What Researchers Did
Researchers compared peak expiratory flow (PEF) measurements from peak flow meters and a volumetric spirometer in seven healthy subjects under varying hyperbaric conditions to assess their accuracy at increased pressure.
What They Found
The spirometer showed a progressive and significant decline in PEF with increasing pressure, measuring 69.46% of baseline at 303 kPa compared to 101 kPa. Conversely, both standard and mini peak flow meters progressively increased their readings, showing an increase of 7.86% at 303 kPa.
What This Means for Canadian Patients
For Canadian patients undergoing hyperbaric oxygen therapy, these findings suggest that peak flow meters may provide inaccurate, inflated readings of airway obstruction at increased pressures. Clinicians should be aware of this discrepancy and consider using volumetric spirometers or applying correction factors if peak flow meters are used in hyperbaric environments to ensure accurate assessment of lung function.
Canadian Relevance
This study has no direct Canadian connection as it was not conducted in Canada or by Canadian researchers.
Study Limitations
A limitation of this study is its small sample size of seven normal subjects, which may not fully represent patients with pre-existing airway obstruction.