Prodigy- Neonatal Anesthesia Flashcards
Approximately what % of oxygenated blood from the placenta is shunted to the IVC and RA via the ductus venosus
35-50%
Blood in the left atrium of the fetus has an o2 sat of what?
65-70%
*the highest seen in fetal ciruclation
is pulm vascular resistance high or low in the fetus
extremely high
due to alveolar collapse and compression of blood vessels and the low PaO2 and pH of the blood entering the pulmonary system
Because of the high PAP in the fetus, approximately 90% of blood is shunted where?
into the descending aorta via the ductus arteriosus
What do the neonatal cardiac myocytes relay primarily on?
the diffusion of calcium through the sarcolema
T/F- sympathetic innervation reaches maturity by early infancy
True
before that, parasympathetic innervation to the heart is dominate
T/F- the SV is fixed in the neonate
true- CO is dependent on HR
During neonatal transition to extrauterine ciruclation, there is a(n) increase/decrease in pulm vasc resistance and a increase/decrease in pulmonary blood flow
significant decrease in PVR
marked increase in pulmonary blood flow
Normal tidal volume of an infant
~ 6-8ml/kg (same as an adult)
will an infant have a faster or slower inhalational induction than an adult- why or why not
why do they desat faster?
faster inhaltional induction
-FRC same + minute ventilation double
^ same
T/F Periodic breathing (clusters of respirations followed by periods of apnea that last 5-10 seconds) are common in the neonate
True
*can last thrhough the first year of life
Baby has a gamma subunit instead of epislon at the NMJ; what significance does this have? (In terms of how it opens)
the NMJ channel is open for a longer period of time, allowing more sodium to enter the cell
→ increased sensitivity to ACH
→increased sensitivty to NDMRs
T/F- infants have increased sensitivity to ACH
what about NDMRs
true
same
Neuromuscular transmission normally reaches maturity by what age?
2 months
prior to this, reserves of ACH in the NMJ are decresed, which can be observed with performing tetanic stimulation
At term, the GFR of a neonate is only about what % of the normal adult rate?
30%
GFR = 3 letters, 30%
why might you want to use cistatracurium in an infant <1 yo?
bc GFR doesn’t mature until infant is about 1yo so using drugs that arent dependent on kidneys for excretion and useful
avoid PCN and gent - or use cautioiuslly
Primary means of maintaining body heat in the neonate
non-shivering thermogenesis
*norepi-mediated mechanism
Infant heat loss occurs (rank from highest to lowest):
evaporation, radiation, conduction, convection
- radiation
- convection
- evaporation
- conduction
3 main changes in body composition in the neonate that affect the pharmacokinetics/dynamics of drugs
- increase total body water
- decrease body fat
- decrease muscle
Weight-based loading doses for (water/lipid) soluable drugs are higher for infants to achieve the same target concentration in the bloodstream
3 examples
water-soluble
dig, aminoglycosides, sux
because of the neonates lower muscle mass, drugs whose termination of action depdends on redistribution into the muscle tissue may have a (higher/lower) initial peak plasma concentration and (shorter/longer) DOA
higher initial peak and longer DOA
Why do neonates exhibit a greater propensity for the development of methemoglobinemia?
due to decreased levels of methemoglobin reductase
Doses of fentanyl between what dose range have been associated with chest wall rigidity, resulting in the need for mechanical ventilation to treat hypoventilation
1-2mcg/kg
onset and duration of IM sux
2 mins onset
DOA 20 mins
How does Vecuronium differ in the neonate?
in the adult it’s considered intermediate-acting
in the neonate, it’s considering to be long-acting bc its hepatic metabolism is limited by immature hepatic function in the neonates (+active metabolites of VOH3 or something)
Low birth weight
Very low birth weight
Extremetly low birth weight (ELBW)
Low birth weight→ <2500g
Very low birth weight→ <1500g
Extremetly low birth weight (ELBW) → < 1000g
Which requires placement of a smaller ETT: subglottic stenosis, tracheal stenosis, both, or neither
subglottic stenosis
*narrowing of the airway BELOW the vocal cords and above the trachea at the level of the cricoid
*tracheal stenosis does NOT necessitate a smaller ETT but airway resistance is increased distal to the ETT
with tracheal stenosis, is airway resistance increased distal or proximale to the ETT
distal
T/F- the premature neonates heart is less compliant and less sensitive to catecholamines
true
in a neonate with a PDA, increased pulmonary vascular resistance will (increase/decrease) the right to left shunt
increase
What are of the brain is at most risk for damage in the micro-preemie?
the peri-ventricular white matter
ovehead lamps decrease what kind of heat loss
radiant (#1 cause of heat loss)
T/F- overhead lamps are the most effective method for preventing heat loss
false - **FORCED AIR WARMER **
forced air warmers use what kind of heat transfer to warm the patient
convection
convection oven- forced air warmer
What is the micro-preemie at risk, especially during laparotomy for NEC?
spontaenous liver hemorrhage
T/F- thrmobcytopenia (<150,000) occurs in 10% of micro-preemies
false- 70%
if hyperglycemia occurs in the neonate, should you decrease the dextrose containing infusion or give insulin
decrease rate of infusion
- dont risk hypoglycemia with insulin
premature infants are more susceptible to brain damage from even mild hypoglycemia
1st intervention of neonate becomes bradycardic
PPV
Following removal of the amnion of an omphalocele, large amounts of fluid may excude. Issue?
it’s ECF and should be replaced with a blanced salt solution
during repair of a TEF, the ETT should be advanced intentionally into the right mainstem bronchus and then slowly withdrawn until the first point at which breath sounds are heard in both lung fields. How should hte bevel of the tube be rotated after that?
rotate so that it faces anteriorly to prevent ventilation of the fistula
What is myelomeningocele?
A cystic mass on the back- typically in the lumbar or sacral area that contains CSF, arachonid, dura, and nerve tissue.
“When neural contents protrude through a defect in the neural tube “
*prevented with folic acid
2 main concerns with myelomeningocele?
- development of hydrocephalus that will require shunt placement (80% of cases)
- high incidence of latex allergy
What is the most common surgical emergency in neonates?
Necrotizing Enterocolitis
T/F- although spinal anesthesia is associated with a decreased risk of apnea in the premature ifant in the early phase following surgery, it does NOT decrease the overall risk of apnea across the entire postop period
True
First sign of a total spinal in neonates
apnea
*NOT HYPOTENSION bc sympathetic innervatio nis not fully developed in noenates
Postop analgesia common dosing:
Acetaminophen
Ibuprofen
Hydrocodone
Acetaminophen→ 10-15mg/kg
Ibuprofen → 5-10mg/kg
Hydrocodone →0.1 mg/kg
Acetaminophen typically provides pain relief for how long?
4 hours
When referring to a premature infant, the term low birth weight indicates a birth weight less than
A. 3000 grams
B. 1500 grams
C. 2500 grams
D. 4000 grams
C
The neonatal response to hypoxia is typically a short period of _____ followed by _____.
A. hypoventilation, hyperventilation
B. hypertension, hypotension
C. hypotension, hypertension
D. hyperventilation, hypoventilation
D
What is the intravenous induction dose of ketamine for a neonate?
A. 0.5 mg/kg
B. 10 mg/kg
C. 5 mg/kg
D. 2 mg/kg
D
Possible causes of this include
A. increased PaCO2
B. intracerebral infection
C. hypovolemia
D. hydrocephalus
C
Which opioid would be most appropriate for intraoperative use in a preterm neonate undergoing a prolonged surgical procedure?
A. Meperidine
B. Remifentanil
C. Morphine
D. Nalbuphine
B
The hepatic function of pediatric patients is approximately equal to that of adults by what age?
A. 1 month old
B. adolescence
C. 3 years old
D. 1 year old
Not D
The ability of newborns to metabolize amide local anesthetics is underdeveloped until about _____ of age.
A. one week
B. three years
C. one year
D. three months
Not C
An infant undergoing surgery for necrotizing enterocolitis is in the ICU but not yet intubated. Which induction method would you anticipate being the most appropriate in this patient?
A. desflurane inhalation induction
B. high-dose opioid IV induction
C. propofol IV induction
D. ketamine IV induction
Not A or B
Conditions dictate that you must use succinylcholine for intubation of a neonate. What dose of intravenous succinylcholine would be appropriate for a patient this age?
A. 0.5-1 mg/kg
B. 5-10 mg/kg
C. 3-4 mg/kg
D. 1-2 mg/kg
C
During repair of a tracheoesophageal fistula,
A. the endotracheal tube should be positioned 4-6 cm above the carina
B. the precordial stethoscope should be positioned over the right side of the chest
C. the bevel of the endotracheal tube should face anteriorly after it is passed through the cords
D. You should intubate the patient with an endotracheal tube 1 size larger than usual
C
Which of the following would be an acceptable intramuscular induction dose of ketamine in a 50 kg patient?
A. 200 mg
B. 800 mg
C. 600 mg
D. 400 mg
D
A neonate is undergoing surgical repair of a myelomeningocele. You know that this patient has a high incidence of adverse reaction to
A. latex
B. succinylcholine
C. preoperative antibiotics
D. fentanyl
A
Subglottic stenosis is narrowing of the
A. nasopharyngeal passages
B. vocal cords
C. airway at the cricoid cartilage level
D. trachea
C
The alveoli and pulmonary vasculature are not mature enough to produce acceptable gas exchange until about _____ weeks gestation.
A. 30 to 32
B. 24 to 26
C. 36 to 38
D. 12 to 16
Not C … so prob A
laparotomy for necrotizing enterocolitis. The patient is hypotensive and has a potassium of 5.6 mEq/L. Which of the following would be an appropriate part of your induction regimen?
A. Succinylcholine
B. High-dose propofol
C. High-dose midazolam
D. High-dose rocuronium
D
Which of the following should take priority in your airway management plan for a pediatric patient with bronchopulmonary dysplasia?
A. Administer diuretics preventively to reduce the chances of pulmonary edema
B. Choose an endotracheal tube that has an internal diameter 0.5-1.0 smaller than normal
C. Administer oxygen in a concentration sufficient to produce a PaO2 of 140-150 mmHg
D. Perform an awake intubation
B
You are performing anesthesia for a micro-preemie undergoing laparotomy for necrotizing enterocolitis. You know that this patient is at significant risk for spontaneous
A. systole
B. intracranial hemorrhage
C. pneumothorax
D. liver hemorrhage
D
A neonate exhibits fade on tetanic stimulation even though no neuromuscular relaxants have been administered. You know that this is most likely
A. diagnostic of Becker muscular dystrophy
B. diagnostic of Duchenne muscular dystrophy
C. normal
D. diagnostic of myasthenia gravis
C
The ductus arteriosus connects the
A. pulmonary artery to the aorta
B. left atrium to the right atrium
C. left ventricle to the right ventricle
D. left atrium to the right ventricle
A
You are preparing to induce anesthesia on a neonate with a right-to-left shunt. All of the following factors will increase the degree of shunt except
A. hypoxia
B. decreased pulmonary vascular resistance
C. acidosis
D. hypothermia
B
Approximately 30-50% of the oxygenated blood from the placenta is shunted into the inferior vena cava and right atrium via the _____.
A. ductus venosus
B. ductus arteriosus
C. portal vein
D. foramen ovale
A
In utero meconium aspiration during the third trimester is most associated with
A. fetal hypoxia
B. myelomeningocele
C. Trisomy 21
D. maternal diabetes
A
Bupivacaine binds heavily to
A. alpha-fetoprotein
B. alpha-1 acid glycoprotein
C. hemoglobin
D. gamma globulin
B
