1. Procedural Sedation & Analgesia in the Emergency Department

2. Objectives Review the current guidelines Review commonly used agents
Briefly discuss alternatives to PSA

3. What’s not covered
Pediatric procedural sedation & analgesia

4. Procedural Sedation & Analgesia
Positives
Avoids discomfort associated with local or regional anaesthetic techniques.
Doesn’t affect anatomy
Relatively simple technique
Negatives
Consumes resources
Relative higher risk than local/regional
General anaesthesia in the ED
is frowned upon…

5. Goals of PSA To consider patient safety & welfare the first priority.
To provide adequate analgesia, anxiolysis, sedation and amnesia during the performance of painful diagnostic or therapeutic procedures in the ED.
To minimize the adverse psychological responses associated with painful or frightening medical interventions.
To control motor behavior that inhibits the provision of necessary medical care.
To return the patient to a state in which safe discharge is possible.
From Procedural sedation and analgesia in emergency department. Canadian Consensus Guidelines
The Journal of Emergency Medicine
January 1999

6. Considerations for PSA in the ED
Personnel requirements
Patient assessment
Fasting status
Equipment & supplies
Choice of agent
Assessment & monitoring
Adapted from: Clinical policy: procedural sedation and analgesia in the emergency department ACEP Clinical Policies Committee on Procedural Sedation and Analgesia February 2005

7. Personnel Requirements
“… a qualified support person should be present for continuous monitoring of the patient.”
Class C Evidence
Clinical policy: procedural sedation and analgesia in the emergency department
ACEP Clinical Policies Committee on Procedural Sedation and Analgesia
“An additional qualified patient observer… must be present during sedation.”
Class B, Level III
Procedural sedation and analgesia in the emergency department
Canadian Consensus Guidelines

8. Patient Assessment The AMPLE history Physical Exam Allergies
Medications
Past medical history
Last meal
Events before & after the incident
Physical Exam
Airway assessment
Respiratory exam
Cardiovascular exam

9. ASA Physical Status Classification
Healthy Patient
Mild systemic disease – no functional limitation
Severe systemic disease – definite functional limitation
Severe systemic disease that is a constant threat to life
Moribund patient that is not expected to survive with the operation
Low inter-observer reliability.

10. “It’s only a little chest pain” ASA Scores & PSA
The ASA classification is not validated outside of the OR.
Malviya et al showed an increased risk of adverse sedation-related events in paediatric patients with an ASA > 2.
The ASA was developed to help identify patients at risk of developing complications as a result of undergoing general anesthesia.
ASA: No formal support by emergency medicine associations; Supported by the American society of anestheologists

11. And the guidelines say…
“The patient’s ASA status should be determined. For non-emergent procedures, ED sedation and analgesia should be limited to ASA class 1 or 2 patients.”
Class B, Level III
Procedural sedation and analgesia in the emergency department
Canadian Consensus Guidelines
The guidelines go on to say that for ASA III-IV patients, anesthesia should be consulted and OR management should be considered.
ASA status was not addressed in the American guidelines.

12. Airway Assessment
Can you bag?
Can you intubate?

13. Predictors of Difficult BVM Ventilation
Beard
Obesity
Old (age > 55 yrs)
Toothless
Snores
Langeron O, Masso E, Huraux C, et al. Prediction of difficult mask ventilation. Anesthesiology ; 92:

14. The LEMON Method of Airway Assessment
Look for external characteristics known to causes problems with BVM or intubation.
Evaluate the Rule:
Mouth opening > 3 fingers
Hyoid – chin distance > 3 fingers
Anterior low jaw subluxation > 1 finger
Mallampati Score
Obstruction – any pathology within or surrounding the upper airway
Neck Mobility - full flexion & extension

15. The Last Supper Fasting & PSA
The Canadian recommendations are based of American Society of Anaesthesiologists recommendations for healthy elective GA patients:
2 h NPO for liquids
6 h NPO for solids
The risk of aspiration during PSA is extremely low.
There is no evidence that fasting improves outcome during procedural sedation and analgesia.
One large paediatric study of ED procedural sedation showed no increase in the number of adverse events in patients that were not fasting.
In addition, the ASA indicates that there is no role for the use of antacids and gastric motility agents to prevent aspiration during elective GA in healthy patients. The ACEP guidelines apply this recommendation to ED PSA patients, while the Cdn guidelines recommend their use in patients who do not meet NPO criteria.
Green proposes a number of reasons why the the ASA guidelines should not be generalized to ED PSA
Aspiration is most likely to occur during airway manipulation – this should not be happening during PSA.
PSA is typically performed in younger patients. The risk of aspiration is higher in older patients.
Most agents used during PSA are not pro-emetic, unlike the gases which are commonly used in the OR.
Ideally, PSA should be in the range of moderate sedation with intact airway reflexes
The use of dissociative amnestics (ketamine) theoretically reduces the risk of aspiration because airway reflexes are “intact”

16. Guidelines for Pre-sedation Fasting
“Recent food intake is not a contraindication for administering procedural sedation and analgesia, but should be considered in choosing the timing and targeted level of sedation.”
Class C Evidence
Clinical policy: procedural sedation and analgesia in the emergency department
ACEP Clinical Policies Committee on Procedural Sedation and Analgesia
“Pre-procedure fasting decreases aspiration risk, though optimal fasting duration remains controversial… the practitioner should consider keeping the patient NPO for 2 h (liquids) or 6 h (solids) before sedation.”
Class C, Level III
Procedural sedation and analgesia in the emergency department
Canadian Consensus Guidelines

17. The Perfect Drug Provides adequate sedation and analgesia for:
Patient comfort
Easy completion of the procedure
Maintains airway reflexes
Does not affect hemodynamics
Does not affect respiratory function

18. Commonly Used Agents
Propofol
Fentanyl
Ketamine
Midazolam
Etomidate

19. What are we using? Propofol is the most commonly used agent.
Fentanyl + midazolam is the next most common.
Source: Articles in the March 2006 edition of CJEM by Campbell et al and Mensour et al regarding at PSA in the ED.

20. Commonly Used Agents Propofol
Category
Sedative-Hypnotic
What is it?
2,6-diisopropofol, an alkylphenol oil in an emulsion
How does it work?
Potentiates GABA activity
How much do you need?
Starting dose of mg/kg
Actual half-life of propofol is 4-7 hrs
Clearance is independent of renal or liver function and is not affected by renal or hepatic disease.
Onset is one arm-brain circulation with peak affect at s.
Anti-emetic properties

21. Commonly Used Agents Propofol
What else does it do?
CNS: Mild analgesic properties; euphoria
CVS: Myocardial depressant; vasodilation
Resp: Respiratory depressant
GI: Antiemetic
MSK: Myoclonus
What does the body do with it?
Rapid redistribution
Hepatic and extrahepatic metabolism

22. Commonly Used Agents Propofol
Pros
Shown to be safe for ED PSA use
Rapid onset and recovery
Cons
Must be combined with an analgesic agent
May cause apnea & loss of airway reflexes
Myocardial depressant and vasodilator
Must be administered via special IV pump
Symington and Thakore conducted a review of the safety of using propofol for procedural sedation in the ED and concluded that while the rate of “minor” adverse events (including transient hypoxia) was similar to other agents, the drug was overall very safe and offered advantages over other agents.

23. Commonly Used Agents Fentanyl
Category
Analgesic agent
What is it?
Synthetic opioid
How does it work?
Decreases conduction along nociceptive pathways and increases activity in pain control pathways in the brain.
How much do you need?
Starting dose of 1-2 mcg/kg
Doses > 5 mcg/kg bolused rapidly are required to cause chest wall rigidity. Rigidity is managed with paralysis or reversal agents.
May cause coughing in 50% of patients.
Peak effect in 2-3 min

24. Commonly Used Agents Fentanyl
What else does it do?
CNS: Euphoria (or dysphoria)
Resp: Respiratory depressant; chest wall rigidity
CVS: May decrease HR
GI: Decreased motility
What does the body do with it?
Hepatic metabolism (inactive metabolite)
Renal excretion

25. Commonly Used Agents Fentanyl
Pros
Good hemodynamic stability
Rapid onset and recovery
Cons
Must be combined with an amnestic agent
May cause bradycardia
May cause chest wall rigidity in high doses
May cause apnea & loss of airway reflexes
Cardiology study using high dose fentanyl for cardiac surgery – patients were hemodynamically stable and pain free.

26. Commonly Used Agents Midazolam
Category
Amnestic
What is it?
Benzodiazepine
How does it work?
Bind to benzodiazepine receptors which up-regulate GABA activity
How much do you need?
0.02 – 0.1 mg/kg IV
Use with caution in patients with renal failure b/c of potential buildup of metabolite.

27. Commonly Used Agents Midazolam
What else does it do?
CNS: Anxiolysis
CVS: Slight decrease in PVR & decreased contractility.
Resp: Respiratory depression
What does the body do with it?
Hepatic metabolism (active metabolite)
Renal excretion

28. Commonly Used Agents Ketamine
Category
Dissociative Amnestic
What is it?
Derivative of phencyclidine with some opioid properties.
How does it work?
Stimulates the limbic system while inhibiting the thalamus & cortex (dissociation)
Binds to NMDA and opioid receptors
Metabolite (norketamine) has 20-30% less activity than ketamine
Onset within 30 s of administration (IV)
Distribution half life is minutes (two compartment metabolism)

29. Commonly Used Agents Ketamine
What else does it do?
CNS: Emergence reactions - nightmare/hallucination, Increase intracranial pressure
CVS: Increased contractility, HR and PVR through sympathetic stimulation. Direct myocardial depressant.
Resp: Laryngospasm, bronchodilation, increased secretions (bronchorrhea), virtually universal maintenance of airway reflexes
GI: Emesis is common
What does the body do with it?
Hepatic metabolism
Renal excretion

30. But won’t it give him nightmares? Ketamine & Emergence Reactions
Frequency is reported to be anywhere from 10% to 20% in adults.
Pre-procedural agitation is the best predictor of emergence reaction.
Co-administered benzodiazepine has NOT been found to reduce incidence in children but may do so in adults.
Ann Emerg Med Aug;54(2):171-80
Am J Emerg Med Nov;26(9):
Emergence reaction: Anxiety, nightmares, hallucinations & delirium while waking up
Ketamine is extensively used in developing countries with great success.
Evidence for benzos is debateable – several peds trials show no benefit. Anecdotally, some people will wait for signs of emergence before giving midazolam while others give it with ketamine. Two trials from the 70’s show a reduction in the incidence of emergence reactions when adult patients were pretreated with midazolam

31. The Bottom Line Ketamine can be useful for adult PSA in the ED.
Contraindications for use in PSA:
Ischemic heart disease
Prolonged stress response
Poorly controlled hypertension
Recent respiratory tract infection
History of psychotic illness
Possible intracranial or ocular injury
Consider co-administration of midazolam to decrease the risk of emergence reaction.
Consider anti-emetic to reduce vomiting.
Green, SM and Li J. “Ketamine in Adults: What Emergency Physicians Need to Know about Patient Selection and Emergence Reactions” Academic Emergency Medicine :

32. Commonly Used Agents Ketamine
How much do you need?
2 mg/kg IV, 3-4 mg/kg IM
How much midazolam?
3-5 mg given at the time of ketamine injection.
Several authors pointed out that this dose of midazolam may be higher than required to prevent emergency reactions.

33. Mix & Match Commonly used combinations: Propofol + Fentanyl
Fentanyl + Midazolam
Propofol + Midazolam + Fentanyl
Ketamine + Midazolam
Combinations of propofol + fentanyl, fentanyl + midazolam etc lead to synergistic effects on the cardiovascular system. This results in greater than expected amounts of hypotension, which is tolerated in the young health individual, but may be problematic in someone with less reserve.
Midazolam may decrease the rate of ketamine metabolism, resulting in greater duration of sedation.

34. How low should you go? Depth of Procedural Sedation
Minimal Sedation (Anxiolysis)
Moderate Sedation/Analgesia
Deep Sedation/Analgesia
General Anaesthesia
Normal LOC
ASA/Joint Commission of Accreditation of Healthcare Organizations – Definitions of Levels of Sedation
Minimal sedation: normal response to verbal commands. Ventillatory & CV function unaffected.
Moderate sedation: pt responds to verbal commons +/- light tactile stimulus. No interventions required to maintain airway. Spont resp. CV function maintained.
Deep sedation: pt cannot be aroused, but responds purposefully to repeated or painful stimulation. May require assistance maintaining a patent airway. Spont vent may be inadequate.
General anaesthesia: Pt is unarousable. Patient typically requires assistance maintaining an airway +/- PPV.

35. Guidelines for Monitoring
“Frequent” monitoring of BP, HR & RR
Continuous O2 sat monitoring
“Frequent” assessment of level of responsiveness
Continue monitoring until the patient is fully awake.

36. Local & Regional Anaesthesia
Trend towards less analgesia and compromise of reduction in patients receiving a hematoma block versus intravenous regional anesthesia.
Insufficient evidence to draw conclusions re other combinations (IV vs regional, etc.)
HHG Handoll, R Madhok & C Dodds. “Anaesthesia for treating distal radial fractures in adults.” Cochrane Database of Systemic Reviews. Issue 3. July 2002.

37. Questions?

38. Key Points Be prepared Know your drugs and your drug interactions
Consider all your options

39. Other References Guidelines
Godwin SA, Caro DA, Wolf SJ, Jagoda AS, Charles R, Marett, BE and Moore J. Clinical policy: procedural sedation and analgesia in the emergency department. Annals of Emergency Medicine. 45:2. February 2005; pp
Innes G, Murphy M, Nijessen-Jordan C, Ducharme J and Drummond A. Procedural sedation and analgesia in the emergency department. Canadian consensus guidelines. The Journal of Emergency Medicine. 17:1. January 1999; pp 145 – 156.
Textbooks
Miller RD. Miller’s Anesthesia, 6th Ed
Marx JA. Rosen’s Emergency Medicine, 5th Ed
Roberts JR. Clinical Procedures in Emergency Medicine, 4th Ed
Tintinalli JE. Emergency Medicine: A Comprehensive Study Guide, 6th Ed

40. Other References Journal Articles
Syminton L and Thakore S. A review of the use of propofol for procedural sedation in the emergency department. Emergency Medicine Journal :
Green SM and Krauss B. Propofol in emergency medicine: pushing the sedation frontier. Annals of Emergency Medicine :
Bahn EL and Holt KR. Procedural sedation and analgesia: a review and new concepts. Emergency Medicine Clinics of North America :
Green SM. Fasting is a consideration – not a necessity – for emergency department procedural sedation and analgesia. Annals of Emergency Medicine :
Green SM and Sherwin TS. Incidence and severity of recovery agitation after ketamine sedation in young adults. American Journal of Emergency Medicine :
Green SM and Li J. Ketamine in adults: what emergency physicians need to know about patient selection and emergency reactions. Academic Emergency Medicine :7(3)