This document discusses procedural sedation and analgesia (PSA). It defines PSA and outlines different levels/depths of sedation from minimal to general anesthesia. It notes key considerations for PSA including patient assessment and selection, fasting guidelines, choice of agents, equipment needs, monitoring, and management of complications. The document emphasizes the importance of patient safety, appropriate staff and setting for the level of sedation, and documentation of the procedure.

1. Procedural sedation
Dave Mcilroy

2. What is it ?
 The American College of Emergency Physicians (ACEP) defines procedural
sedation as "a technique of administering sedatives or dissociative agents
with or without analgesics to induce a state that allows the patient to
tolerate unpleasant procedures while maintaining cardiorespiratory
function. Procedural sedation and analgesia (PSA) is intended to result in a
depressed level of consciousness that allows the patient to maintain
oxygenation and airway control independently.

3. Minimal sedation
 Response to verbal stimulation is normal.
 Cognitive function and coordination may be impaired.
 Ventilatory and cardiovascular functions are unaffected.

4. Moderate (formerly conscious) sedation
 Depression of consciousness is drug-induced.
 Patient responds purposefully to verbal commands.
 Airway is patent, and spontaneous ventilation is adequate.
 Cardiovascular function is usually unaffected.

5. Deep sedation
 Depression of consciousness is drug-induced.
 Patient is not easily aroused but responds purposefully following repeated
or painful stimulation.
 Independent maintenance of ventilatory function may be impaired.
 Patient may require assistance in maintaining a patent airway.
 Spontaneous ventilation may be inadequate.
 Cardiovascular function is usually maintained.

6. General anaesthesia
 Loss of consciousness is drug-induced, where the patient is not able to be
aroused, even by painful stimulation.
 Patient's ability to maintain ventilatory function independently is impaired.
 Patient requires assistance to maintain 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.

7. A light anaesthetic ?
 Guedel in 1937, first widely accepted guide to depth of anaesthesia (I – IV)
 Artusio later divided stage 1 into 3 planes, first plane no analgesia no
amnesia, second amnesia no analgesia and 3rd both analgesia and amnesia
 Entropy and Bis , (around 60 – 80 )

8. When is it used?
Fracture reduction
Joint relocation
Painful procedures, esp children
Radiological procedures, eg CT , MRI
Cardioversion
Foreign body removal
Suturing , and other procedures

9. Other options
 GA in theatre with Image intensifier and anaesthetic support
 Bier’s block
 Haematoma block
 Regional techniques
 Just don’t do it

10. Assessment
 Your own level ability and experience, and that of your assistants
 The state of the department, resource hungry procedure
 Availability of appropriate area and equipment
 Plan for it all to go wrong, don’t just have a plan A
 Patient factors

11. Patient factors
 ASA grade (3+), co-morbidities
 Fasted ?
 Airway assessment
 Obesity or pregnancy
 Intoxicated
 Allergies , previous anaesthetic
 Am I happy to RSI this patient?

12. Patient selection
 Short painful procedure (<20 mins )
 Age
 ASA 1 and 2
 Airway assessment
 PMHx
 fasting

13. fasting
 How important is it?
 Several studies studies , with several different agents , maybe not as
important as we once thought 1,2,3

14. urgency
 Emergency
 Urgent
 Semi-urgent
 elective

15. Other considerations
 Carers / parents
 Informed consent
 Documentation, what was given, how much when and by whom and any
problems
 Post sedation observation
 Instructions on driving and alcohol

16. Staffing
 Minimum 3 trained staff
 Practitioner administering sedation must be familiar with the agent,
experience and able to monitor and detect problems
 Airway competent
 Anaesthetist ?
 ALS competent

17. Equipment (ACEM minimum)
 Adequate room and appropriate lighting
 Tiltable table, preferable but not mandatory
 Suction
 Oxygen
 Means to inflate the lungs, readily available airway equipment
 Appropriate drugs

18. continued
 Pulse oximeter
 BP measurement
 Ready access to ECG and defib
 Means to summon assistance
 ET CO2 monitoring

19. Choice of agent
 Midazolam, diazepam
 Morphine, fentanyl, remifentanyl
 Propofol
 Ketamine
 Etomidate
 Promethazine ( twice now )

20. Choices, choices
 Use what you are familiar with and know how to use
 Titrate dose, it is easier to put more in than take some out

21. ketamine
 Safe
 IV / IM
 Laryngospasm
 Role of atropine / glycopyrolate
 Emergence phenomenon
 Dissociative agent, powerful analgesic

22. Ketamine 2
 Effect on ICP
 Co administration of anxiolytics eg midazolam or propofol
 Dose 0.5 – 2 mg /kg iv
 2 – 4 mg / kg IM
 10 mg / kg IM via syringe dart ( dangerous animal gun )

23. Propofol
 Rapid
 Short acting
 Easily titrated
 Respiratory depression 50% +
 Hypotension
 0.5 – 2 mg /kg iv
 Amnesic

24. midazolam
 Amnesic, but no analgesia
 Fairly rapid and predictable
 Slower recovery than propofol
 Reversable (big advantage for some operators )

25. fentanyl
 Fast acting
 Powerful analgesic
 Duration of action 20 – 40 minutes (at low doses)
 Reversible
 IV or IN popular, but all routes

26. What could possibly go wrong ?
 Loss of airway reflexes
 Depression of respiration
 CV depression
 Drug interactions, adverse reactions and anaphylaxis
 Variations in expected response to drugs used
 Possible deeper sedation than expected
 Risks from the procedure

27. Preoxygenation
 Good idea or not
 How is it best achieved?
 Nasal prongs, hudson, non-rebreather mask, self inflating bag with reservoir,
CPAP mask ?

28. Preoxygenation or denitrogenation
 Lungs can hold much more oxygen than blood (about 20 times)
 Lungs full of air equals about 0.4 l available oxygen (FiO2 0.21 x 2l)
 Lungs full of oxygen equal 2 l (FRC x FiO2)
 Body oxygen consumption about 250 ml under normal conditions
 All the oxygen reserve is provided by preoxygenation

29.  Rate of preoxygenation is a predictor of rate of deoxygenation, as represents
the relationship between alveolar minute volume FRC
 Technique big breaths v TV x longer time
 Really should measure FeO2 (>90%)

30. Prolonging DAWD, apnoiec oxygenation
 General aspects
 Preoxygenation, position, technique, and method of O2 delivery
 Apnoeic oxygenation

31. Duration of apnoea without desaturation
 DAWD = time from onset of apnoea to saturation <90%
 DAWD depends on
 Initial oxygen reserve
 Rate of O2 consumption
 Ongoing apnoeic oxygen delivery or not

32. DAWD
 <1 minute – 8 minutes without apnoeic oxygenation depending on various
factors
 Obesity
 Pregnancy
 Increase rate of consumption, fever, tachycardia
 Inadequate preoxygenation

33. Study Endpoint Tidal Volume
Breaths
4 (in 30 sec)
Deep Breaths
8 (in 60 sec)
Deep Breaths
Gambee DAWD 8.9 (1.0) min 6.8 (1.8) -----
Nimmagadd
a
FeO2 % 88 (5) % 80 (5) 87 (3)
Pandit FeO2 % 92 (1) % 83 (2) 91 (4)
Gagnon FeO2 % 89 (3) % 76 (7) -----
Gambee et al Preoxygenation techniques: comparison of three minutes and four breaths. Anesth Analg 1987; 66: 468–70.
Nimmagadda et al. Preoxygenation with tidal volume and deep breathing techniques: the impact of duration of breathing and fresh gas flow. Anesth Analg 2001; 92: 1337–41.
Pandit etal Total oxygen uptake with two maximal breathing techniques and the tidal volume breathing technique: a physiologic study of preoxygenation. Anesthesiology 2003;
99: 841-6
Gagnon et al When a leak is unavoidable, preoxygenation is equally ineffective with vital capacity or tidal volume breathing. Can J Anesth 2006; 53: 86–91.

34. High flow nasal vs high flow mask oxygen delivery: tracheal gas concentrations through a
head extension airway model
2002 Open Forum Abstracts, Am Assoc Resp Care
High flow nasal cannula delivery > non-rebreather mask at equivalent flows

35. Apnoeic oxygenation
 250 ml oxygen leaving lung per minute
 10 – 20 ml CO2 entering lung
 Results in slightly subatmospheric alveolar pressure
 Net gas flow 240 ml / minute

36. Techniques of O2 delivery
 Nasal cannula
 10 Fc catheter into nasopharynx (distance of mouth angle to ear tragus)
@5l/min O2
 Paediatic south facing Rae tube to angle of the mouth

37. “apneic diffusion oxygenation, diffusion respiration, and mass flow ventilation”

38. Hypotension under anaesthesia, sedation
 Usually temporary
 ? Best agent or way to resolve ?
 Elevate legs, fluid bolus,. Metaraminol ?

39. laryngospasm
 PEEP
 Deepen
 Sux low dose
 Sux full dose
 Iv lignocaine

40. documentation
 consent
 Make sure its clear
 What was given, when, how much, problems encountered
 How long to stay monitored
 How long until fit to discharge
 Driving, avoidance of alcohol

41.  1 Treston G. Prolonged pre –procedure fasting time is unnecessary when using titrated intravenous ketamine for paediatric
procedural sedation. Emergency medicine Australasia 2004; 16(2): 145-150
 2 Agrawal D, Manzi SF, Gupta R et al. Preprocedural fasting state and adverse events in children undergoing procedural sedation
and analgesia in a paediatric emergency department. Annals of emergency medicine 2003: 42(5) 636-646
 3 Roback MG, Bajaj L, Wanthan JE, et al. Preprocedural fasting and adverse events in procedural sedation and analgesia in a
paediatric emergency department are they related? Annals of Emergency Medicine 2004; 44(5): 454 - 459