Chapter 22 – Procedural Sedation and Analgesia in Trauma




Abstract




Procedural sedation and analgesia (PSA) is a core competency for emergency physicians (EP) that is commonly practiced.14 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





Chapter 22 Procedural Sedation and Analgesia in Trauma


Steven G. Schauer and Jason F. Naylor



Background


Procedural sedation and analgesia (PSA) is a core competency for emergency physicians (EP) that is commonly practiced.14 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




Table 22.1 American College of Emergency Physicians (ACEP) Clinical Policy for PSA1

























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.


Indications




  • Traumatic injuries account for the greatest number of sedations in the emergency department (ED).612



  • 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.



  • Agitated trauma patients may require sedation for diagnostic procedures, such as neuroimaging (Box 22.1).14




Box 22.1 Indications For PSA in Trauma Patients




  • Tube thoracostomy



  • Surgical airway



  • Fracture reduction



  • Joint dislocation reduction



  • Laceration repair



  • Wound and burn debridement



  • Foreign body removal



  • Central venous catheterization



  • Diagnostic imaging in agitated or uncooperative patients



Preparation





  • The American Society of Anesthesiology (ASA) physical status classification is a useful tool for risk stratifying patients by their medical history.1416 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




  • Evaluate for difficult bag valve mask ventilation, difficult intubation, allergies, and PSA agent contraindications.



  • Be prepared to respond to airway obstruction, apnea/hypoventilation, hypotension, dysrhythmia, and emesis.1416



  • Fasting state is often considered, but aspiration of emesis during ED PSA is rare, and preprocedural fasting does not decrease risk.1, 19



  • End tidal carbon dioxide monitoring is not required, but it may detect apnea/hypoventilation before pulse oximetry, especially in patients on supplemental oxygen.2022



  • Important equipment recommended for procedural sedation is listed in Box 22.2.





Table 22.2 American Society of Anesthesiologists physical status classification18



































Class Definition Example
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.



Box 22.2 Equipment for PSA1,1416




  • Oxygen



  • NRB



  • BVM



  • LMA



  • Intubation



  • Suction



  • Monitor



  • (Required) Blood pressure, pulse oximetry



  • (Recommended) Cardiac, capnography



  • IV access



  • Defibrillator



  • Reversal and resuscitation medications



Medication Choices




  • Consider airway status, ventilatory function, hemodynamic state, and previous opioid analgesic administrations when selecting the appropriate agent and dose.



  • Reduced doses titrated to sedation goals are appropriate in hypovolemic, elderly, and obese patients.15, 16



Ketamine




  • Favorable adverse effects (AE) profile with respect to ventilation and hemodynamics.14, 15 However, transient apnea/hypoventilation and hypotension may occur, especially if given rapidly.5, 16



  • Recent research counters previous concerns for ketamine-induced elevations in intracranial and intraocular pressures with resultant adverse outcomes.5, 2328 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



Propofol




  • Fewer contraindications and a shorter recovery period than ketamine, but it is associated with decreased blood pressure and hypoventilation.1416



  • Caution with hypovolemic trauma patients and significant traumatic brain injury, as hypotension should be avoided in these situations.15, 16, 29



  • Adjunctive analgesic recommended, as it has no analgesic properties.1416



Ketofol (Ketamine and Propofol)




  • 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



  • 1:1 mixture of 10 mg/mL ketamine and 10 mg/mL propofol in a single syringe given in 0.1–0.5 mL/kg aliquots (5 mg of each agent in each mL) produces reliable sedation effects.8, 9, 11, 30



Etomidate, Midazolam, and Fentanyl




  • Etomidate has the most favorable hemodynamic profile.1416



  • Although not common, all agents may produce hypoventilation, especially if given rapidly or after other agents for analgesia (i.e. opiates) and anxiolysis (i.e. benzodiazepines).1416



  • Etomidate may produce transient myoclonus (up to 20% of patients) that may interfere with procedural completion.15, 16



  • 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



  • Tables 22.322.5 discuss medication options.




Table 22.3 PSA agents5,9,1416,30,32











































Agent Dosing Contraindications Adverse Effects
Ketamine IV:

Adult: 1.0 mg/kg

Peds: 1.5–2.0 mg/kg

Redose: 0.5 mg/kg q3min

IM:

Adult: 4.0–5.0 mg/kg

Peds: same dose

Redose: half or full

IN: 6.0 mg/kg
Absolute:

<3 months old

Schizophrenia

Relative:

Active asthma

Active URI (peds)

Airway instability (e.g. tracheal stenosis, laryngomalacia)

CAD/CHF/HTN
Laryngospasm

Emergence phenomenon

Nausea, vomiting

Hypersalivation

Random movements
Propofol IV:

Adult: 0.5–1.0 mg/kg

Peds: 0.5 mg/kg

Redose: 0.5 mg/kg q1–3min
Absolute:

Allergy egg protein

Allergy soy protein

Relative:

Hypovolemia
↓BP

↓RR

Injection pain
Ketofol

1:1 mix

10 mg/mL Ketamine

10 mg/mL Propofol

1 mL = 5 mg each
IV:

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
Etomidate IV:

Adult: 0.1–0.2 mg/kg

Peds: 0.1 mg/kg

Redose: 0.1 mg/kg q2min
↓RR

Myoclonus

Nausea, vomiting

Adrenal suppression
Midazolam IV:

Adult: 0.05–0.2 mg/kg

Peds: 0.1 mg/kg

Redose: 0.05 mg/kg q2min

IM:

Adult: 0.1 mg/kg

Peds: same dose

Redose: half or full

IN (Peds): 0.2 mg/kg

PO (Peds): 0.5 mg/kg
Relative:

Hypovolemia
↓RR

Paradoxical agitation

Nausea, vomiting

Hiccups, cough
Fentanyl IV:

Adult: 1.0–3.0 µg/kg q1–3min

Peds: same dose

Redose: half or full

TM (Peds): 10.0 µg/kg
↓RR

Rigid chest syndrome

Nausea, vomiting

Pruritis



Table 22.4 PSA agent characteristics9,1416,30





































































Agent Route Onset (minutes) Duration (minutes)
Ketamine IV 1–3 10–20
IM 5–20 30–60
IN 5–10 30–120
Propofol IV 1–2 5–10
Etomidate IV 0.5–1 5–10
Midazolam IV 1–3 30–60
IM 10–30 60–120
IN 10–15 45–60
PO 15–30 60–90
Fentanyl IV 0.5–2 30–60
TM 10–30 60–120



Table 22.5 Potential adjunctive treatments5,1416,32,33








































Medication Dosing Indication
Naloxone IV:

Adult: 0.4–2.0 mg

Peds (<20 kg): 0.1 mg/kg

Peds (≥20 kg): 2.0 mg
Opiate reversal
Flumazenil IV:

Adult: 0.1–1.0 mg

Peds (>1-year-old): 0.02 mg/kg
Benzodiazepine reversal
Crystalloids IV:

Adult: 250–500 mL

Peds: 10–20 mL/kg
Hypotension
Phenylephrine IV:

Adult: 20–200 µg q2–5min

Peds: 0.1–0.5 µg/kg/min
Hypotension
Midazolam IV:

Adult: 0.01 mg/kg

Peds: 0.05–0.01 mg/kg
Emergence phenomenon
Ondansetron IV:

Adult: 4.0–8.0 mg

Peds (8–30 kg): 0.15 mg/kg

Peds (≥31 kg): 4.0 mg
Nausea, vomiting
Glycopyrrolate IV:

Adult: 0.2 mg

Peds: 0.01 mg/kg
Hypersalivation


Discharge Considerations




  • 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.




Box 22.3 Discharge Criteria Following ED PSA34




  • 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



  • Patient is able to verbalize understanding of discharge instructions



Special Populations – Pediatrics





  • Pediatric patients frequently require sedation for additional reasons beyond adults (e.g. psychological challenges, developmental delays).



  • Ketamine is frequently used with a large safety margin35; ketamine-associated emesis and agitation are more frequent with older children.36



  • Barbiturates are not recommended; they have no intrinsic analgesic properties.37



  • Sedation in children is often more difficult to titrate, with greater variability in the level of sedation achieved.38, 39



  • 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



  • NPO status is a consideration; but ED-based procedures are often not “elective” and, thus, clinicians must evaluate each patient encounter risk/benefit.1, 43



  • 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.




  • Consider using the University of Michigan Sedation Scale (UMSS) to guide sedation goals, which is simple and reproducible (Table 22.7).45




  • Box 22.4 depicts discharge criteria for pediatric patients after PSA.





Table 22.6 AAP and ASA recommendations for duration of NPO before elective sedation43,44
























Age Group Solid and Non-Clear Liquids (Infant Formula, Breast Milk, Non-Human Milk) (hours) Clear Liquids (hours)
<6 months 4–6 2
6–36 months 6 2
>36 months 6–8 2


Note: May be adjusted depending on the urgency of the procedure, as not all ED-based procedural sedation is elective.




Table 22.7 University of Michigan Sedation Scale (UMSS)45

























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
4 Unarousable



Box 22.4 AAP Guidelines For Discharge of Children After Sedation46




  1. 1. Cardiovascular function and airway patency are satisfactory and stable.



  2. 2. The patient is easily arousable, and protective reflexes are intact.



  3. 3. The patient can talk (if age appropriate).



  4. 4. The patient can sit up unaided (if age appropriate).



  5. 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.



  6. 6. The state of hydration is adequate.



Special Populations – Pregnancy




  • 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).




    • Flumazenil risk unclear (pregnancy class C).




Special Populations – Elderly




  • 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.



  • Generally, elderly patients often require lower dosing and have higher risk of adverse events compared to other patient populations.50, 51



  • 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



  • In elderly >70 years, half-dose titration of propofol and benzodiazepines is preferred to avoid adverse events.49, 50, 5355



  • While ketamine has some theoretical risks in the elderly, that has not been borne out in the data. Ketamine use appears safe in the elderly.5658



  • 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



Pitfalls




  • 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).




Key Points




  • 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.




References


1.Godwin SA, Caro DA, Wolf SJ, et al. Clinical policy: procedural sedation and analgesia in the emergency department. Ann Emerg Med. 2005;45(2):177–96. CrossRef | Find at Chinese University of Hong Kong Findit@CUHK Library | Google Scholar | PubMed

2.Miner JR, Krauss B. Procedural sedation and analgesia research: state of the art. Acad Emerg Med. 2007;14(2):170–78. CrossRef | Find at Chinese University of Hong Kong Findit@CUHK Library | Google Scholar | PubMed

3.Bellolio MF, Gilani WI, Barrionuevo P, et al. Incidence of adverse events in adults undergoing procedural sedation in the emergency department: a systematic review and meta-analysis. Acad Emerg Med. 2016;23(2):119–34. CrossRef | Find at Chinese University of Hong Kong Findit@CUHK Library | Google Scholar | PubMed

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Jan 10, 2021 | Posted by in EMERGENCY MEDICINE | Comments Off on Chapter 22 – Procedural Sedation and Analgesia in Trauma
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