dystrophy and decreased maximal inspiratory pressure (<60 cmH2O) participated in this prospective study. Training was individually tailored, starting with low resistance levels and progressing according to tolerance and symptoms. The primary outcome measure was maximal inspiratory pressure. Secondary outcomes were maximal expiratory pressure, peak cough flow and the feasibility of the intervention.

Results There were two participants who did not complete the study, and three were lost to follow-up; therefore, only seven patients finished the intervention. In these patients, the authors found a statistically significant improvement in the maximal inspiratory pressure (P=0.018) and peak cough flow (P=0.046) after 3 months of training. There was also an improvement in the maximal expiratory pressure, although this was not statistically significant (P=0.176). Median compliance to training was 99% (94.5–100).

Conclusions This intervention led to statistically significant improvements in inspiratory muscles strength and coughing capacity in patients with muscular dystrophy. The results were significantly positive and contribute to the evidence in support of this underused, yet possibly beneficial, treatment, although larger randomised controlled trials are required to verify this.

Respiratory management of spinal muscular atrophy type 1 patients treated with Nusinersen

INTRODUCTION

The recent development of disease-modifying treatments in spinal muscular atrophy (SMA) type 1 shifted these patients' management from palliative to proactive. The aim of this study was to assess patients' nocturnal gas exchanges before noninvasive ventilation (NIV) initiation and their clinical evolution to determine if capnia is a good criterion to decide when to introduce respiratory support.

PATIENTS AND METHODS

This multicentric retrospective study reports the respiratory management and evolution of 17 SMA type 1 children (10 females) for whom treatment with Nusinersen was initiated between 2016 and 2018.

RESULTS

Median [interquartile range-IQR] age at diagnosis and at first Nusinersen injection was of 4 [3;8] and 4 [3;9] months, respectively. Patients were followed during 38 [24;44] months. Thirteen (76%) patients were started on NIV at a median [IQR] age of 12 [9;18] months. Repeated hospitalizations and intensive care unit admissions were needed for 11 of them. Blood gas and nocturnal gas exchange recordings performed before NIV initiation were always normal. 9/13 X-ray performed before NIV showed atelectasis and/or acute lower respiratory tract infections. There was a significant decrease in the total number of hospital admissions between the first and second year of treatment (p = 0.04).

CONCLUSION

This study shows that patients do not present with nocturnal hypoventilation before respiratory decompensations and NIV initiation, and suggests that a delay in NIV initiation might result in respiratory complications. There is a need for disease-centered guidelines for the respiratory management of these patients, including NIV indications.

Daytime predictors of nocturnal hypercapnic hypoventilation in children with neuromuscular disorders

OBJECTIVES

To examine objective daytime predictors of nocturnal hypercapnic hypoventilation (NHH) and identify a forced vital capacity (FVC) z-score cut off that predicts NHH using the 2012 Global Lung Function Initiative (GLI) reference equations in pediatric neuromuscular patients.

DESIGN

Single-centre retrospective medical record review.

SETTING

Tertiary pediatric hospital in Australia.

PATIENTS

Children (<18 years old) with a neuromuscular disorder (NMD) who had a diagnostic sleep study over a 5-year period.

RESULTS

Fifty children were included, median age 11.9 years (interquartile range [IQR]: 4.5-14.3). The majority of children had a diagnosis of Duchenne Muscular Dystrophy (32%). NHH was diagnosed in 18 children (36%). Multivariate logistic regression analysis performed for the entire cohort confirmed a statistically significant association between NHH and scoliosis (odds ratio [OR]: 3.3, p = 0.03), but not age (OR: 1.01, p = 0.26), body mass index z-score (OR: 0.86, p = 0.26) or use of a wheelchair for mobility (OR: 1.25, p = 0.72). For the subset of 29 children who had spirometry testing (median age 12.9 years [IQR: 10.2-14.3]), FVC z-score was the only statistically significant predictor of NHH (OR: 0.45, p = 0.02). NHH was predicted by an FVC z-score <-3.24 (sensitivity 78%, specificity 73%), or FVC <60% predicted (sensitivity 78%, specificity 73%). There was a strong positive correlation between FVC and forced expiratory volume in 1 s z-scores (r_p  = 0.98, p = 0.00) and FVC and peak expiratory flow  z-scores (r_p  = 0.72, p = 0.00).

CONCLUSION

Children with a NMD and scoliosis or a lower FVC z-score have increased odds of having NHH.

Is there a role of pulmonary rehabilitation in extrapulmonary diseases frequently encountered in the practice of physical medicine and rehabilitation?

There is a group of diseases such as low back pain, osteoporosis, fibromyalgia and obesity for which pulmonary rehabilitation can be applied. Although these diseases do not directly impact the lungs, respiratory dysfunction occurs through various mechanisms during the disease process and complicates the underlying primary disease. Respiratory dysfunction and spirometric abnormalities have been observed from the early stages of these diseases, even without obvious signs and symptoms. These patients should be carefully evaluated for pulmonary problems as a sedentary lifestyle may hide the presence of respiratory symptoms. Once pulmonary problems have been detected, pulmonary rehabilitation should be added to the routine treatment of the primary disease.

Diagnostic and Therapeutic Approach to Children and Adolescents with Obstructive Sleep Apnea Syndrome (OSA): Recommendations in Emilia-Romagna Region, Italy

Obstructive sleep apnoea syndrome (OSA) in paediatrics is a rather frequent pathology caused by pathophysiological alterations leading to partial and prolonged obstruction (hypoventilation) and/or intermittent partial (hypopnoea) or complete (apnoea) obstruction of the upper airways. Paediatric OSA is characterised by daytime and night-time symptoms. Unfortunately, there are few data on shared diagnostic-therapeutic pathways that address OSA with a multidisciplinary approach in paediatric age. This document summarizes recommendations from the Emilia-Romagna Region, Italy, developed in order to provide the most appropriate tools for a multidisciplinary approach in the diagnosis, treatment and care of paediatric patients with OSA. The multidisciplinary group of experts distinguished two different 'step' pathways, depending on the age group considered (i.e., under or over two years). In most cases, these pathways can be carried out by the primary care paediatrician, who represents the first filter for approaching the problem. For this reason, it is essential that the primary care paediatrician receives adequate training on how to formulate the diagnostic suspicion of OSA and on what criteria to use to select patients to be sent to the hospital centre. The relationship between the paediatrician of the patient and her/his parents must see a synergy of behaviour between the various players in order to avoid uncertainty about the diagnostic and therapeutic decisions as well as the follow-up phase. The definition and evaluation of the organizational process and outcome indicators of the developed flow-chart, and the impact of its implementation will remain fundamental.

Management of Spinal Muscular Atrophy in the Adult Population

Spinal muscular atrophy (SMA) is a group of neurodegenerative disorders resulting from the loss of spinal motor neurons. 95% of patients share a pathogenic mechanism of loss of survival motor neuron (SMN) 1 protein expression due to homozygous deletions or other mutations of the SMN1 gene, with the different phenotypes influenced by variable copy numbers of the SMN2 gene. Advances in supportive care, disease modifying treatment and novel gene therapies have led to an increase in the prevalence of SMA, with a third of SMA patients now represented by adults. Despite the growing number of adult patients, consensus on the management of SMA has focused primarily on the pediatric population. As the disease burden is vastly different in adult SMA, an approach to treatment must be tailored to their unique needs. This review will focus on the management of the adult SMA patient as they age and will discuss proper transition of care from a pediatric to adult center, including the need for continued monitoring for osteoporosis, scoliosis, malnutrition, and declining mobility and functioning. As in the pediatric population, multidisciplinary care remains the best approach to the management of adult SMA. Novel and emerging therapies such as nusinersen and risdiplam provide hope for these patients, though these medications are of uncertain efficacy in this population and require additional study.

An observational study of Pseudomonas aeruginosa in adult long-term ventilation

Introduction

Pseudomonas aeruginosa increases morbidity and mortality in respiratory disease. To date the long-term ventilation population does not have clear guidelines regarding its management.

Method

We undertook a retrospective observational study in a regional long-term ventilation population (837 patients). We defined the primary outcome as P. aeruginosa isolation. In addition positive cultures for copathogens (Serratia, Proteus species, Stenotrophomonas, Burkholderia cepacia complex and nontuberculous mycobacteria) were recorded. Logistic regression and odds ratios were calculated.

Results

17.6% of the cohort isolated P. aeruginosa, and this pathogen was cultured more frequently in patients with a tracheostomy (logistic regression coefficient 2.90, p≤0.0001) and cystic fibrosis/bronchiectasis (logistic regression coefficient 2.48, p≤0.0001). 6.3% of patients were ventilated via tracheostomy. In the P. aeruginosa positive cohort 46.9% of patients were treated with a long-term macrolide, 36.7% received a nebulised antibiotic and 21.1% received both. Tracheostomised P. aeruginosa positive patients received a nebulised antibiotic more frequently (OR 2.63, 95% CI 1.23–5.64, p=0.013). Copathogens were isolated in 33.3% of the P. aeruginosa cohort. In this cohort patients with a tracheostomy grew a copathogen more frequently than those without (OR 2.75, 95% CI 1.28–5.90).

Conclusions

P. aeruginosa isolation is common within the adult long-term ventilation population and is significantly associated with tracheostomy, cystic fibrosis and bronchiectasis. Further research and international guidelines are needed to establish the prognostic impact of P. aeruginosa and to guide on antimicrobial management. The increased risk of P. aeruginosa should be considered when contemplating long-term ventilation via tracheostomy.

Pseudomonas aeruginosa isolation is common (17%) in long-term ventilated adults and significantly associated with tracheostomy, cystic fibrosis and bronchiectasis. Tracheostomy patients with P. aeruginosa isolates culture copathogens more frequently.https://bit.ly/3vvxBbB

Natural history of respiratory muscle strength in spinal muscular atrophy: a prospective national cohort study

Background

Respiratory complications are the most important cause of morbidity and mortality in spinal muscular atrophy (SMA). Respiratory muscle weakness results in impaired cough, recurrent respiratory tract infections and eventually can cause respiratory failure. We assessed longitudinal patterns of respiratory muscle strength in a national cohort of treatment-naïve children and adults with SMA, hypothesizing a continued decline throughout life.

Methods

We measured maximal expiratory and inspiratory pressure (PE_max and PI_max), Sniff Nasal inspiratory pressure (SNIP), peak expiratory flow (PEF), and peak cough flow (PCF) in treatment-naïve patients with SMA. We used mixed-models to analyze natural history patterns.

Results

We included 2172 measurements of respiratory muscle function from 80 treatment-naïve patients with SMA types 1c-3b. All outcomes were lower in the more severe phenotypes. Significant differences in PEF were present between SMA types from early ages onwards. PEF decline was linear (1–2%/year). PEF reached values below 80% during early childhood in types 1c-2, and during adolescence in type 3a. PE_max and PI_max were severely lowered in most patients throughout life, with PE_max values abnormally low (i.e. < 80 cmH₂O) in virtually all patients. The PE_max/PI_max ratio was < 1 throughout life in all SMA types, indicating that expiratory muscles were most affected. All but SMA type 3b patients had a lowered PCF. Patients with types 2b and 3a had PCF levels between 160 and 270 L/min, those with type 2a around 160 L/min and patients with type 1c well below 160 L/min. Finally, SNIP was low in nearly all patients, most pronounced in more severely affected patients.

Conclusions

There are clear differences in respiratory muscle strength and its progressive decline between SMA types. We observed lower outcomes in more severe SMA types. Particularly PEF may be a suitable outcome measure for the follow-up of respiratory strength in patients with SMA. PEF declines in a rather linear pattern in all SMA types, with clear differences at baseline. These natural history data may serve as a reference for longer-term treatment efficacy assessments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02227-7.

Characterization of sleep-disordered breathing in children with Duchenne muscular dystrophy by the American Academy of Sleep Medicine criteria vs disease-specific criteria: what are the differences?

STUDY OBJECTIVES

Individuals with Duchenne muscular dystrophy (DMD) frequently develop sleep-disordered breathing. Noninvasive ventilation is often prescribed for sleep-disordered breathing treatment based on the American Academy of Sleep Medicine (AASM) criteria. In 2018, DMD disease-specific criteria for sleep-disordered breathing were established. Our study aimed to examine the clinical interpretation differences using these different criteria.

METHODS

We performed a multicenter, retrospective chart review of children with DMD followed at The Hospital for Sick Children, Toronto, Canada, and Rady Children's Hospital, San Diego, California, who underwent polysomnography from August 1, 2012, to February 29, 2020. Baseline characteristics and polysomnography data were summarized using descriptive statistics. Agreement for the diagnosis of sleep-disordered breathing evaluated by kappa statistics and sensitivity/specificity analysis was assessed.

RESULTS

One hundred five male children with DMD (mean ± SD age: 12.1 ± 3.8 years; body mass index z score: 0.2 ± 2.3) were included. The proportions of children with DMD that met at least 1 AASM criterion and at least 1 DMD criterion were 45.7% and 67.6%, respectively. We found that 32.4% of children met neither AASM nor DMD criteria. Overall agreement between AASM and DMD criteria was moderate (k = 0.57). There was almost perfect agreement in sleep apnea diagnosis (k = 0.90); however, there was only slight agreement in hypoventilation diagnosis (k = 0.12) between AASM and DMD criteria.

CONCLUSIONS

There were more children with DMD diagnosed with nocturnal hypoventilation and prescribed noninvasive ventilation using DMD criteria compared with AASM criteria. Future studies should address whether the prescription of noninvasive ventilation for children with DMD based on both criteria is associated with different clinical outcomes.

CITATION

Hurvitz MS, Sunkonkit K, Massicotte C, Li R, Bhattacharjee R, Amin R. Characterization of sleep-disordered breathing in children with Duchenne muscular dystrophy by the American Academy of Sleep Medicine criteria vs disease-specific criteria: what are the differences? J Clin Sleep Med. 2022;18(2):609-615.

Respiratory prehabilitation in pediatric anesthesia in children with muscular and neurologic disease

Children with neuromuscular, chronic neurologic, and chest wall diseases are at increased risk of postoperative respiratory complications including atelectasis, pneumonia, and respiratory failure with the possible need for reintubation or even tracheostomy. These complications negatively impact patient outcomes, including increased healthcare resource utilization and increased surgical mortality. In these children, the existing respiratory reserve is often inadequate to withstand the stresses brought on during anesthesia and surgery. A thorough clinical assessment and objective evaluation of pulmonary function and gas exchange can help identify which children are at particular risk for poor postoperative outcomes and thus merit preoperative interventions. These may include initiation and optimization of non-invasive ventilation and mechanical insufflation-exsufflation. Furthermore, such an evaluation will help identify children who may require a postoperative extubation plan tailored to neuromuscular diseases. Such strategies may include avoidance of pre-extubation lung decruitment by precluding continuous positive airway pressure trials, aggressively weaning to room air and directly extubating to non-invasive ventilation with a high inspiratory to expiratory pressure differential of at least 10 cm H20. Children with cerebral palsy and other neurodegenerative or neurodevelopmental disorders are a more heterogeneous group of children who may share some operative risk factors with children with neuromuscular disease; they may also be at risk of sleep-disordered breathing, may also require non-invasive ventilation or mechanical insufflation-exsufflation, and may have associated chronic lung disease from aspirations that may require perioperative treatment.