Can a cervical spine injury at the C5 level cause impaired cough reflex and increased oral secretions?

Cervical Spine Injury at C5 Level and Its Impact on Cough Reflex and Oral Secretions

Yes, a cervical spine injury at C5 level can cause impaired cough reflex and increased oral secretions due to respiratory muscle weakness while preserving some diaphragmatic function. 1

Pathophysiological Mechanisms

• C5 cervical spine injury causes significant expiratory muscle weakness while preserving partial diaphragmatic function, leading to ineffective clearance of secretions 1
• Patients with C5 injuries have compromised ability to generate adequate expiratory pressures needed for effective cough, resulting in secretion retention 1, 2
• The major muscles of expiration are innervated by the first thoracic segment and below, so cervical transection results in severely compromised expiratory function and cough 2
• While the neurological cough reflex sensitivity remains intact after cervical spinal cord injury, the mechanical component of cough is impaired due to respiratory muscle paralysis 2
• Reduced lung volumes and inability to take deep breaths impair the normal mucociliary escalator function 1
• Decreased expiratory flow rates fail to stimulate the mucociliary apparatus that would normally assist in secretion clearance 1, 3

Clinical Implications

• Peak expiratory flow during coughing directly correlates with motor level of injury, with higher injuries (like C5) resulting in lower expiratory flow rates 3
• Ineffective cough leads to secretion retention, which can cause atelectasis, pneumonia, and respiratory failure 4
• Patients with C5 injuries often require mechanical ventilation and tracheostomy due to respiratory complications 5
• There is a direct relationship between the level of spinal cord injury and the ability to generate an effective cough, with C5 injuries significantly compromising this function 3

Management Approaches

• A bundle approach is recommended for respiratory management in C5 cervical cord injury patients 5:

  • Active physiotherapy and mechanically-assisted insufflation/exsufflation devices to remove bronchial secretions
  • Abdominal contention belt during periods of spontaneous breathing
  • Aerosol therapy combining beta-2 mimetics and anticholinergics

• Early tracheostomy (within 7 days) is suggested for patients with upper cervical spine injuries (C2-C5) to accelerate ventilatory weaning 5

• Functional electrical stimulation (FES) applied to the abdominal wall can enhance cough in quadriplegics by increasing maximum expiratory pressure 6

• Mechanical aids to improve cough are beneficial for individuals with neuromuscular weakness without concomitant airway obstruction 1

• Protocols combining early extubation followed by intensive respiratory physiotherapy with bronchial drainage and mechanically assisted coughing can sometimes lead to successful respiratory management without tracheostomy 5

Important Considerations

• While the cough reflex sensitivity (neurological component) remains intact after cervical spinal cord injury, the mechanical component is severely compromised 2

• Baclofen, commonly used for muscle spasms in spinal cord injury patients, may further suppress cough reflex sensitivity, potentially worsening secretion management 7

• Lying down is often better tolerated than sitting due to the effects of gravity on abdominal contents and inspiratory capacity in tetraplegic patients 5

• Wearing an abdominal contention belt may increase the tolerance of spontaneous ventilation, particularly when a sitting position has been chosen 5