Pediatric Anesthesia pt1.2 Flashcards
(43 cards)
Opposing factors regarding NMBD distribution leads to what effect? (prolonged NACh-R opening, larger Vd for water-soluble drugs)
unpredictable response
Neonate nicotinic cholinergic receptors are affected how?
stay open for a lot longer than normal
How do GABA receptors differ in a neonate from an adult?
Neonates have about 1/3 GABA receptors as adults
Overall differences in pediatric pharmacology effects include:
- TBW composition differences
- Immature metabolic pathways
- reduced protein binding
- immature BBB
- Reduced GFR
- Immature receptor responses
Respiratory differences in pediatrics that can affect the effects of inhalational agents include:
- Smaller FRC
- Increased Vm
How do the effects of inhalational agents differ in neonates?
- Rapid equilibration
- Rapid induction and recovery
- More/faster CV side effects
How do shunts affect the uptake of inhalational agents?
- Left to right shunts: increase in uptake
- Right to left shunts: decrease in uptake (slower induction)
How does MAC differ from a neonate to an infant to an adult?
- Neonates (0-30days): lower MAC
- Infants(1-6mo): Higher MAC
- Adults: MAC lowers as age progresses
except for sevo
When does MAC of inhalational agents typically peak at its highest level?
Infants 2-3months
How does the MAC of Sevoflurane (ultane) differ from the MAC values of other volatile agents?
Sevo peaks earlier:
- Highest at 0days - 6 months (3.2%)
- 6mo - 12 years: MAC lowers but still higher than adult (2.5%)
What is the preferred agent for inhalational induction?
Sevoflurane (ultane)
- rapid onset
- least pungent volatile
Why is nitrous sometimes used with sevoflurane for inhalational induction in pediatrics?
2nd gas effect: increase the uptake of sevoflurane and allow for a more rapid onset (in theory)
What is the primary downside of using Nitrous?
- increased risk of PONV in adults
Why do infants and children generally have a rapid uptake and equilibrium from inhalation agents?
- greater Vm
- higher ratio of TV:FRC (from greater metabolic rate)
- Higher cardiac output
In the neonate, what causes a greater percentage of blood flow to the vessel-rich groups?
decreased distribution of adipose tissue and decreased muscle mass (less redistribution)
Why are myocardial depressant effects exaggerated from inhalational agents?
Structural and functional immaturity of the pediatric heart
What distributional effects are characterized with the use of IV anesthetics in pediatrics?
- higher cardiac output to vessel-rich tissues
- prolonged DOA
- prolonged CNS effects
lower redistribution to vessel poor groups
Increased metabolic rate and volume of distribution leads to what effects on the propofol dose requirements?
- requires larger dosages
How do the dosage requirements for the ED50 of propofol vary with different age groups?
- 1-6 mo: 3 mg/kg
- 1-12yr: 1.3 - 1.6 mg/kg
- 10-16yr: 2.4 mg/kg
What ketamine induction dose is typically required for children?
- Larger dose
- 1-2 mg/kg
neonates may need reduced dose
What effect from ketamine should warrant caution from the provider?
- ketamine can increase secretions and children have highly reactive airways ⇉ laryngospasm risk
- give ketamine with an antisialogogue
Why is use of etomidate limited in children?
- Concerns with anaphylactoid reactions
- adrenal suppression
dose relatively unchanged 0.3 mg/kg and does offer minimal CV suppression
What route and dose of precedex can beneficially be used in kids?
Intranasal for premedication
- 1-2 mcg/kg
- 30-40 min for peak effect
- minimal respiratory depression
- Decreased emergence delirium/agitation
Why might precedex be avoided?
- High dose may prolong recovery phase and lead to slower turnover times
