How mode of stimulus affects the relative contribution of elastance and hysteresivity to changes in lung tissue resistance

• DOI: 10.1152/jappl.1995.78.1.282
• Publication Date: 2017-12-22T06:38:33Z
• Authors: F. G. Salerno; A. Moretto; M. Dallaire; M. S. Ludwig
• Keywords: Methacholine; Bolus (digestion); Positive End-Expiratory Pressure; Elastance

Challenges with high concentrations of constrictor agonist delivered by intravenous vs. aerosol result in different modifications the mechanical properties lung tissues. We questioned whether low doses a smooth muscle administered via routes (aerosol, i.v. bolus, continuous infusion) or an increase positive end-expiratory pressure (PEEP) would perturbations Tracheal and alveolar pressures flow were measured open-chest mechanically ventilated (frequency 1 Hz, tidal volume 10 ml/kg, PEEP 4 cmH2O) rats under baseline conditions after administration methacholine increases PEEP. calculated elastance (EL), resistance, tissue resistance (Rti) fitting equation motion to changes tracheal pressures. Airway hysteresivity (eta) derived from above measurements. For comparable Rti, groups showed large EL decrease eta, whereas two eta smaller EL. The largest contribution overall Rti was seen bolus group. When induced plotted, relationships found for four groups. conclude that despite similar kind perturbation occurred tissues depended on nature stimulus.