Procedural sedation and analgesia (PSA) is a core competency for emergency physicians (EP) that is commonly practiced.1–4 PSA entails suppressing a patient’s level of consciousness with sedative or dissociative agents to alleviate pain, anxiety, and suffering to enhance medical procedure performance and patient experience (Table 22.1).1,5
Procedural sedation and analgesia (PSA) is a core competency for emergency physicians (EP) that is commonly practiced.1–4 PSA entails suppressing a patient’s level of consciousness with sedative or dissociative agents to alleviate pain, anxiety, and suffering to enhance medical procedure performance and patient experience (Table 22.1).1, 5
|Depths of Sedation||Definition|
|Minimal Sedation||Near-baseline level of alertness. A pharmacologically induced state during which patients respond normally to verbal commands. Although cognitive function and coordination might be impaired, ventilatory and cardiovascular functions are unaffected.|
|Moderate Sedation||Depression of consciousness during which patients respond purposefully to verbal commands, either alone or accompanied by light tactile stimulation. No interventions are required to maintain a patent airway, and spontaneous ventilation is adequate. Cardiovascular function is usually maintained.|
|Dissociative Sedation||Trance-like cataleptic state characterized by profound analgesia and amnesia, with retention of protective airway reflexes, spontaneous respirations, and cardiopulmonary stability.|
|Deep Sedation||Depression of consciousness during which patients cannot be easily aroused, but respond purposefully after repeated or painful stimulation. The ability to independently maintain ventilatory function may be impaired. Patients may require assistance in maintaining a patent airway, and spontaneous ventilation may be inadequate. Cardiovascular function is usually maintained.|
|General Anesthesia||Unresponsiveness to all stimuli and the absence of airway protective reflexes. The ability to independently maintain ventilatory function is often impaired. Patients often require assistance in maintaining a patent airway, and positive-pressure ventilation may be required because of depressed spontaneous ventilation or drug-induced depression of neuromuscular function. Cardiovascular function may be impaired.|
ED PSA for the severely injured trauma patient may be limited to life-saving interventions (LSI). Tube thoracostomy and cricothyrotomy may require PSA in addition to injection of local anesthetic agents.13
LSI and emergent procedures necessitate procedural performance in the ED. For urgent and non-urgent procedures, however, lengthy procedures and higher risk patients may benefit from PSA in the operating room or with anesthesiology staff support in the ED.
The American Society of Anesthesiology (ASA) physical status classification is a useful tool for risk stratifying patients by their medical history.14–16 ASA Class I and II are associated with significant adverse event rates <5%, while risk increases with greater ASA Classes (Table 22.2).16, 17
Important equipment recommended for procedural sedation is listed in Box 22.2.
|I||A normal healthy patient||Healthy, non-smoking, no or minimal alcohol use.|
|II||A patient with mild systemic disease||Mild diseases only without substantive functional limitations. Examples include (but not limited to): current smoker, social alcohol drinker, pregnancy, obesity (30< BMI <40), well-controlled DM/HTN, mild lung disease.|
|III||A patient with severe systemic disease||Substantive functional limitations; one or more moderate to severe diseases. Examples include (but not limited to): poorly controlled DM or HTN, COPD, morbid obesity (BMI ≥40), active hepatitis, alcohol dependence or abuse, implanted pacemaker, moderate reduction of ejection fraction, ESRD undergoing regularly scheduled dialysis, premature infant, PCA <60 weeks, or history (>3 months) of MI, CVA, TIA, or CAD/stents.|
|IV||A patient with severe systemic disease that is a constant threat to life||Examples include (but not limited to): recent (<3 months) MI, CVA, TIA, or CAD/stents, ongoing cardiac ischemia or severe valve dysfunction, severe reduction of ejection fraction, sepsis, DIC, ARDS, or ESRD not undergoing regularly scheduled dialysis.|
|V||A moribund patient who is not expected to survive without the operation||Examples include (but not limited to): ruptured abdominal/thoracic aneurysm, massive trauma, intracranial bleed with mass effect, ischemic bowel in the face of significant cardiac pathology, or multiple organ/system dysfunction.|
|VI||A declared brain-dead patient whose organs are being removed for donor purposes.|
Consider airway status, ventilatory function, hemodynamic state, and previous opioid analgesic administrations when selecting the appropriate agent and dose.
Recent research counters previous concerns for ketamine-induced elevations in intracranial and intraocular pressures with resultant adverse outcomes.5, 23–28 Recent guidelines for ketamine as an ED PSA agent removed head injury as a relative contraindication.5
Prophylactic antisialagogue for hypersalivation and prophylactic benzodiazepines for emergence reaction are not recommended.5
Prophylactic antiemetics may be given, as post-PSA emesis is common.5
Theoretical advantage of limiting AE of each agent by reducing the total dosage of each agent given and intrinsic properties of each agent counteracting some AE of the other. Additionally, analgesic properties of ketamine may obviate opiate co-administration.9, 11, 30, 31
Midazolam is associated with paradoxical agitation (up to 15% of patients) that may be reversed with flumazenil.
Fentanyl administered rapidly in large doses (>5–15 µg/kg) may result in the rare AE of rigid chest syndrome that is irreversible with naloxone and may require intubation and mechanical ventilation.15, 16
Adult: 1.0 mg/kg
Peds: 1.5–2.0 mg/kg
Redose: 0.5 mg/kg q3min
Adult: 4.0–5.0 mg/kg
Peds: same dose
Redose: half or full
IN: 6.0 mg/kg
<3 months old
Active URI (peds)
Airway instability (e.g. tracheal stenosis, laryngomalacia)
Adult: 0.5–1.0 mg/kg
Peds: 0.5 mg/kg
Redose: 0.5 mg/kg q1–3min
Allergy egg protein
Allergy soy protein
10 mg/mL Ketamine
10 mg/mL Propofol
1 mL = 5 mg each
Adult: 0.1–0.5 mL/kg aliquots
Peds: same dose
Redose: half or full q30–60sec
|Same as above, but lower rates of AE|
Adult: 0.1–0.2 mg/kg
Peds: 0.1 mg/kg
Redose: 0.1 mg/kg q2min
Adult: 0.05–0.2 mg/kg
Peds: 0.1 mg/kg
Redose: 0.05 mg/kg q2min
Adult: 0.1 mg/kg
Peds: same dose
Redose: half or full
IN (Peds): 0.2 mg/kg
PO (Peds): 0.5 mg/kg
Adult: 1.0–3.0 µg/kg q1–3min
Peds: same dose
Redose: half or full
TM (Peds): 10.0 µg/kg
Rigid chest syndrome
|Agent||Route||Onset (minutes)||Duration (minutes)|
Adult: 0.4–2.0 mg
Peds (<20 kg): 0.1 mg/kg
Peds (≥20 kg): 2.0 mg
Adult: 0.1–1.0 mg
Peds (>1-year-old): 0.02 mg/kg
Adult: 250–500 mL
Peds: 10–20 mL/kg
Adult: 20–200 µg q2–5min
Peds: 0.1–0.5 µg/kg/min
Adult: 0.01 mg/kg
Peds: 0.05–0.01 mg/kg
Adult: 4.0–8.0 mg
Peds (8–30 kg): 0.15 mg/kg
Peds (≥31 kg): 4.0 mg
Adult: 0.2 mg
Peds: 0.01 mg/kg
The ability to urinate or tolerate PO prior to discharge is not universally required; the need for this may be case-by-case specific.34
All patients should be required to have another responsible party with them prior to discharge.
No data has demonstrated a required amount of time post-sedation before discharge.34
ED should have sedation-specific discharge instructions to provide the patient.
Discharge time needs to be adjusted if a reversal agent was given based on drug-specific pharmacokinetics.
Box 22.3 depict discharge criteria after PSA.
Patient is alert and oriented to baseline
Hemodynamic status is at acceptable level specific to the patient
Protective reflexes, specifically airway, are intact
Pain is adequately controlled
Patient ambulation status at or near baseline (may not always be applicable)
Responsible adult will be present with patient after discharge
Pediatric patients frequently require sedation for additional reasons beyond adults (e.g. psychological challenges, developmental delays).
Barbiturates are not recommended; they have no intrinsic analgesic properties.37
Consider alternative routes of administration in order to obviate challenges associated with IV placement (e.g. oral midazolam, oral ketamine, intranasal ketamine, intramuscular ketamine); consider IV placement after sedation is achieved.40
Advanced airway equipment specific to patient size should be readily available.41
Use of an independent observer of patient hemodynamic/respiratory status reduces the risks of adverse events (does not have to be physician, consider having a dedicated nurse or qualified technician, if available).41
Pediatric-specific protocols may reduce adverse events, especially in very young children.42
ACEP Clinical Policy states: “Do not delay procedural sedation in adults or pediatrics in the ED based on fasting time. Preprocedural fasting for any duration has not demonstrated a reduction in the risk of emesis or aspiration when administering procedural sedation and analgesia.” (Level B recommendation)1
Table 22.6 discusses key considerations in oral intake before sedation from the AAP and ASA, though ACEP recommends that no fasting is required before sedation.
Box 22.4 depicts discharge criteria for pediatric patients after PSA.
|Age Group||Solid and Non-Clear Liquids (Infant Formula, Breast Milk, Non-Human Milk) (hours)||Clear Liquids (hours)|
Note: May be adjusted depending on the urgency of the procedure, as not all ED-based procedural sedation is elective.
|Score||Depth of Sedation|
|0||Awake and alert|
|1||Minimally sedated: tired/sleepy, appropriate response to verbal conversation and/or sound|
|2||Moderately sedated: somnolent/sleeping, easily aroused with light tactile stimulation or a simple verbal command|
|3||Deeply sedated: deep sleep, arousable only with significant physical stimulation|
1. Cardiovascular function and airway patency are satisfactory and stable.
2. The patient is easily arousable, and protective reflexes are intact.
3. The patient can talk (if age appropriate).
4. The patient can sit up unaided (if age appropriate).
5. For a very young or handicapped child incapable of the usually expected responses, the presedation level of responsiveness or a level as close as possible to the normal level for that child should be achieved.
There is very little data to guide PSA in the pregnant patient. ACEP does not have a specific clinical policy on this population.4
Significant physiologic changes occur in pregnancy: plasma volume and cardiac output increase along with a commensurate increase in respiratory volume and rate to compensate for metabolic demands ➔ decreased ability to compensate during hemodynamic stress and more rapid deoxygenation.47
Regional anesthesia may be used as an alternative (lidocaine is pregnancy class B).
Meperidine (pregnancy class B) may be preferred over morphine (pregnancy class C).48
May be reversed with naloxone (pregnancy class B).
Propofol is the preferred agent (pregnancy class B).48
Avoid benzodiazepines (pregnancy class D; known teratogenic effects).
Age, in and of itself, is not a contradiction to sedation.49
Very little ED-specific data on sedation in the elderly; most data are extrapolated from anesthesia and dental literature.
For propofol, consider administering an “age based” test dose. A rough estimate may be 100 mg minus the patient’s age (e.g. for a 75 year old patient, start with 25 mg).52
While we do not recommend etomidate for procedural sedation due to the high-risk of myoclonic reactions, it appears safe for use in the elderly.59
Pushing additional boluses of PSA agents (especially propofol) too quickly and inducing hypotension or hypopnea – wait an appropriate length of time for the drug to take effect before repeat dosing to reduce adverse event risk, which may have dose-dependent effects.52
Drugs can have stacking-effects when given together. Drugs given before the sedation may potentiate the likelihood of an adverse event.60
Airway related complications are not always predictable; have appropriate airway equipment available and ready before starting sedation.
Consider adjusting dosing for patient characteristics that may affect medication metabolism (e.g. age, body mass, liver function, kidney function).
Tube thoracostomy and cricothyrotomy may require PSA in addition to injection of local anesthetic agents.
Lengthy procedures and higher risk patients may benefit from PSA in the operating room or with anesthesiology staff support in the ED.
Reduced doses of PSA agents titrated to sedation goals are appropriate in hypovolemic, elderly, and obese patients.