Orarat Karnjanawanichkul
Department of Anesthesiology,
Faculty of Medicine, Prince of Songkla University
Goals of Sedation
Guard the patient’s safety and welfare
Minimize physical discomfort and pain
Provide anxiolysis, minimize psychological trauma,
and maximize the potential for amnesia
Control behavior and/or movement, in order to
optimize safe procedure
Rapidly recovery
General Considerations
Sedative drugs suppress the CNS
Respiratory depression: the most significant adverse effect
Decreased hypoxic and hypercarbic respiratory drive
Decreased tone in upper airway >> airway obstruction
Decreased protective airway reflex >> aspiration
General Considerations
Depth of sedation is a continuum
light sedation >>> general anesthesia
The greater depth of sedation the greater risk
General Considerations
A systematic approach of
appropriate assessment
monitoring
rescue skills
has become critically important in promoting safe
and effective procedural sedation
Sedation continuum
Levels of sedation are considered to be on a
continuum because a sedated patient can go in and
out of an intended level quite rapidly
Definitions: Four Levels of Sedation
Minimal sedation (anxiolysis)
A drug-induced state during which patients
respond normally to verbal commands
Although cognitive function and coordination
may be impaired, ventilatory and cardiovascular
functions are unaffected
patient is fully responsive
Definitions: Four Levels of Sedation
Moderate sedation
A drug-induced 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
spontaneous ventilation is adequate cardiovascular function is usually maintained
Definitions: Four Levels of Sedation
Deep sedation
A drug-induced depression of consciousness
during which patients cannot be easily aroused, but
respond purposefully following repeated or painful
stimulation
inability to maintain a patent airway
spontaneous ventilation may be inadequate
cardiovascular function is usually maintained
Planning for deep sedation requires that the practitioner must be able to
rescue a patient slipping into (unintentional) general anesthesia
Definitions: Four Levels of Sedation
Anesthesia
A drug-induced loss of consciousness during which patients are not arousable, even by painful stimulation
required assistance in maintaining a patent airway
positive pressure ventilation may be required
because of depressed spontaneous ventilation
cardiovascular function might be impaired
Sedation continuum
Minimal sedation
Moderate sedation
Deep sedation
General anesthesia
Implications
No matter the level of sedation you intend to
produce, you should be able to rescue patients one
level of sedation “deeper” than that which was
intended
– Joint Commission
Implications
For example: You must be prepared/skilled to manage
and rescue a “moderately sedated” patient who slips into
an unintentional state of “deep sedation.”
This highlights the fact that different levels of sedation
require different levels of expertise in airway &
physiological function management of the patient.
• General Description
• Responsiveness
• Airway
• Ventilation
• Cardiovascular
Sedation level and adverse event
Minimal
• General Description “Anxiolysis”
• Responsiveness
• Airway
• Ventilation
• Cardiovascular
“appropriate”
unaffected
unaffected
unaffected
Sedation level and adverse event
Riskof
AdverseEvent
NoSedation
MinimalSedation
Minimal Moderate
• General Description “Anxiolysis” “Conscious”
• Responsiveness
• Airway
• Ventilation
• Cardiovascular
“appropriate”
unaffected
unaffected
unaffected
“Purposeful” to light
stimulation
No intervention
Adequate
Maintained
Sedation level and adverse event
Riskof
AdverseEvent
NoSedation
MinimalSedation
ModerateSedation
Minimal Moderate Deep
• General Description “Anxiolysis” “Conscious” “Deep sleep”
• Responsiveness
• Airway
• Ventilation
• Cardiovascular
“appropriate”
Unaffected
Unaffected
Unaffected
“Purposeful” to light
stimulation
No intervention
Adequate
Maintained
“Purposeful” to pain
stimulation
(±) Intervention
(±) Inadequate
(±) Maintained
Sedation level and adverse event
Riskof
AdverseEvent
NoSedation
MinimalSedation
ModerateSedation
DeepSedation
Risk and complication
AIRWAY, AIRWAY, AIRWAY
Airway obstruction
Hypoventilation
Apnea
Aspiration
Hemodynamic impairment
Risk and complication
Unique pediatric airway anatomy
Relatively large tongue
Risk and complication
Unique pediatric airway anatomy
Higher and anterior larynx
Risk and complication
Pulmonary function
rap
id d
esat
ura
tio
n
small FRC
higher oxygen consumption
decrease RR from sedation
Risk and complication
Cardiovascular physiology
Cardiac output depends on heart rate
Higher vagal tone >>> bradycardic response with
autonomic stimulation (airway manipulation)
Risk and complication
• The Pediatric Sedation Research Consortium
(an international collaborative of 35 institutions
dedicated to improving pediatric sedation/anesthesia
care) study to determine the incidence and nature of
adverse events for procedures outside the OR.
Reviews of over 30,000 records
Risk and complication
Serious adverse event were rare
However , the following adverse events were more
common:
Oxygen desaturation (< 90% more than 30 sec)
Stridor
Laryngospasm
Unexpected apnea
Excessive secretion
Risk and complication
1 in every 200 sedation required airway and
ventilation interventions ranging from
bag mask ventilation
oral airway placement
emergency intubation
Risk and complication
Critical incident analysis (N=95)
80% primary event: respiratory
Poor outcome associated with
inadequate medical evaluation
Inadequate monitoring
Inadequate resuscitation
Inadequate practitioner skill
Pediatrics 2000;105:805-814
Risk and complication
Inadequate sedation•Increase anxiety in children and family•Behavioral changes•Post traumatic stress syndrome in children with repeated procedure
JCAHO© 2000Revisions to Anesthesia Care Standards Comprehensive
Accreditation Manual for Hospitals
1. Evaluating patients prior to moderate or deep sedation
2. Rescuing patients who slip into a “deeper than desired”
level of sedation or anesthesia.
3. Managing a compromised airway during a procedure.
4. Handling a compromised cardiovascular system during a
procedure.
Guidelines
Patient evaluation
Procedural preparation
Resuscitation equipment
Monitoring
Titration of medications
Recovery care
Patient Evaluation
History: medical diagnoses, sedation - anesthesia history, underlying conditions that would increase the risk (URI, wheezing, etc.) medications, allergies, history of previous sedation
Exam: airway (potential complications include: anatomic airway abnormalities, large tonsils, mass, etc.) lungs, heart, CNS (other relevant)
Patient: family counseling: risks, alternatives, informed consent
Fasting status
Airway Evaluation
MALLAMPATI AIRWAY CLASSIFICATION
ClassView = patient seated with mouth open as
wide as possible
ISoft palate, fauces, uvula, tonsillar
pillars
II Soft palate, fauces, full uvula
III Soft palate only
IV Hard palate only
Assess ability to open mouth and protrude tongue
Class III & IV = potential difficult intubation
ASA Physical Status Classification
STATUS DISEASE STATE EXAMPLES
I Healthy, normal patient
II Patient with mild systemic disease Controlled asthma, controlled diabetes
III* Patient with severe systemic disease
Active wheezing, diabetes mellitus w/
complications, heart disease that limits
activity
IV*Patient with severe systemic disease
that is a constant threat to lifeStatus asthmaticus, severe BPD, sepsis
V*Patient who is moribund and not
expected to survive without the
procedure
Cerebral trauma, pulmonary embolus, septic
shock
Candidates for moderate/ deep sedation
ASA Class I or II: Are frequently considered appropriate
candidates. Suitability for sedation is good to excellent.
ASA Class III: Present with special problems which require
individual consideration in determining appropriateness.
Suitability is intermediate to poor: consider benefits relative to
risks
ASA Class IV and V: Suitability is poor; benefits rarely out weigh
risks. Require a consultation with an anesthesiologist to
determine appropriate management.
Patients at Increased Risk
Airway problems:
Unexpected difficult mask ventilation 6.6 %
Unexpected difficult intubation 1.2%
Increased risk in patient with craniofacial
abnormalities
airway obstruction (tonsils/adenoids) loud snoring,
obstructive sleep apnea
Patients at Increased Risk
Significant respiratory symptom
poor control asthma
recent/ active URI/ hyperactive airway
Prematurity: less than 60 weeks postconceptional
age at time of sedation
Patients at Increased Risk
Cardiovascular:
repaired or unrepaired congenital heart
disease with significant symptoms of cyanosis
or congestive heart failure
Patients at Increased Risk
Poorly controlled seizure
Hydrocephalus/ Increased ICP
Risk of pulmonary aspiration
Morbid obesity
Patients at Increased Risk
Management problems
Oversedation (loss of airway reflexes)
Inability to adequately sedate
Hyperactive (paradoxical) response to
sedatives
ASA/AAP NPO Guidelines
NPO Guidelines for Elective* Sedation
INGESTED TIME
Clear Liquids (water, fruit juices w/o pulp, carbonated beverages, clear
tea, black coffee)2 hours
Breast milk 4 hours
Infant formula 6 hours
Solids (light meal; if includes fatty/fried food, consider longer faster
period)8 hours
*In emergency situations, carefully weigh the need for immediacy with the
increased risk of pulmonary aspiration. Use the lightest effective sedation possible.
Sedation Considerations
Consider each of these factors when planning for sedation
Procedural issues:
What type >> therapeutic (painful) vs. diagnostic (non-painful)?
How stressful/anxiety-producing is the procedure (e.g., sexual abuse evaluation)?
Is immobility/behavior control required?
What position will the patient be in during the procedure?
How much time will it take to complete the procedure?
How quickly can rescue resources be available?
Sedation Considerations
Medication issues:
What is the mechanism of action?
How is the sedating/analgesic agent
metabolized?
What is the duration of action?
Medication side effects
Strike a Balance
RISKBENEFIT
The Setting
Conducive environment to conducting safe and effective
sedation
S - Suction
O - Oxygen
A - Airway equipment
P - Pharmacologic agents
M - Monitors
E - Equipment
Airway Equipment
Appropriately sized equipment for
establishing a patent airway and providing
positive pressure ventilation
Monitoring
Level of consciousness: sedation score
Airway patency
not always relate to SpO2 and RR
End tidal CO2 monitoring
Respiration: look, listen, feel
Ventilation and oxygenation
Hemodynamics
Assessment
*purposeful: opens eyes, talk back, push you out of the way
Ϯ non-purposeful: winces, shrugs shoulder, nonspecific withdrawal from pain
Modified Ramsay sedation Scale
1. Awake and alert, minimal or cognitive impatient2. Awake but transquil, purposeful responses to verbal
commands at conversation level3. Appears asleep, purposeful responses to verbal commands
at conversation level4. Appears asleep, purposeful responses to verbal commands
but at louder than usual conversation level or requiring light glabellar tap
5. Asleep, sluggish purposeful responses only to loud verbal commands or strong glabellar tap
6. Asleep, sluggish purposeful responses only to painful stimuli
7. Asleep, reflex withdrawal to painful stimuli only (no purposeful responses)8. Unresponsive to external stimuli, including pain
Richmond agitation sedation scale
Marylen R Miller presentation:“Patient Safety Issues in Sedation: Pitfalls and Best Practices”
Capnograph Monitoring
More precise and direct assessment of the patient’s
ventilatory status
Assessment of airway patency and respiratory pattern
Early warning system for prehypoxic respiratory
depression
Good evidence that capnograph provides a means for
early detection of sedation-related hypoventilation
Capnograph Monitoring
Comparison of oximetry, capnography and clinical
observation in the ED
75% of pediatric patients with respiratory
compromise were noted by EtCO2 monitoring
only
Capnograph Monitoring
Pediatric RCT comparing capnography to clinical
observation in detecting respiratory events
Clinical assessment identified hypoventilation in
3% and did not identify any patients with apnea
Capnography data showed ventilation was
compromised in >50% of cases and nearly 25%
fulfilled criteria for apnea
Minimal Moderate Deep
• General Description “Anxiolysis” “Conscious” “Deep sleep”
• Responsiveness
• Airway
• Ventilation
• Cardiovascular
“appropriate”
Unaffected
Unaffected
Unaffected
“Purposeful” to light
stimulation
No intervention
Adequate
Maintained
“Purposeful” to
pain stimulation
(±) Intervention
(±) Inadequate
(±) Maintained
• Monitoring Observation & intermittent
assessment
• Pulse oximetry-
continuous
• Heart rate
continuous
ETCO2,
• Intermittent recording
of RR and BP
• Pulse oximetry -
continuous
• ECG - continuous
• BP every 3 minutes
• ETCO2,
• Personnel Responsible practitioner * Practitioner - immediately
available
* Practitioner - present
* Support Personnel -
present
Monitorings
Supplemental oxygen
Use supplemental oxygen during moderate
sedation
Titration of Medications
Administer as appropriate for the procedure and
the condition of the patient
Administer IV sedative/analgesic drugs in small,
incremental doses, titrating to the desired
endpoint
Allow sufficient time to reach peak onset before
subsequent drug administration
Safe-effective Sedation
LOW DEGREE
OF IMMOBILITY
HIGH DEGREE
OF IMMOBILITY
HIGH
DEGREE
OF PAIN
LOW
DEGREE
OF PAIN
ANXIETY - FEAR
Anxiolytic/”Light” Sleeper
SLEEP
Hypnotic
ANXIETY-FEAR/
DISCOMFORT (pain)
Analgesic and/or Anxiolytic
SLEEP/PAIN
Analgesic +
Sedative/Hypnotic
Sedative and analgesic medications
Drug Dose Onset (min) Duration (min)
Chloral hydrate 25-100 mg/kg max. 2 gm
15-30 60-120
midazolam IV 0.05 -0.1 mg/kg/doseMax. 0.2 mg/kg
1-3 45-60
Oral 0.5-0.75 mg/kg 15-30 60-90
Fentanyl 0.5-1 mcg/kg every 3 min 3-5 30-60
DR
UG
CO
NC
EN
TR
AT
ION
THERAPEUTIC
WINDOW
ADVERSE
EFFECTS
INADEQUATE EFFECTS
DESIRED EFFECTS
TIME
THERAPEUTIC WINDOW
Tim
e to p
eak
on
set
DR
UG
CO
NC
EN
TR
AT
ION ADVERSE
EFFECTS
INADEQUATE EFFECTS
DESIRED EFFECTS
TIME
Sedation diagram: painful procedure
Tim
e to p
eak o
nset 1
analgesic
DR
UG
CO
NC
EN
TR
AT
ION ADVERSE
EFFECTS
INADEQUATE EFFECTS
DESIRED EFFECTS
TIME
Sedation diagram: painful procedure
Tim
e to p
eak
on
set dru
g 2
Tim
e to p
eak o
nset
1
analgesic
sedative
DR
UG
CO
NC
EN
TR
AT
ION
THERAPEUTIC
WINDOW
ADVERSE
EFFECTS
INADEQUATE EFFECTS
DESIRED EFFECTS
TIME T
ime to
peak
o
nset 2
Tim
e to p
eak
on
set 1
How adverse effect happen???
Reversal agents
The specific antagonists must be available in the
procedure room
Administer naloxone to reverse opioid-induced
sedation and respiratory depression
Administer flumazenil to reverse benzodiazepine-
induced sedation and respiratory depression
Airway management in sedative patient
Spontaneous breathing with no obstruction Oxygen supplement
Positive ventilatory drive with obstruction
Oxygen supplement
Head tilt, Chin lift
Jaw thrust
Oro/nasopharyngeal airway + maneuver
Call for help
Intubation as indicated
No ventilatory drive Call for help
Oro/nasopharyngeal airway + maneuver + PPV
If I turn blue after receive medication, do I really need O2
therapy immediately?
Hypoventilation and decrease airway patency is the common cause of desaturation during sedation!!!You may need oxygen supplement if you still breath spontaneously and airway is patent.
But!!!! If your airway is not patient. You exactly need help by Positive pressure ventilation first!!!
Bradycardia and cardiac arrest will occur after
desaturation
It is VERY IMPORTANT to have
resuscitative medication
Monitoring: During Recovery
Continuously observe and monitor SpO2, heart rate,
and level of consciousness until the patient is fully
awake
Observe for longer periods of time if patient:
o received any reversal agents (duration of sedating
agents may exceed duration of antagonist)
o received sedating agents with a long half-life
that may delay return to baseline or pose risk of
re-sedation
Discharge Criteria
Consider, at minimum, the following measures:
Return to pre-sedation (age/developmentally-
appropriate) activity/ambulation & cognitive level
patient is easily arousable, alert and oriented
Protective airway reflexes are intact
Stable vital signs, pain level, O2 and respiratory effort (e.g.
Modified Aldrete Score ≥ 9)
If reversal agent is given, allow sufficient time (up to 2
hours) after last dose to observe for risk of re-sedation
Modified Aldrete Score
Thank You