Pediatric Anesthesia Flashcards
What associated abnormalities may be found in an infant with TEF/EA?
V: vertebral
A: anal
C: cardiac
T: TEF
E: esophageal atresia
R: renal and radial atresia
L: limb defects
What other condition is common in patients with a myelomeningocele?
hydrocephalus
What are the components of tetralogy of Fallot?
pulmonic stenosis
RVH
VSD
over-riding aorta
Roughly how much will transfusing a pediatric patient 4 mL/kg of pRBCs raise the Hgb?
1 g/dL
What should MAP be in neonates?
Roughly post-conceptual age
What is a normal HR in a neonate/toddler?
preterm: 150
term: 130
1-yr old: 120
toddler: 90
What is appoximate pediatric blood volume?
neonate: 90 mL/kg
infant: 80 mL/kg
toddler: 70 mL/kg
What is a normal blood gas immediately after birth?
pH: 7.20
PaO2: 50
PaCO2: 50
What is a normal umbilical venous blood gas? Umbilical arterial blood gas?
pH/PaO2/PaCO2
venous: 7.35/30/40
arterial: 7.30/20/50
When in fetal hemoglobin replaced with adult hemoglobin?
between 3 and 6 months of age
Describe the fetal circulation.
When does the ductus arteriosus usually close?
about 2 weeks of age
How can the PDA be maintained open in the setting of congenital heart disease?
prostaglandin E1 analogs (e.g., alprostadil)
Which part of the autonomic nervous system is more robust in neonates, sympathetic or parasympathetic?
parasympathetic
Why are neonates more likely to “tire out” than adults during periods of respiratory distress?
lower proportion of type I (e.g., fatigue-resistant) fibers in the diaphragm and intercostals
What is the position of the larynx in neonates vs. adults?
neonates: C4
adults: C6
How is hypoglycemia defined in the neonate?
< 30 mg/dL in the first 24 h
< 45 mg/dL after 24 h
*hypoglycemia should be corrected with a maximum concentration of D10 solution, not D25 or D50*
Where do the spinal cord and dural sac terminate in neonates vs. 1-year-olds?
Neonates: spinal cord at L3, dural sac at S4
1-year-olds: spinal cord at L1, dural sac at S2
What is bronchopulmonary dysplasia?
long-term sequelae of NRDS and mechanical ventilation of immature lungs
What lecithin/sphingomyelin ratio in amniotic fluid indicates fetal lung maturity?
L/S ratio of 2
To which classes of drugs are neonates more sensitive than adults?
opiates
benzodiazepines
barbiturates
*less sensitive to propofol and thiopental due to faster redistribution*
Why can neonates be given similar doses of non-depolarizing muscle relaxants to older children?
their larger hydrophilic compartment is balanced out by an increased sensitivity to these drugs
Why do neonates require a larger dose of succinylcholine than older children?
their larger hydrophilic compartment with similar sensitivity to the drug
How often is masseter muscle spasm after succinylcholine associated with malignant hyperthermia?
30% of the time
Where should the pulse oximeter be placed in a neonate?
pre-ductal (i.e., right arm) to assess lung function
What are the risk factors for retinopathy in neonates?
prematurity (most significant)
high oxygen tension
caucasian males
How does post-conceptual age affect surgical timing and post-op monitoring?
elective surgery should be delayed in patients < 50-60 weeks post-conceptual age
patients < 50-60 weeks post-conceptual age should be monitored for 12-24 hours post-op
What are the neonatal ALS guidelines for a nonvigorous infant born through thick meconium?
PPV with 30% FiO2
*NOT tracheal suctioning*
What is the heart rate cut-off for starting chest compressions in a non-vigorous newborn?
If HR < 60, start PPV with 30% FiO2 then chest compressions at 120/min
What is the recommended chest compression to ventilation ratio in neonatal ALS?
3:1
What is the dose of epinephrine in neonatal ALS if HR is persistently below 60?
0.01-0.03 mg/kg IV
*10-fold more if given transtracheally*
Is gastroschisis or omphalocele more commonly associated with other abnormalities?
omphalocele is commonly associated with other midline defects (GI, GU, and cardiac)
Where is the defect in gastroschisis vs. omphalocele?
gastroschisis is commonly to the right of the umbilicus
omphalocele is a midline defect at the umbilicus
What is the most commonly used vasopressor in the setting of NEC?
dopamine
How can an ETT be ideally placed for TEF repair?
Intentional mainstem intubation then pull back until breath sounds are heard bilaterally but not in the stomach
Why is PPV avoided in congenital diaphragmatic hernia?
high incidence of pneumothorax, particularly contralateral to the hernia
What is the early presenting ABG in pyloric stenosis?
hypokalemic hypochloremic metabolic alkalosis
*may progress to a hypokalemic, hypochloremic metabolic acidosis if hypovolemic shock ensues*
Why should opioids be avoided following pyloromyotomy?
the combination of decreased respiratory drive due to metabolic alkalosis and due to opioids could lead to respiratory failure
Why does phenyephrine imrpove both MAP and SaO2 in patients with tetralogy of Fallot?
Less R to L shunting through the VSD with increased systemic afterload
What are the 5 T’s of cyanotic heart disease?
1) truncus arteriorsus
2) transposition of the great arteries
3) tricuspid atresia
4) tetralogy of Fallot
5) total anomalous pulmonary venous return
What is the formula to estimate appropriate ETT size? Depth?
size: 4 + age/4
depth: 12 + age/2 or ETT size x3
What is the best treatment for post-intubation croup?
racemic epinephrine nebulizer
What are the principles of intubation for epiglottitis?
1) stay calm (crying makes it worse)
2) airway obstruction only gets worse
3) difficult airway equipment should be available
4) obstruction can occur if the epiglottis is manipulated
5) spontaneous ventilation is preferrable
What is the next step if you can’t intubate and can’t ventilate a patient with epiglottitis?
surgical airway
*LMA unlikely to be effective*
What is the most common cause of croup? Treatment?
H. influenza
racemic epi has immediate efficacy, steroids have delayed efficacy
At what Cobb angle does scoliosis become severe enough to cause cardiopulmonary problems?
60o
*restrictive lung disease and pulmonary HTN*
What are the airway concerns in a patient with a peritonsillar abscess?
1) complete airway obstruction
2) abscess rupture
Of the variable airway obstructions, which are extrathoracic, and which are intrathoracic?
Extrathoracic
larygomalacia
laryngeal polyps
epiglottitis
Intrathoracic
mediastinal mass
tracheomalacia
What are the classical difficult to intubate pediatric syndromes?
Pierre-Robin: micrognathia and cleft pallate, get easier with age
Treacher Collins: micrognathia and cleft pallate, get harder with age
Why might a patient with DiGeorge syndome be more prone to laryngospasm?
hypocalcemia due to hypoparathyroidism
What is the greatest anesthetic concern during craniosynostosis?
bleeding profusely from cerebral venous sinuses that lie below the suture lines
What is the landmark for a caudal block?
sacral hiatus
What pediatric condition(s) is associated with a higher risk of MH?
central core disease
King Denborough syndrome
multiminicore disease
*NOT Duchenne muscular dystrophy*
What are the initial steps in treating MH?
discontinue triggering agents
administer 2.5 mg/kg dantrolene
hyperventilate with 100% O2
Why should bicarbonate be given in MH?
to treat hyperkalemia and acidois
Why should mannitol be given in MH?
to increase UOP and avoid renal tubular obstruction from myoglobin
What is the most sensitive test for MH?
halothane-caffeine contracture test
*genetic testing for ryanodine receptor alleles is most specific*
Which drugs increase the triggering threshold for MH?
pancuronium
thiopental
