orarat karnjanawanichkul department of anesthesiology...

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


Depth of sedation is a continuum

light sedation >>> general anesthesia

The greater depth of sedation the greater risk


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


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


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


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


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


Riskof

AdverseEvent

NoSedation

MinimalSedation

ModerateSedation

Minimal Moderate Deep

• General Description “Anxiolysis” “Conscious” “Deep sleep”

• Responsiveness

• Airway

• Ventilation

• Cardiovascular

“appropriate”

Unaffected

Unaffected

Unaffected


stimulation

No intervention

Adequate

Maintained

“Purposeful” to pain

stimulation

(±) Intervention

(±) Inadequate

(±) Maintained


Riskof

AdverseEvent

NoSedation

MinimalSedation

ModerateSedation

DeepSedation

Risk and complication

AIRWAY, AIRWAY, AIRWAY

Airway obstruction

Hypoventilation

Apnea

Aspiration

Hemodynamic impairment


Unique pediatric airway anatomy

Relatively large tongue


Unique pediatric airway anatomy

Higher and anterior larynx


Pulmonary function

rap

id d

esat

ura

tio

n

small FRC

higher oxygen consumption

decrease RR from sedation


Cardiovascular physiology

Cardiac output depends on heart rate

Higher vagal tone >>> bradycardic response with

autonomic stimulation (airway manipulation)


• 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


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


1 in every 200 sedation required airway and

ventilation interventions ranging from

bag mask ventilation

oral airway placement

emergency intubation


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


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


Significant respiratory symptom

poor control asthma

recent/ active URI/ hyperactive airway

Prematurity: less than 60 weeks postconceptional

age at time of sedation


Cardiovascular:

repaired or unrepaired congenital heart

disease with significant symptoms of cyanosis

or congestive heart failure


Poorly controlled seizure

Hydrocephalus/ Increased ICP

Risk of pulmonary aspiration

Morbid obesity


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


Comparison of oximetry, capnography and clinical

observation in the ED

75% of pediatric patients with respiratory

compromise were noted by EtCO2 monitoring

only


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


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

orarat karnjanawanichkul department of anesthesiology...

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