CONGENITAL HD Flashcards
WHAT IS NORM BLOOD FLOW IN UTERO?
OXYGENATED BLOOD IN THROUGH UMBILICAL VEIN—DUCTUS VENOSIS—-PFO——
DEOXYGENATED BLOOD FROM SVC—RA–RV—PULM ART TO AORTA VIA PDA…BYPASSES LUNGS. BACK TO PLACENTA VIA 2 UBILICAL ARTERIES.
WHAT ARE THE 3 NORMAL SHUNTS IN UTERO?
- DUCTUS VENOSUS. CONNECTS IVC TO SVC
- FORAMEN OVALE. CONNECTS R/L ATRIUM
- DUCTUS ARTERIOSUS. CONNECTS PULM ART TO DESCENDING AORTA.
WHEN SHOULD FETAL SHUNTS CLOSE ANATOMICALLY? FUNCTIONALLY THEY ALL CLOSE AT BIRTH EXCEPT PDA WHICH TAKES UP TO 12 HRS.
DV: DAYS
PDA: WEEKS
PFO: MONTHS
WHAT CHANGES IN BLOOD FLOW RESULT IN MATURE CIRCULATION AND CLOSURE OF FETAL SHUNTS?
FALL IN PULM. VR AND INCREASE IN PULM BLOOD FLOW. BLOOD IS ROUTED TO LUNGS. AND PRESSURE GRADIENT OF ATRIA REVERSES. L> R
WHAT IS TRANSITIONAL CIRCULATION?
TEMPORARY POST BIRTH WHERE PULM VR DROPS BUT THERE IS STILL A HIGH PAP. THIS CAUSES A SMALL AMOUNT OF SHUNT L TO R VIA PDA. THIS IS A LABILE STATE B/C FAILURE TO MAINTAIN LOW PVR CAN LEAD TO SHUNT OPENING AND REVERSION TO FETAL CIRCULATION. AS PVR FALLS FURTHER PDA CLOSES PERMANENTLY.
WHAT ARE FACTORS THAT FAVOR TRANSITION FROM FETAL TO MATURE CIRCULATION?
NORMAL O2 EXPANSION OF LUNGS NORMAL PH NITRIC OXIDE FOR VASODILATION PROSTACYCLINE A PULM VASODILATIOR
WHAT IS PROSTACYCLINE?
A LIPID KNOWN AS EICOSANOILS THAT INHIBITS PLT ACTIVATION AND IS A PULM VASODILATOR. ITS IMPORTANT FOR TRANSITIONING FROM FETAL TO MATURE CIRCULATION.
FACTORS THAT FAVOR REVERSION TO FETAL CIRCULATION?
LOW O2
ACIDOSIS HIGH CO2
LUNG COLLAPSE
INFLAMMATORY MEDIATORS
WHAT ARE THE 3 FACTORS THAT AFFECT VENTRICULAR PERFORMANCE.?
1 PRELOAD
2 AFTERLOAD
3. CONTRACTILITY
HOW IS THE MYOCARDIUM DIFFERENT IN THE NEWBORN?
ITS LESS COMPLIANT TO VOLUME SHIFTS…LESS RESPONSIVE TO BOLUSES B/C ITS LESS TOLERANT OF INCR AFTERLOAD AND LESS RESPONSIVE TO INCREASED PRELOAD.
- CO IS GREATLY AFFECTED BY HR!!!! FIXED SV.
- RESTING TENSION IS GREATER
- OPERATING NEAR TOP OF FRANK STARLING CURVE
WHAT ARE NORM HEART PRESSURES OF NEWBORN?
RA 25
PA 25/10
LV 100
AO 100/50
WHAT FACTORS INCREASE PVR AND CLOSE ROAD TO LUNGS?
HYPOXIA, HIGH CO2/ACIDOSIS, HYPERINFLATION (HIGH PEEP), SNS, HIGH HCT (VISCOUS BLOOD), ATELECTASIS, SURGICAL CONSTRICTION, KETAMINE.
WHAT ARE FACTORS THAT DECREASE PULM VR AND OPEN ROAD TO LUNGS?
OXYGEN ALKALOSIS LOW CO2 HYPOBARIC LOW HCT (LOW VISCOSITY) NITRIC OXIDE BLOCK SNS VIAGRA NORMAL FRC
WHAT ARE SYMPTOMS OF CHF IN NEWBORNS?
INABLE TO SUCK SWALLOW BREATH. LOW CO, INCREASED RESPIRATORY WORK, INCREASED METABOLIC WORK.
HOW DO YOU TREAT CHF IN NEWBORNS?
SAME AS ADULTS:
LOW DOSE IONOTROPES, AVOID TACHYCARDIA, VASODILATORS, DIURETICS.