Pediatric Cardiopulmonary PT Flashcards
When does the respiratory system develop?
Begins at the 4th week of gestation
Pseudoglandular period (weeks 6-16):
-lungs have developed except gas exchange
-diaphragm begins to form at end
Canalicular period (weeks 16-26):
-pulmonary capillaries develop
-bronchioles give rise to alveolar ducts
-lung tissue is vascularized and fetus is able to be born at end of this period
Cardiac Development
-the heart beats by day 22-23
-circulates blood to the rest of the embryo by day 27
-development is primarily complete by 10th week
Prenatal blood circulation (complex)
- well oxygenated blood travels from the placenta via the umbilical vein and enters the fetal system through the umbilicus
- 1/2 enters the liver and 1/2 bypasses the liver and drains into the IVC via the ductus venosus
- once in the IVC, blood joins with less oxygenated blood that is returning from the abdomen, pelvis, and lower limbs
- blood reaches the R atrium and the majority of it goes through the foramen ovale into the L atrium
- this blood is then pumped through the aorta to the heart, head, and upper limbs
What is the ductus venosus?
It connects the umbilical vein to the IVC to bring in oxygenated blood from the mother
-it is controlled by a sphincter
What is the foramen ovale?
Connection between the right and left atrium
-allows the blood to bypass the pulmonary system
What is the ductus arteriosus?
Connects the pulmonary artery to the aorta to shunt blood away from the lungs
**When some of the blood doesn’t enter the foramen ovale and goes into the R ventricle, it travels through the pulmonary artery, but since the lungs aren’t functioning, that ductus arterioisus sends the blood through to the aorta
Different prenatal circulation pathways
Majority:
1. Umbilical vein
2. ductus venosus
3. IVC
4. R atrium
5. foramen ovale
6. L atrium
7. L ventricle
8. Aorta
9. Body
Some:
1. Umbilical vein
2. ductus venosus
3. IVC
4. R atrium
5. R ventricle
6. Pulmonary artery
7. Ductus arteriosis
8. Aorta
9. Body
When do fetal shunts close?
over the first few hours or days after birth
1. Foramen Ovale –> fossa ovale (soon after birth)
2. Ductus arteriosis –> ligamentum arteriosis (within 24 hrs)
3. Ductus venosus –> ligamentum venosum
4. Umbilical vein –> ligamentum teres
T/F knowing a pt’s gestational age at birth will help a PT understand potential problems in development of the cardiopulmonary system
True
What are cardiac defects classified as?
- Cyanotic: arterial oxygen saturation is decreased
- Acyanotic: normal oxygen saturation
Examples of Acyanotic lesions
Atrial Septal Defects (ASDs)
Ventricular Septal Defects (VSDs)
Atrioventricular septal defects (AVSDs)
Patent ductus arteriosus
Coarctation of the aorta
Pulmonary stenosis
Aortic stenosis
S/S of Acyanotic lesions
sweating
increased respiratory rate
heart failure
low partial pressure of oxygen
low stroke volume
increased work of heart
Atrial septal defects
When foramen ovale doesn’t fully close at birth
-results in heart murmurs and enlarged pulmonary artery to develop
-treatment: surgery at 2-3 yrs of age
Patent Ductus Arteriosus
if the ductus arteriosus doesn’t fully close
-too much blood may enter lungs
-tachycardia, increased respiratory distress, poor weight gain
-associated with prematurity or DS
Ventricular Septal Defect
When there are one or more small openings in the wall of the ventricular septum
-treatment: may include surgery, small holes may spontaneously close