A spinal cord injury (SCI) involves damage to the spinal cord, disrupting communication between the brain and body parts below the injury site. While often associated with paralysis and loss of sensation, SCIs also significantly affect breathing. Respiratory complications are a leading cause of illness and death for individuals with SCI.
How Spinal Cord Injury Impacts Breathing
The ability to breathe relies on the coordinated action of several muscle groups, primarily the diaphragm and the intercostal muscles.
The diaphragm, a dome-shaped muscle separating the chest and abdominal cavities, receives its nerve supply from the phrenic nerve, which originates from the C3 to C5 spinal cord segments. This muscle is responsible for a significant portion of the air inhaled during quiet breathing.
The intercostal muscles, located between the ribs, are innervated by nerves from the T1 to T11 spinal levels and assist in expanding the rib cage during inhalation and compressing it during forced exhalation. Abdominal muscles, supplied by nerves from T6 to L1, also play a role in forced exhalation and coughing.
When a spinal cord injury occurs, particularly at higher levels like the cervical or upper thoracic spine, the nerve signals to these respiratory muscles can be disrupted or blocked. This damage can lead to weakened or paralyzed breathing muscles, reducing lung capacity and impairing the ability to cough effectively.
Common Respiratory Complications
Individuals with SCI frequently experience a range of specific respiratory complications due to weakened breathing muscles and impaired cough reflexes.
- Pneumonia: A lung infection, pneumonia is common due to reduced ability to clear secretions, leading to bacterial growth. Aspiration pneumonia can also develop from inhaling food or liquids due to swallowing difficulties.
- Atelectasis: This involves the collapse of lung tissue when shallow breathing and retained secretions prevent air sacs from fully inflating, hindering oxygen exchange.
- Respiratory failure: Acute or chronic, this occurs when lungs cannot maintain adequate oxygen or remove sufficient carbon dioxide, sometimes requiring mechanical ventilation.
- Sleep-disordered breathing: Including sleep apnea, this is common due to weakened airway muscles and altered breathing patterns during sleep, leading to pauses or shallow breathing and drops in blood oxygen.
- Pleural effusions: Fluid buildup around the lungs, these can also occur, compromising respiratory function.
Managing Respiratory Health
Diagnosing respiratory issues in individuals with SCI involves several methods to assess lung function and identify complications.
Pulmonary function tests measure lung volumes and airflow. Imaging techniques like chest X-rays and CT scans can reveal changes in lung tissue or fluid accumulation. Blood gas analysis provides information about oxygen and carbon dioxide levels, indicating lung function.
Acute management of respiratory distress may include mechanical ventilation, invasive (via breathing tube) or non-invasive (via masks). Tracheostomy, a surgical opening in the windpipe, may be performed for long-term ventilation or to facilitate secretion removal. Regular suctioning helps clear mucus from the airways, and assisted cough techniques, like manual assisted cough or specialized devices, help individuals with weak coughs expel secretions.
Long-term management focuses on improving respiratory strength and preventing complications. Respiratory muscle training aims to strengthen breathing muscles, while medications like bronchodilators can help open airways and mucolytics can thin secretions. Consistent medical follow-ups are important for ongoing monitoring and care plan adjustments.
Proactive Measures to Prevent Complications
Preventative strategies are important to minimize the risk of respiratory complications in individuals with spinal cord injury.
Vaccinations play a significant role, with annual influenza and pneumococcal vaccines recommended to protect against common respiratory infections. Practicing good hand hygiene and maintaining oral care are important steps to prevent the spread of germs and reduce the risk of infections.
Proper positioning and early mobilization, when appropriate, can aid lung expansion and help clear secretions from the airways. Avoiding smoking is recommended, as it can compromise lung health and increase susceptibility to problems.
Educating both individuals with SCI and their caregivers about recognizing early signs of complications and adhering to care plans. Regular respiratory assessments by healthcare professionals allow for ongoing monitoring and early detection of issues.