Background and purpose: The present study aimed to evaluate the consistency with which physiotherapists apply manual hyperinflation to a test lung using the Air-Viva-2 or Mapleson-B resuscitation circuit, and their ability to modify the technique as pulmonary characteristics change.
Method: A quasi-experimental, randomized, repeated-measures design was used to study 16 volunteer physiotherapists performing manual hyperinflation to a test lung simulating three clinical situations. Each subject applied manual hyperinflation to the test lung for each simulation three times in one day using the resuscitation circuit that they would normally use in their clinical practice. Eight subjects used the Air-Viva-2 circuit and eight used the Mapleson-B circuit. Measurements of tidal volume (Vp), peak airway pressure (Paw) and fraction of delivered oxygen (FDO2) were recorded during each testing period. Inflation rate and minute volume were calculated.
Results: As compliance decreased and airway resistance increased, VT decreased and Paw increased. Of the eight subjects using the Air-Viva-2 circuit, only three subjects delivered greater than 0.80 FDO2. All subjects using the Mapleson-B circuit delivered greater than 0.85 FDO2.
Conclusions: Subjects demonstrated good consistency in the application of manual hyperinflation for all three simulations and modified their technique appropriately as simulated pulmonary characteristics changed.