The practice of endoscopic sedation requires a thorough understanding of preprocedural assessment, sedation pharmacology, intraprocedure monitoring, adverse event management, and postprocedural care. The training process has become increasingly standardized and entails knowledge and practice-based components. The use of propofol in particular requires a higher level of structured training owing to its narrow therapeutic window. Simulation has increased opportunities for practice-based training in a controlled environment. After completion of training, the endoscopist must demonstrate competence in theoretical understanding and technical ability to administer sedation. Although individual institutions have certification processes, there is a lack of validated, standardized methods to confirm competence.
Key points
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Instruction in endoscopic sedation includes theoretical and practice-based components.
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Critical skills needed to safely perform sedation include preprocedural assessment, informed consent, sedation administration, intraprocedure and postprocedure monitoring, adverse event management, and safe discharge.
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The use of propofol by nonanesthesia providers mandates a more intense training curriculum given the narrow therapeutic range and resulting increased risk of deep or general anesthesia induction.
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Simulation allows trainees to gain hands-on experience managing sedation and related adverse events in a controlled environment.
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Methods to assess endoscopic sedation competency differ among institutions, but requires testing of knowledge and technical skills.
Need for sedation training
The purpose of endoscopic sedation is to relieve the patient’s discomfort and anxiety while simultaneously reducing disruptive movements so that an adequate endoscopic examination may be performed. Patient safety needs to be ensured while procedural efficacy is maintained. The delivery of sedation requires multifaceted expertise and the endoscopist needs to be adept at each step of the sedation process ranging from preprocedural planning to patient discharge.
The increasing use of propofol to support endoscopy has intensified awareness of these challenges. Although large studies have demonstrated consistently low morbidity, the classification of this agent as a general anesthetic has led to questions about endoscopists’ lack of proper training in sedation and potential ramifications for patient safety. Furthermore, a significant portion of the American malpractice claims against gastroenterologists originates from sedation-related complications.
Thus, a key challenge currently encountered in fellowship programs and clinical institutions is to ensure that endoscopists are trained properly in the practice of sedation to the level of competency. Traditionally, training in sedation for endoscopy has been done via the informal apprentice and mentor model within the endoscopy suite. Although training under the direct guidance of an anesthesiologist has not been required, the consensus of the gastroenterology community is that the training process needs to be done with a more thorough and programmatic approach. This process includes the need for formal education, simulator-based experiences, immediately supervised hands-on practice, and finally testing for competence. In this review, we aim to cover the current guidelines and approaches to training gastroenterologists in the practice of sedation and the tools available for assessing competency.
Need for sedation training
The purpose of endoscopic sedation is to relieve the patient’s discomfort and anxiety while simultaneously reducing disruptive movements so that an adequate endoscopic examination may be performed. Patient safety needs to be ensured while procedural efficacy is maintained. The delivery of sedation requires multifaceted expertise and the endoscopist needs to be adept at each step of the sedation process ranging from preprocedural planning to patient discharge.
The increasing use of propofol to support endoscopy has intensified awareness of these challenges. Although large studies have demonstrated consistently low morbidity, the classification of this agent as a general anesthetic has led to questions about endoscopists’ lack of proper training in sedation and potential ramifications for patient safety. Furthermore, a significant portion of the American malpractice claims against gastroenterologists originates from sedation-related complications.
Thus, a key challenge currently encountered in fellowship programs and clinical institutions is to ensure that endoscopists are trained properly in the practice of sedation to the level of competency. Traditionally, training in sedation for endoscopy has been done via the informal apprentice and mentor model within the endoscopy suite. Although training under the direct guidance of an anesthesiologist has not been required, the consensus of the gastroenterology community is that the training process needs to be done with a more thorough and programmatic approach. This process includes the need for formal education, simulator-based experiences, immediately supervised hands-on practice, and finally testing for competence. In this review, we aim to cover the current guidelines and approaches to training gastroenterologists in the practice of sedation and the tools available for assessing competency.
Current guidelines
The most widely recognized American curriculum and competency guidelines for sedation training of Gastroenterology professionals are included in the Multisociety Sedation Curriculum for Gastrointestinal Endoscopy (MSCGE; 2012) derived from the combined efforts of the American Society for Gastrointestinal Endoscopy, American Gastroenterological Association, American College of Gastroenterology, the American Association for the Study of Liver Disease, and the Society for Gastroenterology Nurses and Associates. The American Society of Anesthesiologists (ASA) sedation guidelines for nonanesthesiologists (2002) remains highly influential. The most recent European curriculum comes from a consortium of the European Society of Gastrointestinal Endoscopy, European Society of Gastroenterology, and the European Society of and Gastroenterology and Endoscopy Nurses and Associates in 2013. This curriculum was updated in 2015 with a special focus on nonanesthesiologist administered propofol training. Other published guidelines include the Spanish Society of Digestive Endoscopy (2014), Japanese Gastroenterological Endoscopy (2015), Australian Tripartite Endoscopy Sedation Committee (2010), and the German (S3; 2008) guidelines. The impact of the implementation of the S3 guidelines has been the subject of prospective investigation.
Although the guidelines differ in specific content, they emphasize that the training process needs to include both theoretical and practical skills training. The former involves a blend of didactics and self-teaching and the latter entails simulation scenarios as well as direct observation of clinical performance by an instructor. The 2 main curricula defer in that the MSCGE takes a more self-directed, individualized approach to learning, whereas the European curriculum serves as more of an instruction guide to teachers and organizations seeking to organize sedation courses. The MSCGE aims to provide a foundation of knowledge and then create pathways to allow the individual to fill in gaps in their current understanding of endoscopic sedation. The course structure of the European curriculum consists of a 3-day introductory course that combines theory and practice followed by at least a 2-week course of clinical training with a mentor. Both courses recommend detailed training in preprocedure assessment and preparation, appropriate pharmacologic and monitoring strategies during the procedure, management of adverse events, and postprocedure monitoring.
Training in preprocedure management
Training in sedation preparation involves learning how to perform an adequate risk assessment and determining when to enlist the assistance of an anesthesia professional. This should be done congruently with other pre-endoscopic evaluations, such as the need for antibiotic prophylaxis and bleeding tendency. In the United States, fellowship trainees are required to complete institution-specific written or computerized case-based models on sedation risk assessment. However, almost the entirety of their training occurs through “on-the-job” training during faculty-supervised endoscopy.
Risk Assessment
Training to perform an accurate risk assessment begins with learning how to conduct a careful history and focused physical examination. The trainee needs to assess for a previous adverse reaction to sedatives, symptoms of obstructive sleep apnea, and a history of alcohol overuse or drug abuse. These risk factors are associated with sedation complications. The physical examination should focus on vital signs, mental status, and the presence of pathologic anatomic features associated with a greater risk of airway obstruction such as craniofacial malformation, tumors, or restricted mouth opening. The trainee needs to be able to apply the Mallampati scoring system to predict ease of intubation. Cardiopulmonary findings such as wheezing or crackles suggest the presence of underlying asthma or fluid overload. The anticipated complexity of the planned procedure may also contribute to this risk profile and preprocedure management. For example, some facilities mandate that all patients undergoing high complexity procedures such as endoscopic retrograde cholangiopancreatography be sedated by the anesthesia service.
The trainee needs to be able to use the ASA physical status classification. Although endoscopist-directed sedation is usually safe for patients with an ASA class of II or lower, increasing ASA scores positively correlates with a higher rate of sedation complications and requirement for emergency reversal strategies. Various guidelines differ regarding which ASA class is considered high risk for sedation. American guidelines consider physical class IV or higher to have severe systemic disease and suggest an anesthesiologist to manage sedation. The S3 endoscopic sedation guidelines from Germany emphasize patients of class of III or higher are at higher risk for sedation. After the completion of a 3-day training program based on the S3 guidelines, the use of the ASA classification to classify patient risk increased by more than 20% across 224 German institutions.
Special Circumstances
The practice of endoscopic sedation in the pregnant and elderly population warrants discussion during the training process. Endoscopy and the use of sedation should not be used in pregnancy unless absolutely necessary because the fetus may be exposed to hypoxemia and hypotension during the use of endoscopic sedation, which can potentially lead to fetal injury. Certain medications including benzodiazepines are contraindicated in pregnancy. When performing endoscopic sedation on an elderly patient, increased attention needs to be paid to the presence of age-related diseases (eg, cardiac dysfunction), enhanced sensitivity to sedatives, increased risk of aspiration, and prolonged recovery time. During training, endoscopists should practice decreasing the risk associated with sedation by using only a portion of the recommended initial dose, minimizing the total dose given, and slowly titrating sedatives during the procedure. A more detailed discussion of the preprocedure assessment of high-risk patients is included in a dedicated section of this edition of Gastrointestinal Endoscopy Clinics of North America . Ultimately, the decision of whether a gastroenterologist should perform the sedation or defer to an anesthesiologist comes from taking all risk factors into consideration.
Obtaining Informed Consent and Documentation
Despite being a critical part of the preprocedure assessment with the ability to mitigate malpractice risk, a significant proportion of gastroenterology fellowship programs do not offer structured training in informed consent. Obtaining proper informed consent for endoscopic sedation is an underrecognized part of the preprocedural assessment. Sedation represents a significant portion of the complications related to performing endoscopy and in many medicolegal cases patients attested that they were inadequately aware of nonprocedural risks. The trainee must be able to determine that the patient is competent enough to give consent. After establishing competency, the trainee must then accurately explain what endoscopic sedation entails to inform the patient to make an autonomous decision. This includes information regarding the benefits, risks, and alternatives of sedation including the options for anesthesiologist-delivered sedation or unsedated endoscopy. Careful documentation of informed consent is now the standard. The ability to properly perform documentation of other vital information (eg, vital signs, home medications) and time out before the procedure is also expected of the trainee before the start of independent practice.
Training in sedation administration
Level of Sedation
After the preprocedure assessment training is done, the trainee then needs to learn the differences between the different levels of sedation and how to determine which level is ideal for different procedures and situations. Minimal and moderate sedation still leaves the patient able to respond purposefully to actions and commands while cardiovascular and ventilation functions are still preserved. Deep and general sedation represents a continuum in which patients may require assistance with maintaining airway or cardiovascular function ( Table 1 ). General anesthesia is strictly the domain of anesthesia specialists who can perform complex maneuvers to maintain adequate respiration and cardiovascular function. In most situations, the endoscopist’s goal is to achieve moderate sedation successfully. However, a trainee should recognize that the boundary between moderate and deep sedation is often vague and thus should be prepared to manage patients that transiently become deeply sedated. Trainees must be cognizant that all sedative agents they use can result in general anesthesia.
| Minimal Sedation (Anxiolysis) | Moderate Sedation (Conscious Sedation) | Deep Sedation | General Anesthesia | |
|---|---|---|---|---|
| Responsiveness | Normal response to verbal stimulation | Purposeful response to verbal or tactile stimulation | Purposeful response after repeated or painful stimulation | Unarousable, even with painful stimulus |
| Airway | Unaffected | No intervention required | Intervention may be required | Intervention often required |
| Spontaneous ventilation | Unaffected | Adequate | May be inadequate | Frequently inadequate |
| Cardiovascular function | Unaffected | Usually maintained | Usually maintained | May be impaired |
To monitor and quantify a patient’s level of sedation, trainees should be aware of the available validated scoring systems. The most frequently used scale is the Observer’s Assessment of Alertness/Sedation (OAA/S) ( Table 2 ). Other scoring systems include the Sedation-Agitation Scale (SAS), Ramsay Sedation Scale, and the Modified Richmond Agitation-Sedation Score. Upper endoscopies and colonoscopies can usually be managed by moderate sedation, whereas longer and more complex procedures like endoscopic retrograde cholangiopancreatography or endoscopic ultrasound examinations may require deep sedation or general anesthesia. The use of deep sedation by endoscopists is controversial because there is concern that endoscopists lack the training to recognize and rescue a patient who loses their protective reflexes.
| Responsiveness | Numerical Score |
|---|---|
| Responds readily to name spoken in normal tone | 5 |
| Lethargic response to name spoken in normal tone | 4 |
| Responds only after name is called loudly and/or repeatedly | 3 |
| Responds only after mild prodding or shaking | 2 |
| Responds only after painful trapezius squeeze | 1 |
| No response after painful trapezius squeeze | 0 |
Pharmacology and Medication Administration
Trainees need to recognize the appropriate agents, dosing, and timing of sedation medications to administer during endoscopy. The MSCGE advocates for both a cognitive training in medication management involving lectures and independent study as well as a procedure training portion that is bilevel. The first component of hands-on procedure training involves the observation of a faculty member administering sedation and the use of a sedation simulator. Subsequently, the trainee should administer sedation under direct faculty supervision. Ideally, hands-on training is followed by case review sessions to discuss cases and adverse events.
Factors that should be considered when choosing sedation medications not only include type and expected duration of the procedure, but also patient-specific considerations including drug–drug interactions, side effects, and intolerance ( Table 3 ). Institutional regulations as well as state and national statutes may also impact the availability of certain agents. The induction and maintenance of sedation is a dynamic process that requires the trainee to continuously evaluate the depth of sedation, assess how the patient is tolerating the procedure, and recognize when the assistance of an anesthesia professional may be required emergently. More intensive training in sedation techniques, obtained through intensive care and anesthesia rotations, correlates with a decreased reliance of on fixed medication administration protocols (ie, scheduled doses every 3–5 minutes) and improved moderate sedation morbidity.
| Drug | Onset of Action (min) | Peak Effect (min) | Duration of Effect (min) | Side Effects | Antagonism |
|---|---|---|---|---|---|
| Midazolam | 1–2 | 3–4 | 15–80 | Respiratory depression Disinhibition reactions Cardiac dysrhythmia | Flumazenil |
| Diazepam | 2–3 | 3–5 | 360 | Respiratory depression Disinhibition reactions | Flumazenil |
| Propofol | <1 | 1–2 | 4–8 | Hypoxemia Apnea Hypotension Bradycardia Upper airway obstruction Injection site pain Propofol infusion syndrome | None |
| Meperidine | 3–6 | 5–7 | 60–180 | Synergistic respiratory depression Cardiovascular instability Nausea and vomiting Neurotoxicity with renal failure | Naloxone |
| Fentanyl | 1–2 | 3–5 | 30–60 | Synergistic respiratory depression Chest wall rigidity Skeletal muscle hypertonicity | Naloxone |
Endoscopists have been traditionally the most comfortable with the use of the benzodiazepines and opiates combination as both medications have readily available reversal agents. Benzodiazepines induce sedative, amnestic, and anxiolytic effects by activating the gamma-amino butyric acid receptor. Midazolam is the benzodiazepine most often used in practice owing to its potency, relatively short half-life (2–6 hours), and amnesic properties. However, this medication still carries a significant rate of respiratory depression. Opiates exert strong analgesic effects via the μ−opioid receptor. Fentanyl is favored owing to its combination of high potency, rapid onset, and short half-life (2–7 hours), which favors quicker recovery. Opiates induce respiratory depression, particularly when given in combination with benzodiazepines.
Additional medications used in combination with benzodiazepines and opiates include antihistamines such as diphenhydramine and dopamine receptor antagonists including promethazine. However, the addition of these medications may increase the risk of hypoventilation and prolong recovery. Ketamine and droperidol have also been used as adjuncts but the ketamine may result in an unpleasant psychological reaction and the droperidol has a US Food and Drug Administration black box warning for prolongation of QT intervals.
Propofol
Propofol’s favorable pharmacodynamic and pharmacokinetic profile (half-life of 2–4 minutes, onset of action <1 minute) has led to its widespread using in endoscopic sedation. Propofol as a monotherapy in basic and advanced endoscopy has been shown to induce moderate sedation more rapidly than the midazolam and fentanyl or meperidine combinations, while improving recovery time and patient satisfaction in several randomized trials. However, although the overall risk of adverse sedation events in large endoscopic series has been shown to be low, propofol has a much narrower window between moderate sedation and general anesthesia then benzodiazepines and narcotics. Additionally, there is no reversal agent that can be administered if oversedation or loss of protective airway reflexes occurs. Thus, the US Food and Drug Administration has labeled propofol as a general anesthetic. A petition to change the warning labeling on propofol by the American College of Gastroenterology in 2010 was denied. Recently, the 21 European Anesthesiology Societies issued a consensus statement that nonanesthesiologists should not administer propofol. However, the use of dedicated anesthesia providers to provide sedation for endoscopic procedures is costly and may not be financially feasible.
In this controversial setting, guidelines recommend that nonanesthesiologists who administers propofol undergo more structured training and certification than those who administer strictly moderate sedation. Typically this consists of institution-specific training courses and direct hands-on training with an anesthesiologist or another provider with more than 300 cases of propofol sedation experience. For example, at Denmark’s Gentofte University Hospital, a 6-week course was developed for nurse-administered propofol sedation (NAPS) sedation, which included rigorous training in practical airway management, observation, simulation training in adverse event management, and direct supervision. The performance of the NAPS teams during the first 1764 cases after training was assessed by dividing them into 4 temporal quartiles of 441 patients. They requested assistance 8 times during the first quartile but only twice over the next 3 quartiles. Hypotension occurred in 73.2% of cases in the first quartile but in less than 15% in the third and fourth quartiles. Hypoxemia occurred in 4.4% and hypotension in 26%; however, all episodes responded to therapy and none of the procedures were cancelled. The authors concluded that with proper training NAPS is safe for endoscopic procedures. However, given that most challenges occurred during the first quartile, they did qualify that further training in administering propofol would have been helpful and at minimum an anesthesia provider should be available during the first 3 months of implementation (which was the case at their center). In Switzerland, there are also very active NAPS programs and the method of sedation for the majority of procedures is propofol administered by a nonanesthesiologist provider.
Intraprocedural Monitoring
In addition to patient comfort, sedation strategy is driven by changes in vital parameters. Trainees must be able to interpret and respond to continuous pulse oximetry values. The importance of continuous low-flow supplemental oxygen via the nasal or oral route (which prevents hypoxemia) on pulse oximetry values needs to be understood by trainees. The frequency of monitoring additional vital signs, most importantly blood pressure, must be correlated to the patient’s level of sedation. After the introduction of a national endoscopic sedation curriculum and guideline in Germany, the use of routine supplemental oxygen increased from 34% to 64% and the use of automated blood pressure systems increased by 11%. Although the monitoring of pulse oximetry and automated noninvasive blood pressure measurements are sufficient for most patients, an electrocardiogram should be used in patients with a history of cardiac or pulmonary disease. After training, the trainee must be competent in identifying hypoxemia, hypotension, cardiac arrhythmias, and apnea. Implementation of the S3 sedation training curriculum and guidelines resulted in a 2-fold increase in the use of periprocedural electrocardiography.
Pulse oximetry is useful for detecting hypoxemia but has the limitation of being unable to measure hypercarbia, a sign of early hypoventilation. Capnography, which uses infrared spectrography to provide a real-time graphic assessment of CO 2 , is used routinely for this assessment. Vargo and colleagues showed that pulse oximetry did not detect 50% of the apnea or disordered respiration episodes that capnography was able identify. However, capnography has only been shown to be of benefit in preventing hypoxemia in the pediatric population undergoing moderate sedation and in lengthier procedures like endoscopic retrograde cholangiopancreatography and endoscopic ultrasound examinations. A University of Arizona practice project improved the understanding of capnography among nurses through interventions including staff education and nursing protocols. Trainees should also be aware of the emergence of new technologies including the use of an electroencephalogram and the bispectral index for degree of sedation monitoring. The bispectral index is a quantitative variable derived from analyzing a patient’s electroencephalogram that can be used to tailor hypnotic drug doses to a patient’s individual requirements. The bispectral index can be used effectively in patient groups that are at particularly high risk for oversedation and hypoxemia, like the elderly and patients with abnormal pulmonary function.
Managing Adverse Effects
During the training process, trainees need to learn the important sedation-related adverse effects and how to manage them correctly. Trainees should be aware of the rescue techniques for each of the commonly encountered adverse effects ( Table 4 ). Transient hypoxemia and hypotension represent the most common problems that occur during endoscopic sedation, occurring in 5% to 10% of patients. Serious cardiovascular complications such as myocardial infarction are rare and occur in less than 0.5% of patients.
| Counter Measure | |
|---|---|
| Hypoxemia |
|
| Hypotension | Electrolyte solution Catecholamine infusion |
| Bradycardia | Atropine |
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