Keeping up with the Jones’s by Phil Stephens
Part V—Blood Results
| Table 2 | ||
|---|---|---|
| Level | Normal | Suzie |
| Sodium | 136–145mmol/L | 126mmol/L |
| Potassium | 3.6–5.1mmol/L | 2.4mmol/L |
| Calcium | 4.2–5.3mmol/L | 2.9mmol/L |
| Fasting Glucose | 65–95mg/mL | 55mg/mL |
| Iron | 50–140ug/dL | 38ug/dL |
| Protein | 6–7.8g/dL | 3.9g/dL |
The doctor continued, “There’s no need to worry about your son, Mrs. Jones, the nurse will help him if he has any problems with his ankle. Now Suzie, I can’t stress enough that the results of your physical examination show that you are in bad physical shape. I appreciate that you are driven to succeed, but as your doctor it’s my duty to tell you that you are going about this in the wrong way.”
“I feel great, doctor. I’m in the best shape I have ever been. I can run forever. So my blood pressure is a little low and I have had some fainting spells. Maybe I have been overdoing things lately and I’m a bit dehydrated. I am on the ice now, so I won’t be running as much as I concentrate on skating,” Suzie replied.
“I understand that, but I’m afraid that you’re heading down the wrong road. When did you last have your period?” Dr. Fay asked.
“I don’t remember. About a month ago,” replied Suzie, avoiding eye contact with the physician.
“Perhaps a little longer? We didn’t do a percent body fat test, but I would predict it is low. In fact, I would predict that your estrogen levels are too low to produce menses. Do you go to parties with your friends?” the doctor asked.
“She’s lost interest in boys,” replied Mrs. Jones. “She lives to skate.”
The doctor nodded and continued, “I bet you’re on a low-fat diet and your caloric intake is too low. It doesn’t take a medical degree to see that you’re under weight. You are starving yourself, Suzie, and your bones stick out. Sure, you have a nice sun tan because you’re outside a lot, but look at your tan lines; your skin is pale and flaky.”
“But I am almost there,” exclaimed Suzie. “I still have fat under my skin.”
“That’s not fat. You’re so malnourished that what you see as fat is, in fact, an edema; it’s fluid. Your blood protein levels confirm that.”
Questions
- Assuming that the ion levels in the blood plasma are similar to those in the interstitial fluid, what is the effect of low potassium levels on the membrane potential of Suzie’s nerve and muscles?
- Does this explain Suzie’s slow heart rate and ectopic beats?
- How does low plasma calcium level account for her decreased stroke volume?
- What is the role of blood proteins in the movement of fluid between the blood and the interstititial space?
- What would be the effect of low blood protein levels on the colloidal pressure?
- How do low plasma protein levels produce edema?
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