Pediatric Anesthesia Flashcards
What are the most common syndromes associate with Pierre Robin Sequence?
The most common syndromes associated with PRS are:
- Stickler syndrome
- Velocardiofacial syndrome
- Treacher-Collins Syndrome
What physical characteristics define Pierre Robin Sequence (PRS)?
PRS is a collection of:
- Micrognathia
- Glossoptosis
- Cleft palate
- Laryngomalacia
- Hearing loss
- Airway obstruction
What is the advantage of using a circle breathing system vs. a non-rebreathing system in pediatrics?
Circle systems conserve heat and humidity better, which is an advantage in caring for small neonates prone to hypothermia.
What is the advantage of using a non-rebreathing system vs. a circle system in pediatrics?
Non-rebreathing circuits have no valves, which decrease the work of breathing as well as the partial-pressure of inhaled agents increase faster in non-rebreathing circuits since the total volume of the circuit is less compared to a circle system.
At what spinal level does the glottis lye in the pediatric population?
Full-term neonate: C4
Premature baby: C3
What happens to pulmonary vascular resistance (PVR) in a neonate at birth?
Lung expansion decreases the PVR, which results in physiologic closure of the ductus arteriosis.
What are the exclusion criteria for infants presenting for outpatient surgery?
< 56 weeks post conceptual age and < 32 weeks post gestation when born
or
< 54 weeks post conceptual age and < 35 weeks post gestation when born
Cause of epiglottitis and signs and symptoms?
It is caused by Haemophilus influenza type B
Signs and symptoms include: high fever, child leaning forward and drooling
What acid/base derangement will you expect to see in a patient with pyloric stenosis?
Hyponatremic, hypochloremic, hypokalemic metabolic alkalosis with alkalotic urine
possibly compensated by a respiratory acidosis
What are the common metabolic and physiological abnormalities seen in premature babies?
1) Hyperkalmia - due to immaturity/dysfunction of the kidneys, metabolic acidosis, and a low urine output due to a low systemic blood flow
2) Hypothermia - due to their higher surface area to volume ratio
3) Hypocalcemia
4) PT is usually 10% longer due to an immature liver (this normalizes within the first week of life
What is the most common congenital neural tube defect?
Meningomyelocele, which results when the neural tube fails to close in the fourth week of gestation
What is the P50 of an infant?
Leftward shift = 19 mmHg
What metabolic abnormalities is a premature infant prone to?
Hyperkalemia - due to immature or dysfunctional kidneys, metabolic acidosis and a low urine output due to low systemic blood flow.
Hypothermia - due to higher surface area to volume ratio
Hypocalcemia - can present as unexplained hypotension, irritability, and seizures
Prolonged PT - due to immature liver, PT is usually 10% longer
Which congenital anterior abdominal wall defect (gastroschisis vs. omphalocele) is NOT associated with other congenital anomalies?
Gastroschisis
What percentage of a preterm infant’s body is composed of water? vs. term infants? by 6 months old?
85% of their total body weight vs 75% water in a term infant
6 month olds’ bodies are composed of 60% water
How long may patients exhibit bronchial hyperactivity after a URI?
Up to 7 weeks after his/her symptoms have resolved
What are the blood volumes for a premature infant vs. a full term infant vs. 3-12 month old child vs. a child > 1 year old?
Premature infant = 100 mL/kg
Full term infant = 90 mL/kg
3-12 month old chid = 80 mL/kg
> 1 year old child = 70 mL/kg
How is the maximal allowable blood loss (MABL) volume calculated?
MABL = estimated blood volume (EBV) x [(starting Hct - target Hct) / starting Hct]
What are the characteristics of Fetal Hydantoin Syndrome?
It is characterized by growth deficiency, microcephaly, and mental retardation.
How does the chronic use of barbiturates by pregnant women effect the fetus?
Transient coagulation abnormalities which can be treated with vitamin K
LMA sizes (according to weight)
LMA #1 = < 5kg LMA #1.5 = 5-10 kg LMA #2 = 10-20 kg LMA #2.5 = 20-30 kg LMA #3 = 30-50 kg
What age range of children benefit the most for having parental presence in the OR?
Ages 1 to 6 years of age
At what age does separation anxiety become an issue?
Around 8 months of age
What are patients with spina bifida at an increase risk of?
Latex allergy Club foot Hip dislocation Scoliosis Leg weakness Paralysis Bladder and bowel incontinence Frequent UTIs Hydrocephalus
What are the characteristics of a patient with pyloric stenosis?
It is a condition that typically affects MALE babies in the first 2-6 WEEKS of life.
NON-BILIOUS VOMITING and FAILURE TO THRIVE
What patients are advised to receive antibiotic prophylaxis prior to dental procedures?
- Children with prosthetic cardiac valves or prosthetic material used in the valve repair
- Children with unrepaired TOF or other cyanotic lesions (are at the greatest risk for developing infective endocarditis)
[Patients with MVP are no longer recommended to receive antibiotic prophylaxis. Also, children who had their PDA ligated or ASD sutured do NOT require antibiotic prophylaxis.]
Describe the Fontan Procedure and what is used for?
The Fontan procedure involves anastomosing the RA appendage to the PA, allowing better blood flow to the pulmonary circulation.
Tricuspid atresia
What plateau pressures should be maintained in patients with ARDS?
Pressure should be maintained at or below 30 cm H2O
In utero, when does coordinated swallowing begin?
Early in the 2nd trimester
From what embryologic structure does the pharynx, esophagus, stomach, and first part of the duodenum derive?
The Foregut
At what point does a fetus’ GI tract become functional and is able to excrete waste products?
From 9 weeks to 40 weeks post conception, the GI tract become rudimentarily functional and is able to excrete waste products.
What artery supplies the midgut?
The omphalomenteric artery
What electrolyte abnormality are preterm infants at high risk of?
HYPOcalcemia
Signs/symptoms:
- twitching
- irritability
- seizures
What is the equation to determine appropriate ETT size?
(Age in years/4) + 4 = size of uncuffed ETT
The appropriate size for a cuffed ETT is 0.5mm smaller than the calculated uncuffed size.
Describe epigastric omphaloceles vs. hypogastric omphaloceles
- Epigastric omphaloceles are highly associated with congenital heart diseases as well as thoracic defects
- Hypogastric omphaloceles are associated with exstrophy of the bladder and genital malformations
Describe the incidence and findings associated with congenital diaphragmatic hernia (CDH).
The incidence is 1 in 4000, making quite rare
~40-50% of these patients do NOT survive despite treatment
9 out of 10 times, it occurs on the left side
The ventilatory goals is to maintain the O2 sat >90% and permissive hypercapnia is helpful in maintaining respiratory drive with a goal PaCO2 of 60-65 mmHg
Patients with cystic fibrosis need pre-op evaluation assessing what organ function?
Coagulation studies can help gauge the extent of liver pathology
Following a Tonsillectomy, at what time period is a patient at greatest risk for postoperative bleeding?
Up to 6 hours
What happens to hemoglobin levels at the age of 2-3 months?
A physiologic anemia takes place with a Hgb level of ~ 10-12 g/dL.
After the 3 month mark, the Hgb value consistently increases
How can hydralazine used to treat preeclampsia, effect a neonate?
Hydralazine can cause thrombocytopenia and Lupus-like syndrome in neonates
How can HOCM in the pediatric population be treated?
Occlusion of the 1st septal penetrating artery (a branch of the LAD)
What is the dose of epinephrine required to identify intravascular injection for pediatric regional anesthesia during inhaled anesthesia?
0.5 and 0.75 mcg/kg of epinephrine in infants > 3 months
By what age does an infant’s elimination half-life of morphine decrease to adult values?
2 - 3 months of age
What is the typical pediatric dosing of methadone?
A bolus of 0.1 - 0.2 mg/kg followed by 0.05 mg/kg every 6-8 hours
What is the most appropriate medication in treating cardiac lesions where systemic oxygen delivery is dependent on ductus flow?
e.g. interrupted aortic arch
Prostaglandin E1, which maintains ductal patency (connecting the PA to the proximal descending aorta)
What are the side effects of prostaglandin E1?
Apnea
Hypotension
Fever
What dermatomes are covered with a caudal block consisting of 1 mL/kg of local anesthetic in a neonate/infant?
It will provide a sensory block from S5 to T10
What are the risk factors for PONV in the pediatric population?
Eberhart’s classification:
- family history of PONV
- duration of anesthesia
- age > 3 yrs
- strabismus surgery
At what level is the dural sac located in a neonate?
The dural sac in the neonate can extend to S 3-4 (until age 1 year, where it is at the adult level of S2)
