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Chapter 20
1. For the most part, Kyle’s CBC is normal. The only changes from expected normal
values are slight increases in the percentage of lymphocytes and the
concentration of thrombocytes. These results suggest that Kyle is not suffering
from a blood disease.
2. A heart murmur would be heard during both stages of the cardiac cycle because
blood would be continually flowing between the ascending aorta and the
pulmonary trunk. The pressure differences between the ascending aorta and
pulmonary trunk would allow a constant blood flow from the area of higher
pressure (ascending aorta) to the area of lower pressure (pulmonary trunk).
3. Children with PDA have reduced growth because of reduced perfusion of the
systemic circulation. The cells then lack the oxygen and nutrients required for
optimal development. PDA causes pulmonary hypertension and congestion. This
makes it harder to clear the lungs, and the persistent pulmonary fluid provides a
growth medium for bacteria, thus increasing the incidence of lower respiratory
infections.
4. In PDA, blood that should go to the systemic circuit repeatedly reenters the
pulmonary circuit and returns to the left side of the heart. This increases the
workload on the left ventricle, resulting in its hypertrophy.
5. The repeated reentry of blood into the pulmonary circuit produces pulmonary
congestion and edema.
6. A dissecting aortic aneurysm develops more rapidly and is more susceptible to
rupture than a small aortic aneurysm.
7. Angie could make sure that Nancy is supine and elevate her feet by placing them
on a pillow or some books.
8. Medical support hose exert external pressure on the veins and thereby increase
venous return. This is effective in treating orthostatic hypotension because it
improves venous return, thus supporting cardiac output and cerebral perfusion.
Compression of the legs also helps prevent venous pooling and dilation of the
veins. It does not reverse or cure varicose veins, but it makes the veins less
distended and slows worsening of the condition.
9. Coumarin is an anticoagulant. Giving coumarin to a patient with a ruptured
cerebral artery would prevent clotting and prolong the bleeding at the artery.
10. Orthostatic hypotension is treated with antidiuretics. Low blood pressure
(hypotension) is an effect of low blood volume. A diuretic would eliminate fluid
from the body and make this condition even worse. Diuretics are used to treat
hypertension, not hypotension. An antidiuretic promotes fluid retention and thus
supports blood volume and pressure.