Respiratory physiologic changes following spinal cord injury
- Eric Garshick, MD, MOH
Eric Garshick, MD, MOH
- Professor of Medicine
- Harvard Medical School
- Section Editor
- Michael J Aminoff, MD, DSc
Michael J Aminoff, MD, DSc
- Editor-in-Chief — Neurology
- Section Editor — Medical Neurology
- Professor of Neurology
- University of California, San Francisco School of Medicine
- Deputy Editors
- Geraldine Finlay, MD
Geraldine Finlay, MD
- Senior Deputy Editor — UpToDate
- Deputy Editor — Pulmonary, Critical Care, and Sleep Medicine
- Associate Professor
- Tufts University School of Medicine
- Janet L Wilterdink, MD
Janet L Wilterdink, MD
- Senior Deputy Editor — UpToDate
- Deputy Editor — Neurology
- Associate Professor
- Brown University School of Medicine
The annual incidence of spinal cord injury (SCI) in the United States is estimated to be 54 cases per million population or approximately 16,965 new cases in 2012 . Since 2010, the most frequent neurologic category of SCI at discharge has been incomplete quadriplegia (also known as tetraplegia) at 45 percent, followed by incomplete paraplegia at 21 percent, complete paraplegia at 20 percent, and complete quadriplegia at 14 percent .
The majority of causes of traumatic SCI in 2012 included vehicular accidents (31 percent), falls (40.4 percent), and firearm injuries (5.4 percent) . The percentage of SCI associated with falls increased significantly from 28 percent in 1997 through 2000 to 66 percent in 2010 through 2012 in persons aged 65 or older. Causes of nontraumatic SCI include tumor, vascular disease, demyelinating spinal cord diseases, and spinal stenosis . Respiratory failure is common after SCI and respiratory complications are among the most common causes of death [4,5], particularly in the years following acute injury  and in patients who have required mechanical ventilation [7,8].
SCI results in physiologic changes that affect many organ systems. The changes in pulmonary physiology that occur following SCI will be reviewed here. The diagnosis and management of acute and chronic SCI and the management of the respiratory complications of SCI are discussed separately. (See "Acute traumatic spinal cord injury" and "Evaluation and acute management of cervical spinal column injuries in adults" and "Chronic complications of spinal cord injury and disease" and "Disorders affecting the spinal cord" and "Respiratory complications in the adult patient with chronic spinal cord injury" and "Spinal column injuries in adults: Definitions, mechanisms, and radiographs".)
ASSESSMENT OF LEVEL AND COMPLETENESS OF SCI
Pulmonary physiologic changes due to spinal cord injury (SCI) are related to the extent of neurological impairment. The American Spinal Injury Association Impairment Scale (AIS) is used to classify the degree of impairment that is based on strength in key muscles and on a sensory exam (table 1) . An exam guide and worksheet for assessing SCI is available through the American Spinal Cord Injury Association. (See "Acute traumatic spinal cord injury", section on 'Clinical presentation'.)
The patient’s strength in key muscle groups is assessed and graded. A muscle grade of 5/5 is normal, and a grade of 3/5 means the muscle can be moved against gravity. The motor level is defined as the most caudal key muscle that is graded 3/5 or 4/5 with the segment cephalad to that level graded 5/5. The sensory level is defined as the most caudal dermatome to have normal sensation for both pinprick and light touch. For areas that lack key muscles to test, such as between T2 and L1, sensory findings are used to estimate motor levels.
- Jain NB, Ayers GD, Peterson EN, et al. Traumatic spinal cord injury in the United States, 1993-2012. JAMA 2015; 313:2236.
- National Spinal Cord Injury Statistical Center. Spinal cord injury facts and figures at a glance. www.nscisc.uab.edu/Public/Facts%202015%20Aug.pdf (Accessed on April 29, 2016).
- Ho CH, Wuermser LA, Priebe MM, et al. Spinal cord injury medicine. 1. Epidemiology and classification. Arch Phys Med Rehabil 2007; 88:S49.
- Hartkopp A, Brønnum-Hansen H, Seidenschnur AM, Biering-Sørensen F. Survival and cause of death after traumatic spinal cord injury. A long-term epidemiological survey from Denmark. Spinal Cord 1997; 35:76.
- Lidal IB, Snekkevik H, Aamodt G, et al. Mortality after spinal cord injury in Norway. J Rehabil Med 2007; 39:145.
- Kirshblum SC, Waring W, Biering-Sorensen F, et al. Reference for the 2011 revision of the International Standards for Neurological Classification of Spinal Cord Injury. J Spinal Cord Med 2011; 34:547.
- Shavelle RM, DeVivo MJ, Strauss DJ, et al. Long-term survival of persons ventilator dependent after spinal cord injury. J Spinal Cord Med 2006; 29:511.
- Watt JW, Wiredu E, Silva P, Meehan S. Survival after short- or long-term ventilation after acute spinal cord injury: a single-centre 25-year retrospective study. Spinal Cord 2011; 49:404.
- Kirshblum SC, Burns SP, Biering-Sorensen F, et al. International standards for neurological classification of spinal cord injury (revised 2011). J Spinal Cord Med 2011; 34:535.
- McMichan JC, Michel L, Westbrook PR. Pulmonary dysfunction following traumatic quadriplegia. Recognition, prevention, and treatment. JAMA 1980; 243:528.
- Ledsome JR, Sharp JM. Pulmonary function in acute cervical cord injury. Am Rev Respir Dis 1981; 124:41.
- Wicks AB, Menter RR. Long-term outlook in quadriplegic patients with initial ventilator dependency. Chest 1986; 90:406.
- Axen K, Pineda H, Shunfenthal I, Haas F. Diaphragmatic function following cervical cord injury: neurally mediated improvement. Arch Phys Med Rehabil 1985; 66:219.
- Haas F, Axen K, Pineda H, et al. Temporal pulmonary function changes in cervical cord injury. Arch Phys Med Rehabil 1985; 66:139.
- Claxton AR, Wong DT, Chung F, Fehlings MG. Predictors of hospital mortality and mechanical ventilation in patients with cervical spinal cord injury. Can J Anaesth 1998; 45:144.
- Mueller G, de Groot S, van der Woude L, Hopman MT. Time-courses of lung function and respiratory muscle pressure generating capacity after spinal cord injury: a prospective cohort study. J Rehabil Med 2008; 40:269.
- Bluechardt MH, Wiens M, Thomas SG, Plyley MJ. Repeated measurements of pulmonary function following spinal cord injury. Paraplegia 1992; 30:768.
- Brown R, DiMarco AF, Hoit JD, Garshick E. Respiratory dysfunction and management in spinal cord injury. Respir Care 2006; 51:853.
- Derenne JP, Macklem PT, Roussos C. The respiratory muscles: mechanics, control, and pathophysiology. Am Rev Respir Dis 1978; 118:119.
- Urmey W, Loring S, Mead J, et al. Upper and lower rib cage deformation during breathing in quadriplegics. J Appl Physiol (1985) 1986; 60:618.
- McCool FD, Pichurko BM, Slutsky AS, et al. Changes in lung volume and rib cage configuration with abdominal binding in quadriplegia. J Appl Physiol (1985) 1986; 60:1198.
- Banzett RB, Inbar GF, Brown R, et al. Diaphragm electrical activity during negative lower torso pressure in quadriplegic men. J Appl Physiol Respir Environ Exerc Physiol 1981; 51:654.
- Mortola JP, Sant'Ambrogio G. Motion of the rib cage and the abdomen in tetraplegic patients. Clin Sci Mol Med 1978; 54:25.
- Moulton A, Silver JR. Chest movements in patients with traumatic injuries of the cervical cord. Clin Sci 1970; 39:407.
- De Troyer A, Estenne M, Heilporn A. Mechanism of active expiration in tetraplegic subjects. N Engl J Med 1986; 314:740.
- Estenne M, Knoop C, Vanvaerenbergh J, et al. The effect of pectoralis muscle training in tetraplegic subjects. Am Rev Respir Dis 1989; 139:1218.
- Manning H, McCool FD, Scharf SM, et al. Oxygen cost of resistive-loaded breathing in quadriplegia. J Appl Physiol (1985) 1992; 73:825.
- Scanlon PD, Loring SH, Pichurko BM, et al. Respiratory mechanics in acute quadriplegia. Lung and chest wall compliance and dimensional changes during respiratory maneuvers. Am Rev Respir Dis 1989; 139:615.
- Goldman JM, Williams SJ, Denison DM. The rib cage and abdominal components of respiratory system compliance in tetraplegic patients. Eur Respir J 1988; 1:242.
- Estenne M, De Troyer A. The effects of tetraplegia on chest wall statics. Am Rev Respir Dis 1986; 134:121.
- Goldman JM, Rose LS, Morgan MD, Denison DM. Measurement of abdominal wall compliance in normal subjects and tetraplegic patients. Thorax 1986; 41:513.
- Almenoff PL, Alexander LR, Spungen AM, et al. Bronchodilatory effects of ipratropium bromide in patients with tetraplegia. Paraplegia 1995; 33:274.
- Schilero GJ, Grimm DR, Bauman WA, et al. Assessment of airway caliber and bronchodilator responsiveness in subjects with spinal cord injury. Chest 2005; 127:149.
- Spungen AM, Dicpinigaitis PV, Almenoff PL, Bauman WA. Pulmonary obstruction in individuals with cervical spinal cord lesions unmasked by bronchodilator administration. Paraplegia 1993; 31:404.
- Schilero GJ, Spungen AM, Bauman WA, et al. Pulmonary function and spinal cord injury. Respir Physiol Neurobiol 2009; 166:129.
- Radulovic M, Schilero GJ, Wecht JM, et al. Airflow obstruction and reversibility in spinal cord injury: evidence for functional sympathetic innervation. Arch Phys Med Rehabil 2008; 89:2349.
- Grimm DR, Chandy D, Almenoff PL, et al. Airway hyperreactivity in subjects with tetraplegia is associated with reduced baseline airway caliber. Chest 2000; 118:1397.
- BERGOFSKY EH. MECHANISM FOR RESPIRATORY INSUFFICIENCY AFTER CERVICAL CORD INJURY; A SOURCE OF ALVEOLAR HYPOVENTILATION. Ann Intern Med 1964; 61:435.
- Manning HL, Brown R, Scharf SM, et al. Ventilatory and P0.1 response to hypercapnia in quadriplegia. Respir Physiol 1992; 89:97.
- Ben-Dov I, Zlobinski R, Segel MJ, et al. Ventilatory response to hypercapnia in C(5-8) chronic tetraplegia: the effect of posture. Arch Phys Med Rehabil 2009; 90:1414.
- Garshick E, Ashba J, Tun CG, et al. Assessment of stature in spinal cord injury. J Spinal Cord Med 1997; 20:36.
- Miller MR, Hankinson J, Brusasco V, et al. Standardisation of spirometry. Eur Respir J 2005; 26:319.
- Kelley A, Garshick E, Gross ER, et al. Spirometry testing standards in spinal cord injury. Chest 2003; 123:725.
- Tully K, Koke K, Garshick E, et al. Maximal expiratory pressures in spinal cord injury using two mouthpieces. Chest 1997; 112:113.
- Estenne M, De Troyer A. Mechanism of the postural dependence of vital capacity in tetraplegic subjects. Am Rev Respir Dis 1987; 135:367.
- Baydur A, Adkins RH, Milic-Emili J. Lung mechanics in individuals with spinal cord injury: effects of injury level and posture. J Appl Physiol (1985) 2001; 90:405.
- Almenoff PL, Spungen AM, Lesser M, Bauman WA. Pulmonary function survey in spinal cord injury: influences of smoking and level and completeness of injury. Lung 1995; 173:297.
- Linn WS, Spungen AM, Gong H Jr, et al. Smoking and obstructive lung dysfunction in persons with chronic spinal cord injury. J Spinal Cord Med 2003; 26:28.
- Jain NB, Brown R, Tun CG, et al. Determinants of forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC in chronic spinal cord injury. Arch Phys Med Rehabil 2006; 87:1327.
- Mueller G, de Groot S, van der Woude LH, et al. Prediction models and development of an easy to use open-access tool for measuring lung function of individuals with motor complete spinal cord injury. J Rehabil Med 2012; 44:642.
- Stepp EL, Brown R, Tun CG, et al. Determinants of lung volumes in chronic spinal cord injury. Arch Phys Med Rehabil 2008; 89:1499.
- Stolzmann KL, Gagnon DR, Brown R, et al. Longitudinal change in FEV1 and FVC in chronic spinal cord injury. Am J Respir Crit Care Med 2008; 177:781.
- Dicpinigaitis PV, Spungen AM, Bauman WA, et al. Bronchial hyperresponsiveness after cervical spinal cord injury. Chest 1994; 105:1073.
- Grimm DR, Arias E, Lesser M, et al. Airway hyperresponsiveness to ultrasonically nebulized distilled water in subjects with tetraplegia. J Appl Physiol (1985) 1999; 86:1165.
- Singas E, Lesser M, Spungen AM, et al. Airway hyperresponsiveness to methacholine in subjects with spinal cord injury. Chest 1996; 110:911.
- Cragg JJ, Warner FM, Kramer JK, Borisoff JF. A Canada-wide survey of chronic respiratory disease and spinal cord injury. Neurology 2015; 84:1341.
- ASSESSMENT OF LEVEL AND COMPLETENESS OF SCI
- PULMONARY PHYSIOLOGIC CHANGES
- Timing of changes in ventilatory function
- Impairment of ventilatory muscle function
- - Muscles of respiration
- - Injury above C3
- - Injury at C3 through C5
- - Injury at C6 through C8
- - Injuries of the thoracic spinal cord
- Changes in lung and chest wall compliance
- Airflow limitation and bronchial hyperresponsiveness
- Changes in ventilatory control
- ASSESSMENT OF PULMONARY FUNCTION
- Technical considerations in measuring pulmonary function
- - Measurement of height
- - Use of modified ATS standards
- - Mouthpiece for pressure measurements
- Effect of posture
- Expected values for spirometry
- Expected values for lung volumes
- Longitudinal assessment of pulmonary function
- Maximal inspiratory and expiratory pressures
- Bronchial hyperresponsiveness and bronchodilator response
- Other etiologies of PFT abnormalities
- SUMMARY AND RECOMMENDATIONS