Background and purpose: Lung hyperinflation is a technique used by physiotherapists to mobilize and remove excess bronchial secretions, reinflate areas of pulmonary collapse and improve oxygenation. Hyperinflation may be delivered by the ventilator or manually, by use of a manual resuscitation circuit, depending upon the respiratory and cardiovascular status of the patient. The effects of manual hyperinflation, with respect to excess bronchial secretions and static lung compliance, have been well-established. There is, however, only limited evidence as to the efficacy of ventilator hyperinflation as a physiotherapy treatment technique. The purpose of the present study was to compare the effects of manual hyperinflation and ventilator hyperinflation on static pulmonary compliance and sputum clearance in stable intubated and ventilated patients.
Method: Twenty patients who met the inclusion criteria were studied. This was a double crossover study where all patients were randomly allocated to one of two treatment sequences over two days. The first sequence involved manual hyperinflation followed two hours later by ventilator hyperinflation and the order was reversed on the second day. In the second sequence, ventilator hyperinflation preceded manual hyperinflation. The variables of static pulmonary compliance and sputum wet weight were analysed by use of an analysis of variance (ANOVA) for repeated measures. Statistical significance was set at p < 0.05.
Results: There was no significant difference in sputum wet weight production between either technique or on either day of treatment. Static pulmonary compliance improved with both hyperinflation techniques (p < 0.05).
Conclusions: Hyperinflation as part of a physiotherapy treatment can be performed with equal benefit using either a manual resuscitation circuit or a ventilator. Both methods of hyperinflation improve static pulmonary compliance and clear similar volumes of pulmonary secretions.