Table 2 Outcome variables

Primary outcome

 Success rate of sedation (PSSS = 1, 2, or 3) within 15 min from sedative administration

Secondary outcome

 Onset time of sedation (PSSS = 1, 2, or 3)

 Duration of sedation, from onset time to recovery time (PSSS = 4 or 5)

 Sedation failure (PSSS = 4 or 5) after 30 min from administration

  Rescue sedation agent (or method)

 Type of procedure

  Completion of procedure

  Causes of procedure failure

 Total cost of sedation

 PSSS, heart rate, respiration rate, SpO₂ at baseline and every 10 min (blood pressure is measured when heart rate is < 70% of baseline)

 The incidence of PSSS = 0 (abnormal physiologic parameter that require acute intervention)

  The incidence of significant apnea (> 20 s)

  The incidence of significant desaturation (SpO₂ < 95% or < − 10% from baseline, > 10 s)

  The incidence of respiratory intervention: manual ventilation or artificial airway

  The lowest SpO₂ value (%)

  The incidence of significant bradycardia (− 30% from baseline)

  The incidence of significant hypotension (− 30% from baseline)

  The incidence of hemodynamic intervention (fluid management, intravenous medication)

Patients’ acceptance (1 = excellent, 2 = good, 3 = fair, 4 = poor)

Separation anxiety (1 = easy, 2 = whimper, 3 = cry, 4 = cry and cling to parents)

Physicians’ satisfaction (1 = excellent, 2 = good, 3 = fair, 4 = poor)

Other side effects (e.g., nausea/vomit, allergic reaction)