Chapter 34 Pediatric Postoperative Pain

Question 1

Total body water represents about what in full-term newborns

Answer 1

80% of body weight

Question 2

Total body water represents about what in 2 years of age,

Answer 2

This drops to 60% of body weight by 2 years of age, with a large proportional decrease in extracellular fluid volume.

Question 3

The larger extracellular and

total body water stores in infancy lead to

Answer 3

a greater volume

of distribution for water-soluble drugs.

Question 4

Newborns have

smaller skeletal muscle mass and fat stores and have what effect on

Answer 4

decreasing the amount of drug bound to inactive sites in muscle and fat. These stores increase during infancy.

Question 5

Immaturity of the blood–brain

barrier in early infancy allows

Answer 5

increased passage of more

water-soluble medications such as morphine

Question 6

The combination of increased blood flow to the brain and increased drug passage through the blood–brain barrier can lead to

Answer 6

higher central nervous system drug concentrations and

more side effects at a lower plasma concentration.

Question 7

Renal and hepatic blood flow in infants

Answer 7

Renal and hepatic blood flow is also increased in infants
relative to adults. As glomerular filtration, renal tubular function and hepatic enzyme systems mature, generally reaching adult values within the first year of life, increased blood flow to these organs leads to increased drug metabolism and excretion.

Question 8

serum albumin and a-1 acid glycoprotein (AAG)

Answer 8

the quantity and binding ability of serum albumin and a-1 acid glycoprotein (AAG) are decreased in newborns
relative to adults. This may result in higher levels of
unbound drug, with greater drug effect and toxicity at
lower overall serum levels.

Question 9

Effect of serum albumin and a-1 acid glycoprotein (AAG) in neonates on local anesthetic dosing

Answer 9

This has led to lower local
anesthetic dosing recommendations in neonates and young infants, although neonates have shown the ability
to acutely increase AAG levels while on continuous local
anesthetic infusions

Question 10

spinal cord and dura mater in the newborn

Answer 10

The spinal cord and dura mater in the newborn and
infant extend to approximately the third lumbar (L3) and
third sacral (S3) vertebral level, respectively, and reach the
adult levels of approximately L1 and S1 to S2 by about
1 year of age.

Question 11

The intercristal line connecting the posterior superior iliac crests, used as a surface landmark during needle insertion,

Answer 11

crosses the spinal column at the S1 level in neonates versus the L4 or L5 level in adults.

Question 12

Children over approximately 8 to 10 years of age pain assessment

Answer 12

able to use the standard adult numeric rating

or visual analog scale to self-report their pain

Question 13

Children under 8 years of age pain assessment

Answer 13

Behavioral or physiologic measures are available
for younger ages and for developmentally disabled
children

Question 14

Acetaminophen (paracetamol)

Answer 14

very commonly used in
pediatric patients, alone or in combination with other analgesics. It is often administered rectally in the perioperative period in infants or children for whom oral intake is not an option

Question 15

Acetaminophen (paracetamol) side effect

Answer 15

Dose-dependent hepatotoxicity is the most serious acute side effect of acetaminophen
administration.

Question 16

intramuscular, and rectal NSAID administration in pediatric surgical patients demonstrate

Answer 16

reduced postoperative

pain scores and decreased supplemental analgesic requirements.

Question 17

Adverse Effects of NSAID

Answer 17

Bleeding, renal damage, and gastritis are
more likely to occur with prolonged administration and in
the presence of coexisting disease.

Question 18

Why are Acetaminophen and NSAIDs given in

combination?

Answer 18

they work by different mechanisms and

their toxicity does not appear to be additive.

Question 19

Aspirin is not used for postoperative pain management in

infants and children because

Answer 19

highly significant association

with Reye syndrome

Question 20

Reye syndrome

Answer 20

acute, fulminant,and potentially fatal hepatoencephalopathy that
occurs in children with influenza-like illness or varicella
who ingest aspirin-containing medications

Question 21

Acetaminophen*

oral

Answer 21

10–15 mg/kg

Question 22

Acetaminophen*†

rectal

Answer 22

35-40 mg/kg loading dose;

20 mg/kg thereafter

Question 23

Ibuprofen

Answer 23

6–10 mg/kg

Question 24

Naproxen

Answer 24

5–6 mg/kg

Question 25

Ketorolac

Answer 25

0.3–0.5 mg/kg IV

Question 26

Tramadol

Answer 26

1–2 mg/kg

Question 27

Codeine (Oral)

Answer 27

dose of 0.5 to 1 mg/kg and
often in combination with acetaminophen for mild to moderate
pain

Question 28

Morphine

Answer 28

0.3 mg/kg

Question 29

Hydrocodone

Answer 29

0.1–0.2mg/kg

Question 30

Oxycodone

Answer 30

0.1–0.2mg/kg

Question 31

Hydromorphone

Answer 31

0.04–0.08mg/kg

Question 32

Methadone

Answer 32

0.1–0.2mg/kg

Question 33

Patient-Controlled Analgesia

Morphine

Answer 33

Loading dose (over 1–5 min): 0.05–0.20 mg/kg
Demand dose: 0.01–0.02 mg/kg
Lockout time: 5–15 min
1-hr limit (optional): 0.10–0.20 mg/kg
Continuous infusion (optional): 0.01–0.02 mg/kg/hr

Question 34

Patient-Controlled Analgesia

Hydromorphone

Answer 34

Loading dose (over 1–5 min): 1–4 mg/kg
Demand dose: 2–3 mg/kg
Lockout time: 5–15 min
1-hr limit (optional): 30–40 mg/kg
Continuous infusion (optional):2–3 mg/kg/hr

Question 35

Patient-Controlled Analgesia

Fentanyl

Answer 35

Loading dose (over 1–5 min): 0.5–2.0 mg/kg
Demand dose: 0.2–0.4 mg/kg
Lockout time: 5–15 min
1-hr limit (optional): 3–4 mg/kg
Continuous infusion (optional): 0.2–0.4 mg/kg/hr

Question 36

parent- or nurse-assisted epidural analgesia

Answer 36

used to optimize dosing flexibility and pain

relief given via the epidural route.

Question 37

Compared to adults given morphine, neonates and premature infants have

Answer 37

a longer elimination
half-life, lower plasma clearance, and marked interindividual variability in plasma morphine concentration. For a given dose, they will achieve a higher plasma concentration
for a longer duration.

Question 38

“SINGLE-SHOT” CAUDALS indications

Answer 38

SSC is
used in infants and children up to approximately 10 to
12 years of age having surgery from lumbosacral to midthoracic
dermatome levels with anticipated moderate
postoperative pain.

Question 39

“SINGLE-SHOT” CAUDALS medications

Answer 39

Bupivacaine in concentrations of 0.125% to 0.25% is the most commonly used and studied
local anesthetic for SSC. Injection volumes of 0.5 to
1.5 ml/kg will provide upper-lumbar to low-thoracic levels,
respectively. An upper volume limit of 20 ml is generally
used. The maximum recommended bupivacaine dose is 2.5 to 3.0 mg/kg, with an upper limit of 1.25 mg/kg
recommended in early infancy

Question 40

“SINGLE-SHOT” CAUDALS

test dose

Answer 40

0.1 ml/kg (maximum 3 ml) of local anesthetic with 1:200,000 epinephrine (5 mg/kg) is used to ensure correct needle or catheter position. A 25% increase in T-wave amplitude, 10-beat/min increase in heart rate, or 10% increase in systolic blood pressure within 60 s of administration is
considered a positive test dose.

Question 41

additives to prolong the duration and/

or density of analgesia

Answer 41

bupivacaine can be combined

epidurally with fentanyl, morphine, the a-2-adrenergic agonist clonidine

Question 42

Pediatric Epidural Dosing

Bupivacaine

Answer 42

Initial Bolus: <0.4–0.5 mg/kg/hr

Question 43

Pediatric Epidural Dosing

Ropivacaine

Answer 43

Initial Bolus < 0.4–0.5 mg/kg/hr

Question 44

Pediatric Epidural Dosing

Fentanyl

Answer 44

Initial Bolus: 1–2 mcg/kg
Infusion Solution: 2–5 mcg/ml
Infusion Limits: 0.5–2 mg/kg/hr

Question 45

Pediatric Epidural Dosing

Morphine

Answer 45

Initial Bolus: 10–30 mcg/kg
Infusion Solution: 5–10 mcg/ml
Infusion Limits: 1–5 mcg/kg/hr

Question 46

Pediatric Epidural Dosing

Hydromorphone

Answer 46

Initial Bolus: 2–6 mcg/kg
Infusion Solution: 2–5 mcg/ml
Infusion Limits: 1–2.5 mcg/kg/hr

Question 47

Pediatric Epidural Dosing

Clonidine

Answer 47

Initial Bolus: 1–2 mcg/kg
Infusion Solution: 0.5–1 mcg/ml
Infusion Limits: 0.1–0.5 mcg/kg/hr

Question 48

Lower infusion
rates are generally recommended in neonates and infants
less than 3 to 6 months old because

Answer 48

lower protein binding and consequently higher free fractions of drug, and because of pharmacokinetic differences potentially resulting in higher plasma levels and prolonged drug
half-life.

Question 49

As a rule, optimal analgesia is obtained with

the catheter tip positioned

Answer 49

at or near the dermatomes to
be blocked. It is possible in infants and smaller children to
thread caudally inserted catheters to lumbar or thoracic
levels