Exam 4: Pediatric Pharmacology (lecture 1) - Becky M.

Question 1

PK

Is absorption & distribution increased or decreased in neonates?

Answer 1

Increased

d/t higher CO

Question 2

PK

What is the CO for a neonate?

Answer 2

400mL/kg/min

Question 3

PK

What is the CO for an infant?

Answer 3

200 mL/kg/min

Question 4

PK

What is the CO for an adolescent?

Answer 4

100 mL/kg/min

Question 5

PK

Why is elimination decreased in pedi pts?

Answer 5

• immature metabolic pathways
• immature kidneys (GFR & tubular Fx)

Question 6

PK

When does the CYP450 pathway mature?

Answer 6

~3 mos

Question 7

PK

T/F: Unprotein bound lipophilic molecules do not cross the BBB.

Answer 7

False, they do cross

Question 8

PK

What drug class can cross the BBB in neonates & cause seizures?

Answer 8

Local Anesthetics

Question 9

PK - body composition

Infants have:
________ TBW compensation.
________ ECF compartment.
________ ICF.

Answer 9

• greater
• larger
• decreased

Question 10

PK - body composition

T/F: There is a larger Vd for water-soluble drugs

Answer 10

True
Ex: NMBDs

Question 11

PK - body composition

Why do lipid-soluble drugs have a longer clinical effect?

Answer 11

• neonates have lower fat stores → more sensitive to lipophilic drugs

Question 12

PK - body composition

Why do neonates have more free “PB drugs”?

Answer 12

• they have lower protein stores

Question 13

PD

What changes w/ nicotinic cholinergic receptors are present in neonates?

Answer 13

• they remain open a lot longer
• neonate more resistant to NMBD
• reduction in Ach Release (sensitivity to ND NMBDs)

Question 14

PD

Why do neonates experience ↑ resp depression w/ opioids?

Answer 14

• changes in # & affinity of Mu and Kappa Receptors

Question 15

PD

How many GABA receptors do neonates have?

Answer 15

about 1/3 of adults

Question 16

PD

What is an explanation for why MAC is ↓ for neonates but ↑ at ~1mo old?

Answer 16

• 1/2 of the GABA Rs have a high affinity for Bzd binding or other anesthetics

Question 17

PD

Why do neonates have rapid equilibration of inhalation agents?

Answer 17

• ↑ Vm & CO
• ↓ distribution, amount of adipose tissue,
  and ↓ muscles mass

Question 18

PD - Inhalation agents

Why do neonates have more CV side effects w/ inhalation agents?

Answer 18

1. rapid equilibration & recovery
2. bradycardia & cardiac collapse (structural & functional immaturity of the heart)
3. big volume of anesthetic (8% sevo)

Question 19

PD - Inhalation Agents

How does a L→ R shunt affect uptake of inhalation agents?

R→L shunt?

Answer 19

• minimal increase in uptake w/ L to R
• decrease in uptake w/ R to L

Question 20

PD - Inhalation Agents

When does MAC peak at its highest level?

Answer 20

2-3 months old

Question 21

Inhalation Agents

What is the MAC for Sevo @ 0 days to 6 months?

Answer 21

3.2%

Question 22

Inhalation Agents

What is the MAC of Sevo in 6 mos - 1 yr?

Answer 22

2.5%

Question 23

Inhalation Agents

When would using Nitrous Oxide be useful?

Answer 23

• Older, cooperative kids inhalation induction
• 2nd gas effect w/ Sevo!
• decreases time in stage 2

Question 24

IV Anesthetics

Why do infants have a prolonged DOA w/ IV anesthetics?

Answer 24

• less fat & muscle
• immature liver & kidneys

Question 25

# IV anesthetics Why do infants have prolonged CNS effects w/ IV anesthetics?

Answer 25

* Immature BBB * brain has higher stores of fat (lipophilic drugs)

Question 26

# IV Anesthetics Why do pedi patients require larger doses of **propofol?**

Answer 26

* ↑ metabolic rate & Vd * Redistribution ↑ to VRG - gets there faster

Question 27

What is the ED50 of propofol for loss of eyelash reflexes in 1-6 month olds?

Answer 27

3 mg/kg

Question 28

What is the ED50 of propofol for loss of eyelash reflexes in 1-12 yr olds?

Answer 28

1.3-1.6 mg/kg

Question 29

What is the ED50 of propofol for loss of eyelash reflexes in 10-16yr olds?

Answer 29

2.4 mg/kg

Question 30

# IV Anesthetics What is a medication that can be used to pre-med older kids w/ developmental delay that are uncooperative?

Answer 30

Ketamine * IV, IM, PO, IN, rectal

Question 31

# IV Anesthetics Why do children require higher doses of Ketamine?

Answer 31

Greater clearance | * neonates have lower clearance (need less)

Question 32

# IV Anesthetics What other medication should be administered w/ Ketamine?

Answer 32

Anti-sialogogue - prevents laryngospasm d/t ↑ secretions

Question 33

# IV anesthetics What is the induction dose of Ketamine?

Answer 33

1-3 mg/kg

Question 34

# IV anesthetics Why is Ketamine good for unstable pediatric patients?

Answer 34

Has less CV & respiratory depression

Question 35

# IV Anesthetics What are big SE of Etomidate?

Answer 35

* anaphylactoid reactions * adrenal suppression (corticosteroid supplementation may be needed) * *minimal CV suppression*

Question 36

# IV anesthetics Etomidate dose:

Answer 36

0.2-0.3 mg/kg

Question 37

# IV Anesthetics Precedex is used for ________ sedation. What is it similar to?

Answer 37

* procedural sedation * similar to natural sleep | **reduces incidence of emergence delirium**

Question 38

# IV Anesthetics What is the dose for pre-med precedex? Peak effect?

Answer 38

1-2 mcg/kg 30-40 min peak

Question 39

# Opioids What is the morphine dose? Why do neonates/infants need less?

Answer 39

* 0.05-0.1 mg/kg * respiratory depressant effects

Question 40

# Opioids What opioid has a risk of Histamine release?

Answer 40

morphine | **hx of anaphylaxis/allergies = issue?**

Question 41

# Opioids How much Codeine is metabolized to morphine?

Answer 41

10%

Question 42

# Opioids What is the BB warning w/ Codeine?

Answer 42

* caution use in children after tonsillectomy * ultra-metabolizers (profound resp. depression)

Question 43

# Opioids What is the dose of fentanyl?

Answer 43

0.5-2 mg/kg

Question 44

# Opioids Do neonates clear remifentanil slower or quicker than older children?

Answer 44

Quicker | *can cause bradycardia*

Question 45

# NMBD Why do pedi pts have a longer DOA of NMBD?

Answer 45

* reduced clearance * immature NMJ * increased sensitivity

Question 46

# NMBD Is the NMJ more sensitive to Depolarizing NMBD or ND NMBD?

Answer 46

**sensitive to both** * more sensitive to ND NMBD

Question 47

# NMBDs What is the dose of IV Succ for infants? Children?

Answer 47

**2x higher in infants** * infants: 2mg/kg * children: 1mg/kg

Question 48

# NMBDs What is the IM Succ dose in neonates/infants? > 6 months?

Answer 48

Neonates/infants: 5mg/kg >6 months: 4mg/kg

Question 49

# NMBDs Why does Succinylcholine have a longer DOA in neonates?

Answer 49

less plasma cholinesterase 6-10min DOA vs. 3-5min in older kids

Question 50

# NMBDs What is a SE of Succ?

Answer 50

Bradycardia **cardiac arrest after 1st dose, more common w/ repeated doses** | *give w/ atropine or glycopyrrolate*

Question 51

# NMBDs What is the BB warning for Succ? What pt population should we use it cautiously in?

Answer 51

* hyperkalemia/cardiac arrest * male children (Duchenne's muscular dystrophy like rxn)

Question 52

# NMBDs What is the only non-depolarizer that can be given IM?

Answer 52

Rocuronium

Question 53

# NMBD Reversal How can we assess revocery in pedi patients?

Answer 53

1. facial grimacing 2. elbow/hip flexion 3. knees to chest 4. spontaneous breathing 5. inspiratory force

Question 54

# NMBD reversal What are 2 anti-cholinesterase drugs used in reversal? What are the doses?

Answer 54

1. Neostigmine 0.05-0.07 mg/kg **glycopyrrolate** 2. Edrophonium 0.5-1.0 mg/kg **Atropine**

Question 55

# NMBD reversal What is the dose of Sugammadex? SE?

Answer 55

2-4 mg/kg bradycardia!!