Congenital Heart Disease Flashcards
Some of the most common signs to suggest a congenital heart disease?
Shortness of breath Increased work of breathing Tachypnea Cyanosis Shock Diaphoresis with feeding Dehydration
What questions do you want to ask mom when considering possibility of CHD?
Where was the child born? What do the parents already know? What information do they have? Have procedures already been done? What is normal for baby?
What physical exams should be done for suspected CHD?
Sick kid exam: ABC’s
Liver size: hints at CHF
Femoral pulses: coarctation
What are some of the first diagnostic tests done at bedside for CHD?
Pulse ox on right arm and left leg looking for discrepancy
Hyperoxia test with 100% non-rebreather
What is the treatment for all CHD patients? What is the dose and side effect?
PGE1 0.05–0.1 mcg/kg/min load then maintenance at 0.01 mcg/kg/min
Causes apnea in 10%–20% and may require intubation before transfer
Don’t hesitate to give PGE1 if CHD is suspected
Which of the CHD does not respond to PGE1?
TAPVR
What are the 3 major presentations of CHD?
Cyanosis, Shock, CHF
What are the CHD’s that cause CHF?
These lead to increased blood to the lungs
Coarctation, VSD, AS, AV canal
What exam findings suggest CHF?
Large liver, rales in the lungs, dehydration
4 week-old infant presents in respiratory distress. Lungs with rales and you note a large liver. What is the treatment?
PGE1
4 week-old infant presents in respiratory distress. Lungs with rales and you note a large liver. Mom says he has a pulmonary artery band. He is hypotensive. What do you do?
Start PGE 1
Consider giving a pressor:
Dopamine, Milrinone, Digoxin
Explain the dose dependent function of dopamine
Receptors D —> B —> A
Dopamine then Beta then Alpha effects
How does milrinone work?
PDE inhibitor leading to vasodilation and also + inotropy but without chronotropy
Good for CHF patients because of the inotropy and the vasodilation
What are the cyanotic CHD’s?
Five T's, or numbers 1–5 Truncus Transposition Tricuspid Tetralogy TAPVR
3Wk infant presents cyanotic, gray, hypotensive, hypoxic, breathing rapidly. What is first intervention and what to do if abnormal?
Hyperoxia test
Give PGE 1!
Kid has Hx of a corrective operation for CHD and presents with acute decompensation. What are two things to think of when treating this kid?
Dehydration and Thrombosis
Sometimes shunts are placed that have passive flow. Correcting dehydration and optimizing hemodynamics can sometimes fix the problem
Shunts can clot and Heparin at times must be considered
tPA can also be considered in critical situations
Describe how ductal dependent lesions can be affected by changes in flow caused by dehydration.
Flow across ductus is determined by pressure gradient between aorta and the pulmonary artery. When PVR drops, flow can reverse and divert away from the PA into the aorta and bypass the lungs leading to hypoxia. This will be corrected, not by more O2, but by increasing the PVR (maybe with a pressor, or just with hydration) and reverse the flow back into the PA and to the lungs
Describe how ductal dependent lesions can worsen clinically with increased supplemental O2, or decreased CO2, or alkalosis?
Flow across ductus is passive and dependent on pressure gradient between aorta and PA
They have chronic PHTN that is reversed when given O2, or hyperventilated causing decreased CO2 and alkalosis which will increase pulmonary flow and cause hypotension and shock
It may be necessary to hypoventilate and allow hypoxia in order to restore normal systemic flow of blood
What are three cardiac conditions where change in flow can cause issues between pulmonary and systemic circulation?
Ductal dependent lesions, Truncus, and Tetralogy
Describe change in flow in truncus arteriosis and how this changes with different insults
Blood flow to lungs and systemic is with the same pressure. If resistance in the lungs or the system change then flow to both will change.
Septic shock will decrease PVR and flow to the lungs will suffer and a pressor would be needed to correct the balance.
If PHTN is suddenly decreased by giving too much O2, then systemic shock can develop and iatrogenic hypoxia and hypercapnea are needed to restore systemic blood flow
Describe the flow patterns in tetralogy of fallot
Flow here is opposite to truncus
There is resistance to RV outflow and a VSD pushing blood to the systemic side. Blood gets to the lungs by ductus. There is at baseline too much blood going to the system and not to the lungs. These kids get in trouble when they are worked up and breath fast leading to increased systemic flow and decreased pulmonary flow. Squatting increases PVR which aids in pushing blood back to the lungs for oxygeniation.
What are some interventions to reverse a Tet spell?
Knees to chest to increase PVR
Phenylephrine
Esmolol to dilate pulmonary outflow
Morphine to relax the kid and the RV outflow tract which spasms, leading to the spell
What labs are helpful in kids with CHD and why?
O2 sat compared to their baseline
pH, lactate, H/H
If pH and lactate are normal, then the kid is likely at their baseline
Elevated H/H indicate a chronic condition
CHD kids have an increased risk of what catastrophic condition that often isn’t thought of in kids?
Stroke because of the abnormal flow patterns and the communication between left and right side of the heart
