1. PROCEDURAL SEDATION FOR ADULTS
Dr. CATHERINE GALLANT
Department of Anesthesiology
University of Ottawa
General Campus

2. OUTLINE Definition Indications for use Contraindications Pharmacology
Complications

3. DEFINITION
A technique to provide an altered state of consciousness by administration of medications that permits a patient to undergo painful procedures but still respond to verbal commands while maintaining an unassisted airway

4. INDICATIONS
Used to facilitate many diagnostic and therapeutic procedures
May be used intra-operatively
May be performed in a location remote from the operating room
Ever increasing demand fuelled by patients
Limited capacity for anesthesiologists to provide these services
Used to facilitate…in a wide variety of settings such as hospitals. free standing clinics, physician, dental and other offices.

5. APPLICATIONS Primarily day surgeries
Lack of dependence on hospital beds
More flexibility in scheduling
Shorter waiting lists
Improved efficiencies
Low morbidity and mortality
Low rates of complications
Lower costs
Less special investigations required

6. APPLICATIONS Dental Dermatology Gynecology General surgery
Ophthalmology
Orthopedics
Pain Clinic
Plastic surgery
Urology

7. DEFINITIONS
Analgesia - Relief of pain without intentionally producing a sedated state. Altered mental status may occur as a secondary effect of medications administered for analgesia.
Sedation is a continuum

8. DEFINITIONS
Minimal sedation – drug induced state where the patient responds normally to verbal commands. Cognitive function and coordination may be impaired but ventilatory and cardiovascular function are unaffected.
Anxiolysis alternate term

9. DEFINITIONS
Moderate sedation and analgesia – a drug induced depression of consciousness where the patient responds purposefully to verbal commands alone or when accompanied by light touch. Protective airway reflexes and adequate ventilation are maintained without intervention. Cardiovascular function remains stable.
Conscious sedation

10. DEFINITIONS
Deep sedation and analgesia - A drug induced depression of consciousness where the patient cannot be easily aroused but responds purposefully to noxious stimulation. Assistance may be needed to ensure the airway is protected and adequate ventilation maintained. Cardiovascular function is usually stable.

11. DEFINITIONS
General anesthesia – a drug induced loss of consciousness, during which the patient cannot be aroused, even with painful stimuli, and often requires assistance to protect the airway and maintain ventilation. Cardiovascular function may be impaired.

12. EUROPEAN UNION OF MEDICAL SPECIALISTS
Level 1
Fully awake
Level 2
Drowsy
Level 3
Rousable by normal speech

13. OBJECTIVES
To achieve sedation level 2 and 3 (minimal to moderate sedation) which allows patients to undergo and tolerate unpleasant procedures
To avoid deeper levels of sedation and the related complications
This cannot be completely avoided!
Continuum which is difficult to divide into discrete stages
Always maintain verbal contact
Because sedation is a continuum, it is not always possible to predict how an individual patient will respond.
Practitioners intending to produce a given level of sedation should be able to rescue patients whose level of sedation becomes deeper than initially intended. Individuals administering moderate sedation/analgesia should be able to rescue patients who become deep…

14. BENEFITS
Appropriate sedation/analgesia will allow the patient to tolerate unpleasant procedures by relieving anxiety, discomfort or pain
In the uncooperative patient, sedation/analgesia may facilitate those procedures which are not uncomfortable but which require that the patient not move
At times, these sedation procedures may result in cardiac and respiratory depression, which must be rapidly recognized and appropriately managed to avoid the risk of hypoxic brain damage, cardiac arrest or death.
Conversely, inadequate sedation may result in undue patient discomfort or patient injury because of lack of cooperation or adverse response to stress
MUST HAVE QUALIFIED PERSONELL TO ADMINISTER THIS

15. QUALIFIED INDIVIDUALS
Competency based education, training and experience in:
Patient evaluation
Performance of sedation
Knowledge of pharmacology of drugs used
Rescuing the patient from complications of deeper levels of sedation
Airway compromise
Inadequate ventilation
Cardiovascular instability

16. PATIENT EVALUATION Screening for medical risk factors
How will these alter response to sedation?
Abnormalities of major organ systems?
Previous adverse reactions with sedation/analgesia as well as regional and general anesthesia?
Allergies to drugs?
Medications – drug interactions?
History of drug and alcohol abuse?
NPO status

17. PATIENT EVALUATION Abnormalities of major organ systems Cardiac
Respiratory
Renal
Hepatic

18. PATIENT EVALUATION
Previous adverse reactions with sedation/analgesia as well as regional and general anesthesia
Details
Where it happened

19. PATIENT EVALUATION Allergies to drugs? What is the reaction?
When did it occur?
Family history?

20. PATIENT EVALUATION History of drug and alcohol abuse?
May indicate tolerance
Cross tolerance between classes of drugs

21. PATIENT EVALUATION Review medications – possible drug interactions?
MAOIs such as phenelzine (Nardil) , tranylcypromine (Nardil), moclobemide

22. PATIENT SELECTION Focused physical exam Assessment vital signs
Evaluation of airway
Auscultation of heart and lungs
Assessment vital signs
Review labs
Consider consult prn

25. PATIENT SELECTION Airway issues that may present concerns History
Previous problems with anesthesia or sedation
Snoring, stridor or sleep apnea
Advanced rheumatoid arthritis
Chromosomal abnormalities e.g. trisomy 21
Physical examination
Obesity especially involving neck and facial structures
PPV +/- ETT may be needed if respiratory compromise develops during sedation-analgesia. This may be more difficult in patients with abnormal airway anatomy. Some airway abnormalities may increase the likelihood of airway obstruction during spontaneous ventilation.
Sine factors that may be associated with difficulty in airway management are:
History PE

26. PATIENT SELECTION Airway issues that may present concerns
Physical examination
Short neck, limited neck extension, decreased TMD of < 3 cm in adult, neck mass, c-spine disease or trauma, tracheal deviation, dysmorphic features
Small mouth opening (< 3 cm in adult), protruding incisors, loose or capped teeth, dental appliances, high arched palate, macroglossia, tonsillar hypertrophy
Micrognathia, retrognathia, trismus, significant malocclusion

27. DIFFICULT AIRWAY

31. PATIENT SELECTION Who is a candidate for sedation? ASA 1 and ASA 2
ASA 3 in stable condition
Must be compatible with the procedure
Must be capable of giving informed consent

32. PATIENT SELECTION Who is at increased risk of complications?
Extremes of age
Multiple co-morbidities
Severe systemic disease
Drug and/or alcohol abuse
Uncooperative patient
Morbidly obese patient
Potential difficult airway
Obstructive sleep apnea

34. ADVANCED AGE Higher risk of adverse events
Increased sensitivity to sedative drugs
Medication interactions
Higher peak serum levels of medications

35. MULTIPLE CO-MORBITIES
↑ing ASA status correlates with ↑ing risk of adverse events (ASA III or >)
Any co-morbidity that increases risk of cardio-respiratory depression with sedatives is significant
CHF, neuromuscular disease
COPD, dehydration
Anemia

36. PATIENT SELECTION Who is not a candidate? Language barrier
History of problems with previous anesthesia
Known or suspected difficult ventilation or difficult intubation
No person to accompany them home

37. PREPARATION Do you have informed consent? What is the NPO status?
Is patient aware of risks and the limitations? Have they been given alternative choices to procedure? Have questions been answered?
What is the NPO status?
Risks versus benefits
Machine and drug check?
Drugs and antagonists
Emergency equipment available and checked?
Defibrillator and skills of use

38. ASPIRATION RISK
Fasting pre-procedure decreases risks during moderate sedation and strongly decreases risks during deep sedation
ASA guidelines recommend if procedure is elective fasting guidelines should be as for GA
If not met then consider delaying procedure, reducing sedation level or ETT
If emergency then may have to reconsider approach

39. SUMMARY OF ASA PRE-PROCEDURE FASTING GUIDELINES
INGESTED MATERIAL
MINIMUM FASTING PERIOD
Clear liquids
2 hours
Breast milk
4 hours
Infant formula
6 hours
Nonhuman milk
Light meal

40. EQUIPMENT Dedicated qualified personnel IV access Airway adjuncts
Must be uninterrupted and continuous presence
IV access
Airway adjuncts
Bag valve mask, oral and nasal airways, equipment for endotracheal intubation
Suction for secretions

41. MONITORING
Does monitoring level of consciousness decrease risks of complications when administering procedural sedation?
The literature is silent as to whether monitoring patients level of consciousness improves patient outcome or decreases risks but the ASA consultants strongly agree that monitoring reduces risks for moderate and deep sedation.
Task Force ASA believe that many of the complications associated with sedation and analgesia can be avoided if adverse drug responses are detected and treated in a timely manner.
Patients given sedation in an unmonitored setting in anticipation of a subsequent procedure many be at increased risk of these complications

42. MONITORING Maintain verbal contact with patient
Blood pressure, heart rate, respiratory rate measured at regular intervals
Oxygen saturation, cardiac rhythm and ETCO2 should be monitored continuously
The response of patients to commands during procedures performed with sedation-analgesia serves as a guide to their level of consciousness.
Spoken responses also provide an indication that the person is breathing

43. MONITORING Monitor patients response to medication and procedure
Level of alertness, depth of respiration and response to painful stimuli all determine subsequent dosing

44. MONITORING
Supplemental oxygen often recommended to maintain oxygen reserves and prevent hypoxemia
May delay recognition of hypoventilation
ETCO2 monitoring useful
Brief episodes hypoxemia and hypoventilation may occur – clinical significance?

45. TECHNIQUES Technique will vary from patient to patient
Dosing of analgesics and anxiolytics vary widely
Dosing depends on procedure as well as the anxiety of the patient
Comfort measures contribute to reducing anxiety and pain

46. TECHNIQUES
Anxiety may be reduced by other methods than pharmacological
Preoperative explanation of the procedure
Calm and reassuring manner
Quiet atmosphere with appropriate music
Comfortable room temperature or warm blankets

47. AGENTS USED
Ideal drug has rapid onset of action and short duration of action, will maintain hemodynamic stability and have no side effects
No single drug available with all of these features

48. AGENTS USED Anxiolytics Benzodiazepines
Diazepam, midazolam, lorazepam
Benzene ring fused to diazepine ring
All highly lipophilic
Highly protein bound
All absorbable after po administration
Midazolam

49. MIDAZOLAM Midazolam most commonly used
Rapidly enters CNS then redistributed
Works through GABA pathways
Distribution of GABA receptors restricted to CNS
Minimal effects outside of CNS
Most important clinical effects
Sedative-hypnotic
Amnestic
Anxiolysis
Anti-convulsant
No analgesia
GABA receptors almost exclusively on postsynaptic nerve endings in CNS with greatest density in cerebral cortex. This is consistent with the minimal effects of these drugs outside the CNS
Magnitude of depression of ventilation and development of hypotension is lower than barbs when used for induction of anesthesia

50. MIDAZOLAM Favorable side effect profile Synergistic with narcotics
Minimal depression of ventilation
May cause mild ↓BP esp in hypovolemic patient
Synergistic with narcotics
Combo may cause severe respiratory depression
Antagonist available: Flumazenil
Dosage 10 to 25 µcg/kg q 3 to 5 minutes
Minimal depression of ventilation and cardiovascular system
Safe even in large doses
Can promptly antagonize their effects with antagonist
Due to peripheral vasodilatation may drop BP esp if hypovolemic

52. AGENTS USED Propofol Phenol derivative, highly lipophilic
Can be painful on injection
Rapidly metabolized in liver with high plasma clearance
Onset within 40 seconds with duration minutes
Causes peripheral vasodilatation
↓ BP more pronounced with ↑ age , ↓ intravascular volume or with rapid injection
Chemically distinct
Insoluble in aqueous solutions – 10% soybean oil, 2.25% glycerol and 1.2% lecithin
Formulation will support bacterial growth
Use within 6 hours of opening
Rapidly metabolized in liver
Plasma clearance is high and exceeds hepatic blood flow so extra hepatic clearance is important – up to 30% of bolus cleared by lungs
Wake-up within 8 to 10 minutes

53. PROPOFOL Potent respiratory depressant with ↑ doses
↓MV through ↓TV and RR
Has anti-emetic effects
Sedative and amnestic not analgesic
No reversal agent
Difficult to titrate in some cases, can cause very deep sedation
Effect on TV more pronounced

54. PROPOFOL Dosage unchanged if renal or liver impairment
Metabolism appears to be slower in elderly
Reduce doses by 20% and increase dosing interval
100 to 500 µcg/kg every 3 to 5 minutes bolus
Continuous infusion 25 to 100 µcg/kg/min
May require addition of short acting opioids due to absence of analgesic activity. This increases risk of respiratory complications

55. KETAMINE Highly lipid soluble derivative phencyclidine
Rapid onset of action
Use limited by side effects
Dreams, halllucinations, out of body experiences
Significant cardiovascular effects
Sympathomimetic ↑BP, HR, CO
Minimal respiratory depression
Bronchodilatation

56. KETAMINE Profound analgesia Multiple routes of administration
May supplement inadequate regional anesthesia
50 to 100 mcg/kg usual single dose
No more than 10 mg/hour to avoid side effects

57. PENTOTHAL IV barbiturate, induction agent
Hypnotic, sedatives, anticonvulsants
Undergoes hepatic metabolism
Recovery after bolus comparable to propofol because of redistribution to inactive tissue sites
Even single boluses can lead to psychomotor impairment for several hours

58. PENTOTHAL CNS depressant “Anti-analgesic” properties
May reduce pain threshold
↓BP due to peripheral vasodilation
Transient as compensatory ↑ HR
Respiratory depressant
↓ TV and ↓ RR – transient apnea

59. ETOMIDATE IV anesthetic with minimal hemodynamic effects
Hypnotic but no analgesic properties
Rapid onset of anesthesia – almost immediate - with minimal changes in HR and CO
Usual dosing 0.1 to 0.15 mg/kg IV for PSA
Causes adrenocortical suppression so not widely used
Myoclonus also seen frequently

60. AGENTS USED Miscellaneous agents Chloral hydrate Pentobarbital
Methohexital
Dexmedetomidine
Local anesthetics
May reduce doses of sedatives and narcotics
Useful as co-analgesics

61. OPIOIDS High degree of variability in dose response
Inter-individual variation
Analgesia, euphoria, sedation, ↓ concentration
Clearance primarily hepatic metabolism
May be active metabolites

62. SIDE EFFECTS Cardiovascular Respiratory CNS
May produce orthostatic hypotension
Respiratory
Dose dependent depression of ventilation
Decreased responsiveness to CO2
May persist for several hours
Apnea
CNS
Do not reliably produce unconsciousness
Skeletal muscle rigidity

63. SIDE EFFECTS Sedation Nausea and vomiting Biliary tract
Direct stimulation CRTZ dopamine receptors
Biliary tract
Spasm of biliary smooth muscle
May be confused with angina

64. AGENTS USED
Fentanyl
Synthetic opioid structurally related to meperidine (phenylpiperidine derivative)
75 to 125 times more potent than morphine
More lipid soluble than morphine – crosses BBB
Short acting with rapid redistribution to tissue
Clinically rapid onset (2 to 3 minutes)
No amnestic properties

65. FENTANYL Primary side effect is respiratory depression
Will potentiate sedative effects of other drugs
Wide range of doses
0.25 to 0.5 µcg/kg q 3 to 5 minutes
1 to 2 µcg/kg for analgesia
With multiple bolus doses or continuous infusion the duration of action is prolonged

66. ALFENTANIL 1/5 to 1/10th potency fentanyl
More rapid onset and shorter duration
1.4 minutes
May be useful for retrobulbar blocks
10 fold inter-individual variation in dosing
0.1 to 0.4 µcg/kg/min by infusion

67. REMIFENTANIL
Unique because of ester linkage and metabolism by plasma esterases
Short acting, titratable, rapid onset and offset, rapid recovery after infusion
Boluses excellent for short painful procedures
Doses 0.25 to 1 µcg/kg
Infusions for sedation
Doses 0.05 to 0.2 µcg/kg/min

68. TECHNIQUES May be by intermittent bolus or by continuous infusion
“Target controlled infusions”
Plasma levels
Effect site levels

69. TECHNIQUE Monotherapy may be desirable
Short acting drugs may be desirable
Onset of action
Small increments
If synergistic action reduce to ¼ usual dose
Antagonists readily available

70. TECHNIQUE Sedation and inadequate block Restlessness and hypoxia
Surgeon may have to supplement if block is inadequate
Duration of surgery may exceed duration of local anesthetic
Restlessness and hypoxia
Consider in differential diagnosis

71. TIPS
If elderly or co-morbid disease then may be more conservative with approach
Start with lower dose
Administer meds more slowly
Be aware of slower circulation times
Redose at less frequent intervals

72. TIPS
NEVER BE AFRAID TO CALL FOR HELP

73. COMPLICATIONS Serious complications rare
All sedatives and narcotics will cause adverse reactions in some patients even within recommended doses
Extremes of age most at risk
Most sedatives cause dose dependent respiratory depression
Risk of desaturation up to 11% with propofol, even with supplemental oxygen
Hypoventilation and apnea usually easily treated
All sedatives and narcotics will cause adverse reactions in some patients – even within the recommended dosing range. Respiratory depression is usually dose related. Extremes of age are most at risk with children <5 or adults >70 seeing most complications. Respiratory depression and obstruction are most frequent adverse reactions.
Risk of desat with sedation is reportedly 11% if pt has supplemental oxygen and likely higher if they do not have supplemental oxygen. Usually transient and can be easily treated with stimulation of the patient. Rarely requires intervention with bag and mask ventilation. This may be minimized by careful and unhurried med administration.
CV instability is less common. Seen in patients with a history of cardiac disease. Bradycardia and hypotension most commonly seen in patients who are on cardiac depressants such as beta blockers. The problems are usually transient and no intervention is required.

74. COMPLICATIONS
Treat respiratory complications with patient stimulation, oxygen, airway positioning or brief ventilatory support
Cardiovascular instability uncommon
More likely to occur if significant cardiac morbidity
Hypotension and bradycardia may develop in patients on CV depressants
Usually transient

75. COMPLICATIONS Vomiting
Seen in approximately 5% PSA
More common if narcotics given
Little evidence regarding prophylaxis
Inadequate sedation preventing completion of procedure
Over sedation
Agitation
Allergic reactions

76. COMPLICATIONS Inadequate evaluation Inadequate monitoring
Inadequate practitioner skills
Premature discharge

77. RECORDS Vital signs and level of consciousness Document at baseline
Regular, frequent intervals during the procedure
Regular, frequent intervals during recovery
Prior to discharge

78. RECOVERY PERIOD Requires monitoring as during procedure
Patients may be at increased risk after removal of painful stimulus
What is ideal length of recovery period?
Various criteria available such as Aldrete
Consciousness Activity
Respiration Saturation
Circulation
Consider pain and nausea

79. DISCHARGE CRITERIA Fully conscious Respond appropriately
Walk unassisted
Baseline vital signs
Pain, nausea and vomiting, bleeding all under control
Must have accompanying responsible person

80. AFTERCARE Responsible accompanying person for 24 hours
Written detailed instructions for dealing with complications
Medical assistance readily available
Should be contacted next day by phone
No major life decisions, driving or alcohol for 24 hours

81. REFERENCES
Practice Guidelines for Sedation and Analgesia by Non-Anesthesiologists - ASA
Basics of Anesthesia 5th edition - Stoelting

82. CLINICAL SCENARIOS
You are asked to provide sedation for cataract surgery to an 80 year old male. He has a history of controlled hypertension. NKDA. Medications: Atenolol 50 mg bid
Any concerns? What would you choose for sedation for this patient?

83. What is your differential diagnosis?
The procedure finishes and you bring the patient back to the PACU in stable condition. 15 minutes later you receive a call that your patient is no longer responsive
What is your differential diagnosis?
How do you approach the management?
What if patient had received RBB? Onset of brainstem anesthesia????
Did you hear of cases of death in unmonitored RBB?

84. What are your first steps? What treatment would you give – if any?
You are monitoring a 62 year old patient under spinal anesthesia for a total knee replacement when she suddenly becomes bradycardic - HR drops to 45 (from 70)
What are your first steps?
What treatment would you give – if any?
Check BP – is systolic < 80? Call for help
If < 80 give atropine 0.4 mg IV, may repeat in one min after 1st dose
If age > 70 consider glyco

85. You are in the endoscopy suite providing sedation for colonoscopy
You are in the endoscopy suite providing sedation for colonoscopy. Your patient is a 50 year old for routine screening with no significant past medical history. 10 minutes into the procedure BP drops to 100/60 from baseline 135/72
Any concerns?
Repeat BP, if <90 then bolus 250 ml crystalloid and decrease anesthesia 25%
If < 80 and no response to fluid bolus then ephedrine 5 to 10 up to 20 mg or phenyl 40 depending on HR (>80) to max 120 phenyl

86. You are monitoring a 73 yo male under SAB who is undergoing TURP
You are monitoring a 73 yo male under SAB who is undergoing TURP. One hour into the procedure he is becoming increasingly restless. You give 1 mg midazolam IV. He becomes more confused and pulls out his IV
Differential??