Which benzodiazepine has rapid onset is short acting relieves anxiety and provides sedation before and during procedures?

PSA should be done, in accordance with institutional guidelines, by a clinician or service proficient with the procedure and with equipment and trained personnel available to provide emergency airway and ventilatory support.

  • Select a PSA strategy: A decision to do PSA and the selection of PSA drugs to use (including alternative or additional drugs) must consider factors such as clinical need, patient risk factors for complications and difficult intubation, and adequacy of provider training and familiarity with PSA drugs.

  • Ensure the availability of reversal agents as well as PSA drugs.

  • Ensure the availability of a nearby resuscitation cart, airway suction, and rescue airway equipment.

  • Assemble bag-valve-mask and oxygen line, to be able to provide immediate oxygen support, as needed.

  • Attach monitoring devices to the patient and verify that they are working correctly.

  • Establish intravenous access. Consider cannulating a large vein (eg, antecubital vein) if propofol or etomidate are to be used for sedation, to help decrease the pain of those injections.

  • Recommended: Begin slow IV infusion (eg, 0.9% saline at 30 mL/h) to ensure IV patency and thereby be able to provide immediate blood pressure support, as needed.

  • Before giving PSA drugs, establish the patient's pre-sedation vital signs, cardiac rate and rhythm, mental status (level of consciousness), and quality of breathing and ventilation.

Monitor the patient throughout PSA, to ensure PSA safety (absence of respiratory depression or cardiovascular compromise) and effectiveness (relief of pain and anxiety):

  • Breathing: Continuously assess the state of spontaneous breathing. Changes in the rate, depth, or noise of breathing may precede other signs of respiratory depression.

  • End-tidal CO2 (capnography) and O2 saturation (pulse oximetry): Maintain continuous vigilance for hypoventilation. Changes in end-tidal CO2 occur virtually simultaneously with drug-induced hypoventilation and precede hypoxia.

    Respiratory depression due to short-acting PSA drugs usually resolves quickly (as the drugs wear off).

    If hypoventilation or apnea occurs, provide supplemental oxygen, airway repositioning maneuvers, nasal and oral airways, and bag-valve-mask ventilation as needed. Provide verbal and tactile patient stimulation as needed. If necessary, continue bag-valve-mask ventilation and use appropriate reversal agents. More advanced respiratory support is seldom needed.

  • Blood pressure, heart rate, heart rhythm: Frequently check hemodynamics. Transient hypotension may occur, but other cardiovascular events are rare.

    If procedural hypotension occurs, infuse IV fluid as needed to support blood pressure.

  • Patient response to verbal and tactile stimuli: Periodically check patient responsiveness, which is used primarily to detect undersedation (insufficient relief of pain and anxiety), not to determine oversedation (which is more efficiently recognized as respiratory depression).

    Do not check patient responsiveness too frequently or aggressively, because doing so can unnecessarily disrupt an effective sedation and possibly incur an additional drug titration. If the patient is calm and pain-free, rely on monitoring of breathing, ventilation, oxygenation, and hemodynamics to ensure the patient's safety during PSA.

Continue patient monitoring until the patient has fully recovered from the sedation.

To avoid oversedation, always wait at least 2 minutes after a midazolam dose before giving another dose—of midazolam or any other PSA drug.

  • IV midazolam: Titrate to patient response (sedation) as follows:

    Initial dose: 0.5 to 2 mg IV over 2 minutes

    Subsequent doses (after 2 to 5 minutes): 0.5 to 2 mg IV doses over 2 minutes

    Maximum dose: 2.5 mg/dose and 5 mg cumulative IV dose (1.5 mg and 3.5 mg for patients 60 years of age)

  • 5 mg IM (0.1 to 0.15 mg/kg in children). Do not rapidly titrate.

  • For children, 0.2 to 0.5 mg/kg intranasally. Do not rapidly titrate.

PSA using midazolam and fentanyl

When used together, use smaller doses of each drug than when used alone and titrate carefully to avoid respiratory depression. Always wait at least 2 minutes after a midazolam dose before giving another PSA drug. Either drug may be given first; one strategy is to give midazolam first for primarily anxiety-provoking procedures and fentanyl first for more painful procedures.

  • IV midazolam: Titrate to patient response (mild sedation), as follows:

    Initial dose: 0.02 to 0.1 mg/kg IV over 2 minutes

    Subsequent doses (after 3 to 5 minutes): 0.005 to 0.025 mg/kg IV over 2 minutes

    Maximum dose: 2.5 mg/dose and 5 mg cumulative dose (1.5 mg and 3.5 mg for patients 60 years of age).

  • IV fentanyl: Titrate to patient response (analgesia) as follows:

    Initial dose: 50 to 100 mcg (or 1 mcg/kg) IV

    Subsequent doses: May repeat 50-mcg IV dose every 3 minutes as needed.

    Maximum dose: Use extreme caution if exceeding 0.5 mcg/kg/dose if given with other sedatives (eg, midazolam, propofol) as the combination may cause respiratory depression.

  • Avoid propofol in hypotensive patients.

  • Give supplemental oxygen (eg, nasal oxygen at 2 to 4 liters per minute).

  • IV propofol: Titrate doses to patient response (deep sedation), as follows:

    Initial dose: 0.5 to 1.0 mg/kg IV (1.0 to 2.0 mg/kg for children)

    Subsequent doses (after 1 to 3 minutes): 0.25 to 0.5 mg/kg IV every 1 to 3 minutes

    For obese and older patients, start with lower doses. For otherwise healthy adults, start at the higher doses.

  • IV etomidate: Titrate doses to patient response (deep sedation), as follows:

    Initial dose: 0.1 to 0.15 mg/kg IV

    Subsequent doses: 0.05 mg/kg IV every 3 to 5 minutes

Before and during the initial ketamine dose, converse with the patient about a happy or joyful topic (eg, a favorite person, place, or activity). This may reduce unpleasant emergence phenomena (confusion, anxiety, panic) following ketamine PSA.

  • IV ketamine: Give doses over 30 to 60 seconds and titrate to patient response (sedation) as follows:

    Initial dose: 1 to 1.5 mg/kg IV (1 to 2 mg/kg for children) over 1 to 2 minutes

    Subsequent doses (after 10 minutes): 0.5 to 0.75 mg/kg IV (0.5 to 1 mg/kg for children)

    Use lower doses (0.25 to 0.5 mg/kg) depending on the patient's clinical status (eg, older age) or other sedation; however, note that patients may experience partial dissociation and anxiety that is sometimes severe at doses of 0.5 to 1 mg/kg.

  • Intramuscular ketamine (for children):

    Initial dose: 4 to 5 mg/kg IM

    Subsequent doses 2 to 2.5 mg IM every 10 minutes

  • Intranasal ketamine (for children):

    2 to 10 mg/kg intranasally. Do not rapidly titrate.

PSA using nitrous oxide inhalation

A trained individual is required to administer or supervise nitrous oxide inhalation.

  • Assemble gas-delivery and scavenger systems: Select a demand valve mask for a cooperative adult or child >5 years of age or a continuous flow mask for patients 2 to 5 years of age or who are unable to cooperate.

  • Give 100% oxygen for 2 minutes.

  • Then switch to a nitrous oxide/oxygen mixture (eg, 40% N2O [N2O 4 L/m and O2 6 L/m]).

  • Cooperative patient (self-administered N2O): Instruct the patient to hold the demand valve mask over the face (without strapping it on) and to breathe normally. As the patient becomes drowsy, the mask falls away from the face, the patient will breathe room air, and gas flow from the demand valve mask will stop. When the patient is once again awake or experiencing pain, tell him or her to resume breathing through the mask.

  • Uncooperative patient/child (closely supervised N2O administration): Strap a continuous flow mask over the patient's nose and mouth and observe the patient's respirations and sedation level continuously.

  • Titrate the gas mixture to provide mild sedation with normal respirations. Prolonged N2O delivery of concentrations > 50% are not typically needed.

  • When mild sedation is achieved, add an analgesic, sedative, or nerve block as needed for pain control.

  • When the procedure is concluded, give 100% O2 for 5 minutes or more, to prevent diffusion hypoxia during recovery.