D. Wong 2002

Pain Assessment in Infants and Children

Donna L. Wong, PhD, RN, PNP, CPN, FAAN

Web site: www.mosby.com/WOW

; Copyright.

Facts about Pain in Infants and Children

• Infants, regardless of age, feel pain.

• The youngest premature infant has the anatomic and physiologic components to perceive pain or “nociception” and demonstrates a severe stress response to painful stimuli.

Pain Mechanisms in Newborns

• Complete myelination of nerve pathways not required for pain transmission

• C-fibers are unmyelinated and A-delta fibers are thinly myelinated

• Incomplete myelination results in slower conduction velocity but offset by shorter distances

Pain Mechanisms in Newborns, cont.

• Complete myelination of pain pathways to brainstem and thalamus by 30 weeks gestation; thalamus to cortex by 37 weeks

• Nociceptive nerve endings in cutaneous and mucous surfaces by 20 weeks of gestation

Pain Mechanisms in Newborns, cont.

• Threshold for responding to cutaneous stimulation is lowest in youngest neonates

• Inhibitory pathways do not develop until after birth

Stress Responses to Postoperative Pain in Neonate

Biochemical Changes: stress hormones• corticosterone• adrenaline, noradrenaline• glucagon• aldosterone metabolites• glucose• lactate• pyruvate

Facts about Pain in Infants and Children

• Unrelieved pain in infants can permanently change their nervous system and may “prime” them for having chronic pain.

Changes in Peripheral Nervous System

• Sensitization -- sensitivity of receptor (nociceptor)

frequency of firing of receptor• Neuronal sprouting -- receptor field, eg,

neuromas • When sensitized, receptors respond to

new forms of stimulation, eg, hyperalgesia, allodynia

Changes in Central Nervous System

• Central sensitization – formation of spontaneous impulses

• Wind-up -- in magnitude of response to C fiber activity by dorsal horn neurons

• Long-term potentiation – cellular “memory” for pain may lead to responses to nociceptor stimuli

• Facilitation – impulse threshold and intensity of response

• Neuronal sprouting -- nerve endings into adjacent laminae (I and II may spread to III)

Children Do Not Tolerate Pain Better Than Adults

• Children’s tolerance to pain actually INCREASES with age.

Children Can Tell You Where They Hurt

• Children beyond infancy can accurately point to the body area or mark the painful site on a drawing; children as young as three years can use pain scales.

Children Do Not Always Tell The Truth About Pain

• Children may not admit having pain to avoid an injection, because of constant pain, or because they believe others know how they are feeling.

Children Do Not Become Accustomed To Pain or

Painful Procedures

• Children often demonstrate INCREASED behavioral signs of discomfort with repeated painful procedures.

Consequences of inadequate analgesia during painful procedures in children

N = 21 children, BMA or/and LP, RCT placebo vs transmucosal fentanyl (TF)

• Placebo group rated pain higher than TF group

• Placebo group then received TF• Children <8yrs. (n=5) still rated pain higher

than TF group

Ref: Weisman SJ, Bernstein B, Schechter NL: Arch Pediatr Adolesc Med 152(2):147-149, Feb 1998.

Behavioral Manifestations of Pain May Not Reflect

Pain IntensityChildren’s developmental level,

coping abilities, and temperament, such as activity level and intensity of reaction to pain, influence pain behavior.

N=17 children, ages 3-15 yrs, during LP Active Behaviors = Pain Rating

– Resists, denies, attacksPassive Behaviors = Pain Rating– Avoids, cooperates, ignores

Mean Pain Rating = 4.9/6 (SD = 1.5) Fear Rating: low not related to behaviors

Ref: Broom M, et al: ONS, 17(3):361-367, 1990.

Coping Behaviors vs Pain/Fear Ratings

Parents Want to be Involved in Their Child’s Pain Control

• Parents need information about assessing pain and using interventions to relieve pain.

• Parental presence during painful procedures is generally desirable for the child and parent.

Narcotics Are No More Dangerous for Children

Than Adults

• Addiction from narcotics (opioids) used to treat pain is extremely rare in adults; no reports substantiate this fear in children; reports of respiratory depression in children are rare.

3 of 3,263 patients developed respiratory depression from parenteral meperidine (Demerol) during hospitalization (0.09%)

No patient developed respiratory depression from oral meperidine

Ref: Miller, RR & Jick, H; J. of Clin. Pharm. 18:180-189,1978.

Risk of respiratory depression from opioids to treat pain

Incidence of anaphylaxis in penicillin administration

Anaphylaxis 4 of 1000 – 4 of 100 (0.004 – 0.04%)

At least 300 deaths/year

Ref: Hardman J, Limbird L, Gilman A: Goodman & Gilman’s the pharmacological basis of therapeutics, ed. 10, 2002, p. 1204.

Protective benefits of opioids

As tolerance to analgesic effect of opioids occurs, tolerance to respiratory depressant effect also occurs.

Pain = opioids = respiratory

depression

Risk of Addiction in Children

– Adolescent/198 with SCD admitted for 423 hospitalizations for pain (Morrison, 1991)

– Children/610 with SCD (Brozovic & others, 1986)

– Children/135 with Cancer (Rogers, 1990)

– Children/144 postoperative intravenous opioids (Dilworth & Mackellar, 1987)

Definitions confused with addiction

Involuntary and physiologic responses:

• Drug tolerance: need for larger dose of opioid to maintain original effect.

• Physical dependence: withdrawal symptoms when chronic use of opioid is discontinued or opioid antagonist (Narcan) is given.

Narcotic Addiction

Behavioral and voluntary pattern

– characterized by compulsive drug-seeking behavior

– leading to overwhelming involvement with procurement, and

– use of opioid NOT for medical reasons, such as pain relief.

Operational Definition of Pain

“Pain is whatever the experiencing person says it is, existing whenever he says it does.”

BELIEVE THE PATIENT! Ref: McCaffery and Pasero: Pain: Clinical

Manual, 1999).

Children’s Pain Continues To Be Poorly Controlled

• Pain during procedures and surgery, postoperative pain, and disease-related pain are inadequately controlled.

End of Life: Pediatric Cancer

– Survey of 103 parents whose child died of cancer (1990 – 1997)

– Interviews conducted average 3.1 years after death

Focused on quality of life during last month of life

Ref: Wolfe J & others: NEJM 342(5):326-333, 2000.

End of Life: Pediatric Cancer, cont.

89% of children suffered from 1 of 4 problems; 50% suffered from 3 or more:

– Fatigue

– Poor appetite

– Pain -- treated in 76%, successful in 27%

– Dyspnea -- treated in 65%, successful in 16%

Multidimensional Model of Pain Assessment

QUESTT• Question the patient

• Use pain rating scale

• Evaluate behavior and physiologic signs

• Secure family’s involvement

• Take cause of pain into account

• Take action and assess effectiveness

Question the Child

Verbal Indications of Pain

• Much less common than in adults• May not understand term, such as

“pain”• May speak globally, such as “I don’t

feel good”• May deny pain for fear of injection• Cries, screams, groans, moans

• Use a variety of words to describe pain, such as owie, boo-boo, ouch, hurt, ow ow

• Know words in other languages– Spanish: Ay ay, duele, lele, dolor

Question the Child, cont.

Have Child Locate Pain by:

• Marking body parts on a human figure drawing

• Point to area with one finger on self, doll, stuffed animal

• Point to “where mommy or daddy would put a bandage”

Use diagram to have child locate pain

Burn patient’s drawing

Use Pain Rating Scale

• In 2001 Joint Commission on Accreditation of Healthcare Organizations (JCAHO) published Pain Standards

• One of the standards is to make pain rating the 5th vital sign.

Use Pain Rating Scale, cont.

• Select a scale that is suitable for the child’s age, abilities, and preferences

• Teach child to use scale before pain is expected, such as preoperatively

• Use same scale with child each time pain is assessed

• Ask child about acceptable or functional pain level

Types of Pain Rating Scales

• Numbers

• Visual analogue

• Words

• Colors

• Faces

• Behavior/physiologic

signs

Samples of Pain Rating Scales From JCAHO Pain Standards

• 0-10 Numeric Scale

• Simple Descriptive Scale

• Visual Analog Scale (VAS)

• Wong-Baker FACES Pain Rating Scale

No Pain Worst Pain

0 1 2 3 4 5 6 7 8 9 10

Numeric Scale

No Pain Mild Moderate Severe Very Severe Worst

Simple Descriptive Scale

No Pain Worst Pain

Visual-Analogue Scale*

Usually 0-10 cm long line.Placed either vertical or horizontal.

VAS: Coloured Analogue Scale(Ref: McGrath, PA, et al: Pain, 1996.)

Wong-Baker FACES Pain Rating Scale

0 2 4 6 8 10

Sample of Child’s FACES Pain Rating Scale

Sample of Child’s FACESand Body Outline

• Oucher scale (Beyer)

• White child, 3 year-old male

Photographic/Numeric Pain

Scale

• Oucher scale (Beyer)

• Black child, school age, male

Photographic/Numeric Pain Scale, cont.

• Oucher scale (Beyer)

• Hispanic child, school age, male

Photographic/Numeric Pain Scale, cont.

Cultural Preference for Scales

100 African-American children with SCD rated preference of 3 scales:

• FACES -- 56%• Black Oucher -- 26%• VAS -- 18%• Validity was strongest for FACES, then

Oucher and VAS

Ref: Luffy R: Pediatric Nursing, Jan 2003.

Cultural Preference for Scales

Study of children in native country and preference of 0-5 vs FACES scales:

• 132 Chinese: FACES, 109 (82%)• 167 Japanese: FACES, 120 (72%)• 151 Thai: FACES, 115 (76%)

Ref: Wong D, DiVito-Thomas P: Multicultural study of the FACES scale, unpublished, 2003.

Acute Pain vs Chronic Pain• Acute pain activates body’s fight or

flight stress response. • When pain persists, body begins to

adapt and there is a decrease in the sympathetic responses.

• In chronic pain, stress response is absent or diminished.

Evaluate behaviors and physiologic changes

Physiological Indications of Acute Pain

• Dilated pupils

• Increased perspiration

• Increased rate/ force of heart rate

• Increased rate/depth of respirations

• Increased blood pressure

• Decreased urine output

• Decreased peristalsis of GI tract

• Increased basal metabolic rate

Possible Physiologic Signs of Pain in the Neonate

Physiological Variables HR, RR, PB• shallow respirations vagal nerve tone (shrill cry) pallor or flushing• diaphoresis, palmar sweating TcPO2 and O2 saturation• EEG changes

Possible Signs of Pain in the Neonate: Behavioral Variables

Vocalizations:

• Crying (often with apneic spells)

• Whimpering, groaning, moaning

State changes:

• Changes in sleep/wake cycles

• Changes in activity level

• Agitation or listlessness

Possible Signs of Pain in Neonate: Behavioral Variables, cont.

Bodily Movements:

• Limb withdrawal, swiping, or thrashing

• Rigidity

• Flaccidity

• Clenching of fists

Possible Signs of Pain in Neonate: Behavioral Variables, cont.

Facial expression (most reliable sign):

• Eyes tightly closed or opened

• Mouth opened, squarish

• Furrowing or bulging of brow

• Quivering of chin

• Deepened nasolabial fold

Facial Expression of Physical Distress

NASO-LABIAL FOLDdeepened

Observe for Specific Behaviors that Indicate Local Body Pain

• Pulling ears

• Rolling head from side to side

• Lying on side with legs flexed on abdomen

• Limping

• Refusing to move a body part

For infants and non-verbal children, use appropriate observational scales:CRIES (32-60 weeks gestational age) (Kretchel & Bildner, 1995)

FLACC (full term neonate – 7 years) (Merkel & others, 1997) 

NPASS (Neonatal Pain, Agitation and Sedation Scale) (prematurity)

(Hummel & Puchalski, 2002)

Behavioral Pain Rating Scales

FLACC

NPASS (Neonatal Pain, Agitation and Sedation Scale)

Pain Indicator for Communicatively Impaired

Children (PICIC)

Most common cues identified by 67 parents:• Screwed up or distressed looking face• Crying with or without tears• Screaming, yelling, groaning, moaning• Stiff or tense body• Difficult to comfort or console• Flinches or moves away if touched

Ref: Stallard P, et al: Pain 98(1-2):145-149, 2002.

Observe for Improvement in Behavior Following an Analgesic

Observe for Improvement in Behavior Following an Analgesic

Secure Family’s Involvement

• Take pain history before pain is expected, such as on admission to hospital or preoperatively

• Involve family in recording response to pain relief measures

Secure Parents’ Involvement, cont.

Take Cause of Pain into Account

• Use common sense and logic.

• Realize that for a an infant and small child, punctures are proportionally larger on their tiny bodies.

The only reason to assess pain is TO TAKE ACTION TO RELIEVE PAIN.

After intervention, assess child’s response to pain relief measures.

• Determine timing of assessment based on expected onset and peak effect of intervention:

• IV analgesic: assess after 5 minutes and 15 minutes

Take action and assess effectiveness

The Golden Rule

What is painful to an adult is painful to an infant and child

unless proven otherwise.

Questions, Comments, Concerns