Comparison of Volume-controlled and Pressure-controlled Ventilation in Clasp-knife Position

Hemodynamic variables, respiratory variables and arterial blood gas were measured and recorded 15 minutes after induction of anesthesia (T1), 15 minutes after establishment of a folding knife position (T2), 30 and 60 minutes after CO2 pneumoconiosis (T3 and T4), and 15 minutes after pneumoconiosis (T5). Hemodynamic variables measured included mean arterial pressure , heart rate , cardiac output, cardiac index, stroke volume index and stroke volume variation. Breathing variables include tidal volume, minute ventilation , respiratory rate , airway frontal pressure , mean airway pressure , plateaus airway pressure , peripheral oxygen saturation , oxygen saturation , and oxygen response . Arterial blood gas variables include pH value, arterial carbon dioxide, arterial oxygen pressure , alkali surplus , alveolar oxygen pressure , and bicarbonate of soda ion concentration .