Chief Complaint: 8-year-old girl with excessive thirst, frequent urination, and

Question

Chief Complaint: 8-year-old girl with excessive thirst, frequent urination, and weight loss. History: Cindy Mallon, an 8-year-old girl in previously good health, has noticed that, in the past month, she is increasingly thirsty. She gets up several times a night to urinate, and finds herself gulping down glassfulls of water. At the dinner table, she seems to be eating twice as much as she used to, yet she has lost 5 pounds in the past month. In the past three days, she has become nauseated, vomiting on three occasions, prompting a visit to her pediatrician. At the doctor's office, blood and urine samples are taken. The following lab results are noted: blood glucose level = 545 mg/dl blood pH level = 7.23 urine = tested positive for glucose and for acetone / acetoacetate.

12. What does Cindy's Hb A1C level indicate that a one-time direct measurement of blood glucose doesn't indicate?

The years progress, and Cindy has considerable difficulty controlling her diabetes. She has been told that she has "brittle" diabetes, a form of the disease marked by wide swings in bloodglucose levels despite the best efforts at control. Cindy is advised by her physician that she is at risk for developing certain complications of diabetes.

13. What are the possible long-term complications of her disease?

14. Cindy is advised that she must take very good care of her feet, never walking barefoot. Why is this important? In her mid-forties, Cindy began to show early signs of diabetic nephropathy (kidney disease), consisting of persistent proteinuria, hypertension, and gradually decreasing renal function as measured by chemical tests. She nonetheless felt fairly healthy over the next 10 years. At age 55, however, she has noticed becoming increasingly fatigued upon mild physical exertion and requiring more sleep than previously. In addition, she has generally felt nauseated most of the time, and in the past two weeks, has vomited on several occasions. She has increased swelling in her ankles, and is short of breath. She has also become less responsive over the past day or so. Laboratory tests reveal that her kidney disease is now progressing at a much faster rate: BUN (blood urea nitrogen) = 56 mg / dl (normal = 10 - 20 mg / dl) Urinary output = 25 cc / hour (normal = 50-60 cc / hour) Cindy is advised by her physician that her kidneys are failing. She is informed about treatment options: hemodialysis vs. continuous ambulatory peritoneal dialysis (CAPD) vs. kidney transplant. In consultation with her physician, Cindy chooses to undergo hemodialysis. A checkup two weeks after beginning dialysis reveals the BUN has decreased to 35 mg / dl. Although hemodialysis is fairly effective, it is not fool-proof. For example, patients with chronic renal failure, despite a regular schedule of hemodialysis, will experience disruptions in calcium and phosphate balance. 15. Failing kidneys have a harder time excreting phosphate, and thus blood-phosphate levels tend to rise. What effect will rising blood-phosphate levels have on blood calcium levels? 16. What danger is presented to soft tissues when blood-phosphate levels are too high? 17. How might the endocrine system compensate for the change in blood calcium levels? 18. What effect will the compensatory mechanism have on the skeletal system (i.e. the bones)? What is "renal osteodystrophy" (which, in children with chronic renal failure, is sometimes called "renal rickets")?

Explanation / Answer

Answer 12) Cindy's elevated Hb A1C indicates that her blood glucose levels have been elevated over the time. Because the normal lifespan of red blood cells is about 120 days, therefore the average amount of sugar present in the blood i.e blood glucose levels can be determined by measuring a Hb A1c level. A one-time direct measurement of Cindy's blood-glucose level will indicate the blood-glucose level of Cindy at that particular time when the blood sample was taken.

Answer 13) Cindy's Hb A1C levels were elevated and she was suffering from insulin-dependent diabetes mellitus.
The long-term complications of her disease are as follows:
a) It causes damage to the blood vessels of the retina, kidneys and peripheral nerves which result into the thickening of the basement membrane, bulging of the wall of the blood vessel, lysis of red blood cells (hemorrhage) and ultimately lead to the decreased blood flow to these organs and thus, a diabetic patient may develop blindness, renal failure, and reduced sensation in the lower extremities.

b) The excess fatty substances and lipid compounds are deposited in the arteries of the diabetic patient which may result in the formation of plaques. These plaques narrow the artery lumen and thus reduce blood flow. This may cause a heart attack and pain in the legs.

Answer 14) Cindy is more prone to infections in the lower legs which are difficult to treat. Because of reduced and limited blood flow in the blood vessels limits her sensation to touch and proprioception, when she walks with barefoot an excessive pressure is experienced on matatarsal heads. This mechanically inefficient pressure distribution over the soles of her feet can lead to the development of thick calluses. Such calluses can limit the blood flow and increase the possibility of ulceration of the skin. The damaged skin may allow bacteria to proliferate. The reduced oxygen availability due to the reduced blood flow will favor the growth of anaerobic bacteria, such as Clostridium difficile.This bacterium is the causative agent of gangrene which is a life-threatening infection.

Answer 15) If the blood phosphate levels tend to rise, then more phosphate is allowed to bind with freely dissolved calcium ions in the plasma and thus, lowering the blood calcium level which leads to a condition known as hypocalcemia.

Answer 16) When blood phosphate levels are too high, the rate of binding of phosphate to calcium in the bloodstream is greatly increased and soft tissues can lead calcification. Calcification is characterised by the formation of calcium phosphate crystals. These crystals can cause various diseases on the basis of the site of their deposition such as calcification in the walls of arteries can cause arteriosclerosis, in joint cavities can cause arthritis, in the skin can cause painful ulcers, in conjunctivae of the eyes can cause conjunctivitis, etc.

Answer 18) Due to excessive deposition of calcium in the bones of Cindy, the bone demineralization becomes more severe which results in the developments of osteomalacia (or softening of the bones)  and osteoporosis These conditions, along with the renal failure (inability to maintain calcium and phosphate levels), are collectively referred to as renal osteodystrophy. Such changes in her skeleton increase the risk of spontaneous fractures of the hip, vertebrae, and other weight-bearing bones.

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.