The effect of intermittent positive pressure breathing on lung volumes in acute quadriparesis
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K Stiller1, R Simionato, K Rice
1Physiotherapy Department, Royal Adelaide Hospital, South Australia.
Insights
Patients with acute quadriparesis experience severe breathing impairment, including reduced vital capacity. Intermittent positive pressure breathing (IPPB) offers temporary lung volume improvement but lacks clinically significant sustained benefits.
Area of Science:
- Pulmonary Medicine
- Neurology
- Critical Care
Background:
- Acute quadriparesis significantly impairs respiratory function.
- Reduced vital capacity and expiratory flow rates are characteristic of this condition.
Purpose of the Study:
- To assess ventilatory function in acute quadriparesis patients.
- To evaluate the immediate effects of intermittent positive pressure breathing (IPPB) on lung volumes.
Main Methods:
- Daily measurements of resting tidal volume and vital capacity over 7-10 days.
- Assessment of expiratory flow rates.
- Measurement of lung volumes before and immediately after IPPB administration.
Main Results:
- On admission, vital capacity was markedly reduced (26% predicted), improving to 33% predicted by study end.
- Expiratory flow rates also showed significant decrements.
- IPPB temporarily increased lung volumes, but tidal volume returned to baseline post-treatment; vital capacity showed a small, non-clinically significant increase (43 ml).
Conclusions:
- Acute quadriparesis causes severe ventilatory impairment.
- IPPB provides transient lung volume enhancement during administration.
- The post-treatment benefits of IPPB on vital capacity are not clinically significant in acute quadriparesis.
Abstract:
Resting tidal volume and vital capacity were measured daily in 5 patients with acute quadriparesis during the first 7 to 10 days of their hospitalisation. On admission, vital capacity was significantly reduced to 26% of the predicted value (p less than 0.001). This increased significantly over the study period to 33% of the predicted value (p less than 0.02). Expiratory flow rates, measured on one occasion during the study period, showed similar decrements. Tidal volume and vital capacity were also measured immediately following administration of intermittent positive pressure breathing (IPPB). Although the lung volume achieved during IPPB was significantly higher than resting values of tidal volume and vital capacity (p less than 0.001), tidal volume returned to baseline values as soon as IPPB was ceased. Vital capacity remained significantly higher than baseline values at this stage (p less than 0.02), although the mean increase in vital capacity immediately following IPPB was only 43 mls. Acute quadriparesis is associated with a severe ventilatory impairment which includes a reduced vital capacity and expiratory flow rates. IPPB has a positive effect on lung volume whilst it is being administered. Immediately following treatment, this effect does not appear to be sustained at a level which would be considered clinically significant.