Transcript THE USE OF ANALGESICS, SEDATIVE MEDICATIONS AND …

THE USE OF ANALGESICS,
SEDATIVE MEDICATIONS AND
MUSCLE RELAXANTS IN
CHILDREN
CHERI LANDERS, M.D.
University of Kentucky
LYNNE W. COULE, M.D.
Medical College of Georgia
Why sedate a child?
improve patient tolerance of procedures,
invasive monitors and unfamiliar
environments
 airway control
 decrease the work of breathing
 decrease oxygen demand
 reduce anxiety and pain
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Examples
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Procedures:
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Radiologic Imaging
Bone marrow aspiration
Minor surgical procedures
PIC/deep line placement
Decrease agitation while on mechanical
ventilation
 Facilitate air exchange in severe asthma
 Decrease oxygen demand in septic shock
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Analgesia/Sedation Myths and
Concerns
Children don’t feel pain/anxiety like adults
 Respiratory depression
 Hemodynamic compromise
 Addiction
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Analgesia/Sedation Myth
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Children DO feel pain/anxiety
– Anatomy
Myelinated and unmyelinated fibers transmit
electrical impulse
 Impulse travels faster when myelinated
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– Psychological
Analgesia/Sedation Concerns
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Respiratory depression
– Receptor based phenomenon
– Need to titrate
– Caveat in the < 6 month old infant
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Opioids can cause apnea prior to pain relief
Analgesia/Sedation Concerns
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“Addiction”
– Addiction vs. Tolerance vs. Dependance
Addiction
A common fear voiced by parents
 Less common in hospitalized patients than
in the general population
 Includes a psychological “need” or craving
along with physical withdrawal symptoms if
medication is discontinued
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Tolerance
The same dose of medication no longer has
the same effect as when first started
 More commonly occurs in patients on long
term continuous infusions of sedatives or
analgesics rather than intermittent dosing
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Dependence
Removing medication results in withdrawal
symptoms
 To avoid withdrawal, may need to wean
sedative or analgesic when patient has been
on the medication for 1 week or more
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What is sedation?
Continuum of Consciousness
Awake,
baseline
General
anesthesia
Conscious
sedation
Drowsy
Deep
sedation
Level of Sedation Required
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In general, the younger the child and the
lower their cognitive abilities, the more
deeply sedated they will need to be to
accomplish the same procedural goal
Conscious Sedation
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“ A medically controlled state of
depressed consciousness that
allows reflex ability to maintain a
patent airway, and permits
appropriate neurological responses
to verbal stimuli.”
Deep Sedation
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“A medically controlled state of
depressed consciousness or
unconsciousness from which a patient
is not easily aroused. It may be
accompanied by a loss of protective
reflexes and includes an inability to
maintain a patent airway and respond
appropriately to stimuli”.
Benzodiazepines
 Bind
CNS GABA receptors
 Skeletal muscle relaxation
 Amnesia
– Antegrade and retrograde
 Anxiolysis
 Respiratory
Depression
Midazolam (Versed)
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Advantages:
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anxiolysis, sedation, motion control
retrograde amnesia
PO, IV, IM, IN, PR dosing routes
onset 2-6 min after IV administration, 45-60
min duration
– available reversal agent
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Flumazenil
Midazolam (Versed)
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Disadvantages
– No analgesia
– Paradoxical reactions
– More than additive risk of respiratory
compromise when added to opiate
– Neonates: hypotension and seizures with rapid
injection
– Peak serum level increased with itraconazole,
erythromycin and clarithromycin
Barbiturates
 General
CNS depressants
 Induction of anesthesia
 Hypnosis
 Sedation
 Respiratory depression
Pentobarbital (Nembutal)
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Advantages:
– Fairly safe
– Sedation, motion control, anxiolysis
– Short onset (3-5 min. given IV) and duration
(15-45 min.)
– Alternative to chloral hydrate in older children
– PO, IV, IM, PR dosing routes
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longer time to onset and longer duration with routes
other than IV
Pentobarbital
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Disadvantages
– Enhances pain perception
– No reversal agent
Chloral Hydrate
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Advantages
– PO, PR dosing
initial 25-100 mg/kg
 repeat after 30 min if need 25-50 mg/kg
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Anxiolysis, sedation, motion control
Single dose toxicity is low
Successful in younger patients (< 2-3 yrs)
Many practitioners familiar with its use
Chloral Hydrate
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Disadvantages
– 15-30 min to onset, lasts 1-2 hours
– Less successful in older children
– High doses can cause respiratory depression
and dysrhythmias
– No pain control
– Not reversible
– Repetitive doses cause metabolites to
accumulate with unknown toxicities
What is pain?
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Physical or mental suffering or distress
Two components of pain
Physical stimulus
 Affective response
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Analgesia
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“I can’t think of any other area in medicine
in which such an extravagant concern for
side effects so drastically limits treatment.”
M. Angell. The quality of mercy. NEJM,
1982;306.
What is Analgesia?
“Relief of the perception of pain
without intentional production
of a sedated state. Altered
mental status may be a
secondary effect of medications
administered for this purpose.”
Local analgesia for procedures
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EMLA Cream
– Apply to intact skin with occlusive dressing 3060 min prior to procedure
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Buffered Lidocaine
– (1 ml bicarb/9 ml 1% lidocaine)
– Maximum dose lidocaine
4.5 mg/kg without epinephrine
 7 mg/kg with epinephrine
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Narcotic Analgesics
 Activate
descending CNS tracts
 Sedation
 Analgesia
 Respiratory
depression
 Moderate anxiolysis
Fentanyl
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Opioid
Advantages
– analgesia
– 100x more potent than morphine
– shorter duration than morphine
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onset in 2-3 min, lasts 30-60 min
– less histamine release than morphine
– available reversal agent
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naloxone
Fentanyl
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Disadvantages:
– no amnesia
– “Steel chest” or “rigid chest” phenomenon
 more likely with large bolus dose
 Treat with reversal of fentanyl or
paralyzation
Morphine
Opioid
 Advantages
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– Analgesia
– Less expensive than fentanyl
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Disadvantages
– no amnesia, anxiolysis
– Histamine release - wheezing, hypotension
– Longer onset than other opioids
Ketamine
Dissociative anesthetic
 Advantages
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– provides both analgesia and amnesia
– preserves upper airway tone and reflexes
– causes bronchodilatation
Ketamine
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Disadvantages
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increases intracranial pressure
laryngospasm
hypersecretory response
parents disturbed by blank stare
emergence phenomenon/agitation
Ketamine
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Relative contraindications
– head injury
– airway abnormalities
– procedures where posterior pharynx will be
stimulated
– glaucoma, acute globe injury
– psychosis
– thyroid disorder
Pre-sedation
History
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General health
Risk factors for sedation
Current medications
Allergies
Previous anesthetic reactions
– patient / patient’s family
Why is sedation required?
Medications to be used
ASA Physical Status
Class I:
Class II:
Class III:
Class IV:
Healthy patient
Systemic disease
Severe systemic disease
Severe systemic disease that is
a constant threat to life
Class V: Moribund / not expected to
survive without surgery
In general, consider anesthesia or
critical care involvement in
patients that are ASA Class III or
above and are not in the PICU
Pre-sedation
Physical Examination
 Neurologic
exam
 Airway exam
 Respiratory status
 Cardiovascular exam
Personnel Responsibilities
 Evaluation
 Monitoring
 Familiarity
with medications
 Anticipation of side effects
 Resuscitation
Monitoring
General considerations
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Heart Rate, Respiratory Rate, Blood Pressure
Continuous pulse oximetry
ECG
Perfusion
Neurologic status
– State of consciousness
– Pupillary responses
Discharge after Sedation for Short
Procedure
Ability to sit unassisted or flex their neck
 Verbal responses appropriate for age
 Protective airway reflexes intact
 Hemodynamic stability
 Spontaneous breathing/good oxygenation
 The patient has returned to their presedation level of function
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Neuromuscular Blockade
Achieves profound weakness of
striated muscle without affecting
the function of the cerebral cortex,
smooth muscle or the myocardium.
Neuromuscular Blockade
 NEVER
muscle relax a patient
without assuring adequate
sedation/analgesia beforehand.
 ALWAYS confirm the patient is
easily hand-bag-ventilated prior to
paralyzing
Monitoring
Muscle Relaxants
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Progression of weakness:
– small rapidly moving muscles of the
fingers and eyes
– muscles of the neck, limbs and trunk
– muscles of respiration
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Recovery occurs in reverse order; the
diaphragm recovers first
Monitoring
Muscle Relaxants
Nerve stimulators:
Stimulate nerve causing contraction of the
corresponding muscle
Train-of-four monitoring:
1 out of 4 twitches = 90% receptor blockade
Fade
Absent muscular response
Monitoring
Muscle Relaxants
Clinical monitoring:
Negative inspiratory force
Flexion of neck muscles
Infants:
Hand grasp
Grimace
Flexion of hips
Muscle Relaxants
Cause weakness followed by a flaccid
paralysis
 Depolarizing muscle relaxants
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– Stimulate motor nerve endings
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Non-depolarizing muscle relaxants
– Compete at receptor site
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All cause diaphragmatic paralysis
Muscle Relaxants
Depolarizing Agents
Imitate the affects of acetylcholine
 Initial fasciculations followed by
paralysis
 Prevent repolarization of the muscle
membrane
 Quick onset
 Succinylcholine is the only depolarizing
muscle relaxant in clinical use
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Succinylcholine – adverse
effects
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Profound bradycardia
Hyperkalemia
Increased intracranial and ocular pressure
Hypersensitivity reactions
Muscle pains
Malignant hyperthermia
Rhabdomyolysis
Succinylcholine
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Contraindications
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Patients with paraplegia
following strokes or burns
muscular dystrophies, myotonia
patients with a family history of malignant
hyperthermia.
Muscle Relaxants
Non-depolarizing Agents
Competitively inhibit the binding of
acetylcholine
 Most are steroid based
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Pancuronium
Non-depolarizing
 Tachycardia and hypertension due to
muscarinic cholinergic blockage
 Renal elimination
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Vecuronium
Non-depolarizing
 No cardiovascular effects
 More expensive than pancuronium
 Hepatic elimination
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Atracurium and Cisatracurium
Non-depolarizing
 Short duration
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– Best to use as continuous infusion
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Hofmann elimination
– Ideal agent in hepatorenal failure
Summary
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The hospital and especially the PICU are
scary places for children. Therefore, the use
of anxiolytics and analgesics to facilitate
procedures and medical therapies is key to
the proper care of the child.
Summary
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Safe use of sedatives requires knowledge of
the medication used as well as close
observation and monitoring of the child
throughout the period of altered
consciousness.
Summary
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When muscle relaxation is necessary,
confirm that the child is adequately sedated
and able to be ventilated manually prior to
administering a paralyzing agent.