Early identification of respiratory disease in children with neurological diseases: improving quality of life?

Abstract

Respiratory disease is a leading cause of death in central nervous system (CNS) conditions such as cerebral palsy (CP) and neuromuscular disorders (NMD). It negatively impacts health-related quality of life by necessitating unplanned and prolonged medical hospitalizations. Non-modifiable risk factors for CP respiratory disease are: Gross Motor Function Classification System level V, a respiratory illness requiring admission, and (or) at least two courses of antibiotics in the past year. Modifiable risk factors for respiratory disease are: oropharyngeal dysphagia, gastro-oesophageal reflux disease (GORD), seizures and frequent respiratory symptoms during or between mealtimes, and snoring. The majority of these persist from birth, implicating chronic aspiration in the genesis of CP respiratory disease. To improve morbidity and mortality, modifiable risk factors require management. Clinically-based consensus guidelines for CP respiratory disease have been published. We advocate for a paradigm shift: to communicate early and openly about the risks posed by respiratory disease to expedite their mitigation, and to normalize this discussion as part of standard care. An understanding of the pathophysiology of aspiration and the multifactorial nature of the slowly progressive respiratory failure in CNS conditions is also required to inform management. Hov et al. reported the prevalence and use of long-term mechanical insufflation-exsufflation (MI-E) and concomitant mechanical ventilation in children with neurological conditions. They detailed the reasons for initiating treatment in a population-based cross-sectional sample in Norway, a country in which MI-E devices are publicly funded when prescribed by a specialized physician. This paper highlights the disparity between the use of MI-E in NMD and CNS conditions. In NMD, the prescription of MI-E was more often preventative, guided by respiratory function tests. This may reflect reduced compliance with testing or uncertainty of interpretation and expected treatment gains in CNS conditions. The prescription of MI-E devices was often initiated during respiratory admission, by which time the respiratory disease in CNS conditions is likely already established and possibly irreversible. The clinical stage, during which MI-E is introduced, may be critical to its efficacy. In CNS conditions, abnormal oropharyngeal sensation, tone, and coordination contribute to an inadequate cough and poor airway clearance. In NMD, muscle weakness and fatigue are implicated in the weak cough; however, oropharyngeal sensation is preserved and muscle weakness gradual. Hence, chronic aspiration may contribute less to the onset of respiratory disease in NMD than in CNS conditions. In both conditions, an ineffective cough, reduced chest wall compliance, and mechanically disadvantaged respiratory musculature contribute to poor respiratory health. The biomechanics worsen when scoliosis emerges. The already superior evidence base for respiratory management in NMD will continue to evolve as effective medical treatments are employed. In children with CNS conditions, the risks and benefits of MI-E require evaluation, including its use in young children, children with GORD, and children recovering from chronic neonatal lung disease. The relationships between quality of life, MIE, and mechanical ventilation in CNS conditions need exploration in the expanding clinical landscape of prescription and access to medical technology. Historically, paternalistic decisions – unchallenged by evidence and perhaps influenced by the higher incidence of cognitive impairment in CNS conditions – checked access in this cohort. Effective methods of promoting airways clearance are required to optimize respiratory care. Hov et al. provide a first step in identifying which methods of airway clearance are tolerated by children with neurological conditions at risk of respiratory disease. Reliable outcome measures to guide use and assess their efficacy are required. Early identification and discussion about respiratory risk in children with neurological conditions will help generate an evidence-based tool kit including when, how, and whether to use MI-E and mechanical ventilation.