THE USE OF ANALGESICS, SEDATIVE MEDICATIONS AND MUSCLE RELAXANTS IN CHILDREN

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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

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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

• Procedures
• 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 dont feel pain/anxiety like adults
• Respiratory depression
• Hemodynamic compromise
• Addiction

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Analgesia/Sedation Myth

• Children DO feel pain/anxiety
• Anatomy
• Myelinated and unmyelinated fibers transmit
  electrical impulse
• Impulse travels faster when myelinated
• Psychological

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Analgesia/Sedation Concerns

• Respiratory depression
• Receptor based phenomenon
• Need to titrate
• Caveat in the lt 6 month old infant
• Opioids can cause apnea prior to pain relief

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Analgesia/Sedation Concerns

• Addiction
• Addiction vs. Tolerance vs. Dependance

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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?
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Continuum of Consciousness
General anesthesia
Awake, baseline
Conscious sedation
Drowsy
Deep sedation
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Level of Sedation Required

• 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

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Conscious Sedation

• A medically controlled state of depressed
  consciousness that allows reflex ability to
  maintain a patent airway, and permits appropriate
  neurological responses to verbal stimuli.

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Deep Sedation

• 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.

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Benzodiazepines

• Bind CNS GABA receptors
• Skeletal muscle relaxation
• Amnesia
• Antegrade and retrograde
• Anxiolysis
• Respiratory Depression

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Midazolam (Versed)

• Advantages
• 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
• Flumazenil

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Midazolam (Versed)

• 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

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Barbiturates

• General CNS depressants
• Induction of anesthesia
• Hypnosis
• Sedation
• Respiratory depression

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Pentobarbital (Nembutal)

• 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
• longer time to onset and longer duration with
  routes other than IV

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Pentobarbital

• Disadvantages
• Enhances pain perception
• No reversal agent

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Chloral Hydrate

• Advantages
• PO, PR dosing
• initial 25-100 mg/kg
• repeat after 30 min if need 25-50 mg/kg
• Anxiolysis, sedation, motion control
• Single dose toxicity is low
• Successful in younger patients (lt 2-3 yrs)
• Many practitioners familiar with its use

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Chloral Hydrate

• 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

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What is pain?

• Physical or mental suffering or distress

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Two components of pain

• Physical stimulus
• Affective response

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Analgesia

• I cant 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, 1982306.

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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.

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Local analgesia for procedures

• EMLA Cream
• Apply to intact skin with occlusive dressing
  30-60 min prior to procedure
• 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

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Fentanyl

• Opioid
• Advantages
• analgesia
• 100x more potent than morphine
• shorter duration than morphine
• onset in 2-3 min, lasts 30-60 min
• less histamine release than morphine
• available reversal agent
• naloxone

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Fentanyl

• Disadvantages
• no amnesia
• Steel chest or rigid chest phenomenon
• more likely with large bolus dose
• Treat with reversal of fentanyl or paralyzation

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Morphine

• Opioid
• Advantages
• Analgesia
• Less expensive than fentanyl
• Disadvantages
• no amnesia, anxiolysis
• Histamine release - wheezing, hypotension
• Longer onset than other opioids

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Ketamine

• Dissociative anesthetic
• Advantages
• provides both analgesia and amnesia
• preserves upper airway tone and reflexes
• causes bronchodilatation

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Ketamine

• Disadvantages
• increases intracranial pressure
• laryngospasm
• hypersecretory response
• parents disturbed by blank stare
• emergence phenomenon/agitation

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Ketamine

• Relative contraindications
• head injury
• airway abnormalities
• procedures where posterior pharynx will be
  stimulated
• glaucoma, acute globe injury
• psychosis
• thyroid disorder

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Pre-sedationHistory

• General health
• Risk factors for sedation
• Current medications
• Allergies
• Previous anesthetic reactions
• patient / patients family
• Why is sedation required?
• Medications to be used

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ASA Physical Status

• Class I Healthy patient
• Class II Systemic disease
• Class III Severe systemic disease
• Class IV Severe systemic disease that is a
  constant threat to life
• Class V Moribund / not expected to
  
• survive without surgery

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• In general, consider anesthesia or critical care
  involvement in patients that are ASA Class III or
  above and are not in the PICU

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Pre-sedationPhysical Examination

• Neurologic exam
• Airway exam
• Respiratory status
• Cardiovascular exam

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Personnel Responsibilities

• Evaluation
• Monitoring
• Familiarity with medications
• Anticipation of side effects
• Resuscitation

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MonitoringGeneral considerations

• Heart Rate, Respiratory Rate, Blood Pressure
• Continuous pulse oximetry
• ECG
• Perfusion
• Neurologic status
• State of consciousness
• Pupillary responses

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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 pre-sedation
  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.

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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

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MonitoringMuscle Relaxants

• Progression of weakness
• small rapidly moving muscles of the
  fingers and eyes
• muscles of the neck, limbs and trunk
• muscles of respiration
• Recovery occurs in reverse order the diaphragm
  recovers first

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MonitoringMuscle 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

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MonitoringMuscle Relaxants

• Clinical monitoring
• Negative inspiratory force
• Flexion of neck muscles
• Infants
• Hand grasp
• Grimace
• Flexion of hips

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Muscle Relaxants

• Cause weakness followed by a flaccid paralysis
• Depolarizing muscle relaxants
• Stimulate motor nerve endings
• Non-depolarizing muscle relaxants
• Compete at receptor site
• All cause diaphragmatic paralysis

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Muscle RelaxantsDepolarizing 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

• Profound bradycardia
• Hyperkalemia
• Increased intracranial and ocular pressure
• Hypersensitivity reactions
• Muscle pains
• Malignant hyperthermia
• Rhabdomyolysis

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Succinylcholine

• Contraindications
• Patients with paraplegia
• following strokes or burns
• muscular dystrophies, myotonia
• patients with a family history of malignant
  hyperthermia.

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Muscle RelaxantsNon-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
• Best to use as continuous infusion
• Hofmann elimination
• Ideal agent in hepatorenal failure

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Summary

• 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.

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Summary

• 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.

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Summary

• When muscle relaxation is necessary, confirm that
  the child is adequately sedated and able to be
  ventilated manually prior to administering a
  paralyzing agent.