Pediatric Pain Management

Avni M. Bhalakia M.D.St. Barnabas Hospital

Learning Objectives

• Define & classify pain• Understand general principles of pain

management• Understand pharmacology of

different analgesics• Know how to manage pain depending

on the type of pain

Definition of Pain

• International Association for the Study of Pain – An unpleasant sensory and emotional

experience arising from actual or potential tissue damage or described in terms of such damage

– Sensory, emotional, cognitive, and behavioral components that are interrelated with environmental, developmental, socio-cultural, and contextual factors

Barriers to Pediatric Pain Control

• Belief that children, especially infants, do not feel pain the way adults do

• Lack of routine pain assessment • Lack of knowledge in pain treatment• Fear of adverse effects of analgesics,

especially respiratory depression and addiction

• Belief that preventing pain in children takes too much time and effort

Pediatrics, 18 (3) 2001

Background

• Historically children and infants received less post-operative analgesia than adults

• Well documented that children are often undertreated for pain

• Specifically in neonates:– Recent studies show that neonates can

experience pain by 26 weeks of gestation• Mature afferent pain transmission

– Untreated pain in neonates lead to increased distress and altered pain response in the future

Classification of Pain

Nocioceptive• Somatic

– Bone, joint, muscle, skin, or connective tissue

– Well localized– Aching & throbbing

• Visceral– Visceral organs such as

GI tract– Poorly localized– Cramping

Neuropathic• Central

– Injury to peripheral or central nervous system causing phantom pain

– Dysregulation of the autonomic nervous system (e.g. Complex regional pain syndrome)

• Peripheral– Peripheral neuropathy

due to nerve injury – Pain along nerve fibers

http://www.med.umich.edu/PAIN/pediatric.htm

5 General Principles ofPain Management

• Anticipate & prevent pain• Adequately assess pain• Use multi-modal approach• Involve parents• Use non-noxious routes

Pediatrics in Review 2003; 24 (10)

1: Anticipate & Prevent Pain

• Prepare patient and parent on what to expect

• Guide them on ways to minimize pain and anxiety

• Utilize quiet environment • Treat pain prophylactically when anticipated

– E.g. Following surgery or local anesthetic for lumbar puncture

– Takes more medication to treat pain than to prevent its occurrence

2: Pain Assessment

• Obtain a detailed assessment of pain– HPI, description of pain, experience with pain

medications, use of non-pharmacologic techniques, parent experience with pain

– Quality, location, duration, intensity, radiation, relieving & exacerbating factors, & associated symptoms

• Use age appropriate tool– Scales for neonate, infant, children ages 3-8,

>8 years, and children with cognitive impairments

• Directly ask child when possible• Pain can be multi-dimensional and

therefore, tools can be limited

Assessment in Neonates & Infants

• Challenging • Combines physiologic and behavioral

parameters• Many scales available

– NIPS (Neonatal Infant Pain Scale)– FLACC scale (Face, Legs, Activity, Cry

Consolability)

Neonatal Infant Pain Scale (NIPS)

FLACC scale

Children between 3-8 years

• Usually have a word for pain• Can articulate more detail about

the presence and location of pain; less able to comment on quality or intensity

• Examples:– Color scales– Faces scales

Children older than 8 years

• Use the standard visual analog scale• Same used in adults

Children with Cognitive Impairment

• Often unable to describe pain• Altered nervous system and

experience pain differently

• Use behavioral observation scales – e.g. FLACC

• Can apply to intubated patients

3: Multi-modal Approach

• Cognitive-behavioral– Education– Relaxation, imagery– Psychotherapy,

counseling– Hypnosis– Biofeedback– Music, literature,

art, play– Prayer, meditation

• Physical Approach– Massage– Acupuncture– Acupressure– Heat or Cold– TENS– Therapeutic

exercise

Sucrose for Infants

• Sucrose 24% oral solution• Can be used for procedures such as heel

stick, venipuncture, catheterization, etc.• Effective analgesic in preterm and term

infants– Not effective beyond 3 months old

• Dip pacifier in sucrose solution or give 0.2 mL to buccal area– May repeat but be cautious with many doses to

younger infants

4: Patient & Parental Involvement

• Parent– Excellent sources of information on child– Learn techniques to help coach through pain – Reduces anxiety

• Patient– Age & developmentally appropriate– Gives them control in their pain experience– Learn techniques to help with pain control– Reduces anxiety

5: Non-noxious Routes

• Administer analgesia through most painless route– Avoid IM injections– Oral and Intravenous routes are

preferred• Oral route for mild to moderate pain• Intravenous route for immediate pain relief

and severe pain

Pharmacology of Pain Management

Principles of Pharmacology

• Consider patient’s age, associated medical problems, type of pain, & previous experience with pain

• Choose type of analgesia• Choose route to control pain as rapidly and

effectively as possible• Titrate further doses based on initial

response• Anticipate side effects • Recognize synergistic effects

NEJM 2002; 347 (14).

Non-opioid Analgesics

• Mild to moderate pain• No side effects of respiratory depression• Highly effective when combined with opioids

• Acetaminophen• NSAIDs• COX-2 inhibitors• Aspirin

– No longer used in pediatrics

Acetaminophen

• Antipyretic • Mild analgesic• Administer PO or PR• Pediatric Oral dose 10-15 mg/kg/dose

every 4 hr– Infant dose is 10-15 mg/kg/dose every 6-8

hr– Adult dose 650 mg-1000 mg/dose

• Onset 30 minutes

Acetaminophen

• Per rectum dose 40 mg/kg once followed by 20 mg/kg/dose every 6 hours– Uptake is delayed and variable– Peak absorption is 60-120 minutes – Unreliable to cut suppositories

• Maximum daily dosing– Infants: 60-75 mg/kg/day– <60 kg: 100 mg/kg/day– >60 kg: 4 grams/day

Side Effects of Acetaminophen

• Generally a good safety profile– Do not use in hepatic failure

• Causes hepatic failure in overdose– Infant drops are MORE concentrated

than the children’s suspension• Infant’s Acetaminophen 80 mg/0.8 mL• Children’s Acetaminophen 160 mg/5 mL

NSAIDs

• Antipyretic • Analgesic for mild to moderate pain• Anti-inflammatory

– COX inhibitor Prostaglandin inhibitor

• Platelet aggregation inhibitor

NSAIDs: Ibuprofen

• Dose 10 mg/kg/dose every 6 hours– Adult dose 400-600 mg/dose every 6

hours

• Onset 30-45 minutes• Maximum daily dosing

– <60 kg: 40 mg/kg– >60 kg: 2400 mg

• May use higher doses in rheumatologic disease

NSAIDs: Ketorolac

• Intravenous NSAID (also available P.O.)• Dose 0.5 mg/kg/dose every 6 hours• Onset 10 minutes• Maximum I.V. dose 30 mg every 6 hours

• Monitor renal function• Do not use more than 5 days

– Significant increase in side effects after 5 days

Side Effects of NSAIDs

• Gastritis– Prolonged use increases risk of GI bleed– Still rare in pediatric patients compared to adults– NSAID use contraindicated in ulcer disease

• Nephropathy (ATN)• Bleeding from platelet anti-aggregation

– Increased risk versus benefit post-tonsillectomy– NSAID use contraindicated in active bleeding

• Delayed bone healing?

COX-2 inhibitors

• Selectively inhibits Cyclooxygenase-2 which reduces risk of gastric irritation and bleeding

• Same risk for nephropathy as non-selective COX inhibitors

• Shown to have increased cardiovascular events in adults

• More studies needed in pediatric patients– COX-2 inhibitors used in rheumatologic

diseases

Opioids Analgesics

• Moderate to severe pain• Various routes of administration• Different pharmacokinetics for

different age groups– Infants younger than 3 months have

increased risk of hypoventilation and respiratory depression

• Low risk of addiction among children

Principles of Opioid Use

• Work at opioid (mu) receptors in the CNS and peripheral nervous system

• Each opioid has different affinities for different receptors, so there is variability in response among patients

Side Effects of Opioids

• All opioids have side effects that should be anticipated & managed– Respiratory depression– Nausea, vomiting– Constipation– Pruritis– Urinary retention

Opioids

• Codeine• Oxycodone• Morphine• Fentanyl• Hydromorphone• Methadone

Codeine

• Oral analgesic (also anti-tussive)• Weak opioid

– Used often in conjunction with acetaminophen to increase analgesic effect

• Metabolized in the liver and demethylated to morphine– Some patients ineffectively convert

codeine to morphine so no analgesia is achieved

• Dose 0.5-1 mg/kg every 4-6 hours

Oxycodone

• Oral analgesic• Mild to moderate pain• Hepatic metabolism to noroxycodone

and oxymorphone • Can be given alone or in combination

with acetaminophen• Dose 0.05-0.15 mg/kg every 4-6 hours• Maximum 5-10 mg every 4-6 hours

Morphine

• Available orally, sublingually, subcutaneously, intravenous, rectally, intrathecally

• Moderate to severe pain• Hepatic conversion with renally excreted

metabolites– Use in caution with renal failure

• Duration of I.V. analgesia 2-4 hours– Oral form comes in an immediate and sustained release

• Dose dependent on formulation• I.V. Dose 0.05-0.2 mg/kg/dose every 2-4 hours• Onset 5-10 minutes• Side effect of significant histamine release

Fentanyl

• Available intravenous, buccal tab, lozenge and transdermal patch– Use buccal tabs, lozenges and patch only in opioid

tolerant patients• Severe pain• Rapid onset, brief duration of action

– With continuous infusion, longer duration of action• I.V. Dose 1 mcg/kg/dose every 30-60 minutes• Side effect of rapid administration may

produce glottic and chest wall rigidity• Careful observation, CRM and immediate

availability of airway equipment and skills

Other Opioids

• Hydromorphone– 5 x more potent than Morphine (IV)– Available P.O. or I.V.– Used in patients with renal insufficiency

• Methadone– Very long half-life with slow peak– Good for steady level of analgesia– Accumulates slowly and takes days to

reach steady state

Patient Controlled Analgesia (PCA)

• Programmable pump that allows patient control of intravenous analgesia

• Patient can choose when to deliver a dose of opioid and achieve relief quickly

• Inherent safety in the PCA: patient will fall asleep when over sedated and is unlikely to administer too much drug

• Teaching is integral and essential• Control of the button rests solely with the

patient, NOT the parent

When to use PCA

• Useful for sickle cell vaso-occlusive episodes, postoperative pain, cancer pain, palliative care

• Take patient’s age, maturity, and medical condition into the decision

• Bray et al (1996) compared morphine infusion and PCA in children– Children over 5 able to use PCA– Children between 5-8 years showed no difference in

analgesia– Children over 8 years had better analgesia with PCA

How to set up a PCA• Loading dose if patient is in pain so that there is a

therapeutic serum level to start• Basal infusion rate can deliver continuous

background dose of opioid to maintain therapeutic level

• Patient demand dose is the dose administered with each patient activation of the pump (usually small)

• Lockout interval (5-10 min) prevents a second PCA dose before the previous bolus has taken effect (important to prevent overdosing)

• Maximum hourly limit can be set based on the average hourly use of morphine

• Sedation and vital sign assessment is mandatory

Monitor Patients receiving Opioids

• Close observation of all patients receiving opioids– Routine vital signs– Sedation scales when indicated

• Particular close attention to patients:– History of OSA– Craniofacial anomalies– Infants who are younger than 6 months or older

infants with history of apnea or prematurity– Opioid-naïve patients with continuous infusions

Naloxone

• Opioid antagonist• 1 ampule = 0.4 mg/mL• Use when unresponsive to physical stimulation,

shallow respirations (<8 breaths/min), pinpoint pupils

• Stop Opioid• Mix Naloxone 1 ampule with NS 9 mL = 40 mcg/mL

– For <40 kgs: Naloxone ¼ ampule with NS 9 mL = 10 mcg/mL

• Administer slowly and observe response– 1-2 mcg/kg/min

• Discontinue naloxone as soon as patient responds• Duration 30-45 minutes

– Monitor the patient; repeat doses may be needed

Local Anesthetics

• For needle procedures, suturing, lumbar puncture, etc.

• Topical or infiltration• Acts by blocking nerve conduction at Na-channels• If administered in excessive doses, can cause

systemic effects– CNS effects of perioral numbness, dizziness, muscular

twitching, seizures & cardiac toxicity– Aspirate back before injecting to avoid direct injection

into blood vessels– Calculate maximum mg/kg dose to avoid overdose

• Buffering lidocaine can help with pain of infiltration– 9 mL lidocaine mixed with 1 mL sodium bicarbonate

Anesthesia

• Regional– Blocks afferent pathways to CNS– Good for post-operative pain relief – Epidural and caudal anesthesia– Peripheral nerve blocks

• General

Types of Pain

• Procedural pain• Post-operative pain• Sickle cell pain• Neuropathic pain• Cancer pain• Pain in palliative care

Procedural Pain

• Consider the type of procedure, expected duration of pain, the patient and parents involved, and child’s pain history

• Educate the parents and patients on what to expect

• Utilize non-pharmacologic methods and local anesthesia

• Calm environment• Consider anxiolytic

– Be skilled in airway management

Post-operative Pain

• Anticipate pain depending on type of surgery

• Utilize different classes of analgesics• Control pain as soon as possible to allow

for steady serum levels • Use continuous/around-the-clock dosing

at fixed times for moderate to severe pain

• Address side effects of opioid medications

Sickle Cell Pain

• Typically vaso-occlusive crisis– Complete careful history and physical to rule out

other causes of pain– VOC may involve 2-3 sites and maybe migratory

• Assess pain (generally relies on self-report)• Pay attention to degree of pain relief and

any adverse reactions• Change medications and doses depending

on clinical response of patient• Utilize non-pharmacologic management• Involve patient in plan

Vaso-occlusive Crisis• Acetaminophen and NSAIDS typically first line for

mild to moderate pain– Maybe combined with opioid for moderate pain

• Opioids to treat moderate to severe pain– PCA if appropriate

• Rapid triage, physical assessment, and analgesia– Start with appropriate dose of medication and re-evaluate– If need more opioid, give 25-50% more of initial dose

• Once relief achieved, around-the-clock medication with breakthrough medications available

• Adjunct management with I.V. fluids• Monitor patients closely for respiratory depression

– Hypoventilation may precipitate acute chest syndrome

Neuropathic Pain

• Abnormal excitability in the PNS or CNS that may persist after injury heals or inflammation subsides

• Acute or chronic• Burning, shooting, tingling, or stabbing

quality• Post-traumatic, post-surgical, phantom pain

after amputation• Responds poorly to opioids• Best treated with TCAs and anticonvulsants

(carbamazepine, gabapentin)• Complex Regional Pain Syndrome

Cancer Pain

• WHO analgesic ladder• Pain at diagnosis• Pain during treatment

– Mucositis– Peripheral neuropathy– Repeated procedures

• Pain from tumor growth– Spread to spinal cord

and nerve roots or metastasis to organs

Palliative Care

• Many children have sub-optimal pain control in the last days of life

• Significant psychological impact on the child and family

• Use WHO Analgesia Ladder– Follow general principles of pain management– Give medication to provide stable blood

concentrations, through least invasive routes– Some patients will need escalated opioid doses

• Use complementary/non-pharmacologic methods

Key Points

• Treat pain• Adhere to general principles of pain

management– Anticipate & prevent pain– Adequately assess pain– Use multi-modal approach– Involve parents & patients– Use non-noxious routes

• Understand the pharmacology of non-opioid and opioid analgesics

• Approach and treat different types of pain accordingly

ReferencesAmerican Medical Association, Module 6 Pain Management: Pediatric Pain

Management. September 2007.American Pain Society, The Assessment and Management of Acute Pain in

Infants, Children, and Adolescents. Pediatrics 2001; 18 (3): 793-797.Berde, Charles and Navil Sethna. Analgesics for the Treatment of Pain in

Children. New England Journal of Medicine 2002; 347 (14): 1094-1103.Ellison, Angela and Kathy Shaw. Management of Vasoocclusive Pain

Events in Sickle Cell Disease. Pediatric Emergency Care 2007; 23(11): 832-841.

Friedrichsdorf, Stefan and Tammy Kang. The Management of Pain in Children with Life-limiting Illnesses. Pediatric Clinics of North America 2007,645-672.

Greco, Christine and Charles Berde. Pain Management for the Hospitalized Pediatric Patient. Pediatric Clinics of North America 2005, 995-1027.

Hillenbrand, Karen. Pain. Pediatric Hospital Medicine, 2003, 756-771.Polaner, David. Acute Pain Management in Infants and Children. Pediatric

Hospital Medicine, 2nd Edition. 743-754.University of Michigan, Pediatric Pain Management Staff Education,

http://www.med.umich.edu/PAIN/pediatric.htm.Zeltzer Lonnie and Heather Krell. Pediatric Pain Management. Nelson’s

Textbook of Pediatrics, 18th Edition. 475-484.Zempsky, William and Neil Schechter. What’s New in the Management of

Pain in Children, Pediatrics in Review; 24 (10): 337-337-348.