What problems can these conditions have on the respiratory system?
These conditions can cause several problems:
• Mucus/secretion retention.
• Restrictive lung disease.
• Obstructive lung disease.
• Risk of reduced lung compliance/chest wall compliance/lung growth.
• Ineffective cough.
• Scoliosis/stiff thoracic joints/chest deformity.
• Weak respiratory muscles.
• Reduced mobility/exercise tolerance.
• Recurrent chest infections /pneumonia requiring regular antibiotics and hospital admissions.
• Shortness of breath.
• Ventilator dependence.
• Increased work of breathing.
• Poor oxygenation.
• Discomfort/pain.
In a healthy child, mucus in the airways is cleared by the mucociliary system and the ability to cough. The respiratory system is lined with cells that secrete mucus. The mucus membrane of the nose has mucus-coated hair which traps and filters air containing microbes, dust and pollutants. The mucus membrane of the lower respiratory airways contains cilia which are tiny hair like structures that move the bacteria and other foreign matter to the upper airway. An effective cough and swallow is then required to completely clear the mucus from the airways.
When the mucociliary system and the ability to cough are impaired, this can lead to the build up of mucus. Excessive mucus in the airways can cause a cycle of inflammation, pulmonary infection, increased production of excess mucus, and airway obstruction, lung damage, and respiratory failure.
An effective cough relies on several components i.e bulbar muscle function, inspiratory and expiratory muscle strength. If the diaphragm is weak or if there is spinal deformity, this affects the ability to take a deep breath in. Weak expiratory muscles reduce the expulsive force in order to clear the mucus. Cough function is frequently impaired in neuromuscular diseases (eg. muscular dystrophy, spinal muscular atrophy, and multiple sclerosis), neuromotor conditions (eg. cerebral palsy, spinal cord injury, and severe traumatic brain injury) and who require mechanical ventilation either invasively via a tracheostomy or non-invasively.
Restrictive lung disease is where the respiratory muscles are weak or the spine and thorax are deformed. Therefore the ability to take a deep breath in, to generate expiratory force, and to cough effectively are often affected.
Obstructive lung diseases is where airway size is decreased as a result of structural changes, bronchospasm and/or excess mucus limiting the ability to exhale eg Asthma, Cystic fibrosis, Primary ciliary dyskinesia.
Therefore airway clearance therapy can be essential.
