Results
mellitusChronic kidney disease15
Two hundred ninety-three patients were assessed for eligibility, and 248 patients were enrolled in the study. Five and thirteen patients in the Ventilation and Apnea groups, respectively, dropped out due to changes in surgery plan, inaccurate ultrasound findings, L-tube or intubation failure, and loss of data. Finally, 119 and 111 patients were assessed in the Ventilation and Apnea groups, respectively (Fig. 
Flow diagram of patient selection in this studyThere were no differences in patient characteristics between the groups (Table 
Characteristics of patients undergoing pressure-controlled ventilation or non-ventilation during anesthesia inductionIIIIII54 (45%)60 (51%)5 (4%)48 (43%)60 (54%)3 (3%)Diabetes mellitusChronic kidney disease15 (12.6%)1 (0.8%)17 (15.3%)1 (0.9%)0.5730.367Values are mean (SD) or number (proportion). *, body-mass index
Gastric antral cross-sectional area, laparoscopic surgical grade and amount of gastric volumePre-induction (PI)Post-intubation (PT)Changes3.97 (1.36)4.01 (1.45)0.04 (0.3)4.16 (1.32)4.15 (1.41)0.02 (0.28)0.360.5020.225123443 (36%)68 (57%)8 (7%)0 (0)52 (47%)52 (47%)7 (6%)0 (0)AirFluidTotal16.4 (17.6)14.1 (18.0)30.5 (28.6)15.6 (13.5)13.9 (16.7)29.5 (25.8)0.7790.9900.943Values are mean (SD) or number (proportion). Changes in vital signs during induction were analyzed by repeated measures general linear model. Oxygen saturation was maintained at a safe level during induction in both groups. Mean blood pressure significantly changed in both groups over time (
Values of various hemodynamic parametersValues are mean ± SD. SpO
Vital sign changes during anesthesia induction. SpO