On Monday, Carmen, a 35-year-old woman, complains to her physician of chest and arm pain. The...

On Monday, Carmen, a 35-year-old woman, complains to her physician of chest and arm pain. The pain started after Carmen worked hard in the backyard the previous Saturday, lifting and carrying plants, fertilizer, and concrete blocks. She says that had continued working despite arm pain that developed about midday. Carmen has no problem breathing, but she cannot raise her arms above her shoulders, and her shoulder and chest muscles are sore to the touch. On questioning, Carmen reports that her hands are not numb and her urine is not dark.

On physical examination, muscles around the elbows, arms, shoulders, and anterior chest are swollen and tender. Carmen can move her fingers and wrists normally, but she has some pain in the proximal forearm muscles. The ranges of motion at the elbow and shoulder joints are reduced. No bruises are evident, and Carmen has normal sensation in her fingertips. On inspection, her urine is cloudy and light brown; on dipstick testing, it tests positive for protein and hemoglobin (or myoglobin). Microscopically, there are no RBCs in the urine.

Blood tests are ordered to check for CPK (creatine phosphokinase) and LDH (lactate dehydrogenase). Kidney function tests are also done to check for the levels of BUN (Blood Urea Nitrogen) and creatinine. Treatment initially consists of pain medication, ice applied to the sore muscles, and a high fluid intake; at least 4 quarts every 24 hours.

Carmen is asked to call the physician if her urine remains cloudy, if the volume decreases, or if her hands or forearms feel worse. Carmen returns the next day to have her urine rechecked and to get the results of her lab tests. Her arms and chest are still sore and swollen, her hands still have normal sensation, and her urine is clear and dilute, but tests still show traces of protein and hemoglobin. Her lab tests from the previous day show CPK and LDH levels 10 times normal values, but kidney tests are normal.

Questions:

1. On the basis of the case description which starts with chest pain, try to determine the possible causes of these symptoms. Please consider several body systems to build your hypothesis and try to rank those causes from high probability to low probability.

2. Why was Carmen asked about her hands and her urine?

3. What might the observations such as tenderness, range of motion, sensation and lack of bruising, indicate?

4. Why are these blood and urine tests selected?

5. Would you be able to form a diagnosis for Carmen?