Peds Flashcards
Most of the blood bypasses fetal liver via the _____ and mixes w/ deoxygenated blood in inferior vena cava
Ductus venosus
Why is blood shunted away from fetal lungs?
High resistance
Connects pulm artery to aorta
Ductus arteriosus
Fetal circulation
Umb vein > ductus venosus > IVC > RA > LA (through foremen ovale) > LV > aorta > body
What closes ductus arteriosus? What helps close PDA?
Increase in O2 from respiration and decrease in prostaglandins d/t placental separation; Indomethacin
Keep PDA open
Prostaglandins E1 & E2
Fetal PaCO2? PaO2?
PaCO2 = 48; PaO2 = 30 (+10 if mom on 100% O2)
Pulm resistance increases in:
Hypoxia, hypercarbia, & hypothermia
Large VSD cause:
PHTN, growth failure, CHF, infection
Large ASD
SOB, hyper dynamic pericardium, RV heave, systolic ejection murmur, fixed splitting of S2, paradoxical embolism
I corrected VSD, ASD, or PDA leads to PHTN. Increased pulm resistance causes shunt to reverse from L>R to R>L causing late cyanosis (clubbing & polycythemia)
Eisenmenger’s Syndrome
Blood flows from aorta to pulm artery. Additional blood is deoxygenated in lungs & returns to LA & LV -> increased work load -> LVH.
PDA
PDA tx
Surgical ligation. COX1 & 2 inhibitors & indomethacin “medical ligation”
A difference of ___ in pulse ox suggests marked pulmonary HTN w/ PDA
10%
4 features of Tetralogy of Fallot
- Pulm stenosis (RV outflow obstruction);
- Overriding aorta (comes from LV and RV);
- Large VSD;
- RV hypertrophy
Most common CHD causing cyanosis
TOF
RV outflow obstruction + VSD result in
Ejection of mixed blood into aorta
The _____ infusion will keep PDA open allowing mixed blood to circulate to lungs to get more oxygenated
PGE1
How does squatting help with TOF
Increases SVR & aortic pressure, which decreases R -> L shunt so lungs can get more blood. -> increase arterial O2 sat
TET spells
Hypercyanotic & hypoxic spells. PO2 < 50 mmHg during feeding or crying. Unresponsive to supplemental O2
TOF physical findings
RV heave, harsh systolic ejection murmur, boot shaped heart on X-ray, right axis deviation/RVH
Conditions that increase R -> L shunt
Increase PVR or decrease SVR, acidosis, hypercardbia, hypotension
TOF surgery
Blalock-Taussing shunt (connects subclavian artery to pulm artery “creating duct”, more blood to lungs);
Closing VSD;
Resecting obstruction
Foramen of Bochdalek or Morgagni
Gut herniates into thorax in diaphragm
Most common type of tracheoesophageal fistula
Type IIIB
3C’s with tracheoesophageal fistula
Cyanosis, choking, coughing with feeding
Other defects with tracheoesophageal fistula (VATER syndrome)
Vertebral defect, Anal atresia, TE fistula, Esophageal atresia, Radial dysplasia
Why avoid LR with pyloric stenosis?
Met alkalosis and LR is metabolized to bicarb by liver
Anesthetic considerations for pyloric stenosis
Fix fluid & lytes first, suction/high risk aspiration, high risk resp depression d/t prolonged alkalosis, awake intubation and rapid induction, UO 1-2ml/kg/hr
Anesthetic considerations for acute epiglottitis
Lateral neck X-ray to determine extent of obstructions, prepare for trach, avoid laryngoscope, inhalation induction in sitting position, intubation with smaller size tube
Steeple sign on AP neck film. Strider improves with aerosolized racemic epi
Croup
Thumbprint sign on lateral neck film
Epiglottitis
Subglottic narrowing
Tracheitis
Cleft palate, small face and glottis
Pierre-robin syndrome
Small lower jaw, absent or malformed ear, more severe
Treacher-collins syndrome
1:5000; persistence of herniating of abd contents into umbilical cord, covered w/ peritoneum.
Occurs at base of umbilicus;
Have hernia sac; associated w/ Down syndrome & increased maternal a-fetoprotein
Omphalocele
1:15000; failure of lateral body folds to fuse -> extrusion of abd contents through abd folds.
Does NOT have hernia sac
Gastroschisis
Staged closure of omphalocele and gastroschisis if:
Intragastric pressure > 20 cmH2O;
Peak inspiratory pressure > 35 cmH2O;
ETCO2 > 50 mmHg
Bowel compartment syndrome may:
Impair ventilation, obstruct venous return, impair renal functions, high mortality
Telescoping of bowel segment into itself. MCC of bowel obstruction in first 2 yrs. Colicky pain, vomiting, blood in stool, “current jelly stool”, sausage shape mass
Intussuception
Hereditary dz of exocrine glands of lungs and GIT. Result form a defect in Cl channels caused by mutation
Cystic fibrosis
Diagnosis CF by
Sweat chloride test
Clinical presentation of CF
Increased Residual volume, increased airway resistance, decreased vital capacity, decreased expiratory flow rate
Making a hole for drainage of any fluid in middle ear cavity
Myringotomy
Is N2O safe during myringotomy?
Yes d/t short duration (10-15 min)
Duchenne Muscular Dystrophy is x-linked disorder d/t deficiency of _____ - a cytoskeletal protein (like glue)
Dystrophin
Fetal deposition of bilirubin in basal ganglia w/ bilirubin > 20mg/dl
Kernicterus
If ______ bilirubin is elevated, check blood smear for hemolysis
Indirect
If ______ bilirubin is elevated, check liver enzymes
Direct
Murmur associated with PDA
Continuous (systolic & diastolic) murmur “machinery”
Omphalocele is a/w?
Down syndrome & increased maternal a-fetoprotein
Midsystolic harsh blowing murmur
VSD
