[Application of fuzzy algorithms for ventilatory control during clinical anesthesia].
A computer program, which calculates the required minute volume using fuzzy set rule incorporating the authors' clinical experiences, was developed to keep a stable PCO2 during anesthesia, and its clinical usefulness was examined on 30 consecutive patients. The program requires the value of end-tidal CO2 concentrations at present, and 5 minutes before, and arterial-end-tidal CO2 tension difference (aEDCO2), and generates the adjustable value of minute volume to maintain the constant PaCO2 (acceptable range; 37 to 33 mmHg). Twenty-three cases were successfully controlled after adopting the calculated minute volume, which closely coincided with our clinical experiences. Seven cases, on the other hand, did not show the anticipated PaCO2 change, because of incidental leakage of endotracheal cuff (2 cases), larger aEDCO2 than the expected value of 4 mmHg (4 cases), or mild pulmonary edema (1 case). It has become clear that in the steady anesthetized patients, the program based on the authors' clinical experiences, which was made possible with the concept of fuzzy set rule, can be used to control the PaCO2 within the strict range during variable anesthetic situations.
Kuramoto
T
T
Department of Anesthesia, Tane General Hospital, Osaka.
Yamashita
S
S
Tsutsui
T
T
Arita
S
S
D000328:Adult; D000465:Algorithms; D000758:Anesthesia; D006801:Humans; D008875:Middle Aged; D012984:Software; D012122:Ventilators, Mechanical