Pain Management Flashcards
Types of Pain (6)
- Acute pain – lasts <6 months
- Chronic pain – lasts >6 months
- Acute on chronic pain
- Somatic Pain – Originating from bones, joints, muscles, skin, or connective tissue
- Neuropathic Pain – Originating from peripheral or central nervous system
- Visceral Pain – Originating from internal organs
Barriers to the Treatment of Pain in Children (6)
The myth that children, especially infants, do not feel pain Or if they do, there is no untoward consequence
Lack of assessment and reassessment for the presence of pain
Misunderstanding of how to conceptualize and quantify a subjective experience such as pain
Lack of knowledge of pain treatment
Notion that addressing pain in children takes too much time
Fear of adverse effects from analgesics
Consequences of Unrelieved Pain (8)
- Rapid, shallow breathing, and inadequate expansion of lungs
- Increased HR and BP
- Increased stress hormones
- Slowing/stasis of gut and urinary systems
- Muscle tension, spasm, and fatigue
- Behavioral disturbances- Fear, Anxiety, Reduced Coping, Developmental regression
- Allodynia – what was not painful before is now painful
- Hyperalgesia – what was painful before is now exponentially painful
Pain Assessment Tools by Age
Toddlers (5)
o Nonverbal cues to indicate pain and can point to area of pain
o Grimacing
o Whimpering, crying
o Grabbing/tugging/holding affected area
o Inactivity, disinterest in usual activities
Pain Assessment Tools by Age
Preschoolers
Simple self-report scales or assessment via observational scales
Pain Assessment Tools by Age School age (7-12 years)
Verbal numerical scales or visual analog scale
Pain Scale (5)
- Verbal Rating Scales
- Numerical Rating Scales
- Visual Analog Scale
- Graphic Rating Scales
- Faces Pain Scale
Pharmacologic Pain Management (9)
Non-opioid
- Acetaminophen
- Nonsteroidal anti-inflammatories (NSAIDs)
Opioids
- Morphine
- fentanyl
- methadone
- oxycodone
- Local anesthetics
Topical patch, cream or ointment
- Lidocaine
- Prilocaine or tetracaine
- Capsaicin
- Nerve blocks (lidocaine)
Adjuvant analgesics (5)
- Antidepressants
- Anticonvulsants
- Sedatives/anxiolytics
- Antihistamines
- Ketamine
Acetaminophen (Tylenol)
Absorption (3)
Metabolism (4)
Elimination(2)
Absorption:
- Oral: well absorbed
- Peak serum concentration: 60 minutes after oral dose
- Rectal: variable and prolonged; recommend q6h dosing
Metabolism:
- Extensively metabolized in the liver
- Primary mechanism: sulfate and gluconuronide conjugates
- **glutathione depletion leads to toxic levels of NAPQI
- Small amounts metabolized via CYP enzymes (NAPQI)
Elimination
Half-life:
- 3x in neonates compared to children
- Metabolites excreted via kidneys
Acetaminophen (Tylenol)
Mechanism of Action (3)
Mechanism of Action:
- Analgesic effects – inhibition of prostaglandin synthesis via COX enzymes increasing pain threshold
- Antipyretic effect – decreases production of endogenous pyrogens
- Minimal anti-inflammatory effects
Most commonly used analgesic in pediatrics for mild to moderate pain
Acetaminophen (Tylenol)
Available Dosage Forms (3)
Acetaminophen (Tylenol)
IV ($$$)
PO (liquid 160 mg/5 ml, tablets; max daily dose = 75 mg/kg/day)
PR (80 mg is the smallest dose; 20 mg/kg = max dose rectally)
What is the international name for acetaminophen?
Paracetamol
Acetaminophen (Tylenol) Side effects (1)
GI upset
Tylenol is often combined with opioids for…
More severe pain
o Indirect synergistic effects
NSAID (1)
Use
Used for treatment of mild to moderate pain, especially inflammatory-mediated conditions
NSAID (3)
Place in therapy
o Antipyretic
o Anti-inflammatory
o Analgesic activity
NSAID Agents (4)
Ibuprofen (Advil®)
Ketorolac (Toradol®, IV/PO)
Naproxen (Aleve®)
Celecoxib (Celebrex®)
NSAIDS Mechanism of Action (3)
- Reversible Inhibition of COX1 and COX2 enzymes decreased prostaglandin synthesis
- Resulting in decreased formation of prostaglandin precursors
- Anti-inflammatory properties potentially due to effect on immune cells themselves
NSAIDS
Onset of action
60-120 minutes after oral dose
NSAID Half-life
Ibuprofen
Ketorolac
Naproxen
Ibuprofen – 1-2 hours (can be given 4x/day)
Ketorolac – 3-6 hours (only should be given 2x/day)
Naproxen – 8-17 hours
Metabolism for NSAIDS
Extensively metabolized in the liver
Excretion for NSAIDS
Metabolites excreted via kidneys
ADEs FOR NSAIDS (4)
- Edema/fluid retention
- Acute kidney damage
- Risk with ketorolac
- Avoid in patients with renal dysfunction
- Abdominal pain
- GI bleed (rare but can occur especially at high doses)
Aspirin
Not used in peds because…
Not used regularly in pediatrics due to association with Reye’s Syndrome
Aspirin
Mechanism of Action (3)
- Irreversibly bind to COX-1 and COX-2 enzymes via acetylation decreasing effects of prostaglandins and Thromboxane A2
- Analgesia, anti-inflammatory, anti-pyretic
- Anti-platelet activity
What is the most common indication for aspirin in children ?
Anti-platelet activity
Opioids (4)
- Not first line therapy for pain
- Different levels of potency and efficacy
- May be used in combination with non-opioids at reduced doses without loss of analgesic effect
- Long term, chronic use may result in dose tolerance and need for dose increases
Partial Opioids (3)
- Effective for mild-to-moderate pain with or without a non-opioid
- Eg. nalbuphine
- If inadequate pain control, change to a stronger opioid
Codeine (4)
- Analgesic effect derived from pro-drug being metabolized to morphine
- Often given in combination with acetaminophen
- FDA warning for children < 18 years
- Avoid use in children April 2015
Opioid Antagonists
6
Manage moderate to severe pain o Morphine o Hydromorphone o Fentanyl o Methadone o Oxycodone o Hydrocodone
Morphine Overview (4)
- Widely studied in infants and children
- Narcotic analgesic that stimulates brain opioid receptors
- Increases venous capacitance, caused by release of histamine and central suppression of adrenergic tone
- Decrease GI secretions and motility
Pharmacokinetics for Morphine (3)
Converted in the liver to two metabolites that are renally excreted
- Morphine-6-glucuronide (active)
- Morphine-3-glucuronide (inactive)
Half-life for Morphine (4)
- 10-20 hours in preterm neonates
- 6 hours in neonates and infants up to 3 mos
- 2.9 hours in infants 6 months to 2.5 years
- 1-3 hours in children 6-9 years
Hydromorphone (3)
- More potent than morphine
- Used in opioid-tolerant patients who require larger than usual doses of opioids for pain relief
- Binds to opiate receptors in the CNS
Fentanyl (4)
- Synthetic opoid narcotic analgesic that is 50-100 times more potent than morphine
- High lipid solubility and rapidly penetrates the CNS
- Metabolized extensively in the liver and excreted by the kidneys
- Half-life highly variable: 2-21 hours
Methadone Overview
Long-acting narcotic analgesic
- Moderate to severe pain unresponsive to non-narcotics
- Treatment of neonatal abstinence syndrome and opioid dependence
Binds to opiate receptors in the CNS, causing inhibition of ascending pain pathways, altering perception of and response to pain
Onset of action: Methadone
Oral
Parenteral
Oral – within 30-60 minutes
Parenteral – within 10-20 minutes
Methadone
Half-life…
Metabolized…
Eliminated…
Half life: 4-62 hours
Metabolized in the liver, eliminated via the kidneys
Patient Controlled Analgesia
Binds to opiate receptors in the CNS, causing inhibition of ascending pain pathways, altering the perception of and response to pain
No injectable form
Topical Anesthetics
Use (3)
Examples (3)
Localized therapy
- Act on peripheral sensory nerves or pain modulators following dermal penetration
Reduce systemic toxicity Effective for acute procedural pain Effective in reducing pain from dermatologic procedures, venipuncture, etc. • EMLA • LMX4 • Buffered lidocaine
Lidocaine Topical Patch 5% (Lidoderm®) Clinical Pearls (4)
12 hrs on/ 12 hrs off
Patches can be cut
Caution with toxicity in little kids
Local pain only
Adjuvant Analgesic Medications
Use (2)
Examples (2)
- Not true analgesics in pharmacological sense; however, contribute significantly to pain relief
- May be used alone or in combination with analgesics
Examples:
o Anticonvulsants
o Sedatives/hypnotics/anxiolytics
Anticonvulsants
Use (2)
Examples (2)
Reduce neuronal excitability
Used for neuropathic pain
• Gabapentin
• Carbamazepine
Sedatives/Hypnotics/Anxiolytics
Use (3)
Examples (3)
- Block reuptake of neurotransmitters
- Rapid onset of analgesic effect
- Used to reduce anxiety, as muscle relaxant and pre-medication for painful procedures
Diazepam
Lorazepam
Midazolam
Alpha-2 Agonists
Use
Example (1)
Reduce central sympathetic output and increase firing of inhibitory neurons
Clonidine
- Sedation and analgesia without respiratory compromise
