Moderate Sedation

Course #40952 - $20 • 5 Hours/Credits


Study Points

  1. Define moderate sedation, including its goals and objectives.
  2. Adhere to guidelines for moderate sedation, especially those developed for one's particular specialty/setting.
  3. Describe the necessary patient assessment and monitoring before, during, and after a procedure requiring sedation.
  4. List the most commonly used pharmacologic agents used for moderate sedation and their advantages and disadvantages.
  5. Select the optimal moderate sedation agent(s) on the basis of patient characteristics and the setting.
  6. Discuss the most common complications occurring during or after moderate sedation and their appropriate management.
  7. Discuss risk management issues related to moderate sedation.

    1 . According to the American Society of Anesthesiologists' definition, which of the following is a characteristic of moderate sedation?
    A) Unaffected cardiovascular function
    B) Inadequate spontaneous ventilation
    C) Purposeful response to verbal stimulation
    D) Reflex withdrawal from a painful stimulus

    OVERVIEW OF MODERATE SEDATION

    DEFINITION OF GENERAL ANESTHESIA AND LEVELS OF SEDATION/ANALGESIA

    ParameterLevel of Sedation/Analgesia
    Minimal (Anxiolysis)ModerateDeepGeneral Anesthesia
    ResponsivenessNormal response to verbal stimulationPurposefula response to verbal or tactile stimulationPurposefula response after repeated or painful stimulationUnarousable, even with painful stimulus
    AirwayUnaffectedNo intervention requiredIntervention may be requiredIntervention often required
    Spontaneous ventilationUnaffectedAdequateMay be inadequateFrequently inadequate
    Cardiovascular functionUnaffectedUsually maintainedUsually maintainedMay be impaired
    aReflex withdrawal from a painful stimulus is not considered a purposeful response.
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    2 . A survey of American Society for Gastro­enterology Endoscopy (ASGE) members showed that which of the following is a primary reason for offering sedation for endoscopy?
    A) Cost
    B) Ease of procedure
    C) Patient preference
    D) Lower risk of complications

    OVERVIEW OF MODERATE SEDATION

    Among the diagnostic procedures for which moderate sedation is most commonly used are routine endoscopic examinations, the number of which has escalated because of their value in colorectal cancer screening [23]. According to a survey of American Society for Gastrointestinal Endoscopy (ASGE) members, 45% of the 724 respondents did not routinely offer unsedated endoscopic procedures and more than 70% said they would choose to be sedated for a routine endoscopic procedure [23]. In a survey of American College of Gastroenterology (ACG) physician members, more than 98% of 1,353 respondents said they used sedation during their endoscopic procedures [24]. People scheduled for endoscopic procedures have come to expect sedation; in the ASGE survey, lack of patient acceptance was the most common reason given for not offering unsedated endoscopy [23].

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    3 . According to the AGA Institute and the ASGE guidelines, it is strongly recommended that an anesthesia specialist administer moderate sedation to a patient with a(n)
    A) neurologic disorder.
    B) history of tobacco use.
    C) history of alcohol abuse.
    D) ASA physical status of IV.

    OVERVIEW OF MODERATE SEDATION

    In their guidelines on moderate sedation for endoscopy, the AGA Institute and the ASGE follow the ASA guidelines and recommend that the use of an anesthesia professional be strongly considered for patients classified as having ASA physical status IV or V [28,31]. In addition, several other patient-related and procedure-related factors are "possible indications" for an anesthesia specialist, including a history of alcohol or substance abuse, morbid obesity, neurologic disorders, and complex therapeutic procedures [28,31]. The ACEP guidelines note that there are no specific level A or B recommendations regarding personnel requirements needed to provide procedural sedation and analgesia in the emergency department. However, the guidelines state that a "nurse or other qualified individual" should be present during procedural sedation and analgesia for continuous monitoring of the patient in addition to the provider performing the procedure (level C recommendation) [7]. The guidelines also state that emergency physicians working or consulting in the emergency department should coordinate procedures that require administration of procedural sedation and analgesia [7]. All clinicians providing moderate sedation must be trained to administer drugs to achieve a desired level of sedation, monitor patients and maintain a desired level of sedation, and manage complications [7]. In 2011, the ACEP published comprehensive recommendations for physician credentialing, privileging, and practice; the ACEP also strongly supports the administration of propofol, ketamine, and other sedatives by qualified emergency department nurses under the direct supervision of a privileged emergency physician [7,33]. The AAP guidelines note similar requirements for training and add that clinicians must have training in how to oxygenate a child in whom airway obstruction or apnea develops and in advanced pediatric airway skills [13].

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    4 . During a preprocedure assessment for colonoscopy, a patient says she takes ginkgo biloba to help her memory. What should she be advised as part of preparing for the colonoscopy?
    A) She can continue taking the supplement until the day before the colonoscopy.
    B) She should stop taking the supplement 48 hours before the colonoscopy.
    C) She should stop taking the supplement seven days before the colonoscopy.
    D) She should stop taking the supplement 14 days before the colonoscopy.

    PATIENT ASSESSMENT AND MONITORING

    POTENTIAL COMPLICATIONS ASSOCIATED WITH PRESCRIBED MEDICATIONS, OVER-THE-COUNTER DRUGS, AND HERBAL SUPPLEMENTS

    Medication or SupplementPotential Complication(s)Action Needed
    Prescribed and OTC Drugs
    Angiotensin-converting enzyme (ACE) inhibitorsHypotension, bradycardia, intolerance to hypovolemiaMaintain hydration, give moderate doses of vasopressor
    DiureticsHypokalemia, hypovolemiaMaintain hydration, check serum potassium level
    Hypoglycemic agents (insulin and oral agents)Hyperglycemia, hypoglycemiaWithhold or reduce dose on morning of procedure
    Monoamine oxidase (MAO) inhibitorsHypertension, excitatory state (meperidine), depressive reaction (opioids)Stop older, nonselective MAO inhibitors two to three weeks before procedure; withhold new MAO inhibitors on morning of procedure
    Nonsteroidal anti-inflammatory drugsAltered renal function, gastrointestinal bleeding, impaired platelet function
    WarfarinIncreased hemorrhageDiscontinue three to five days before procedure and check prothrombin time
    Herbal Supplements
    Black cohoshHypotension, bradycardiaDiscontinue two weeks before procedure
    EphedraHypertension, dysrhythmiasDiscontinue seven days before procedure
    FeverfewProlonged bleeding timeDiscontinue two weeks before procedure
    GarlicAnticoagulant effectsDiscontinue two weeks before procedure
    GingerProlonged bleeding timeDiscontinue two weeks before procedure
    Ginkgo bilobaProlonged bleeding timeDiscontinue two weeks before procedure
    GinsengHypoglycemia, hypertension, tachycardiaDiscontinue two weeks before procedure
    KavaInteraction with barbiturates and benzodiazepines, anticoagulant effectsDiscontinue 24 hours before procedure
    St. John's wortProlonged sedative effects of anestheticsDiscontinue seven days before procedure
    ValerianIncreased sedative effect of anesthetics or sedativesDiscontinue seven days before procedure
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    5 . Which of the following is the most appropriate measure to prevent moderate sedation-related complications in a patient with coronary artery disease?
    A) Administer supplemental oxygen
    B) Avoid use of longer-acting opioids
    C) Use local anesthesia as a supplement
    D) Titrate drugs in small incremental doses

    PATIENT ASSESSMENT AND MONITORING

    HIGH-RISK FACTORS DURING MODERATE SEDATION AND MEASURES TO PREVENT COMPLICATIONS

    Risk FactorPossible ComplicationPreventive Measures
    Obesity
    Gastroesophageal reflux
    Upper airway obstruction
    Oversedation
    Consider treatment with an oral H2 antagonist and metoclopramide before the procedure.
    Administer small incremental doses and allow time for onset of action before additional dosing.
    Chronic obstructive pulmonary diseaseRespiratory depression
    Administer all prescribed bronchodilators before sedation is initiated.
    Administer supplemental oxygen.
    Titrate drugs in small incremental doses and monitor closely.
    Consider local anesthesia as supplement for pain control.
    Coronary artery disease
    Undersedation
    Oversedation
    Have patient take all routine cardiac medications on the day of the procedure.
    Take care to balance use of sedation.
    Administer supplemental oxygen.
    Chronic renal failure
    Overdose or prolonged effect of drug
    Exaggerated reaction to benzodiazepines
    Avoid use of longer-acting opioids, such as meperidine (although fentanyl is thought to be safe).
    Use smaller doses of benzodiazepines with incremental dosing.
    Drug addictionUnknown drug requirements
    Have patient take prescribed replacement drug (e.g., methadone) on day of procedure.
    Use local anesthesia as supplement to reduce amount of parenteral sedative needed.
    Use short-acting benzodiazepines with incremental dosing.
    Avoid reversal agents.
    Children
    Respiratory depression
    Airway obstruction
    Consult with subspecialists and/or an anesthesiologist for children with special needs or with anatomic airway abnormalities or extreme tonsillar hypertrophy.
    Older individuals (≥65 years)
    Comorbidities
    Age-related changes in drug metabolism
    Use lower doses of sedative agents.
    Follow conservative incremental dosing.
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    6 . For healthy patients younger than 65 years of age, which of the following diagnostic tests should be done before moderate sedation?
    A) No testing
    B) Electrolytes
    C) Electrocardiogram
    D) Complete blood count

    PATIENT ASSESSMENT AND MONITORING

    The guidelines agree that routine laboratory or other diagnostic testing is not needed before moderate sedation [7,11,31]. However, if the results of testing may affect the management of sedation, such testing should be done before the patient is sedated [7,11,31].

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    7 . During moderate sedation for routine screening colonoscopy for a healthy man 50 years of age, which of the following should be used?
    A) Capnography
    B) Electrocardiography
    C) Supplemental oxygen
    D) Bispectral index spectrometry

    PATIENT ASSESSMENT AND MONITORING

    A noninvasive method of assessing the level of consciousness is bispectral index (BIS) monitoring, which has been used since the mid-1990s in the setting of general anesthesia. BIS records electroencephalographic (EEG) waveforms from a probe adhered to the forehead, and the EEG recording is analyzed with an algorithm to generate a score on a scale of 0 to 100. EEG activity is a sensitive measure of sedation, with a low-amplitude, high-frequency signal representing the awake state and a high-amplitude, low-frequency signal representing sedation. BIS monitoring is helpful in ensuring that patients are not oversedated or undersedated, and research has shown that BIS results correlate with validated sedation scales. The ASA guideline does not mention BIS explicitly and notes that although monitoring of the level of consciousness reduces the risk of deep sedation, no data have shown that such monitoring improves outcomes [11]. The ACEP and the ASGE found insufficient or poor evidence to recommend the routine use of BIS [31,69]. The AAP recommends against the routine use of BIS monitoring in children [13].

    Recommendations about noninvasive monitoring of end-tidal carbon dioxide with capnography have evolved. At the time of their guidelines on monitoring during moderate sedation, the ASA and the AGA Institute found insufficient evidence to recommend the routine use of capnography, and the ASA only recommended capnography during moderate sedation when ventilation could not be directly observed. The ACEP noted only that procedural monitoring "may include" capnography, and the ASGE stated that capnography may improve patient safety [7,11,28,31]. However, since the publication of those guidelines, several studies have demonstrated that capnography readings are a more sensitive measure of ventilatory function, detecting hypoventilation earlier than changes in vital signs, clinical observations, or pulse oximetry [70,71,72,73]. In a study in the emergency department setting, capnography had a sensitivity of 100% (and specificity of 64%) in detecting hypoxia before onset [72]. In addition, a meta-analysis (five studies) demonstrated that respiratory depression was more than 17 times more likely to be detected during procedural sedation when capnography was used than when it was not used [73]. In 2010, the ASA issued standards for anesthetic monitoring (reaffirmed in 2015) stating that monitoring for the presence of exhaled carbon dioxide should be carried out during moderate (or deep) sedation. This is supported in the 2018 ASGE guidelines [31,74]. In 2018, the ASA issued updated guidelines for moderate procedural sedation that include a new recommendation for continual monitoring with capnography to supplement observation and pulse oximetry [11]. Use of capnography during sedation is also recommended by the Emergency Nurses Association, and, in a joint position statement, the ASGE, the AASLD, the ACG, and the AGA Institute acknowledge that capnography reduces the occurrence of apnea and hypoxemia during gastrointestinal endoscopy with propofol sedation [41,75]. A multisociety-developed curriculum on sedation during gastrointestinal endoscopy notes that proper training should include interpretation of capnography readings [69].

    The routine use of supplemental oxygen has also been debated. The ASA and ASGE guidelines note that supplemental oxygen should be considered for moderate sedation, and the ASGE states that supplemental oxygen can reduce the magnitude of oxygen desaturation during sedated endoscopy [11,31]. The ASGE additionally states that supplemental oxygen should be administered if hypoxemia is anticipated or develops [31]. However, the AGA Institute asserts that there is little evidence to indicate that the use of supplemental oxygen reduces the incidence of significant cardiopulmonary complications in patients monitored with pulse oximetry [28]. In addition, the results of several studies have shown that supplemental oxygen may actually increase the rate of complications associated with sedation, as its use may delay recognition of hypoxemia and apnea [76,77]. As a result, the AGA Institute recommends the use of supplemental oxygen during endoscopy only for older individuals and people with significant comorbid disease (ASA class IV and V) [28]. According to one survey, approximately 73% of endoscopists routinely use supplemental oxygen [24].

    There is no evidence to indicate that continuous electrocardiography (ECG) monitoring is of benefit during moderate sedation, especially for patients who have no underlying cardiopulmonary disease [7]. Guidelines from the ASA, the AGA Institute, and the ASGE all note that ECG monitoring is not needed for low-risk patients [11,28,31]. The ASA guidelines suggest ECG monitoring to decrease risks for patients who have significant cardiovascular disease or dysrhythmia, and the AGA Institute and the ASGE state that ECG monitoring should be considered for high-risk patients, such as patients with a history of significant cardiac or pulmonary disease [11,28,31]. The AAP recommends that an ECG monitor and defibrillator be readily available [13].

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    8 . Which of the following statements about discharge criteria is true?
    A) Standard evidence-based criteria have been established.
    B) A patient should not be discharged until he or she has voided.
    C) Two adults should accompany a young child home if in a car seat.
    D) Patients should not be discharged for at least four hours if a reversal agent was used.

    PATIENT ASSESSMENT AND MONITORING

    Scoring systems for anesthesia recovery are available, but no evidence has established standard discharge criteria; healthcare facilities should establish their own standardized criteria [11,13,28,31]. In general, the following parameters are used to indicate that a patient can be discharged: stable vital signs, alert and oriented status, patent airway, good skin color and condition, minimal nausea and vomiting, adequate pain control, ability to walk without dizziness, and ability to dress independently [11,28]. Many facilities have eliminated criteria related to the ability to eat or drink or void before discharge [28,78]. If a reversal agent has been used, the patient should be observed for two hours after the agent was given to ensure that he or she will not become re-sedated after the effects of the reversal agent wear off [11].

    Discharge criteria must also include the availability of a responsible adult to escort the patient home [11,28]. The AAP suggests that at least two adults be available to take home a child who still uses a car seat [13]. Parents should be told that the child is at risk for airway obstruction if his or her head falls forward while in the car seat [11].

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    9 . Which of the following drugs has the quickest time to onset of action?
    A) Etomidate
    B) Droperidol
    C) Nitrous oxide
    D) Diphenydramine

    MOST COMMONLY USED DRUGS FOR MODERATE SEDATION

    PHARMACOLOGIC PROFILES OF MOST COMMON DRUGS USED FOR MODERATE SEDATIONa

    DrugTypical Initial DoseTime to Onset of Action (min)Time to Peak Effect (min)Duration of Effect (min)Notes
    Sedative Hypnotics
    Midazolam
    Adult: 1–2 mg
    Pediatric: 0.05 mg/kg
    1–23–415–80For patients older than 60 years or who have an ASA physical status of 3 or higher, reduce the dose by 20% to 30%.
    Diazepam
    Adult: 5–10 mg
    Pediatric: 0.2–0.5 mg/kg
    2–33–5360Use lower doses in older or debilitated patients.
    Lorazepam
    Adult: 0.044 mg/kg (IV), 2–4 mg (IM)
    Pediatric: 0.05 mg/kg (PO)
    1–2 (IV)
    15–30 (IM)
    15–30 (IV)
    60–90 (IM)
    360–480Use with caution in patients with limited pulmonary reserve.
    Propofol
    Adult: 10–40 mg (endoscopy), 1.0 mg/kg (ED)
    Pediatric: 1–2 mg/kg
    <11–24–8Do not use for patients who are allergic to egg or soy. Patients with ASA physical status III or IV are at higher risk for propofol-associated hypotension.
    Etomidate
    Adult: 0.2–0.6 mg/kg
    Pediatric: 0.2–0.6 mg/kg
    <115–15Respiratory depression is more common among patients older than 55 years.
    Opioids
    Meperidine
    Adult: 25–50 mg
    Pediatric: 0.5–1 mg/kg (IM, IV), 2–4 mg/kg (PO)
    3–65–760–180Contraindicated for patients taking an MAO inhibitor.
    Fentanyl
    Adult: 50–100 mcg (endoscopy)
    Pediatric: 0.5–2 mcg/kg
    1–23–530–60For patients older than 65 years of age, reduce by at least 50%.
    Dissociative
    Ketamine
    Adult: 0.5 mg/kg IV (endoscopy), 1–2 mg/kg IV (ED), 4–5 mg/kg (IM)
    Pediatric: 1–3 mg/kg IV, 5–10 mg/kg (IM)
    <1110–20Emergence reactions are common among adults.
    Other Drugs (Used as Adjuncts)
    DiphenhydramineAdult: 25–50 mg2–360–90>240
    PromethazineAdult: 25–50 mg2–5Unknown>120
    DroperidolAdult: 1.25–2.5 mg3–1030120–240
    MethohexitalPediatric: 0.5–1.5 mg/kg (IV), 20–35 mg/kg (PR)

    1 (IV)

    5–15 (PR)

    7–10 (IV)
    60–90 (PR)
    PentobarbitalPediatric: 1–3 mg/kg (IV), 2–6 mg/kg (IM)3–5
    15–45 (IV)
    60–120 (IM)
    Used primarily for children. Use has generally been replaced by other agents.
    Chloral hydratePediatric: 8–25 mg/kg10–2030–60240–480Used primarily for children, but rarely. Not approved in the United States.
    Nitrous oxideInhaled and titrated to effect2–3Dose dependent15–30Used primarily for children.
    Dexmedetomidine1 mcg/kg5–1015–3060–120
    aThe typical initial doses given here should be used as guidelines only. Drug dosing should be done on an individual basis with each patient, with consideration of the patient's age, condition, likelihood of complications, and length and complexity of the procedure. Pediatric doses are given only for those drugs recommended for use in children.
    ED = emergency department, IM = intramuscular, IV = intravenous, MAO = monoamine oxidase, PR = rectal.
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    10 . Which of the following drugs has the shortest duration of effect?
    A) Propofol
    B) Fentanyl
    C) Ketamine
    D) Midazolam

    MOST COMMONLY USED DRUGS FOR MODERATE SEDATION

    PHARMACOLOGIC PROFILES OF MOST COMMON DRUGS USED FOR MODERATE SEDATIONa

    DrugTypical Initial DoseTime to Onset of Action (min)Time to Peak Effect (min)Duration of Effect (min)Notes
    Sedative Hypnotics
    Midazolam
    Adult: 1–2 mg
    Pediatric: 0.05 mg/kg
    1–23–415–80For patients older than 60 years or who have an ASA physical status of 3 or higher, reduce the dose by 20% to 30%.
    Diazepam
    Adult: 5–10 mg
    Pediatric: 0.2–0.5 mg/kg
    2–33–5360Use lower doses in older or debilitated patients.
    Lorazepam
    Adult: 0.044 mg/kg (IV), 2–4 mg (IM)
    Pediatric: 0.05 mg/kg (PO)
    1–2 (IV)
    15–30 (IM)
    15–30 (IV)
    60–90 (IM)
    360–480Use with caution in patients with limited pulmonary reserve.
    Propofol
    Adult: 10–40 mg (endoscopy), 1.0 mg/kg (ED)
    Pediatric: 1–2 mg/kg
    <11–24–8Do not use for patients who are allergic to egg or soy. Patients with ASA physical status III or IV are at higher risk for propofol-associated hypotension.
    Etomidate
    Adult: 0.2–0.6 mg/kg
    Pediatric: 0.2–0.6 mg/kg
    <115–15Respiratory depression is more common among patients older than 55 years.
    Opioids
    Meperidine
    Adult: 25–50 mg
    Pediatric: 0.5–1 mg/kg (IM, IV), 2–4 mg/kg (PO)
    3–65–760–180Contraindicated for patients taking an MAO inhibitor.
    Fentanyl
    Adult: 50–100 mcg (endoscopy)
    Pediatric: 0.5–2 mcg/kg
    1–23–530–60For patients older than 65 years of age, reduce by at least 50%.
    Dissociative
    Ketamine
    Adult: 0.5 mg/kg IV (endoscopy), 1–2 mg/kg IV (ED), 4–5 mg/kg (IM)
    Pediatric: 1–3 mg/kg IV, 5–10 mg/kg (IM)
    <1110–20Emergence reactions are common among adults.
    Other Drugs (Used as Adjuncts)
    DiphenhydramineAdult: 25–50 mg2–360–90>240
    PromethazineAdult: 25–50 mg2–5Unknown>120
    DroperidolAdult: 1.25–2.5 mg3–1030120–240
    MethohexitalPediatric: 0.5–1.5 mg/kg (IV), 20–35 mg/kg (PR)

    1 (IV)

    5–15 (PR)

    7–10 (IV)
    60–90 (PR)
    PentobarbitalPediatric: 1–3 mg/kg (IV), 2–6 mg/kg (IM)3–5
    15–45 (IV)
    60–120 (IM)
    Used primarily for children. Use has generally been replaced by other agents.
    Chloral hydratePediatric: 8–25 mg/kg10–2030–60240–480Used primarily for children, but rarely. Not approved in the United States.
    Nitrous oxideInhaled and titrated to effect2–3Dose dependent15–30Used primarily for children.
    Dexmedetomidine1 mcg/kg5–1015–3060–120
    aThe typical initial doses given here should be used as guidelines only. Drug dosing should be done on an individual basis with each patient, with consideration of the patient's age, condition, likelihood of complications, and length and complexity of the procedure. Pediatric doses are given only for those drugs recommended for use in children.
    ED = emergency department, IM = intramuscular, IV = intravenous, MAO = monoamine oxidase, PR = rectal.
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    11 . Which of the following is contraindicated for patients with an allergy to egg?
    A) Propofol
    B) Fentanyl
    C) Ketamine
    D) Diazepam

    MOST COMMONLY USED DRUGS FOR MODERATE SEDATION

    PHARMACOLOGIC PROFILES OF MOST COMMON DRUGS USED FOR MODERATE SEDATIONa

    DrugTypical Initial DoseTime to Onset of Action (min)Time to Peak Effect (min)Duration of Effect (min)Notes
    Sedative Hypnotics
    Midazolam
    Adult: 1–2 mg
    Pediatric: 0.05 mg/kg
    1–23–415–80For patients older than 60 years or who have an ASA physical status of 3 or higher, reduce the dose by 20% to 30%.
    Diazepam
    Adult: 5–10 mg
    Pediatric: 0.2–0.5 mg/kg
    2–33–5360Use lower doses in older or debilitated patients.
    Lorazepam
    Adult: 0.044 mg/kg (IV), 2–4 mg (IM)
    Pediatric: 0.05 mg/kg (PO)
    1–2 (IV)
    15–30 (IM)
    15–30 (IV)
    60–90 (IM)
    360–480Use with caution in patients with limited pulmonary reserve.
    Propofol
    Adult: 10–40 mg (endoscopy), 1.0 mg/kg (ED)
    Pediatric: 1–2 mg/kg
    <11–24–8Do not use for patients who are allergic to egg or soy. Patients with ASA physical status III or IV are at higher risk for propofol-associated hypotension.
    Etomidate
    Adult: 0.2–0.6 mg/kg
    Pediatric: 0.2–0.6 mg/kg
    <115–15Respiratory depression is more common among patients older than 55 years.
    Opioids
    Meperidine
    Adult: 25–50 mg
    Pediatric: 0.5–1 mg/kg (IM, IV), 2–4 mg/kg (PO)
    3–65–760–180Contraindicated for patients taking an MAO inhibitor.
    Fentanyl
    Adult: 50–100 mcg (endoscopy)
    Pediatric: 0.5–2 mcg/kg
    1–23–530–60For patients older than 65 years of age, reduce by at least 50%.
    Dissociative
    Ketamine
    Adult: 0.5 mg/kg IV (endoscopy), 1–2 mg/kg IV (ED), 4–5 mg/kg (IM)
    Pediatric: 1–3 mg/kg IV, 5–10 mg/kg (IM)
    <1110–20Emergence reactions are common among adults.
    Other Drugs (Used as Adjuncts)
    DiphenhydramineAdult: 25–50 mg2–360–90>240
    PromethazineAdult: 25–50 mg2–5Unknown>120
    DroperidolAdult: 1.25–2.5 mg3–1030120–240
    MethohexitalPediatric: 0.5–1.5 mg/kg (IV), 20–35 mg/kg (PR)

    1 (IV)

    5–15 (PR)

    7–10 (IV)
    60–90 (PR)
    PentobarbitalPediatric: 1–3 mg/kg (IV), 2–6 mg/kg (IM)3–5
    15–45 (IV)
    60–120 (IM)
    Used primarily for children. Use has generally been replaced by other agents.
    Chloral hydratePediatric: 8–25 mg/kg10–2030–60240–480Used primarily for children, but rarely. Not approved in the United States.
    Nitrous oxideInhaled and titrated to effect2–3Dose dependent15–30Used primarily for children.
    Dexmedetomidine1 mcg/kg5–1015–3060–120
    aThe typical initial doses given here should be used as guidelines only. Drug dosing should be done on an individual basis with each patient, with consideration of the patient's age, condition, likelihood of complications, and length and complexity of the procedure. Pediatric doses are given only for those drugs recommended for use in children.
    ED = emergency department, IM = intramuscular, IV = intravenous, MAO = monoamine oxidase, PR = rectal.
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    12 . Myoclonus is the most common side effect of
    A) ketamine.
    B) etomidate.
    C) nitrous oxide.
    D) promethazine.

    MOST COMMONLY USED DRUGS FOR MODERATE SEDATION

    Potential Adverse Events and Side Effects. Respiratory depression may occur, but myoclonus is the most common side effect, reported in 20% to 45% of patients during procedural sedation. In one small study, myoclonus occurred in 72% of patients receiving etomidate [81,90,92,93]. There are protocols for minimizing myoclonus, including pretreatment with a fraction dose of etomidate or a small dose of a short-acting benzodiazepine. Pain at the injection site has also been common, occurring in up to 40% of patients [81]. Nausea and vomiting during emergence have also been reported at low rates [83,90].

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    13 . Which of the following moderate sedation drugs is contraindicated for patients taking MAO inhibitors?
    A) Propofol
    B) Ketamine
    C) Meperidine
    D) Lorazepam

    MOST COMMONLY USED DRUGS FOR MODERATE SEDATION

    Meperidine is contraindicated for patients taking an MAO inhibitor, as life-threatening complications may develop from the interaction of these two drugs [28]. The drug should be used with caution in patients with renal disease because the accumulation of normeperidine can lead to a neurotoxic reaction [69].

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    14 . Which of the following is a relative contraindication for ketamine?
    A) Asthma
    B) Head trauma
    C) Age of 3 to 12 months
    D) Significant cardiac arrhythmia

    MOST COMMONLY USED DRUGS FOR MODERATE SEDATION

    Absolute contraindications for ketamine include an age younger than 3 months (because of the high risk of airway-related complications) and known or suspected schizophrenia [79,96]. Relative contraindications include major procedures that stimulate the posterior pharynx; a history of airway instability; active pulmonary infection or disease; significant cardiac arrhythmia, coronary artery disease, or hypertension; CNS abnormalities; glaucoma or acute globe injury; and thyroid disorders [96]. Head trauma, minor oropharyngeal procedures, and an age of 3 to 12 months are no longer contraindications [96].

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    15 . Flumazenil may be used as a reversal agent for which of the following?
    A) Propofol
    B) Ketamine
    C) Diazepam
    D) Etomidate

    MOST COMMONLY USED DRUGS FOR MODERATE SEDATION

    The ASA recommends that, whenever possible, antagonists should be on hand during the use of moderate sedation [11]. Antagonists are available to reverse the effects of opioids and benzodiazepines, but as yet no antagonist agents exist for propofol, etomidate, or barbiturates [69]. Naloxone hydrochloride can be used to reverse the effect of opioids, and flumazenil (Romazicon) can reverse the effects of benzodiazepines (Table 12) [28,69].

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    16 . According to the results of a systematic review, the most effective sedation for children and adolescents undergoing endoscopy was provided by
    A) propofol.
    B) etomidate.
    C) pentobarbital.
    D) chloral hydrate.

    COMPARISON OF MODERATE SEDATION DRUGS IN SPECIFIC SETTINGS

    Data on sedation for children and adolescents undergoing endoscopy are limited. The authors of a systematic review published in 2012 (11 randomized and 15 nonrandomized controlled trials) targeted studies involving children and adolescents younger than 18 years of age [106]. Few of the trials compared different drugs, but the review demonstrated that propofol-based sedation had a safety profile similar to that of an opioid and benzodiazepine [106]. Data on midazolam- and ketamine-based sedation were too limited to draw conclusions. Sedation was most effective with propofol; the authors noted that adding midazolam, fentanyl, or ketamine to propofol may enhance the effectiveness without increasing adverse events [106].

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    17 . Compared with ketamine in the emergency department setting, propofol was associated with
    A) less pain.
    B) shorter time to baseline mental status.
    C) no difference in patient recall of the procedure.
    D) higher rate of subclinical respiratory depression.

    COMPARISON OF MODERATE SEDATION DRUGS IN SPECIFIC SETTINGS

    COMPARISON OF EFFICACY AND SAFETY OF PROPOFOL WITH TRADITIONAL MODERATE SEDATION DRUGS IN THE EMERGENCY DEPARTMENT SETTING

    Comparative DrugEfficacySafety
    Several alternatives
    Significantly higher number of cases in which a single agent was sufficient for sedation
    Significantly lower rate of sedation with propofol
    Significantly lower rate of complications
    Midazolam
    Higher rate of procedural success with propofol
    Shorter recovery time and length of stay
    No significant difference in safety profiles
    EtomidateHigher rate of procedural success with propofolComparable rates of adverse eventsa
    Ketamine
    Significantly shorter time to regaining of baseline mental status
    Similar procedure times, number of successful procedures, pain, and recall of the procedure
    Significantly lower rate of subclinical respiratory depression
    Similar rates of clinical interventions related to respiratory depression
    Less frequent recovery agitation
    MethohexitalEqually effective, with no differences in the rates of patient satisfaction, patient recall, or procedure-related painEqually safe
    aThe rate of myoclonus was higher among patients who received etomidate (20% vs 2%).
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    18 . Most serious complications related to moderate sedation are caused by
    A) incorrect drug.
    B) inadequate monitoring.
    C) unintended oversedation.
    D) nonadherence to fasting requirement.

    MANAGEMENT OF COMPLICATIONS

    Knowledge and skill in managing potential complications of moderate sedation is essential. Most complications occur because of sedation becoming deeper than intended (rather than not reaching adequate sedation) [11]. This is especially important for children, as studies have indicated that children often reach a level of sedation that is deeper than intended [13]. Clinicians who administer moderate sedation must be qualified to rescue patients who reach a deep level of sedation [11].

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    19 . While sedated for a therapeutic procedure, a patient emits a loud crowing sound. This is a clinical sign of
    A) aspiration.
    B) laryngospasm.
    C) bronchospasm.
    D) airway obstruction.

    MANAGEMENT OF COMPLICATIONS

    MANAGEMENT OF COMMON SERIOUS COMPLICATIONS DURING MODERATE SEDATION

    ComplicationClinical SignsInterventionsa
    Respiratory depression/soft tissue obstruction
    Decreased, shallow, or labored respirations
    Rocking motion of chest
    Weak cough, high-pitched noise during inspiration (partial obstruction)
    No movement of air (complete obstruction)
    Decreased oxygen saturation
    Put patient in supine position
    Stimulate patient (call name or gently shake)
    Administer supplemental oxygen
    Perform head tilt-chin lift or jaw-thrust maneuver
    Insert artificial airway (nasopharyngeal or oropharyngeal)
    Administer positive pressure ventilation with bag-valve-mask device
    Insert endotracheal tube
    Administer reversal agent
    Laryngospasm
    Loud crowing sound (partial spasm)
    Lack of air exchange (complete)
    Administer supplemental oxygen
    Provide calming measures
    Ask patient to breathe slowly and deeply and to cough
    Administer low dose of midazolam or lidocaine
    Administer positive pressure ventilation with 100% oxygen and suction
    Administer low dose of succinyl choline
    Insert endotracheal tube
    Bronchospasm
    Mild wheezing heard only on auscultation (only smaller bronchioles affected)
    Audible wheezing, tachypnea, dyspnea, decreased lung compliance, decreased oxygen saturation, restlessness (greater area of lung affected)
    Administer bronchodilator
    Administer humidified oxygen
    Hypotension>20% decrease in blood pressure for more than two minutes
    Place patient in Trendelenburg position
    Perform ABC assessment
    Confirm appropriate ECG rate and rhythm: treat arrhythmia or notify cardiologist if signs of MI or ischemia are present
    Consider hypovolemia: administer rapid IV bolus of 0.9% saline (in the absence of contraindications)
    Consider other causes: if drug effect, administer reversal agent; if decreased vascular resistance, administer vasopressor
    aIn general, interventions should be carried out in order of simple to aggressive, but more aggressive measures may be needed immediately depending on the patient's condition.
    ABC = airway, breathing, circulation, ECG = electrocardiogram, MI = myocardial infarction.
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    20 . Which of the following is a potential legal issue related to moderate sedation?
    A) Patient's discharge status
    B) Failure to obtain appropriate informed consent
    C) Failure to administer sedation according to the standard of care
    D) All of the above

    LEGAL/RISK MANAGEMENT ISSUES

    Determining the number of malpractice claims related to the use of moderate sedation is difficult. It has been estimated that approximately one in every 500 malpractice claims involves complications related to endoscopic sedation [28]. (Data on claims related to sedation in the emergency department setting are not available.) Potential legal issues related to moderate sedation are associated with a failure to administer sedation according to the standard of care, failure to obtain appropriate informed consent, and the patient's discharge status [28,133]. In addition, patient expectation of pain-free procedures may increase the risk of malpractice claims for two reasons: patients' claims of inadequate sedation, and oversedation as a way to ensure a pain-free status [28]. Some key measures can help clinicians reduce their risk of malpractice related to moderate sedation (Table 18) [134]. All clinicians should discuss the possibility that the patient may have pain or discomfort despite appropriate sedation [28]. The discussion about sedation should also note that the patient may not remember the procedure and postprocedure discussion and that there is a risk for allergic drug reactions and local reactions at the IV site [28]. The discussion of these points should be carefully documented to provide proof in the event of legal action. The preprocedure discussion should also address informed consent, as outlined previously.

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