Anesthesia, Analgesia, Anxiolysis, Amnesia, And so on…

Report
Anesthesia, Analgesia,
Anxiolysis, Amnesia,
And so on…
Ivy Pointer, M.D
Pediatric Critical Care Fellow
UNC Department of Anesthesiology
Overview
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Role of sedation in critical care
Elements of sedation
Levels of sedation
Choosing a sedation plan
Choosing the right drug
Preventative medicine
Sedation in Critical Care
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Medical illness
Post-operative care
Diagnostic imaging
Invasive procedures
Mechanical ventilation
Elements of Sedation
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Anesthesia
Analgesia
Anxiolysis
Amnesia
Anesthesia
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Definition
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Loss of sensation & loss of
consciousness
Examples (Intravenous anesthetics)
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Etomidate
Ketamine
Propofol
Thiopental
Analgesia
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Definition
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Inability to sense pain
Examples
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Non-sedating Analgesics
 Lidocaine/L.M.X. 4
 Acetaminophen
 NSAIDs (Ibuprofen, Ketorolac)
Sedating Analgesics
 Narcotics (Fentanyl, Morphine, Oxycodone,
Methadone)
 Ketamine
Anxiolytics
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Definition
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Relief of apprehension, fear, and/or
agitation
Examples
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Benzodiazepines (Midazolam,
Lorazepam, Diazepam)
Chloral Hydrate
Amnestics
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Definition
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Loss of memory, inability to recall
events
Examples
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Benzodiazepine
Ketamine
Levels of Sedation
Awake
Moderate
Sedation
Deep
Sedation
General
Anesthesia
Moderate Sedation
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Purposeful response to verbal
stimulation
Airway patent
Spontaneous ventilation adequate
Cardiovascular function unaffected
Deep Sedation
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Difficult to arouse
Purposeful response only to painful
stimulation
Airway may be obstructed
Spontaneous ventilation may be
impaired
Cardiovascular function usually
unaffected
General Anesthesia
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Loss of consciousness
Positive pressure ventilation
Cardiovascular function may be
affected
Choosing a Sedation Plan
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Remember mnemonic AMPLE!!
A
llergies
M
edications
P
ast Medical History
L
ast Meal
E
vents leading to sedation
Allergies
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Drug allergies
Environmental allergies
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Egg & soy allergy no Propofol
Contrast allergies
Medications
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Knowing current medications &
therapeutic interventions can help tailor
your sedation plan…
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Sedatives already being used
Vasoactive medications
Neuromuscular blockers
Respiratory medications
Hemofiltration/dialysis
And so on…
Past Medical History
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Know current patient problem list
and significant past medical/surgical
history
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Respiratory (hypoxia, pneumothorax)
Cardiovascular (hypotension,
myocardial dysfunction)
Neurologic (increased ICP, seizure
disorder)
Hepatic/Renal failure
Past Medical History
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Past history of sedation
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Medications used in the past
Prior adverse events with sedation
Ability to manage airway (Pierre Robin,
croup, mediastinal mass, prior
radiation, asthma)
Family history of problems with
sedation
Past Medical History
 ASA
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Physical Status Score
ASA I : normally healthy patient
ASA II: mild systemic disease
ASA III: severe systemic disease
ASA IV: severe systemic disease that is
a constant threat to life
ASA V: moribund patient not expected
to survive without operation
Physical Exam
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Mallampati/Samsoon Classification
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Class
Class
Class
Class
I: soft palate, uvula, pillars
II: soft palate, portion of uvula
III: soft palate, base of uvula
IV: hard palate only
Other predictors of difficult airway
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Obesity with short neck
Reduced neck movement
Inability to protrude the lower teeth
Reduced mouth opening
Receding mandible
Thyromental distance of less than 3 fingers
Last Meal
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Full stomach is a risk of aspiration during
sedation!!!
NPO status
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Last solid intake > 6 to 8 hours
Last opaque liquid/formula intake > 4 hours
Last clear liquid/breastmilk intake > 2 hours
These guidelines do not apply for patients
with GI disturbances
Last Meal
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Full stomachs include the following…
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Any patient with material in their stomach
 Food
 Medications
 Contrast
 Charcoal
 Blood
Any patient with delayed gastric emptying
 Morbid obesity
 Small bowel obstruction
 Pyloric stenosis
 GI dysmotility
 And so on…
Events leading to sedation…
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Know why your patient needs
sedation!!
Is it safe to sedate your patient??
What kind of sedation are you
trying to achieve??
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Analgesia, anxiolysis, amnesia, or a
combination
Anticipated duration of therapy
Choosing the Right Drug
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There is no magic cocktail…all drugs have
potential complications
Drugs to consider should fit your goals for
sedation with minimum risk to the patient
Considerations when choosing a drug
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Route of administration
Onset of action
Duration of action
Contraindications
Therapeutic advantages
Our favorite PICU drugs
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Anesthetics:
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Analgesics:
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Fentanyl, Morphine
Anxiolytics:
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Propofol, Ketamine, Pentobarbital
Midazolam, Lorazepam, Diazepam
Other:
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Dexmedetomidine, Clonidine
Propofol
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Onset: 30 sec
Duration: 3-10 min
Dose: 1 mg/kg
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Infusion: 50-150 mcg/kg/min
Disadvantages: respiratory
depression, hypotension,
bradycardia, NO analgesia,
metabolic acidosis with prolonged
infusion
Ketamine
 Onset:
30 sec (IV), 3-4 min (IM)
 Duration: 5-10 min (IV), 12-25 min (IM)
 Dose: 0.5-1 mg/kg (IV), 4-5 mg/kg (IM)
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Infusion: 5-20 mcg/kg/min
 Analgesia
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and amnesia
preserves upper airway tone and reflexes
 Disadvantages:
excess secretions,
increased ICP, emergence reaction
Pentobarbital
 Onset:
3-5 min (IV)
 Duration: 15-45 min
 Dose: 1-2 mg/kg
 Disadvantages: NO reversal agent,
no analgesia (enhances pain
perception)
Fentanyl
 Onset:
2-3 min
 Duration: 30-60 min
 Dose: 1 mcg/kg
 100x more potent than morphine
 Available reversal agent
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Naloxone
 Disadvantages:
no amnesia/
anxiolysis, “steel chest”
Morphine
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Onset: 5-10 min (IV)
Duration: 4-6 hours
Dose: 0.05-0.1 mg/kg
Available reversal agent:
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Naloxone
Disadvantages: no amnesia/
anxiolysis, histamine release
Midazolam (Versed)
 Onset:
2-6 min
 Duration: 45-60 min
 Dose: 0.05-0.1 mg/kg
 Available reversal agent
 Flumazenil
 Retrograde
amnesia
 Disadvantages: NO analgesia,
paradoxical reactions
Diazepam (Valium)
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Onset: 1-1.5 hours (oral)
Duration: variable but LONG (oral)
Dose: 0.1-0.8 mg/kg/day (oral)
Useful for tapering
Disadvantages: accumulation, long
half-life, avoid rapid IV push
Lorazepam (Ativan)
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Onset:15-30 min (IV)
Duration: 3-4 hours (up to 12 hrs)
Dose: 0.05-0.1 mg/kg
Disadvantages: mixed with
propylene glycol
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Anion gap metabolic acidosis, osmolar
gap
Avoid infusions
Dexmedetomidine (Precedex)
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IV alpha-2 agonist
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Onset: 15-30 min
Duration: 60-120 min
Dose: load with 0.5-1 mcg/kg
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1700x more selective for alpha 2
Infusion of 0.3 – 1.5 mcg/kg/hr
Disadvantages: bradycardia, only
approved for 24 hr infusions
Clonidine
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Centrally acting alpha-2 agonist
Onset: 30-60 min (oral)
Duration: 6-10 hours
Dose: 0.05 mg/day (oral)
Can convert to transdermal patch
Eases withdrawal & decreases
anesthetic requirements
Contraindications
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All drugs should be used judiciously!!!
Commonly seen relative contraindications
and adverse effects
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Ketamine  increased ICP, excess salivation,
emergence reaction
Propofol  hypotension, acidosis
Dexmedetomidine  bradycardia, arrhythmia
Benzodiazepine  hypotension
Therapeutic Advantages
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Not all side effects are harmful
Considerations for choice of drug
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Ketamine  bronchodilator
Pentobarbital or Midazolam  anticonvulsant
Diazepam  muscle relaxation
Cases
Case #1
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An 8 year old known asthmatic is in the
ED having received continuous albuterol
nebs, steroids, and subcutaneous
epinephrine. You check on him and find
him unresponsive with a RR of 6 and very
poor air movement. An RT runs in with a
ABG showing pH 6.9, pCO2 190. What
medications do you consider for
intubation & sedation?
Case # 2
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A transport team has just arrived to pick
up a 4 year old child with severe stridor.
On exam she is alert, sitting in Mom’s lap
& maintaining her sats, but has severe
retractions with every breath and
drooling. She appears frightened, and
the paramedic asks you to order
something to sedate her so that she can
be strapped to the gurney. What is your
response?
Case # 3
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You consult in the ED on a 7 year old who
has presented with sore throat and noisy
breathing. He has received 2 gm of
chloral hydrate 1/2 hour before for an
attempted CT scan of the neck. In the ED
you find him in the back room with his
mother, with a sat probe on his finger not
attached to a monitor. He has retractions
and poor air movement with every
breath. What happened and what would
you do?
Case # 4
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You are taking care of a 9 mo post-op
cardiac patient who is intubated and
requiring sedation. She initially had issues
with heart block and required pacing but
is now in a sinus rhythm of 110. She has
been difficult to sedate with Fentanyl &
Midazolam and the nurses ask you if you
can add a 3rd agent. What agents would
you want to avoid in this patient and what
do you need to consider?
Case # 5
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You are called to the ED to see a 6 year
old trauma patient who luckily has a
normal head CT but unfortunately has a
severely displaced tib-fib fracture. The
orthopedic surgeons are gathering
equipment to reduce and splint the
fracture. What drugs do you think about
using and what else do you consider?
Preventative Medicine is Key!!
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Optimize your patient prior to sedation
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Anticipate difficulties and be prepared
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Correct acidosis
Keep euvolemic
Know “AMPLE”
Bag, mask, oxygen, +/- airway box
Suction
Normal saline/Lactated Ringer’s
Monitors – O2, CO2, CR monitor, BP
Titrate medications to effect…it is easier to
give more drug than it is to remove it!!!
Summary
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Many situations require sedation in the ICU
Components of sedation include anesthesia,
analgesia, anxiolysis, & amnesia
There are several levels of sedation
Remember mnemonic “AMPLE” when evaluating a
patient for sedation
Choosing the right drug involves knowing the
goals of sedation alongside drug profile for
sedatives
Always anticipate possible complications & be
prepared to deal with them

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