Reference no: EM134040610

Case Study

Balun is an 81-year-old man with a history of hypertension treated with a diuretic and ACE inhibitor. He had broken two toes and, as a result, had spent two months resting more than usual in his easy chair. When he stood up from bed in the morning, or stood up from his easy chair, he became very dizzy and light-headed. His partner remarked that he also became disoriented and confused, and he saw a physician after an episode in which he fainted. When questioned, Balun mentioned that he sweated during those episodes, but did not notice undue sweatiness at other times or dryness of his mouth, nor did he have difficulties with his digestion or urination that were different from those occurring before the dizziness episodes. Balun stated that he felt weak and stood carefully after meals but did not have the extreme dizziness that occurred upon standing from bed. The physician measured Balun's blood pressure and pulse in a supine position, and a half-hour later, in the tilted and upright positions. His supine measurements were within the normal range, but a few minutes after standing his systolic pressure fell by 24 mm Hg, his diastolic pressure fell by 10 mm Hg, and his pulse increased. Balun didn't have problems moving his eyes to follow an object, had normal pupillary reflexes, and seemed aware with reasonably good memory.

Balun is elderly, is taking drugs that act to lower blood pressure, and had been especially inactive for an extended period. His blood pressure dropped significantly upon standing, despite an increased heart rate. His remarks suggest that his blood pressure may have also decreased somewhat after a meal. He seemed mentally aware and competent when he saw the physician, with normal control of his extrinsic eye muscles and a normal pupillary reflex. Although he was unable to maintain adequate blood pressure upon standing, he seemed to have normal autonomic control of his bladder, gastrointestinal system, sweat glands, and salivary secretions. There was no history of heart disease or signs of cardiovascular problems, other than his previously well-controlled hypertension.

Questions

1. How do diuretics and ACE inhibitors act to lower blood pressure?

2. What is the mechanism that causes heart rate to increase upon standing?

3. How does eating influence blood flow around the body?

4. How does the autonomic system affect blood pressure?

5. What is the most likely explanation for Balun's symptoms?