Chronic respiratory dysfunction and ageing

A spinal cord injury (SCI) above T12 causes changes to respiratory function and at high neurological levels of injury, significantly increases the risk of respiratory complications. Even after the acute phase, a person with SCI may have persistent respiratory dysfunction and therefore, remains highly susceptible to respiratory issues when acutely unwell or hospitalised, even for non-respiratory conditions.

One recent study with > 1000 subjects, reported that respiratory function improves following SCI, but declines below baseline by 6 years post-injury, with people who have motor complete injuries experiencing the most significant change.

More research is indicated, but presumably, residual respiratory function may decline for 2 main reasons which compound each other:

the chronic effects of SCI, such as postural changes and untreated sleep-disordered breathing
the natural ageing process, including reduced immune function and musculoskeletal changes.

When combined, this can result in complex health conditions—which are associated with premature ageing—and an increased susceptibility to respiratory complications later in life.

The summary below outlines key aspects of respiratory health decline following SCI, along with contributing risk factors.

Functional changes over time

Declining activity levels and fitness

This may be related to:

a loss of cardiorespiratory fitness, body flexibility and muscle mass/strength
a slowing metabolism, increasing the risk of
- cardiovascular disease
- obesity, insulin resistance, and type 2 diabetes
- osteopenia and osteoporosis
increasing body shape and weight
neurological deterioration, including syringomyelia
an increase in pain, including upper limb repetitive strain injuries and joint degeneration
an increase in spasticity, impacting pain, function and safety
a deterioration in functional skills and independence
a general loss of balance reactions and confidence, combined with an increased incidence of falls and fractures
an increase in energy demands for ADLs and earlier onset of fatigue
untreated sleep-disordered breathing
a diminished network of social supports (e.g. death of a partner, change in care team)
mental health issues
other evolving co-morbidities, including respiratory diseases.

Reducing lung volumes and overall ventilation

This may be related to:

decreased activity levels and fitness (as above)
a loss of respiratory muscle mass/strength
a decreased vital capacity and peak cough flow
an increase in secretion retention and airway bronchospasm
a decrease in lung and chest wall compliance from
- chronic micro-atelectasis and hypoventilation
- progressive basal lung fibrosis related to repeated infections and ageing
- the onset of respiratory disease
- perpetual trunk spasticity patterns
- ankylosing thoracic and spinal joints, in addition to past surgical spinal fixations
- habitual asymmetrical postures (24-hour positioning for bed, seated mobility and ADL), promoting development of a kyphosis and/or scoliosis
untreated sleep-disordered breathing.

Worsening sleep-disordered breathing

This may be related to:

reducing lung volumes and overall ventilation (as above)
an undiagnosed sleep-disordered breathing condition following initial SCI
changes to central brain responsiveness when regulating CO₂ or O₂ during sleep
changes in airway patency and diaphragm efficiency during sleep caused by
- a reduction in lung volume and overall ventilation
- an introduction of a supine sleep position
- issues with laryngeal function
- increasing neck circumference and abdominal girth
- certain medications
lifestyle issues
- hydration
- substance use
- sleep patterns.

For more information, refer to: Sleep-disordered breathing.

Diminishing immune function

This may be related to:

an SCI related “immune fatigue” that develops over time due to
- autonomic nervous system (ANS) dysfunction which impairs immune signalling
- chronic suppression of the immune system
- persistent low-grade systemic inflammation
- recurrent infections and antibiotic use
an age-related and gradual deterioration in capacity to mount an immune response (immunosenescence)
elevated cortisol from chronic stress, depression and other mental health issues.

Increasing respiratory infections

This may be related to:

a combination of any or all of the above respiratory health changes and risk factors
inadequate prophylactic respiratory health practices for
- ventilation support
- lung volume augmentation
- secretion management
- other respiratory diseases
- hygiene
a non-existent or outdated respiratory action plan.

Other factors

Other situational factors can further compound respiratory health changes, and may also need addressing as respiratory issues emerge. These include:

an inaccessible home environment
ageing or inappropriate equipment
insufficient care support
lack of health professional monitoring
inadequate funding.

Assessment

A comprehensive assessment should involve a multidisciplinary team, the person with SCI and their support network.

The review process determines both acute and chronic respiratory health indicators—particularly hospital admissions and reported impacts on activities of daily living (ADLs), community participation and quality of life.

Further investigation identifies specific respiratory function changes and explores contributing factors as discussed above.

Completing a current respiratory function assessment establishes a baseline, along with other relevant medical and physical assessments e.g. sleep-disordered breathing, pain, spasticity and posture.

Finally, goal setting is an important process to initiate and promote a person-centred approach, while identifying measurable health outcomes to address.

Management

A multidisciplinary team review with collaborative goal setting, will guide respiratory health recommendations and management interventions. A client-centred approach to education, as well as addressing issues related to respiratory and other health, along with lifestyle will be important.

Education

Education is an important starting point in the management of chronic health and ageing issues for a person with SCI. Introducing change may be difficult for many reasons, including limited health knowledge, diminishing supports and entrenched lifestyle habits. Hence, improving health literacy may improve understanding of complex health issues and contributing factors. It may also aid compliance with recommendations, while fostering insight into the negative consequences of inaction.

The aim of education is to promote engagement, while also building confidence and capacity in self-management and informed decision-making. It is typically a staged and repeated process, involving: the sharing of information, encouraging dialogue, checking comprehension, and exploring values and beliefs. When aligned with initial goal setting, education can support negotiation to address the following management issues.

Respiratory health management

Identified respiratory health issues may be addressed by initially trialling low-cost/simple strategies before progressing to high cost/complex strategies, which may include:

reviewing adequacy of overall ventilation support, including review of risk for sleep-disordered breathing
implementing lung volume augmentation
- incorporating a balanced approached between positive pressure therapies and demand ventilation and targeted inspiratory muscle training, to avoid respiratory fatigue
improving secretion management
managing sleep-disordered breathing and any other respiratory diseases e.g. chronic obstructive pulmonary disease
addressing other respiratory diseases eg. chronic obstructive pulmonary disease
reviewing hygiene practices
promoting cessation of smoking/vaping and substance use
implementing a respiratory action plan, including updating vaccinations.

Other health and supports management

Other health, including lifestyle and functioning issues may need to be addressed using evidence-based approaches, which may include:

enhancing cardiovascular and metabolic health
addressing weight management: diet, cardiorespiratory fitness program and caloric tracking
improving pain and spasticity management
managing stress and mental health issues
reviewing medications and other co-morbidities
improving flexibility and muscle strengthening related to function, including core strength and balance
optimising 24-hour positioning for bed, seated mobility and ADL
problem-solving functional skills for independence and confidence, while minimising risk of injury and falls
maintaining or increasing capacity for physical ADL, while managing fatigue
improving home or community access
replacing ageing equipment or introducing new equipment supports
addressing insufficient care support
improving linkage with and monitoring by appropriate health professional
advocating for adequate funding.

Discharge and community planning

A person with SCI, who has had chronic respiratory dysfunction and is also ageing, may need a review of their funding, care and health professional supports for community living. This may include addressing issues related to their home environment, as well as equipment, including trialling and prescribing respiratory devices.

For more information on these considerations, refer to Discharge and community planning.

Resources

Aging with Spinal Cord Injury
NSW Agency for Clinical Innovation (ACI)

Respiratory Management (Rehab Phase)
SCIRE Professional

Respiratory Health and Spinal Cord Injury
Model Systems Knowledge Translation Center

Understanding and Managing Respiratory Complications after SCI
University of Alabama

References

Berlowitz, D. J., Wadsworth, B., & Ross, J. (2016). Respiratory problems and management in people with spinal cord injury. Breathe (Sheff), 12(4), 328–340. https://doi.org/10.1183/20734735.012616

Sho, K. Y., Mun, C., Lim, J.-C., Kim, O., & Lee, J. W. (2024). Long-term pulmonary function post spinal cord injury. Archives of Physical Medicine and Rehabilitation, 105(11), 2142–2149. https://doi.org/10.1016/j.apmr.2024.07.007

Smith, J. A., Aliverti, A., Quaranta, M., McGuinness, K., Kelsall, A., Earis, J., & Calverley, P. M. (2012). Chest wall dynamics during voluntary and induced cough in healthy volunteers. The Journal of Physiology, 590(3), 563–574. https://doi.org/10.1113/jphysiol.2011.213157

van Silfhout, L., Peters, A. E. J., Berlowitz, D. J., Schembri, R., Thijssen, D., & Graco, M. (2016). Long-term change in respiratory function following spinal cord injury. Spinal Cord, 54(9), 714–719. https://doi.org/10.1038/sc.2015.233