Название: Gastroenterological Endoscopy
Автор: Группа авторов
Издательство: Ingram
Жанр: Медицина
isbn: 9783131470133
isbn:
While propofol can induce and maintain all levels of sedation, ranging from moderate sedation to general anesthesia, it has a narrow therapeutic window, so that sedation might become more deeply than intended, and reversal agent exists.3 However, data from the world-wide safety registry of 646,080 patients who received propofol sedation administered by gastroenterologists showed a mortality rate of 1 per 161,515, lower than that seen when standard sedation (opioids and benzodiazepines) is used (1 per 10,000),43,44 and comparable to published data on general anesthesia administered by anesthesiologists (1 per 10,000–50,000).44,45 The most common severe complications are dose-dependent hypotension, particularly in volume-depleted patients, and transient apnea following induction doses.
The wide variability in patient response to propofol should be considered. In some patients, only small doses of propofol induce deep sedation or even anesthesia. Because it is lipophilic, it should be handled in an aseptic fashion and measures should be taken to minimize the risk of bacterial contamination. Propofol contains soybean and egg lecithin and is therefore contradicted in patients with egg or soybean allergy.3
Administration Techniques
Propofol might be administered intravenously as repeated bolus injection, continuous infusion, or a combination. For gastrointestinal endoscopy sedation, propofol is most commonly administered by an initial bolus, adapted to patient’s weight, age, and comorbidities, followed by repeated boluses (10–20 mg), or by a continuous propofol infusion adapted to the desired sedation and patient conditions. The latter technique of continuous infusion is most commonly used by anesthesiologists, whereas the bolus application is currently used when nonanesthesiologist-administered propofol (NAAP) sedation is used. Another mode for the administration of propofol is the so-called balanced propofol sedation (BPS). This is achieved by a small induction dose of a benzodiazepine and/or an opioid, followed by small incremental doses of propofol. BPS might provide the benefits of propofol sedation, with a reduced risk of dose-related adverse reactions.13,46,47 However, most guidelines recommend the use of propofol monosedation.4,5,6,11,12,13,14,15,16,17
4.4.5 Who Should Perform Endoscopic Sedation?
This question is still a matter of debate within the medical community.3,47 Some anesthesiologists believe that only those trained in the administration of general anesthesia should administer propofol, and that the use of propofol by nonanesthesiologists is unsafe. While the package insert of propofol restricts its use to anesthesiologists, this insert was created in the late 1980s before evidence accumulated that nonanesthesiologists can safely administer propofol for endoscopic procedures. Of course, it is necessary for endoscopists and nursing staff to be able to manage the typical adverse effects of propofol and be trained in life support techniques.3,47 All currently available guidelines state that the endoscopist is not permitted to administer propofol and to monitor the patient. This task must be done by an additional person, who has the sole responsibility to administer the sedative and to monitor the patient.4,5,6,11,12,13,14,15,16,17 This person can be an anesthesiologist (monitored anesthesia care [MAC]), a specially trained nonanesthesiologist physician (NAAP sedation), or a dedicated nurse (nurse-administered propofol sedation, NAPS). The mode of propofol application is, in most countries, regulated by law, for example, in most states of the United States and in France, the use of propofol is restricted to anesthesiologists; therefore, the only mode of propofol sedation is MAC in these countries. However, there is no proven clinical benefit of providing MAC for low-risk patients (ASA I–II) undergoing routine endoscopic procedures, and it is suggested that MAC should be reserved for patients with an increased risk of sedation-related complications.6,47 Recently, it was shown that NAAP is safe in patients with obstructive sleep apnea, and that the use of MAC in ASA I and II patients for upper endoscopy and colonoscopy is not cost-effective.48 The use of NAAP or even NAPS is now recommended by most international guidelines for patients with a lower risk profile (excluding ASA class IV–V and those with expected difficult airway management).3,4,5,6 Furthermore, NAAP and NAPS should only be performed where appropriately trained staff and facilities for monitoring and providing proper airway management, including availability of supplemental oxygen and equipment for advanced cardiac life support, are available. To optimize patient safety, many guidelines recommend regular participation in structured education curricula for teams involved in NAAP/NAPS.4,5,6
4.5 Postprocedure Care
4.5.1 Monitoring during Recovery
Following conclusion of the procedure the patient remains at risk for cardiopulmonary complications because the sedation/anesthesia medications have not been completely metabolized, while at the same time the procedure stimulation is gone. Therefore, postprocedural monitoring of the cardiopulmonary system by qualified staff is necessary. This monitoring should take place in a separate recovery room/area with equipment for appropriate cardiopulmonary monitoring and resuscitation.3 No defined recommendations regarding postprocedure monitoring exist. Because most of the serious adverse effects of sedation occur within 30 minutes after the last administration of benzodiazepines and opioids,49 patients should be monitored for at least 30 minutes in a recovery room. Furthermore, patients who have obstructive sleep apnea and patients who have received reversal agents need special postsedation management based on ASA guidelines, because prolonged recovery times or rebound may occur in these patients.3
4.5.2 Discharge
There is no consensus on the duration of postprocedure monitoring, because it varies widely based on the individual patient, type of sedation, and procedure performed. Some authors recommend patients can be safely discharged approximately 30 minutes after the last application of sedation/analgesia/anesthesia agents if no adverse effects have occurred.49 Others would discharge the patient once vital signs are stable and the patient has reached an appropriate level of consciousness.17 Therefore, defined discharge criteria might be useful for objective guidance. Various scoring systems exist, of which the Aldrete score is the most commonly used.50 It evaluates respiration, oxygen saturation, blood pressure, consciousness, and activity. Irrespective of which scoring system is used, a checklist to assess discharge criteria (suggested minimum criteria are shown in
Table 4.4) is recommended. The results should be documented before the patient is allowed to leave the endoscopy unit, and with an accompanying adult.3,4,5,6 In general, patients should have sufficient return of their motor skills, with the ability to walk, tolerate liquids, and dress themselves. The patient should be strongly advised not to drive a car or operate machinery until full recovery can safely be expected. The exact time until the patient will regain the ability to drive or work depends on the half-life of the drugs administered, the patient’s comorbidity, and intended activities (e.g., employment as a traffic pilot, heavy equipment operator, etc.). Time to full recovery using psychomotor tests is significantly less after monosedation with propofol as compared to midazolam monotherapy or midazolam/opioid sedation.3 Driving skills return to baseline levels within 2 hours after last propofol administration.51,52,53 However, whether patients should be allowed to drive after propofol monosedation remains uncertain.3 Patients should be able to drive, work, and engage in legally СКАЧАТЬ