The factors responsible for the apnea observed during high-frequency ventilation (HFV) was evaluated in 14 pentobarbital sodium-anesthetized cats. A multiple logistic regression analysis provided an estimate of the probability of apnea during HFV as a function of four respiratory variables: mean airway pressure (Paw), tidal volume (VT), frequency, and arterial PCO2 (Pa(CO2)). When mean Paw was 2 cmH2O, Pa(CO2), VT, and their interaction contributed significantly to the probability of apnea during HFV. At a low value of Pa(CO2) (25 Torr), the probability of apnea had a minimum value of 0.19 and gradually increased toward 1.0 as VT increased from 0.5 to 7 ml/kg. At higher levels of Pa(CO2) (30 and 35 Torr) the probability of apnea was zero in the low range of VT but sharply approached 1.0 above a VT of ~2.0 ml/kg. However, when Paw was increased to 6 cmH2O, only Pa(CO2) was an important determinant of apnea. In this case, the probability of apnea was 0.51 when Pa(CO2) as 25 Torr but decreased to 0.22 when Pa(CO2) was raised to 35 Torr. At neither Paw was the probability of apnea dependent on frequency. These results suggest that chemoreceptor inputs, in addition to both static and dynamic lung mechanoreceptor afferents, are responsible for determining the output of the central respiratory centers during HFV.
|Original language||English (US)|
|Number of pages||8|
|Journal||Journal of Applied Physiology|
|Publication status||Published - 1988|
ASJC Scopus subject areas
- Orthopedics and Sports Medicine
- Physical Therapy, Sports Therapy and Rehabilitation