Kidney Function & Electrolyte Disorders

Which of the following is the appropriate initial treatment for a patient with central diabetes insipidus?

a. Amiloride

b. Desmopressin

c. Furosemide

d. 3% NaCl

b. Desmopressin

A patient was started on bumetanide approximately 1 week ago. During a follow-up appointment, she is noted to be confused, lethargic, and weak. Vital signs are taken and she is found to be hypotensive, tachycardic, and orthostatic. STAT laboratory studies are sent, and the serum sodium is reported as 159 mEq/L (mmol/L). Which one of the following is the most appropriate initial fluid to administer to this patient?

a. 0.9% NaCl

b. D5W

c. 3% NaCl

d. 0.45% NaCl

a. 0.9% NaCl

A 24-year-old construction worker (weight, 70 kg) experiences a syncopal episode on the roof of a new apartment building on a hot summer day (100°F). He presents to the emergency department with a BP of 76/30 mm Hg, HR of 138 bpm, and significant orthostasis. His serum sodium is 164 mEq/L. He has no significant past medical history. Which of the following is the most appropriate initial intervention?

A. A 500-mL IV bolus of Dextrose 5% in water (D5W) over 30 minutes

B. A 750-mL bolus of oral rehydration solution ingested over 4 hours

C. A 1,000-mL IV bolus of 0.9% NaCl over 30 minutes

D. A 1,000-mL IV bolus of Dextrose 5%/0.45% NaCl over 30 minutes

C. A 1,000-mL IV bolus of 0.9% NaCl over 30 minutes

Which one of the following represents the usual determinants of serum osmolality?

a. Serum sodium, glucose, and blood urea nitrogen concentrations

b. Serum sodium, potassium, and glucose concentrations c. Serum potassium, bicarbonate, and glucose concentrations

d. Serum sodium, bicarbonate, and blood urea nitrogen concentrations

a. Serum sodium, glucose, and blood urea nitrogen concentrations

A 26-year-old who takes lithium 1,200 mg daily presents to clinic with a serum sodium concentration of 145 mEq/L and complaints of excessive urination over the previous few days. The patient’s psychiatrist recommends continuing the lithium due to the patient’s treatment-resistant bipolar disorder. Which of the following is the most appropriate recommendation for this patient?

a. Indomethacin 50 mg by mouth twice daily

b. Amiloride 5 mg by mouth daily

c. Sodium restriction to 4,000 mg NaCl per day

d. Demeclocycline 300 mg by mouth three times daily

b. Amiloride 5 mg by mouth daily

Which of the following treatments for hyperkalemia works by preventing intestinal absorption of potassium?

a. Albuterol

b. Sodium polystyrene sulfonate

c. Sodium bicarbonate

d. Insulin + dextrose

b. Sodium polystyrene sulfonate

Which of the following drugs would be expected to result in hyperkalemia?

a. Hydrochlorothiazide

b. Fosinopril

c. Furosemide

d. Albuterol

b. Fosinopril

Which of the following is immediate first-line therapy for hyperkalemia associated with electrocardiogram (ECG) changes?

a. Furosemide 40 mg PO

b. Calcium gluconate 1 g IV

c. Hemodialysis

d. Regular insulin 10 Units IV

b. Calcium gluconate 1 g IV

Which of the following statements regarding IV potassium is correct?

a. The infusion rate should not exceed 20 mEq/h in a peripheral line.

b. IV potassium is preferred in all hospitalized patients.

c. Potassium should be diluted in dextrose 5% water.

d. Continuous ECG monitoring is always necessary when infusing potassium.

a. The infusion rate should not exceed 20 mEq/h in a peripheral line.

A patient who cannot tolerate oral potassium preparations most likely has which of the following adverse effects?

a. Itching

b. Hypoglycemia

c. Gastrointestinal (GI) upset

d. Muscle cramps

c. Gastrointestinal (GI) upset

Which of the following is a possible adverse effect of intravenous magnesium replacement therapy?

a. Diarrhea

b. Renal failure

c. Muscle pain

d. Flushing

d. Flushing

A patient on a general medicine floor has morning laboratories drawn, which include a serum potassium of 3.2 mEq/L and serum magnesium of 0.9 mg/dL. He is given 40 mEq of liquid potassium chloride by mouth. Repeat laboratories drawn 8 hours later reveal a serum potassium of 3.4 mEq/L and serum magnesium 0.9 mg/dL . What is the most appropriate therapy to order for this patient to increase his serum potassium?

A. Potassium chloride 60 mEq (mmol) PO

B. Magnesium sulfate 2 g IV

C. Potassium chloride 40 mEq (mmol) IV

D. Magnesium oxide 400 mg PO

B. Magnesium sulfate 2 g IV

A 65-year-old female with asymptomatic hypercalcemia secondary to metastatic lung cancer presents with a serum calcium of 12.2 mg/dL. Her serum creatinine is 0.9 mg/dL estimated GFR>60 mL/min/1.73 m2 . The decision is made to initiate therapy with an agent that inhibits bone resorption. Based on the efficacy and toxicity profile of the following agents, which would be the most appropriate to initiate in this patient?

A. Prednisone

B. Pamidronate

C. Calcitonin

D. Denosumab

B. Pamidronate

A 85-year-old patient with chronic kidney disease stage 3b (estimated GFR 40 ml/min/1.73m2 ). Her present medications include ramipril 10 mg qd, furosemide 80 mg BID, and amlodipine 10 mg qd. She is scheduled to have a colonoscopy and she is advised to purchase a sodium phosphate bowel preparation (Fleet Phospho-Soda). All but which of the following put her at increased risk for phosphate nephropathy or acute kidney injury?

A. Chronic kidney disease

B. Ramipril therapy

C. Metoprolol therapy

D. Diuretic therapy

C. Metoprolol therapy

An 85-year-old patient who resides in a nursing home develops hypophosphatemia (serum phosphorus 1.1 mg/dL) secondary to limited oral intake associated with advanced dementia. His other laboratory data include: serum potassium 3.4 mEq/L and total corrected calcium 8.5 mg/dL. Which of the following is the best therapy to initiate in this patient?

A. Neutra-phos-K

B. K-phos Neutral

C. Neutra-phos

D. Potassium phosphate IV

A. Neutra-phos-K

A 42-year-old patient receiving hemodialysis has a parathyroidectomy. He develops symptomatic hypocalcemia immediately post-surgery. The most likely cause of this is:

A. Vitamin D deficiency

B. Hypothyroidism

C. Hungry bone syndrome

D. Hypomagnesemia

C. Hungry bone syndrome

What value represents normal serum osmolality?

~280 mOsm/L

Hypotonic/Hyponatremia

Serum osmolality <280 mOsm/L

Hypertonic hyponatremia

Serum osmolality >280 mOsm/L

Sequence of assessing hyponatremia

Step 1: Affirm whether patient has hyponatremia or not via lab results

Step 2: Look at the serum osmolality value (if hypotonic, continue to step 3)

Step 3: Evaluate the fluid status

What type of hyponatremia requires calculating Corrected Na?

Hypertonic

How do you know a patient is hypovolemic?

Patient will appear to be dry

The glomerulus is primarily responsible for ____ of unbound drug in the kidney.

a. Filtration

b. Reabsorption

c. Secretion

d. Endocytosis

a. Filtration

Active drug secretion occurs most often in which of the following nephron segments?

a. Glomerulus

b. Proximal tubule

c. Loop of Henle

d. Distal tubule

b. Proximal tubule

According to the intact nephron hypothesis, single nephron GFR _____ in the surviving nephrons.

a. Decreases

b. Increases

c. Remains the same

b. Increases

The kidney is responsible for synthesizing each of the following hormones, except:

a. Erythropoietin

b. Prostaglandin

c. PTH

d. Renin

c. PTH

Which of the following kidney function indices is least affected by dietary protein intake?

a. Serum creatinine

b. Blood urea nitrogen (BUN)

c. Creatinine clearance

d. Urine sodium

d. Urine sodium