Question

Mrs. PH, 78 years old, a nursing home resident was taken to the hospital after feeling unsteady on her feet and then suffering from a fall. She was also complaining of feeling nauseous and appeared to be very irritable and confused. Nursing home staff stated she was normally pleasant to be around and her current behavior was uncharacteristic. Neurologic evaluation revealed no deficits or signs that she had any neurologic damage, and all other vital signs were normal. Her medical history revealed she has a history of hypercholesterolemia, depression, chronic back pain, sciatica, acid reflux, and osteopenia. She was also taking several medications: esomeprazole, fluoxetine, carbamazepine, oxycodone, atorvastatin, low-dose aspirin, and calcium and vitamin D supplements. Blood work showed the following results: Mrs. PH’s Test Results Results Reference range Serum sodium 108 mmol 135–145 mmol Potassium 4.5 mmol 3.5–5.0 mmol Serum calcium 8.9 mg/dL 8.6-10.3 mg/dL Creatinine 40 µmol/L 40–90 µmol/L Estimated glomerular filtration rate 90 mL/min/1.73 m2 >90 mL/min/1.73 m2 Serum osmolality 254 mOsm/kg >275 mOsm/kg Urine osmolality 140 mOsm/kg <100 mOsm/kg Urine sodium 39 mmol/L <20 mmol/L Thyroid function tests Normal Chest X-ray Normal Computed tomography of the head Normal

A1. (2 pts) Which lab results are abnormal? Highlight or list them below.

A2. (4 pts) Based on the lab results, provide a diagnosis for Mrs. PH. Explain how you arrived at your diagnosis, specifically the test results and symptoms that are consistent with your diagnosis.

A3. (6 pts) For the medications Mrs. PH is taking, list which condition they were likely prescribed for based on her medical history.

A4. (3 pts) For the diagnosis you provided, which medication(s) is/are most like contributing to her problem?

Answer 1

Answer to A1:

Lab test	Test Results	Reference range	Interpretation
Serum sodium	108 mmol	135–145 mmol	Abnormal- low sodium levels.
Potassium	4.5 mmol	3.5–5.0 mmol	Normal – within the reference range.
Serum calcium	8.9 mg/dL	8.6-10.3 mg/dL	Normal – within the reference range.
Creatinine	40 µmol/L	40–90 µmol/L	Normal – within the reference range.
Estimated glomerular filtration rate	90 mL/min/1.73 m2	>90 mL/min/1.73 m2	Normal – Borderline to the reference range.
Serum osmolality	254 mOsm/kg	>275 mOsm/kg	Abnormal – lesser than the reference range.
Urine osmolality	140 mOsm/kg	<100 mOsm/kg	Abnormal
Urine sodium	39 mmol/L	<100 mOsm/kg	Normal – within the reference range.
Thyroid function tests	Normal	Normal	Normal
Chest X-ray	Normal	Normal	Normal
Computed tomography of the head	Normal	Normal	Normal

Therefore Serum sodium, Serum osmolality, and Urine osmolality results are abnormal.

Answer to A2:

A low blood sodium level is caused due to:

• Dehydration
• Excessive or overhydration.
• Kidney or liver disease
• Adrenal gland disorders such as Addison’s disease.
• Hypothyroidism
• Addison's disease.

A low blood osmolality level is caused due to:

• Excessive or overhydration.
• Dehydration
• Hyponatremia - low blood sodium.

A high urine osmolality level is caused due to:

• Congestive heart failure
• Dehydration
• Kidney failure
• Addison’s disease.

Also, Mrs. PH showed the following symptoms:

• Nausea
• Confusion
• Irritability
• Fall or fainting
• Extreme fatigue – unsteadiness

From the symptoms and the lab results, it can be concluded that Mrs. PH had severe dehydration.

Answer to A3:

List of medications and their indications as per Mrs. PH’s medical history.

Esomeprazole – It is a proton pump inhibitor that reduces the production of stomach acid. It is used to treat acid reflux in the stomach.

Fluoxetine – It is a selective serotonin reuptake inhibitor (SSRI) class of antidepressants. Used to treat depression.

Carbamazepine – Used to treat neuropathic pain and epilepsy. Since Mrs. PH had sciatica, she was prescribed Carbamazepine.

Oxycodone – It is an opioid analgesic used to treat moderate to severe pain. Prescribed for chronic back pain and sciatica.

Atorvastatin – Used to treat high levels of cholesterol (Hypercholesterolemia) and to lower the risk of heart attack and stroke.

Low dose aspirin – Prescribed to lower the risk of heart attack and stroke.

Calcium and Vitamin D supplements – Prescribed to protect bone health. Calcium build and maintain the bones and Vitamin D helps in effective absorption of calcium.