Test 3 Flashcards
Children have _____ protein binding compared to adults
Lower
Pediatrics have ______ volume of distribution
Results in what adjustment to water soluble drugs
Larger Vd
Larger loading dose of water soluble
4 ways children pharmacokinetics differ from adults
- lower protein binding
- larger volume of distribution
- smaller proportion of fat and muscle
- immature renal and hepatic function
Lipid soluble drugs have ______ volume of distribution in infant compared with adult
Smaller
What drugs have larger volume of distribution in infant compared with adult?
What have smaller Vd?
Larger Vd- water soluble drugs
Smaller Vd- lipid soluble
Some medications may displace bilirubin from protein binding site predisposing infant to
Kernicterus
2 reasons why neonate require a higher dose of succinylcholine compared to adults
Larger volume of distribution
NM junction in neonates are immature (more resistant)
Neonates require how much succinylcholine on body weight basis than older children/adults
Twice as much
Neonates and nondepolarizing NMB
Neonates are more sensitive to NDNMR
Mechanism of neonates requiring same dose of nondepolarizers as adults on weight basis
- greater sensitivity
- greater Vd
Balances out
Sensitivity of human neonates to most sedatives, hypnotics, and narcotics is partly related to
Increased brain permeability
Immature BBB
Also incomplete myelination
Incomplete myelination in infants results in
Easier for drugs that are not lipid soluble to enter brain at greater rate than if BBB intact
3 reasons volatile concentration increases more rapidly in alveoli in children than adults
- high level alveolar ventilation in relation to FRC
- higher proportion of vessel-rich tissues that rapidly equilibrate with blood levels
- lower BGP of volatile in infants
Excretion/recovery of inhaled anesthetics is ______ in children than adults
Faster
Quick on- Quick off
Why should N20 be avoided in laparoscopic surgery?
Avoid expanding CO2 bubbles that reach venous circulation
To speed up induction and emergence with volatiles do what
N20
Second gas effect
Examples of gas filled cavities within the body that are vulnerable for expansion if N20 is used (5)
Bowel obstruction
Pneumothorax
Cuff of ETT
LMA
Bubbles in veins
Factor identified in causing retinopathy of prematurity
Hyperoxia
Retinopathy of prematurity occurs in infants weighing ______
Or __________ weeks gestation
Less than 1500gm
Less than 28 weeks gestation
It is recommended to blend air with 02 to maintain sat _______
90-95%
However while avoiding hyperoxia, one must not lose sight of importance of _____________
Avoiding hypoxemia
Check for negative Hcg before any medication to girl who has reached
12 years of age
Or younger if post-menses
Why isoflurane not appropriate for inhalation induction
Pungent odor
Irritates airway reflexes (causes laryngospasm, breath-holding, coughing, etc)
Rapid increase of Iso concentration effects on CV profile
Decreased BP, HR, RR
Especially with hypovolemia
Iso and des react with desiccated soda lime or baralyme to release
Carbon monoxide into breathing circuit
Why Desflurane not suitable for inhalation induction
Very pungent odor
Irritant to airway
Emergence from des
Very rapid
May cause delirium if pain present especially
Risk of emergence delirium is increased when
If pain not well controlled
High levels of sevo given throughout the case
Dissociated state of consciousness in which children are inconsolable, irritable, uncompromising, and/or uncooperative
Emergence delirium
Highest incidence of emergence delirium occurs in children of what age
1-5 years of age
Appropriate________ often attenuated emergence delerium
Pain relief
Sevo hydrolyzed to _______ in presence of soda lime/baralyme
Compound A (potentially nephrotoxic)
Triggers for malignant hyperthermia
All potent volatile anesthetics
Succinylcholine
Why did FDA issue black box warning against routine use of succinylcholine in children
Several case reports of
- hyperkalemic cardiac arrest
Esp in children with undiagnosed duchenne muscular dystrophy
Duchenne muscular dystrophy more common in
Male children under 8 years old
Use of succinylcholine in peds should be reserved for
Emergency intubation
Laryngospasm
When to avoid succinylcholine in children
- eye trauma (increases IOP)
- burns
- massive trauma
- major neurologic disease
- renal failure compounded by neuropathy
Single dose of succinylcholine can cause _____ in children
Prevention
Bradycardia and asystole
Tx. Atropine 10-20mcg/kg IV or 20-40mcg/kg IM before succ
Infusion rate for propofol in children compared to adults
Higher in children
Neonates are __________ sensitive to barbiturates due to
More sensitive
Reduced protein binding
Contraindicated in patients with porphyria
Barbiturates
Barbiturates should be administered with extreme care in patients which are
Hypovolemic
Limited cardiac reserve
Reduces IOP and ICP
Thiopental
Good for neurosurgical and ocular procedures
Hypersalivation with ketamine increases risk of
Laryngospasm
Give antisialagogue
Why ketamine not used for neuro or eye cases
Increases CBF, ICP, CMRO2, IOP, nystagmus movement
Ketamine has high incidence of emergence phenomena (hallucinations, bad dreams, frank psychosis)
How do you prevent
Midazolam intraop
Dexmedetomidine is selective A2 agonist
Why good for sg
Decreases sympathetic tone
Attenuates stress response to anesthesia and surgery
Causes sedation and analgesia
Steroid based hypnotic induction agent
Etomidate
Why Etomidate mostly avoided
- risk of anaphylactoid reaction
- suppression of adrenal function
- inhibition of steroid synthesis
Patient population Etomidate is useful
Head injury
Unstable CV status (cardiomyopathy)
Fentanyl is ______ lipid soluble
Effect on BBB
Highly lipid soluble
Crosses BBB rapidly
Dilaudid peds prep and administration
Dilute 1 mg in 10ml syringe (100mcg/ml)
Initial dose 10mcg/kg
Titrated 5-10mcg/kg during case
Hydromorphone is not appropriate for
Infants and children <2 yo
Morphine and neonates and infants
Ventilatory depressant effects more in neonates and infants
Ventilatory depressant effect of morphine on neonates and infants due to
Increased permeability of BBB
Less predictable clearance of morphine
Adverse effects of morphine
Histamine release causes hypotension, sedation, PONV
Sufentanil not appropriate for
Infants and small children for same day surgery with planned discharge home
Adverse effects of sufentanil
Respiratory depression
Chest wall rigidity
Remi should be continuous infusion only
If bolus see
Severe bradycardia and hypotension
S/S widrawal
Crying
Hyperactivity
Fever
Tremors
Poor feeding
Poor sleeping
Extreme cases:vomiting and convulsions
Primary indication for methadone in children
Wean from long-term opioid infusions
Prevent withdrawal
Provide analgesia when other opioids have failed
Methadone protein binding
Main determinant of free factor of methadone
60-90%
Alpha 1- acid glycoprotein
Methadone in children
Large Vd
High plasma clearance
Long half life
Midazolam enhances what type of amnesia
Antegrade
Analgesic and antipyretic drug without anti-inflammatory actions
Acetaminophen
NSAID with very potent analgesic properties
Ketorolac
Ketorolac avoided in
Children <2
Caution with toradol in what patients
Renal (reduced renal BF)
Asthmatics (allergic reaction)
Major concern with toradol
Inhibition of platelet function through inhibition of cyclooxygenase
Difference in ASA and Toradol on platelet inhibition
Toradol platelet inhibition is reversible
Gone when drug excreted
Toradol in TB syringe
Each ml has ______mg
3MG
Narcan prep
Dilute a vial (0.4mg/ml) in 10cc syringe
40mcg/ml
Side effects of Narcan
Systemic HTN
Cardiac arrhythmia (VF)
Noncardiogenic pulmonary edema
Specific GABA receptor competitive antagonist
Flumazenil
Flumazenil reverses effects of
Benzodiazepines
Which more sensitive to Roc neonates or infants
Neonates
Elimination of Cisatracurium
Hoffman elimination and ester hydrolysis
Nondepolarizer NMB are prolonged with
Tobramycin
Neomycin
Gentamicin
Hypothermia
Because some Down syndrome children have ________ administer atropine cautiously
Narrow angle glaucoma
Used for prophylaxis and treatment of PONC and reduce severity of established NV
Zofran
Children < ______ dont require antiemetic in general
24 months of age