Abstract

In the beginning of anesthetic training, one of the clinical practices that anesthetists have to learn is manually controlled ventilator techniques. The popularity of manually controlled ventilatory techniques has been gradually decreased with increased use for anesthetic ventilators. However it is important and basic for the anesthetists to master manually controlled ventilator techniques skillfully. Recently, we analyzed the arterial blood gas in 30 cases before and during general anesthesia, and studied the effects of the manually controlled ventilation on the pulmonary gas exchange. The results were as follow; 1) Mean value of PaCO₂ during the manually controlled ventilation, 29.9±2.0 mmHg was decreased statistically comparing with that of PaCO₂ before the anesthesia, 39.8±2.8 mmHg. 2) Mean values of pH and HCO₃⁻ during the manually controlled ventilation were 7.48±0.03, 22.2±2.4 mEq/1, respectively and values before the anesthesia were 7.41±0.02, 25.2±1.8 mEq/1, respectively. 3) Mean value of PaO₂ and O₂ saturation during the manually controlled ventilation were 270.0±28.8 mmHg, 99.6±0.2%, respectively and values before the anesthesia were 92.5±4.0 mmHg, 96.9±1.0%, respectively. These results indicates that manually controlled ventilation at our department of anesthesiology produced mild hyperventilatory state. However these were no significant changes in cerebral blood flow and other biochemical parameters.