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.
WHAT ARE ACYANOTIC SHUNT LESIONS?
FETAL OPENINGS STAY OPEN AFTER BIRTH. BLOOD SHUNTS LEFT TO RIGHT. MOST COMMON ARE ASD, VSD, AND PDA.
WHAT DOES THE AMOUNT OF SHUNTING DEPEND ON?
- SIZE OF THE LESION
- RELATIVE RESISTANCES OF THE SYSTEM AND PULMONARY CIRCULATION
- ABILITY TO MANIPULATE PVR TO CONTROL SHUNT
WHAT ARE S/S OF PDA AND MANAGEMENT?
S/S: WIDENED PULSE PRESSURE! B/C LOW VOL BLOOD IN SYSTEMIC CIRC COMPARED TO THE LARGE AMT THAT GOES TO LUNGS. ISCHEMIC BODY PARTS. MOSTLY IN PREMIES B/C THEY HAVE HYPOXIA.
TX: INDOMETHACIN…AN NSAID THAT INHIBITS PROSTAGLANDIN. IF INDO IS CONTRAINDICATED D/T KIDNEY FAILURE OF IVH THEY GO TO OR.
HOW DO YOU KEEP A LESION LIKE PDA OPEN AND WHY WOULD YOU WANT TO?
KEEP OPEN WITH PROSTAGLANDIN INFUSION .05 MCG/KG/MIN.
PDA’S ARE SOMETIMES PRESENT IN COMBO WITH OTHER CARDIAC LESIONS THAT ARE INCOMPATIBLE WITH LIFE. SO THE THE PDA MUST REMAIN OPEN TO MIX BLOOD UNTIL THE DEFECT CAN BE REPAIRED.
WHAT IS THE MOST COMMON CONGENITAL HEART DEFECT?
VSD.
WHAT IS ANESTHETIC MANAGEMENT OF LEFT TO RIGHT LESIONS? THESE ARE ACYANOTIC LESIONS WITH INCREASED PULM BLOOD FLOW, INCREASED RIGHT HEART PRESSURES.
AVOID MI DEPRESSION/AVOID PROPOFOL…..USE HIGH NARCOTIC TECH. AVOID AIR BUBBLES IN LINES. MAINTAIN PVR TO AVOID INCREASING LEFT TO RIGHT SHUNT..SO….AVOID HYPERVENTILATION, 100% O2. SLOW VENTILATION TO KEEP CO2 HIGH NORMAL. ISO IS OK.
IN WHICH TYPE OF SHUNT/LESION IS INHALATION INDUCTION FASTER AND WHY?
IN A LEFT TO RIGHT SHUNT (ACYANOTIC LESION)B/C MORE BLOOD IS GOING TO LUNGS.
THE OPPOSITE IS TRUE FOR CYANOTIC LESIONS.
WHAT ARE CYANOTIC LESIONS?
BLOOD FLOWS FROM RIGHT TO LEFT. MORE BLOOD GOES TO SYSTEM THAN LUNGS SO LOTS OF UNOXYGENATED BLOOD IS BEING CIRCULATED. SO YOU WANT TO MANIPULATE PVR SO THAT QP=QS. 1:1 KEEP THE DUCT OPEN.
MAJOR ONES ARE SINGLE VENT, TOF, TGA, EISENMENGER.
WHAT ARE THE 4 MAIN ANATOMICAL DEFECTS IN TOF?
- LARGE UNRESTRICTED VSD( BLOOD FLOWING FREELY BTW VENT)
- ANY FLOW TO LUNGS IS OBSTRUCTED (RVOT?)
- OVERRIDING AORTA
4 RIGHT VENT HYPERTROPHY
WHAT ARE TOF S/S? BLUE VERSUS PINK TETS?
BLUE: RVOT OBSTRUCTION SO EXTREME CYANOSIS….PROFOUND RIGHT TO LEFT SHUNT.
PINK TETS: MINIMAL RVOT OBSTRUCTION SO NO CYANOSIS. A NET LEFT TO RIGHT SHUNT.
WHAT IS A TET SPELL?
INFUNDIBULAR SPASM WITH AN ACUTE DECREASE IN PULM BLOOD FLOW WHICH SHUNTS DESATURATED BLOOD INTO THE SYSTEMIC CIRCULATION.
CAUSE: CRYING, POOPING, AGITATION, INJURY, FRIGHT.
PRECIPITATED BY ACUTE FALL IN SVR (INDUCTION)
WORSENS CYANOSIS: ANEMIA, ACIDOSIS, INFECTION, STRESS AND POSTURE
TX FOR TET SPELL?
PULMONARY VASODILATION TO IMPROVE AMOUNT OF BLOOD BEING OXYGENATED. 100% O2. B-BLOCKERS TO REDUCE SPASMS. SEDATION TO REDUCE RESPONSE TO TIM OF SURGERY. MORPHINE TO DILATE PULM ART. FLUID TO INCREASE PRELOAD. NEO (ABDOMINAL COMPRESSION) TO INCREASE SVR, REROUTES MORE BLOOD TO PULM ART. CORRECT ACIDOSIS. SQUATTING/LEGS UP TO INCREASE SVR.
WHAT DO YOU AVOID WITH TOF?
INCR HR, INCREASED CONTRACTILITY, DEHYDRATION.
HYPOVOLEMIA, HYPOTENSION.
ULTIMATELY YOU WANT TO INCREASE PRELOAD, INCREASE SVR RELATIVE TO PVR, AND INCREASE DIASTOLIC FILLING TIME.
WHAT IS TRANSPORTATION OF THE GREAT ARTERIES? TGA.
PULMONARY AND SYSTEMIC CIRCULATION ARE SEPARATE AND PARALLEL. VENOUS BLOOD IS RECIRULATED TO RV AND AORTA IS NOT OXYGENATED. SURVIVAL DEPENDS ON MIXING VIA VSD ASD OR PDA….SO THEY WILL BE ON PROSTAGLANDIN GTT. THEY WILL UNDERGO ARTERIAL SWITCH OPERATION TO PUT VESSELS WHERE THEY BELONG.
WHAT IS EISENMENGERS SYNDROME?
AN UNREPAIRED LEFT TO RIGHT ACYANOTIC CARDIAC SHUNT (ASD, VSD, PDA) CAUSES IRREVERSIBLE PULM. VASCULAR DISEASE CAUSING PVR > SVR SO THAT SHUNT CHANGES DIRECTION AND BECOMES RIGHT TO LEFT SHUNT (CYANOTIC LESION).
WHAT IS HYPOPLASTIC LEFT HEART SYNDROME? HLHS. AKA SINGLE VENTRICLE. ?
A SMALL USELESS LEFT VENTRICLE. BLOOD FLOW DEPENDENT ON PATENT PDA…THEYLL BE ON PROSTAGLANDIN GTT. RIGHT VENTRICLE IS MAJORLY OVERLOADED. THEY WILL GET A HEART TRANSPLANT, A NORWOOD PROCEDURE, OR DIE.
WHAT IS GOAL OF STAGE 1 NORWOOD PROCEDURE?
CREATE PULMONARY BLOOD FLOW WITH BLALOCK TAUSSIG (BT) SHUNT!
A NEW AORTA IS CREATED SO RIGHT VENT PROVIDES SYSTEMIC BLOOD FLOW. BT SHUNT FOR PBF, AND A COMMON ATRIUM (HOLE) IS CREATED.
WHAT ARE ANESTHESIA CONSIDERATIONS FOR A NORWOOD 1?
AVOID HIGH FIO2 AND DECREASED CO2. B/C EXCESSIVE PULMONARY VASODILATION CAN STEAL FROM SYSTEMIC CIRCULATION AND CORONARIES RESULTING IN MI AND DEATH.
WHAT IS THE GOAL OF STAGE 2 NORWOOD DONE AT 4-6 MONTHS?
PARTIALLY SEPARATE RED AND BLUE BLOOD.
BT SHUNT TAKEN DOWN. SVC CONNECTED TO RPA.
WHATS THE GOAL OF STAGE 3 NORWOOD?
COMPLETELY SEPARATE RED AND BLUE BLOOD.
WHAT CHILDREN SHOULD BE REFERRED TO TERTIARY CARE FACILITY?
- SINGLE VENTRICLE
- UNREPAIRED CYANOTIC CHD
- REPAIRED CHD WITH POOR VENT FXN.
