Question

1.What does the bluish coloration of Mr. L's lips and fingertips indicate? What is a pulse oximeter and why does it give blood oxygen in percentages?

The doctor comes in and examines Mr. L's legs. His ankles are bluish and swollen, and the doctor says she is worried about pulmonary hypertension (high blood pressure).

2. Why is the doctor worried about hypertension (high blood pressure) when Mr. L's blood pressure is only a little bit above normal? Describe the flow of blood and how hypertension could affect it. Also, why can’t the doctor just measure it?

She notes “possible cor pulmonale.”

3. What is “cor pulmonale” and how could this be linked to COPD? What are the two major factors controlling blood pressure (the blood pressure equation)? How is arteriole vasoconstriction (a hallmark of hypertension) related to blood pressure?

4. Which side of the heart has to do the work of pushing blood through the constricted pulmonary arterioles? If this side of the heart cannot move the blood through the lungs fast enough, where will the blood accumulate and where did you notice this from earlier?

5. The patient is prescribed beta blockers to reduce heart rate and blood pressure. Describe the mechanism that beta-blockers do to achieve this.

Answer 1

1) Bluish discoloration Indicate Cynosis.

Pulse oxymeter is s device used to measure the blood % sauration. It is measured using infrared light absorbed by the blood. Oxygenated blood blood absorbs infrared light. Hence % saturation can be determined.

2) Doctor is worried because Hypertension Increases the work load on left heart. Which gradually leads to left heart failure. This further leads to further backpresssure of lungs. Pulmonary Congetion and Increased pressure in Pulmonary vasculature. This further leads to right heart failure, condition called as Cor Pulmonale. Doctor can not measure directly, as it requires catheterization and wedging of catheter in Pulmonary artery.

3) CorPulmonale is right sided heart faiulre dur to Pulmonary Hypertension. COPD leads to hypoxia in Pulmonary circulation, this lead to Pulmonary vasoconstriction. Hence pulmonary Hypertension occurs.

Blood pressure = Stroke volume x Total peripheral Resistant

Hence arteriolar constriction will lead to increased blood pressure.

4) Right side of the heart has to pump the blood out of Pulmonary capillary.

Right side of heart wall is thinner and has less tension and force of contraction to push this blood out of Pulmonary capillary.

5) beta blockers act on Beta 1 receptors on heart and Beta 2 receptors on blood vessel and lead to decrased heart rate and vasodilation respectively. Hence decreses HR and BP.