1. University of Kentucky Medical College of Georgia
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

2. 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

3. 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
As an example of the variety of procedures for which children are sedated, I looked back at the procedures that Dr. Werner and I were requested to provide sedation for pediatric sedation service over the past year.

4. Analgesia/Sedation Myths and Concerns
Children don’t feel pain/anxiety like adults
Respiratory depression
Hemodynamic compromise
Addiction

5. Analgesia/Sedation Myth
Children DO feel pain/anxiety
Anatomy
Myelinated and unmyelinated fibers transmit electrical impulse
Impulse travels faster when myelinated
Psychological

6. Analgesia/Sedation Concerns
Respiratory depression
Receptor based phenomenon
Need to titrate
Caveat in the < 6 month old infant
Opioids can cause apnea prior to pain relief

7. Analgesia/Sedation Concerns
“Addiction”
Addiction vs. Tolerance vs. Dependance

8. 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

9. 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

10. 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

11. What is sedation?

12. Continuum of Consciousness
Awake,
baseline
General
anesthesia
Conscious
sedation
Drowsy
Deep
sedation

13. 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

14. 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.”

15. 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”.

16. Benzodiazepines Bind CNS GABA receptors Skeletal muscle relaxation
Amnesia
Antegrade and retrograde
Anxiolysis
Respiratory Depression

17. Midazolam (Versed) Advantages: anxiolysis, sedation, motion control
retrograde amnesia
PO, IV, IM, IN, PR dosing routes
onset 2-6 min after IV administration, min duration
available reversal agent
Flumazenil

18. 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
Now, moving on to those commonly used medications that have an analgesic effect that would be used to sedate for a painful procedure.

19. Barbiturates General CNS depressants Induction of anesthesia Hypnosis
Sedation
Respiratory depression

20. 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

21. Pentobarbital
Disadvantages
Enhances pain perception
No reversal agent

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

23. 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
Repetitive doses as in those used for insomnia
“High doses” mean about 6 times higher
than those used for sedation

24. What is pain?
Physical or mental suffering or distress

25. Two components of pain
Physical stimulus
Affective response

26. Analgesia
“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.

27. 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.”

28. Local analgesia for procedures
EMLA Cream
Apply to intact skin with occlusive dressing 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

29. Narcotic Analgesics Activate descending CNS tracts Sedation Analgesia
Respiratory depression
Moderate anxiolysis

30. Fentanyl Opioid Advantages analgesia 100x more potent than morphine
shorter duration than morphine
onset in 2-3 min, lasts min
less histamine release than morphine
available reversal agent
naloxone
Fentanyl is preferred over other opioids because of its faster onset and shorter recovery period and lack of histamine release.

31. Fentanyl Disadvantages: no amnesia
“Steel chest” or “rigid chest” phenomenon
more likely with large bolus dose
Treat with reversal of fentanyl or paralyzation
Next, ketamine…...

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

33. Ketamine Dissociative anesthetic Advantages
provides both analgesia and amnesia
preserves upper airway tone and reflexes
causes bronchodilatation
May be the preferred agent when fasting not possible due to UA reflexes maintained.
Also a good agent in patients with asthma.

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

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

36. Pre-sedation History General health Risk factors for sedation
Current medications
Allergies
Previous anesthetic reactions
patient / patient’s family
Why is sedation required?
Medications to be used

37. 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

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

39. Pre-sedation Physical Examination
Neurologic exam
Airway exam
Respiratory status
Cardiovascular exam

40. Personnel Responsibilities
Evaluation
Monitoring
Familiarity with medications
Anticipation of side effects
Resuscitation

41. Monitoring General considerations
Heart Rate, Respiratory Rate, Blood Pressure
Continuous pulse oximetry
ECG
Perfusion
Neurologic status
State of consciousness
Pupillary responses

42. 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

43. Neuromuscular Blockade
Achieves profound weakness of striated muscle without affecting the function of the cerebral cortex, smooth muscle or the myocardium.

44. 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

45. Monitoring Muscle 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

46. 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

47. Monitoring Muscle Relaxants
Clinical monitoring:
Negative inspiratory force
Flexion of neck muscles
Infants:
Hand grasp
Grimace
Flexion of hips

48. 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

49. 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

50. Succinylcholine – adverse effects
Profound bradycardia
Hyperkalemia
Increased intracranial and ocular pressure
Hypersensitivity reactions
Muscle pains
Malignant hyperthermia
Rhabdomyolysis

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

52. Muscle Relaxants Non-depolarizing Agents
Competitively inhibit the binding of acetylcholine
Most are steroid based

53. Pancuronium Non-depolarizing
Tachycardia and hypertension due to muscarinic cholinergic blockage
Renal elimination

54. Vecuronium Non-depolarizing No cardiovascular effects
More expensive than pancuronium
Hepatic elimination

55. Atracurium and Cisatracurium
Non-depolarizing
Short duration
Best to use as continuous infusion
Hofmann elimination
Ideal agent in hepatorenal failure

56. 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.

57. 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.

58. 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.