Sedation is defined as the depressed level of consciousness induced by administration of drugs. When gastrointestinal endoscopy is performed, sedation is frequently used for the sake of both the patient and the endoscopist. For a patient, anxiety and discomfort can be relieved. Moreover, amnesia, regarding memory of the event, may be anticipated. For an endoscopist, the quality of the examination is improved through the control of unintended movements. The level of sedation is a continuum ranging from minimal sedation (anxiolysis) to general anesthesia, which is defined by a patient’s degree of spontaneous ventilation, maintenance of cardiovascular function, and response to verbal and tactile stimuli (Table 1).1 The targeted level of sedation may differ depending on a patient’s condition and the duration or complexity of the procedure. Usually, moderate sedation is the preferred level. Deep sedation, however, may be achieved with or without intention, in which case the risk of serious adverse events (AEs), e.g., cardiopulmonary compromise, increases. In this article, sedation guidelines for the Accreditation of Qualified Endoscopy Units (AQEUs), issued by the Korean Society of Gastrointestinal Endoscopy (KSGE), are presented (Table 2).

Rationale: Prior to endoscopic sedation, previous medical history of the patient, including cardiopulmonary disease, neurological disease, sleep apnea, AEs from using sedatives, current medication, alcohol abuse, and compliance with fasting time, must be checked to determine if any of these factors may affect the outcome of sedation [1,2]. The findings must be recorded in the pre-screening chart or pre-procedure assessment report (Supplementary file 1).

Rationale: Sedatives and analgesics administered during endoscopic sedation may cause cardiovascular and/or respiratory AEs, such as a temporary drop in blood pressure, respiratory depression, or arrhythmia. In particular, greater caution should be taken in cases comorbid with chronic diseases. Accordingly, pre-procedure assessment on these factors is necessary, and appropriate measures should be taken when required.

Rationale: The endoscopic sedation consent form must include an explanation on the sedative endoscopic procedure; purpose and necessity of sedation; processes and methods of endoscopic sedation; problems, AEs, and sequelae associated with endoscopic sedation; alternative treatment options besides endoscopic sedation; and prognosis, if left untreated (Supplementary file 2). Even after an endoscopic sedation has been completed, the patient may still face the risk of AEs associated with the sedative(s) used. Although the patient is discharged after the state of recovery is adequately assessed, each individual may experience a different duration of sustained sedative effect. Therefore, it is necessary for the patient to be accompanied by a guardian when being discharged.

Rationale: Life-threatening AEs, such as cardiopulmonary dysfunction, may occur during endoscopic sedation; thus, endoscopists and other assistants must have completed sedation-related education on symptoms to check prior to the procedure, monitor during the procedure, and after the procedure, and on emergency measures to ensure patient safety.

Rationale: During the procedure, the patient’s blood pressure, heart rate, respiratory rate, and oxygen saturation must be monitored regularly, to discern possible endoscopic sedation-related AEs [3]. The findings must be recorded in the sedation report (Supplementary file 3).

Rationale: An endoscopy findings report serves as evidence of the most important outcomes in endoscopy. Therefore, records of sedatives, analgesics, spasmolytics, and antagonists used during the endoscopic procedure must be available. The use of drugs that are managed under narcotics control is to be confirmed from the narcotics control records, and the use of non-narcotics could be found in relevant records. Records contained in computer storage media or hand written reports are acceptable.

Rationale: The patient’s age, health status, current medication, tension, and sensitivity to pain, are factors that may affect the efficacy of sedation, and thus, must be considered prior to endoscopic sedation. Because the required dose of sedatives used for endoscopic sedation may change depending on the patient’s general condition, age, and current medication, it is necessary to have sedative administration guidelines in place. In this context, the guidebook for endoscopic sedation issued by the KSGE recommends the following administration method:

When administering midazolam alone to healthy adults aged <65 years, 2.5–3 mg of midazolam (or 0.05 mg/kg of body weight) should be slowly administered intravenously, followed by repeated administration of 1–2 mg (or 0.02–0.03 mg/kg) in 2- to 3-minute intervals until adequate sedation is achieved. For general diagnostic examinations, a dose within 5 mg should be sufficient and a higher dose is not recommended since it increases the risk of AEs. For patients with a high risk of endoscopic sedation-related AEs, such as the elderly aged ≥65 years, patients with ASA class III or higher, and patients with airway obstruction, a dose reduction of ≥20% should be applied. Co-administering midazolam with narcotic analgesics has a synergistic effect, and thus, the injection should be accompanied by a single administration of midazolam reduced by 20% from the dose described above. When using meperidine, adequate sedation could be achieved with an initial intravenous injection of 12.5–25 mg, followed by repeated administration of 12.5–25 mg in 3- to 5-minute intervals when necessary. If the length of the procedure is short, a single injection is sufficient and the maximum dose of 50 mg should not be exceeded. When using fentanyl, an initial intravenous injection of 25–50 μg should be used, followed by repeated administration of 12.5–25 μg in 3- to 5-minute intervals when necessary. However, a single injection is sufficient in most cases and the maximum dose of 100 μg should not be exceeded. For patients with high risk of endoscopic sedation-related AEs, elderly patients aged ≥65 years, or patients with ASA class III or higher, the analgesic dose should be reduced by ≥50% (meperidine 12.5 mg/fentanyl 25 μg).

When administering propofol alone to healthy adults aged <65 years, 30–40 mg (or 0.5 mg/kg) should be administered, and an additional 10–20 mg should be administered with at least a 20-second intermission, as necessary. For patients with a high risk of endoscopic sedation-related AEs, elderly aged ≥65 years, or patients with ASA class III or higher, the administered dose should be reduced by ≥50%. When opting for a balanced propofol sedation, midazolam (0.025–0.05 mg/kg), meperidine 25 mg (or fentanyl 50 μg), and propofol (10–20 mg or 0.25 mg/kg) should be administered in sequence to healthy adults aged <65 years; sedation should be maintained by repeated administration of 10–20 mg of propofol with at least 20-second intermission. For patients with high risk of endoscopic sedation-related AEs, elderly aged ≥65 years, or patients with ASA class III or higher, the administered dose should be reduced by ≥50% or midazolam should be used alone.

Rationale: Nurses assigned to the recovery room are needed for proper patient monitoring following endoscopic sedation, assessment of discharge criteria, and for providing adequate explanation to the patient and guardian at the time of discharge.

Rationale: There are individual differences with respect to recovery from endoscopic sedation, and in rare cases, AEs, such as respiratory distress, apnea, hypotension, bradycardia, and shock, may occur. Therefore, the patient’s oxygen saturation, heart rate, and blood pressure must be monitored and even electrocardiogram (ECG) should be performed when necessary, until discharge in accordance with the guidelines. Therefore, patient monitoring and oxygen-supply equipment must be available and countermeasures need to be established.

Rationale: After endoscopic sedation, the risk of AEs associated with the sedative used still remains. Therefore, standards and manuals for patient care in the recovery room and discharge from the recovery room are absolutely necessary. The most commonly used recovery assessment scales include the Aldrete score (Table 3) and the Postanesthetic Discharge Scoring System (PADSS) [4].

Rationale: Narcotics act on the human central nervous system and are recognized to cause serious harm to the human body when misused or abused. Therefore, they must be kept in a reserved area that is not easily accessible by patients and in an area protected by a double lock to avoid misuse and abuse.

Rationale: Close attention must be paid to the storage of narcotics since they have a high risk of theft and loss, which may lead to misuse and abuse. Drugs containing a lipid emulsion must be dispensed and prepared immediately before the administration owing to a potential risk of infection due to bacterial contamination.

Rationale: Emergencies may occur during endoscopic sedation. Accordingly, areas, equipment, and personnel for monitoring and responding to such situations are needed [5].

Rationale: To determine cases with respiratory depression severe enough to require endotracheal intubation, the Mallampati score should be assessed prior to endoscopic sedation to determine the risk of hypoxia and the expected degree of difficulty when intubating the patient. The Mallampati classification is as shown below (Fig. 1) [6]. For cases characterized as Class IV, assistance from an anesthesiologist may be required [3].

Rationale: Endoscopic sedation involves administration of sedative(s) that can lower the patient’s level of consciousness for the procedure. Therefore, it is necessary to assess the patient’s level of consciousness accurately, prior to the procedure and determine whether sedation could be performed. An example of assessment of the level of consciousness is as follows (Table 4) [7]:

Rationale: When performing moderate or deep sedation on patients with serious cardiovascular disease or arrhythmia, continuous ECG monitoring is recommended. It may also be helpful in cases involving elderly patients or patients with respiratory disease, and when the procedure is expected to prolong.

Rationale: ECG monitoring should be performed on patients with serious cardiovascular disease or arrhythmia or in cases for which it is recommended. It may also be helpful in cases involving elderly patients or patients with respiratory disease, when bradycardia or arrhythmia occurs during the procedure, and when the patient shows unstable vital signs during the procedure.

When performing endoscopic sedation, practitioners should do their best to maximize the benefits while minimizing the risks. Principles regarding the personnel, facility and equipment, as well as performance itself, should be followed to prevent unfavorable incidents.