Penh Studies

For asthma studies on conscious unrestrained subjects, use whole body plethysmography and the Enhanced Pause (Penh) software analyzer.

Benefits

• Subjects are conscious: no anesthesia effects
• Subjects are unrestrained: natural breathing pattern, low stress
• High throughput: run several subjects simultaneously
• Long-duration studies: can provide food and water
• Repeated studies: reevaluate subjects over days and weeks
• No surgical prep: subjects survive studies
• Easy calibration and setup
• Clear results that are easy to interpret
• Easily used with telemetry for combined pulmonary-cardiovascular studies
• Widely-used and published

For asthma dose-response studies, subjects are placed in whole body plethysmographs and are provided with fresh air. Baseline readings are collected and subjects are challenged with an aerosol control followed by increasing dosages of an agonist. Bronchoconstriction is reflected in the Enhanced Pause (Penh) parameter, a unit-less index of airway hyper-reactivity.

The practice of drawing conclusions solely on the basis of Penh alone is controversial. In most cases, the Penh system should be combined with pulmonary mechanics or non-invasive airway mechanics for high throughput screening followed by confirmatory direct measurements of resistance.

To learn more about Penh and the controversy surrounding it, click here.