The mechanism of respiratory rhythm generation during constant flow assisted mechanical ventilation in the decerebrated dog.
In awake human subjects input from the forebrain has significant effects on the respiratory pattern during assisted (AMV) and controlled (CMV) mechanical ventilation. The hypothesis in this animal study was that if the influence from the forebrain is eliminated, the respiration during AMV and that during CMV is controlled by the same mechanism. Fifteen decerebrated and tracheostomized dogs were subjected to CMV with a variety of combinations of tidal volume and frequency. The respiratory rhythm during CMV was simulated by a mathematical model composed of the central respiratory activity and inputs from pulmonary receptors. During AMV, the respiratory cycle duration was prolonged, and this was found to be the summated effect of prolonged Ttg (ventilator trigger period) and shortened Tinf (lung inflation period). When these changes in Ttg and Tinf were included, the model for CMV predicted respiratory changes during AMV. We concluded that the basic mechanism controlling AMV and CMV may be the same.
Kondo
T
T
Department of Internal Medicine, Tokai University School of Medicine, Isehara.
Kobayashi
I
I
Suzuki
H
H
Ohta
Y
Y
D000818:Animals; D003655:Decerebrate State / Q000503:physiopathology*; D004285:Dogs; D008954:Models, Biological; D012123:Pulmonary Ventilation; D012121:Respiration, Artificial / Q000379:methods*; D015656:Respiratory Mechanics