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How To Do Procedural Sedation and Analgesia
Equipment
Monitoring equipment (pulse oximeter, capnograph [end-tidal CO2 monitor], blood pressure cuff, cardiac monitor) IV catheters and fluid (eg, 0.9% saline) Supplemental oxygen (with high-flow capacity) Suction source and tips Airway management equipment, especially a bag-valve-mask (BVM) Cardiopulmonary resuscitation equipment PSA drugs and reversal agents (see examples below) Additionally, for nitrous oxide administration: Fail-safe gas administration equipment (built-in lower limit of 30% oxygen delivery); demand valve mask or continuous flow mask; ambient nitrous oxide sensor and gas scavenger apparatus (for removal of exhaled nitrous oxide from room air) Sedative-hypnotics (primarily sedative, anxiolytic, and amnestic): MidazolamIV, IM, intranasal: Short-acting sedation (benzodiazepine); IV onset 1 to 2 minutes, duration 10 to 40 minutes PropofolIV: Ultra-short-acting, deep sedation; onset 30 seconds, duration 5 minutes EtomidateIV: Ultra-short-acting, deep sedation; onset 5 to 15 seconds; duration 5 to 15 minutes The sedative-hypnotics are highly sedating (with accompanying decreased response to pain), but they provide no direct analgesia. They may be given alone when pain control is not required. They may be supplemented with opioid analgesia (eg,fentanyl) or injectable regional or local anesthesia if needed. Midazolamis often used alone to provide mild sedation (anxiolysis) before painless or mildly painful procedures. It has a potent amnestic effect. Propofolandetomidateprovide rapid-onset, deep sedation useful for quick, painful procedures (eg, cardioversion or joint reduction); their short duration can also help decrease the risk of accumulation that reach toxic drug levels resulting from repeated dosing during longer procedures. Propofolmay be anticipated to cause hypotension that usually is brief and readily managed. Etomidateneither lowers nor raises blood pressure or pulse. It may be considered in patients with hypotension and in those with cardiovascular disease (ie, those at risk of decompensation from changes in pulse and blood pressure). Opioids (primarily analgesic): FentanylIV: Short-acting analgesia; onset 2 to 3 minutes, duration 30 to 60 minutes Opioids produce analgesia but also cause sedation. In PSA, opioid analgesia is typically used as an adjunct to a sedative when analgesia is required, which increases the risk of respiratory depression.Fentanylis often used withmidazolam; a reversal agent (naloxoneandflumazenil) is available for each. A longer-acting opioid such asmorphinemay be chosen if the patient's pain is likely to continue after the procedure (eg, with certain fractures or other persistently painful injuries). Dissociative agent (primarily analgesic and amnestic): KetamineIV, IM, intranasal: Dissociative sedation; IV onset<1 minute, duration 10 to 20 minutes Ketaminecauses a dissociative state (trance-like mind-body dissociation) that provides analgesia, sedation, and amnesia but does not cause respiratory depression or diminish upper airway tone or protective reflexes and may be a first choice for patients at risk of aspiration. Moreover,ketaminedoes not cause hypotension but typically increases pulse and blood pressure modestly.Ketaminemay be given alone or with a sedative. However, at PSA doses,*ketamineshould not be supplemented with another analgesic. *Low-dose (sub-dissociative)ketamine(eg, 0.1 to 0.2 mg/kg) provides substantial analgesia without causing dissociation; it may be used to supplement opioid analgesia (eg, allowing smallerfentanyldoses). Nitrous oxide gas (primarily anxiolysis): Nitrous oxide (30% to 50%) in oxygen: Short-acting anxiolysis; onset and offset<5 minutes each Nitrous oxide provides excellent anxiolysis but only mild amnesia and analgesia. It is not typically used alone for analgesia but may be given with (or as an adjunct to) an analgesic, sedative, or nerve block. It is particularly useful for children because it does not require IV catheterization. In children, it may be preferred tomidazolamorketamine. At the low doses used for PSA, it is safe. Reversal agents: Flumazenil(0.1 mg/mL—benzodiazepine antagonist) Naloxone(opioid antagonist) 