Endoscopy Practice and Sedation: Endoscopy Practice and Sedation: The Sedation Plan

0:00Welcome to Board Pearls. This is episode two of four of the Endoscopy Practice and Sedation chapter, in the Endoscopic Procedures module. This episode is the sedation plan. The patient is a man with lung disease and severe obesity booked for an endoscopic ultrasound, EUS, with fine-needle aspiration, and his case shows how the American Society of Anesthesiologists class frames his risk, what separates minimal, moderate, and deep sedation and why the team must be able to rescue one level deeper, when midazolam with fentanyl is the right choice and how it's dosed, why propofol is preferred for him and what its main danger is, and when etomidate, ketamine, and dexmedetomidine are the better choice. Short cases with a bleeding patient, a septic patient, and an opioid-tolerant patient show those last three.

0:46Here's the patient. A fifty-eight-year-old man is booked for EUS with fine-needle aspiration of a pancreatic cyst. He has chronic obstructive pulmonary disease on two inhalers, poorly controlled diabetes, and a body mass index, BMI, of forty-two. He walks a block before he has to stop. He had a colonoscopy five years ago with midazolam and fentanyl and remembers being uncomfortable. He asks to be completely out this time.

1:15His lungs, his weight, and his diabetes make him a high-risk sedation patient, and his American Society of Anesthesiologists, ASA, physical status class puts a number on that. The classification runs from one to six. ASA one is a healthy patient. Two is mild systemic disease, such as controlled hypertension, well-controlled diabetes, or mild obesity. Three is severe systemic disease, such as poorly controlled hypertension or diabetes, chronic obstructive pulmonary disease, a BMI over forty, or stable angina. Four is severe systemic disease that's a constant threat to life: a recent myocardial infarction, unstable angina, severe heart failure, or end-stage kidney disease on dialysis. Five is a moribund patient not expected to survive without the operation, and six is a declared brain-dead organ donor. His lung disease, his poorly controlled diabetes, and his BMI over forty each make him ASA three. Patients in classes three and four have more cardiovascular and respiratory complications around procedures, which is why deeper sedation with anesthesia support, and propofol rather than a benzodiazepine with an opioid, are preferred for them.

2:26His request to be completely out has a precise meaning, because sedation depth is defined. The ASA describes four depths on a continuum. Minimal sedation is anxiolysis, with a normal response to voice, an intact airway, and unaffected breathing. Moderate, or conscious, sedation is a purposeful response to voice, alone or with light touch, with an airway that stays open without help and adequate spontaneous breathing; reflex withdrawal from pain isn't a purposeful response. Deep sedation is a purposeful response only to repeated or painful stimulation, with an airway that may need help and breathing that may be inadequate. General anesthesia is no response even to pain, often with airway intervention and frequently with positive-pressure ventilation.

3:14Because the levels form a continuum and individual responses vary, whoever gives sedation has to be qualified and equipped to rescue the patient from one level deeper than intended. His request could mean deep sedation or general anesthesia, both reasonable for a long EUS. But the deeper the level, the more his airway matters, and a BMI over thirty-five predicts a difficult airway, as episode three covers. His last experience was moderate sedation, which keeps patients responsive by design. Today's plan is deeper, with the people best placed to manage his airway.

3:47His last colonoscopy used the standard regimen for routine procedures in healthier patients. Moderate sedation with intravenous midazolam plus fentanyl is standard for ASA one and two patients having routine upper endoscopy or colonoscopy. It gives anxiolysis, some amnesia, and enough analgesia for the procedure while preserving airway reflexes and spontaneous breathing. Midazolam starts with a half-milligram to two-milligram intravenous bolus, titrated with one-milligram boluses every two to five minutes. It peaks three to five minutes after an intravenous dose, and the total for routine endoscopy is typically two to five milligrams in healthy adults. It potentiates the gamma-aminobutyric acid type A receptor, causing dose-dependent sedation and anterograde amnesia, which is useful because remembering the procedure leaves patients dissatisfied.

4:38Fentanyl supplies the analgesia that midazolam doesn't. It starts at twenty-five to one hundred micrograms intravenously, titrated with twenty-five-microgram to fifty-microgram boluses, and peaks at three to five minutes. It's preferred over morphine for its rapid onset, its short duration of thirty to sixty minutes, and its minimal histamine release, which means less hypotension and itching than morphine. The combination's synergy is both its benefit and its main danger: respiratory depression from the two classes together is multiplicative. So doses go in small increments, the next dose waits for the previous one to peak, and capnography is essential at moderate and deep levels.

5:16Propofol is the right drug for him, and he meets the criteria for it twice. Deep sedation with propofol is preferred for ASA three and four patients, for prolonged or technically complex procedures, such as endoscopic retrograde cholangiopancreatography, EUS, endoscopic submucosal dissection, and deep or double-balloon enteroscopy, and for patients at high aspiration risk. He's ASA three and is having EUS. Propofol's pharmacokinetics suit procedures: it acts within thirty to forty seconds, it has a short context-sensitive half-time that stays short even after long infusions because of redistribution, and it's cleared quickly by hepatic glucuronidation, so recovery is fast. It's dosed as a half to one milligram per kilogram induction bolus, followed by ten-milligram to twenty-milligram boluses or an infusion, typically twenty-five to one hundred micrograms per kilogram per minute, titrated to depth. It acts at a different site on the gamma-aminobutyric acid type A receptor from benzodiazepines.

6:16Propofol also carries his main danger, because it can't be reversed. It has no antagonist, and apnea and loss of protective airway reflexes are common at therapeutic doses, so airway-trained staff must be available. It also lowers systemic vascular resistance and causes dose-dependent hypotension, so it's titrated cautiously in patients who are hypovolemic, have cirrhosis, or have heart disease.

6:40Who gives it depends on the patient and the procedure. Monitored anesthesia care is a service, not a sedation depth: an anesthesiologist or nurse anesthetist at the bedside titrating sedation continuously and managing the airway as needed. The American Society for Gastrointestinal Endoscopy and ASA position is that propofol-based moderate to deep sedation in healthy patients can be given by trained endoscopist-led teams with capnography, supplemental oxygen, and airway-trained staff immediately available, while ASA three and higher, and complex procedures, generally warrant anesthesia involvement. His plan is deep propofol sedation with an anesthesia team, because his airway is what's most likely to go wrong.

7:23Propofol isn't right for every patient, and three other agents fill the gaps it leaves. Etomidate, a tenth to two-tenths of a milligram per kilogram intravenously, is reserved for hemodynamically unstable patients, because it preserves blood pressure and cardiac output with minimal vasodilation. But a single dose suppresses cortisol production for six to twenty-four hours by inhibiting eleven-beta-hydroxylase, so it's avoided in sepsis, where adrenal function is already stressed. A patient with a blood pressure of eighty and a heart rate of one hundred thirty from bleeding would suit etomidate. The same instability from sepsis caused by cholangitis would argue against it.

8:03Ketamine and dexmedetomidine are used when breathing has to be preserved. Ketamine, a half to one milligram per kilogram intravenously, gives dissociative anesthesia with preserved respiratory drive and increased airway tone. That makes it useful for patients at high aspiration risk who can't tolerate propofol-induced apnea, and for analgesia in opioid-tolerant patients. Its drawbacks are sympathomimetic, raising blood pressure, heart rate, and intracranial pressure, plus emergence reactions in adults, which benzodiazepines reduce. A patient on high-dose opioids for chronic pain might benefit from ketamine's analgesia, with his blood pressure watched. Dexmedetomidine, an alpha-2 agonist given as a half to one microgram per kilogram loading dose and then two-tenths to seven-tenths of a microgram per kilogram per hour, sedates without respiratory depression. It's useful for opioid-sparing sedation when maintaining the airway is critical, as in achalasia or severe obstructive sleep apnea, but its slow onset and bradycardia limit its routine use.

9:06Here are the traps the boards set in these patients. Chronic obstructive pulmonary disease or a BMI over forty is ASA three, not two. An ASA three patient having a complex procedure isn't sedated with midazolam and fentanyl. Withdrawal from pain isn't a purposeful response. The team has to be able to rescue one level deeper than intended. Benzodiazepine and opioid boluses aren't stacked without waiting for the peak. Propofol has no reversal agent. A hypovolemic patient doesn't get full-dose propofol. Etomidate isn't used in sepsis. And ketamine raises blood pressure, which has to be accounted for.

9:46So, start to finish. Classify the patient by ASA, because classes three and four bring more complications and favor propofol with anesthesia support. Sedation depth is a continuum, so be able to rescue one level deeper than intended. Midazolam plus fentanyl suits ASA one and two patients for routine procedures, titrated in small boluses because the two depress breathing together.

10:09Propofol suits long or complex procedures, higher ASA classes, and aspiration risk, but it has no antagonist and lowers blood pressure, so airway-trained staff must be present. Use etomidate for hemodynamic instability but not in sepsis, ketamine when breathing must be preserved, and dexmedetomidine for opioid-sparing sedation when the airway is critical.

10:31Episode three is keeping sedation safe: capnography, the difficult airway, reversal, and sedation in special populations.

10:40For the full chapter, the practice vignettes, and the topic-tagged question bank, head to board pearls dot com. You'll find the rest of the series on Apple Podcasts, Spotify, or wherever you listen to podcasts. That brings us to the end of episode two of four of chapter twenty-eight, and I'll see you in the next one.