Secondary study outcomes
airway abnormalities, bradycardia, hypoxia, apnea, hypotension, PONV
HYPOXIA, EVENT, ALVEOLAR HYPOVENTILATION, EVENTS, PREMATURE VENTRICULAR CONTRACTIONS
The incidence of severe hypoxia was markedly lower in the capnography group (5.4% vs. 14.2%, In the capnography group, 30 and 66 patients developed altered ventilation and apnea, respectively. Thus, 96 (85.7%) patients underwent intervention in the capnography group(Fig. 
The violin plots show the frequency density of the five last interventions recorded during the sedation. In the event of inadequate alveolar ventilation during sedation, the investigators sequentially implemented five interventions until all respiratory-related parameters returned to normal. The five interventions are represented in alphabetical order(a-e): a: increasing oxygen flow (5 L/min), b: a chin lift or jaw thrust maneuvre, c: placement of the nasopharyngeal airway and chin lift, d: mask positive-pressure ventilation, and e: ventilator-assisted ventilation with tube insertionWhen alveolar hypoventilation occurred during intravenous anesthesia, 47 (49%) of patients in the capnography group resolved their ventilation changes or airway abnormalities by increasing oxygen flow as opposed to only 1 (2.9%) patient in the standard group. Among the patients who received the intervention, 46 (47.9%) of the capnography group and 26 (76.5%) of the standard group had a chin lift or jaw thrust. Nasopharyngeal airways with jaw support were placed in 2 (2.1%) and 5 (14.7%) of patients in the capnography and standard groups, respectively. Two patients in the standard group and one in the capnography group underwent manual mask positive-pressure ventilation (Fig. The differences in minimum SpOAdverse events of anesthesia sedation which occurred during the experiment, such as PONV, hypotension, bradycardia, and premature ventricular contractions, were treated with ondansetron hydrochloride, atropine, noradrenaline, and lidocaine, respectively. There was no statistically significant difference between the two groups (Table 