CHAPTER 17
RESPIRATORY DISTURBANCES
Disturbances of the ventilatory function may present most serious complications in the
immediate and early stages following spinal cord injuries. This applies to three groups
of patients: (i) tetraplegics who are deprived of the function of their main respiratory
muscles, in particular intercostals and abdominals; (2) those patients with thoracic and
lumbar lesions associated with fractures of ribs and sternum resulting in haemo- or
pneumothorax; (3) patients of any level, in particular those of advanced age, who were
suffering from respiratory afflictions before their spinal injuries, such as asthma, chronic
bronchitis, pneumokoniosis etc. Therefore, all these patients demand the utmost vigilance
of both the medical and paramedical staff day and night from the start, as ability to
ventilate is greatly reduced in these patients, leading to anoxia, and obstruction in their
respiratory tract may occur by aspiration of fluid or tracheal stenosis following tracheos-
tomy. In fact, airway obstruction represents one of the main causes of early death in these
patients. Therefore, repeated assessment of the patient's condition is essential. Details
of clinical symptoms are given in the chapter on Clinical Symptomatology.
PATHOPHYSIOLOGICAL ASPECTS
(i)
Vital capacity
Since Hutchinson (1846) studied measurement of vital capacity, this remained the
standard test of pulmonary function. Sturgis
et al.
(1922), searching for a more dynamic
index than vital capacity, found that maximum ventilation was achieved in the last
minute of exhausting exercise, while Hermannsen (1933) postulated that the highest
ventilation was achieved by maximum voluntary effort and that this far exceeded venti
lation on exercise or in response to breathing CO2 . This was the start of the maximum
breathing capacity test (MBC) or maximum voluntary ventilation test (MW). Cournand
et al.
(1939) and Baldwin
et al.
(1948) found that airway obstruction reduced MW.
Research on vital capacity in tetraplegics and paraplegics developed only in recent
years. In co-operation with Gilliatt & Whitteridge, we found (1947) tnat> while the vital
capacity in the early stages of tetraplegia was low, in later stages a patient with a complete
lesion below C6 lying in supine position had a vital capacity of 2-8 litres and an inspira-
tory capacity of 2-2 litres, measured while sitting in a wheelchair. This was found to be
sufficient to ensure adequate ventilatory function in his daily activities, including sport.
In a more recent study on this subject (Guttmann & Silver, 1965), we found the vital
capacity in the initial stages of tetraplegia as low as 0-3 litres (in the writer's further
experience even o-i litre) but increased later to 1-2-3-3 litres. Cameron
et al.
(1955)
studied the effect of posture on vital capacity in 11 tetraplegics and found that it was
only 65 per cent of a predicted normal, when examined with the patients in supine
position, but that it could be increased by strapping the patient to a tilting table and
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