Neonatal II Flashcards
Most neonates with esophageal atresia also have:
Tracheoesophageal Fistula
What is the most common type of TEF?
C
What percentage of neonates with TEF suffer from other congenital anomalies?
50-70%
What congenital anomalies are associated with tracheoesophageal fistulas?
VACTERL
What percentage of neonates with esophageal atresia also have a cardiac defect?
20%
What type of induction is ideal for neonates with TEF?
An induction that maintains spontaneous breathing and avoids positive pressure
Where should an ETT be placed if the neonate has TEF?
Below the fistula but above the carina
What are risk factors for neonatal RDS?
Maternal Diabetes
Intubation
Oxygen toxicity
Prematurity
SGA
Barotrauma
How is an amniocentesis used to assess fetal lung maturity?
Allows comparison between Lecithin (surfactant) to Sphingomyelin (the precursor to surfactant)
What L/S ratio is reassuring?
> 2 suggests adequate lung development
Where is a preductal SpO2 measured?
RUE
Where is a postductal SpO2 measured?
Lower extremity
If an arterial line is required for a neonate, what artery is preferred?
A preductal one
A wide gradient between pre and post ductal SpO2 suggests:
pHTN
R-to-L shunt
Return to fetal circulation via the PDA
Where do diaphragmatic hernias usually occur?
Foramen of Bochdalek (usually left)
What are the three possible sites for diaphragmatic hernia?
Foramen of Bochdalek (posterolateral)
Foramen of Morgagni (Parasternal)
Around the esophagus (paraesophageal)
In a neonate with a diaphragmatic hernia, PIP should be kept less than:
25-30
After diagnosis, how long is surgical repair of a diaphragmatic hernia delayed?
5-15 days to optimize
What are three things that must be avoided in the neonate with a diaphragmatic hernia?
Hypoxia
Acidosis
Hypothermia
What’s the difference between gastroschisis and omphalocele?
How does pyloric stenosis present?
Palpable olive-shaped mass just below the xiphoid
Non-bilious projectile vomiting
When does pyloric stenosis occur?
the first 2-12 weeks of life
Is pyloric stenosis more common in males or females?
Males
What bolus and maintenance fluid should be used in a neonate with pyloric stenosis?
Bolus: 20ml/kg NS
Maintenance: D5 1/2 NS at 1.5x the normal maintenance rate
What is the most common complication after surgical repair of a pyloric stenosis?
Postop apnea, because the CSF remains alkalotic longer than serum, so their respiratory drive is suppressed
How does pyloric stenosis impact neonatal urine?
Initially, alkalotic because it’s wasting bicarb
Late stage, acidotic, because dehydration is so bad it’s excreting H to retain Na
What are the two biggest risk factors for NEC?
Low birthweight
Prematurity
What is the most likely cause of NEC?
Early feeding
Which regions of the bowel are affected by NEC?
Terminal Ileum
Proximal Colon
When is retinal maturation complete?
Up to 44 WGA
Which anesthetics have been shown to cause apoptosis in animal models?
Any drug that:
1. Antagonizes NMDA
2. Agonizes GABA
Which anesthetic does not seem to cause apoptosis?
Precedex, Opioids, Xenon
Bilirubin is a byproduct of:
RBC breakdown
How is bilirubin metabolized?
Glucuronyl Transferase. This pathway isn’t mature until a week or so
What is kernicterus?
Fetal encephalopathy from bilirubin
The umbilical vein carries:
oxygenated blood TOWARD the fetus
The umbilical arteries carry:
Deoxygenated blood AWAY from the fetus
The Ductus Venosus shunts blood from:
The umbilical vein to the IVC, bypassing the liver
The Ductus Arteriosus shunts blood from:
The pulmonary artery to the aorta, bypassing the lungs
In the fetus, SVR is (low/high) and PVR is (low/high)
SVR is low
PVR is high
What causes the ductus arteriosus to close?
a decrease in PGE1, which is produced by the placenta
A PDA causes what kind of murmur?
Continuous murmur, throughout systole and diastole
When does the ductus venosus anatomically close?
Cord clamping
When does the foramen ovale anatomically close?
About three days
What does the DA become in adults?
Ligamentum Arteriosum
What is the calculation for PVR?
What is the calculation for SVR?
Does light anesthesia increase or decrease PVR?
Increases
Does hypothermia increase or decrease PVR?
Increase
Does anemia increase or decrease PVR?
Decrease, because hemodilution reduces viscosity
Does atelectasis increase or decrease PVR?
Increase
What are the cyanotic defects?
What are the acyanotic defects?
Will a neonate with Tetralogy of Fallot have a faster or slower inhalation induction?
Slower
Any cyanotic defect decreases flow through the lungs, which will slow down induction
Which inhalational induction agents will be MOST effected by a cyanotic heart defect?
The more insoluble, the more they’ll be delayed
Nitrous and Des will be most effected, Iso will be least
Will a neonate with truncus arteriosus have a faster or slower IV induction?
Faster, because the anesthetic is bypassing the lungs (cyanotic) and entering the VRG group faster
What are the hemodynamic goals with cyanotic defects?
What are the hemodynamic goals with acyanotic heart defects?
Will an acyanotic heart defect prolong or shorten an inhalation induction?
Shouldn’t have any effect
Will an acyanotic heart defect prolong or shorten an IV induction?
Maybe prolong, but not by a whole lot
What is Eisenmenger’s Syndrome?
A patient with a L-to-R (acyanotic) shunt develops pulmonary HTN, and the defect converts to a R-to-L shunt (cyanotic)
What is Ebstein’s Anomaly?
The tricuspid leaflets are further down toward the apex, resulting in a tiny RV and a massive RA
What is Ebstein’s Anomaly a cyanotic heart defect?
Because it occurs with an ASD about 50% of the time, and since the pressure is higher than normal because of the TV abnormality, blood shunts from R to L
Trisomy 21 is associated with what heart defects?
ASD, VSD, PDA
Turner syndrome is associated with what heart defects?
Coarctation of the Aorta
Maternal infection with Rubella is associated with what defect?
PDA and VSD
Maternal diabetes increases the risk of what defect?
VSD
How does a PFO differ from an ASD?
An ASD is a straight up hole, and it allows blood to flow from L to R according to pressure
A PFO allows is a channel that allows clots to flow from R to L when a clot blocks flow from the RA to the RV
What is the most common sign of R sided heart failure in infants?
It’s usually JUST hepatomegaly. They rarely have pedal edema or JVD
What is the most common cyanotic heart defect?
Tetralogy of Fallot
What are the four defects of ToF?
- RVOT obstruction
- RV Hypertrophy
- VSD
- Overriding Aorta (receives blood from both ventricles)
What precipitates a Tet Spell?
SNS activation: pooping, crying, pain, agitation etc.
Just like with HOCM, any increase in contractility increases RVOT obstruction
What do children squat when they’re having a tet spell?
It increases preload -> increases RV pressure -> decreases RVOT obstruction
What is the treatment for a perioperative Tet Spell?
100% FiO2
IVF to increase preload
Increase SVR (pressors)
Reduce contractility (deepen anesthesia or give esmolol)
Avoid inotropes
Avoid high airway pressures
Put the child in knee-chest position
What are the hemodynamic goals for a patient with ToF?
What is the best induction agent for a ToF patient?
Ketamine (the increase in contractility is lower than the increase in SVR)
Which narcotics should be avoided in patients with ToF?
Any drug that releases histamine should be avoided, because histamine reduces SVR:
Morphine and meperidine, atracurium
Do babies with ToF tend to be anemic or polycythemic?
Polycythemic, because of chronic hypoxia
Would you expect to see a R or L axis deviation on the ECG of a neonate with ToF?
R, because of RV hypertrophy
