Relationship between frequency of ventilation, airways and pulmonary artery pressures, cardiac output and tracheal tube deadspace

Publisher Website
Google Scholar
Abstract
Intravascular and airway pressures, cardiac output (CO) and blood gas tensions were measured in five adult patients after hepatobiliary surgery. They were ventilated at frequencies of 15, 100 and 200 breaths min‐1 (bpm) with the respiratory fresh gas (RFG) supplied at the proximal and distal end of a Malinkrodt Hi‐Lo tracheal tube. The peak airway pressure (Paw) fell from 1.20 kPa at 15 bpm to 0.6 kPa at 100 bpm, rising again to 1.9 kPa at 200 bpm, and both changes were significant (PPP2 occurred when the RFG was moved to the distal end of the tracheal tube. A theoretical analysis predicts that the minimal Paw to maintain CO2 homeostasis will occur between 30 to 100 bpm, which is reflected in the results of the present study.