perfusion: alterations in pediatric cardiovascular function Flashcards
FETAL CIRCULATION STRUCTURES
- 1 umbilical vein , 2 umbilical arteries
- foramen ovale
- ductus arteriosus
- ductus venosus
CHANGES AT BIRTH
- umbilical cord cut= increase systemic vascular resistance
- increased blood and pressure in LA and LV causes foramen ovale to close
- ductus arteriosis constricts and closes in 10-15 hours after birth
A&P OF PEDIATRIC DIFFERENCES
- infants have increased metabolic and oxygen demands, so HR increases to maintain high cardiac output
- infants at increased risk for heart failure because heart is more sensitive to fluid overload
- muscle fibers of heart less developed
ANATOMOY AND PHYSIOLOGY OF PEDIATRIC DIFFERENCES
- decreased compliance- ventricles do not expand well
- stroke volume cannot increase much
- heart fully developed age 5 yrs
- ventricles same size at birth ,but by 2months of age LV is twice size of RV
CHD:ETIOLOGY
- defect in heart or great vessels
- persistence of fetal structure after birth
- most develop in first 8wks of gestation
- caused by exposure to drugs ,alcohol , secondary smoke
ETIOLOGY : CHD
- maternal metabolic disorders( hypercalcemia,DM,phenylketonuria)
- advanced maternal age, maternal viral infection (rubella,coxsackle
- genetic factors
- chromosomal abnormalities- sydromes :turner, down, digeorge, marfan
CLASSIFICATION OF CHD
- increased pulmonary blood flow
- decreased pulmonary blood flow
- obstructed systemic blood flow
- mixed defects
INCREASED PULMONARY BLOOD FLOW DEFECTS
- abnormal connection between two sides of heart
- blood shunts from left to right
- if untreated , pulmonary overcirculation leads to RV hypertrophy, CHF, pulmonary HTN, and eventually death
DEFECTS THAT INCREASED PULMONARY BLOOD FLOW
- patent ductus arteriosus PDA
- atrial septal defect ASD
- ventricular septal defect VSD
- atrioventricular can defect AV CANAL
CLINICAL MANIFESTATIONS
- tires during feeding
- poor weight gain
- tachypnea, tachycardia
- murmur
- CHF
- diaphoresis
- periorbital edema
- freq. resp infections
- crackles
- cardiomegaly
PDA : PATENT DUCTUS ARTERIOSUS
- fetal ductus arteriosus does not close
- common in preterm infants
- blood shunted from the aorta to the PAs and lungs
- may close spontaneously
- IV indomethacin or ibuprofen -10 -14 days of life
- can be closed during cardiac cath with coils and other devices, surgical ligation
- prognosis is god
ASD
- small or large opening in atrial septum
- closure: spontaneous , transcatherter device in cath lab, or surgery - age 4 to 5 years
- prognosis good is ASD is closed
- untreated adults - CHF,pulmonary HTN,atrial arrhythmias
VSD
- opening in ventricular septum
- increased PVR and RV enlargement with large VSD
Clinical closure therapy
-small VSD- may close spontaneously
surgery - patch
closure in cath lab
prognosis- highest risk if repair needed in first few months of life : good prognosis for older children
AV CANAL
- ASD+ VSD +tricuspid and mitral valve defects
- blood moves freely among the 4 chambers
- associated with down syndrome
-severity of symptoms depends on degree of mitral valve regurgitation
- repair: surgical -done in infancy
- may need O2 until surgery
- prognosis: mitral valve insufficiency and arrhythmias are common
NURSING MANGNAGMENT
pre op
-family education, psychosocial support
post op
monitor for complications, impaired perfusion, arrhythmias, infections
- heart sound -bradycardia ,irregular HR
- pulse ox , cap refill, LOC, urine output, pedal pulses
- monitor vital signs , inspect incision site
- assess respiratory system, breath sounds signs of distress , pneumonia
- pain assessment
- manage fluids and nutrition
NURSING MANAGEMENT
- maintain oxygenantion and myocardial function
- administer and monitor prescribed medications
- promote rest
- foster development
- provide adequate nutrition
- provide emotional support
- discharge planning and teaching
OUTCOMES OF NURSING CARE
- the child’s pain is effectively managed
- full lung expansion is achieved with spirometry exercises or chest physiotherapy
- incision heals without infection
CLINICAL THERAPY FOR CHF
GOAL: make heart work more efficiently and remove excess fluid
Diuretics: remove accumulated fluid and sodium
-monitor potassium
ACE inhibitors- lessen workload of heart by decreasing peripheral vascular resistance
-Iomotropics
Digoxin- improves contractility and increases cardiac output
Hold dig for ?
CLINICAL THERAPY FOR CHF
beta blockers
- improves cardiac function
- propananolol, carvedilol
oxygen
-improve tissue oxygenation
surgery or cardiac catheterization to correct CHD
supportive treatment - rest , fluid and dietary management