Pain and Sedation Flashcards
1
Q
Differences in Pain Between Children and Adults
A
- Neonate:
- Descending pain pathway not complete until 30-32 weeks gestation
- Under 32 weeks have lower pain threshold and hypersensitivity that develops after repeat painful procedures
- Final stage of neural development complete at 37 weeks gestation
- Infants:
- Decreased accuracy in pain perception, difficulty in distinguishing painful response from non-painful response
- Children may have higher oxygen consumption & smaller lung volumes, more prone to periods of apnea with an opioid or sedative
- Consider ADME differences
- Neonates/Infants – higher exposure of topically administered medications
- Transdermal fentanyl should be avoided in children younger than 2 years of age due to unpredictability of dosing
- Neonates and infants may have inability to metabolize medications via hepatic system and inability to clear medications via renal system
- Children between 1-9 may have increased metabolic clearance
- Obese children will have a higher Vd for lipophilic medications
- Dosing continuous intravenous fentanyl by actual body weight may lead to higher risk of overdosing and adverse effects
- Compare adult dose to pediatric dose and consider using lowest dose
2
Q
A
3
Q
AAP Guidelines for Use of Topical Lidocaine in the ED
A
- Consider topical anesthetics in any patient with likelihood of non-emergent invasive procedure on intact skin in ED:
- Contraindications:
- Emergent need for IV access
- Allergy to amide anesthetics
- Non-intact skin
- EMLA only: congenital or idiopathic methemoglobinemia
4
Q
AAP Guidelines for Use of Sucrose in ED
A
Indications:
- Neonates and infants younger than 6 months
- Adjunct for limiting pain associated with procedures such as heel sticks, venipuncture, IV line insertion, arterial puncture, insertion of Foley catheter, and lumbar puncture
Procedure:
- Administer 2 mL of 25% sucrose solution by syringe into infant’s mouth (1 mL in each cheek) or allow infant to suck solution from a nipple (pacifier) no more than 2 min before the start of the painful procedure
- Sucrose seems more effective when given in combination with a pacifier; nonnutritive suck also contributes to calming the infant and decreasing pain-elicited distress
- Contraindications: None
5
Q
Pain Assessment Tools
A
6
Q
Opioid Receptors
A
μ (mu)
- Supraspinal and spinal analgesia; sedation; inhibition of respiration; slowed gastrointestinal transit; modulation of hormone and neurotransmitter release
δ (delta)
- Supraspinal and spinal analgesia; modulation of hormone and neurotransmitter release
κ (kappa)
- Supraspinal and spinal analgesia; psychotomimetic effects; slowed gastrointestinal transit
7
Q
Calculating a PCA - Hydromorphone
A
- Children ≥5 years weighing <50 kg & Adolescents weighing <50 kg:
- Usual concentration: 0.2 mg/mL
- Demand dose: Usual initial: 0.003 to 0.004 mg/kg/dose
- Lockout: Usual initial: 5 doses/hour
- Lockout interval: Range: 6 to 10 minutes
- Usual basal rate: 0 to 0.004 mg/kg/hour
- Sammy is a 10 year old patient who weights 20 kg
8
Q
Morphine
A
- Available as oral elixirs, tablets, SR products, intravenous
- Metabolism
- Metabolized via glucuronidation to active and inactive metabolites
- Neonates can not metabolize (to active or inactive), less effective
- AE:
- Significant hypotension
- Histamine release: induced bronchospasm in history of asthma, higher risk of itching
9
Q
Hydromorphone
A
- 5x more potent opioid – oral and intravenous dosage forms
- Preferred over morphine for intermittent dosing for patients in renal failure due to less metabolites
- Pharmacologically similar to morphine
10
Q
Fentanyl
A
- Synthetic opioid structurally similar to meperidine
- 70-100x more potent IV opioid – intravenous
- Other formulations – spray, tablets/film/solution for sublingual or
- buccal administration, intranasal solution, transdermal, lozenge
- More lipophilic than morphine and has a quicker onset of action with shorter half-life
- Useful for intubation and procedures (dressing changes, lumbar puncture)
- AE: Chest wall rigidity observed with bolus doses (managed with a dose of naloxone and dose of NMB before fentanyl bolus)
11
Q
Methadone
A
- Long acting opioid
- Used for chronic pain and treatment of iatrogenic opioid withdrawal in critically ill children; (detoxification programs for heroin substance abuse in adults)
- Has an extended half-life 19 +/- 14 hours (range 4-62 hours) in children
- Same potency as morphine, but longer peak onset of action
- Similar structure to verapamil
- May exert calcium channel blockade
- Bradycardia, hypotension, cardiac arrhythmias (QRS prolongation)
- Higher risk of cardiac toxicities with rapid IV administration
12
Q
Meperidine
A
- Less potent synthetic opioid with shorter duration of action
- Limiting AE due to metabolite accumulation:
- Seizures, agitation, hyperreflexia
- Risk factors for AE
- Higher doses
- Renal Failure
- Reserved use for
- Prevention of rigors after administration of blood product or amphotericin
- Treatment of post-anesthetic shivering
- Limited use for acute pain
13
Q
Hydrocodone and Oxycodone (PO)
A
Oral administration, similar to morphine and more potent than codeine
- Oxycodone – more potent than hydrocodone, indicated for moderate to severe pain
-
Hydrocodone – moderate pain, only available as combination with acetaminophen (combination products have limited acetaminophen content to 325 mg)
- **Counsel on excessive acetaminophen content**
14
Q
Codeine and Tramadol
A
Codeine
- Metabolized to morphine via CYP2D6
- Poor metabolizers (decreased analgesic effects) versus ultra-fast metabolizers (increased respiratory depression)
- Not routinely utilized
Tramadol
- Centrally acting opioid (binds to mu receptors) plus inhibits reuptake
- of norepinephrine and serotonin
- Decreases seizures threshold
- Avoid with concomitant SSRI – serotonin syndrome
- FDA approved for 17 years and older only
15
Q
Opioid-related AE
A
[removed many because duh]
Tolerance: Increase opioid dose or switch to a longer-acting agent. Add non-opioid analgesic, or agent that prevents/delays tolerance
Withdrawal: Taper opioid dose slowly or add long-acting opioid agonist; Add alpha2 agonist
17
Q
Benzodiazepines
A
Benzodiazepines
- Enhances GABAergic inhibition (increases effects)
- Increase frequency of GABA-gated channel openings
- Do not activate receptors (need GABA)
Absorption: Most are lipid soluble. Ethanol enhances absorption.
Distribution: High lipid solubility increases rate of CNS penetration
Metabolism*: Major pathway for most agents. Caution with active metabolites.
- Phase I reactions – oxidation reaction to active or inactive metabolites
- Primarily involves CYP-450 system
- Phase II reactions – metabolite conjugated to form glucuronides that are excreted in the urine
Excretion: Dose adjustment not typically needed
-
Agonists – facilitate GABA actions
- BZD binds to BZD receptor to facilitate GABA binding to GABA receptor, increases frequency of channel opening
- Benzodiazepines
- Non-benzodiazepines (selective for α1 subunit)
- BZD binds to BZD receptor to facilitate GABA binding to GABA receptor, increases frequency of channel opening
-
Antagonists – blocks BZD & non-BZD actions
- Flumazenil – antidotes for overdose
- Shorter t1⁄2 compared to BZD – requires multiple doses
- Caution w/inducing abstinence/withdrawal syndrome
- Flumazenil – antidotes for overdose
24
Q
Rapid Sequence Intubation
A
- Means of securing airway of decompensating patient
- Goal of RSI
- Conscious unconscious/intubated without positive-pressure ventilation
- Medications used include induction agents and neuromuscular blocking agents
36
Q
Monitoring Sustained Blockade
A
- Train-of-four (twitch response)
- Monitors degree of neuromuscular blockade
- Assessment to find lowest possible dose to use
- At least once every 24 hours
- Ulnar nerve most common
- 2-3 twitches generally adequate
- Heart rate and blood pressure
- Drug holidays
- Intermittent discontinuation of continuous infusion neuromuscular blocking agents
- When safe to do so
- At least once every 24 hours
- Lasting until spontaneous movement returns
- Facilitates neurological examination
- Allows assessment of analgesia and sedation level
- Reduces total dose of agent being administered
- Intermittent discontinuation of continuous infusion neuromuscular blocking agents
- Clinical observation
- Movement of fingers and toes, breathing, coughing
Problems
- Difficult to perform in small children
- Direct stimulation of muscle group
- Dose-response curve varies by muscle group
- Results may be variable depending on other factors
- Peripheral edema
- Hemodynamic status
- Hydration
- Acid-base derangements
- Electrolyte disturbances
