The effect of the level of ventilatory assist on the level of respiratory drive in decerebrate cats.
The present study was undertaken to investigate whether, independent of changes in PaCO2, ventilatory assist influences not only the pattern but also the level of the respiratory drive. The experiments were performed on decerebrate and paralyzed cats ventilated by a phrenic-driven servo respirator at three different FICO2 levels (0, 0.30, 0.05). The level of ventilatory assist was altered within the range where PaCO2 did not exceed 80 Torr. A higher FICO2 accompanied a higher level of ventilatory assist. The relationship between the minute phrenic activity and log10 PaCO2 at a given FICO2 was linear. No significant difference was found in the regression lines at different levels of FICO2. We conclude that ventilatory assist has little effect on the respiratory drive at a constant level of chemical feedback during hypercapnia.
Muro
S
S
Department of Clinical Physiology, Kyoto University, Japan. muro@chest.kyotou.ac.jp
Oku
Y
Y
Chin
K
K
Mishima
M
M
Ohi
M
M
Kuno
K
K
D000818:Animals; D002245:Carbon Dioxide / Q000097:blood / Q000502:physiology*; D002415:Cats; D003655:Decerebrate State; D005246:Feedback / Q000502:physiology; D005260:Female; D008297:Male; D010243:Paralysis; D010791:Phrenic Nerve / Q000502:physiology; D012044:Regression Analysis; D012121:Respiration, Artificial; D015656:Respiratory Mechanics / Q000502:physiology*
D002245:Carbon Dioxide