Casos clínicos Nefrología Flashcards
A 70-year-old man comes to the emergency department because of a 1-week history of progressively worsening dyspnea. His symptoms are worse when lying flat, and he has been sleeping in a recliner for 2 weeks. He denies a history of fever or exposure to sick contacts. He has chronic obstructive pulmonary disease and coronary artery disease. He had a myocardial infarction 3 years ago. Current medications include albuterol, ipratropium, aspirin, and lisinopril. His pulse is 90/min and blood pressure is 135/70 mm Hg. Physical examination shows 2+ pitting edema of the lower extremities. A grade 3/6 pansystolic murmur is heard maximally at the left sternal border. Serum studies show:
- Na+: 140 mEq/L
- Cl-: 100mEq/L
- K+: 4.5 mEq/L
- Urea nitrogen: 80 mg/dL
- Creatinine: 1.5 mg/dL
- Brain natriuretic peptide: 450 pmol/L
Which of the following is the most appropriate next step in management?
- Coronary artery bypass grafting
- Dialysis
- Furosemide
- Albuterol inhalado
- Propranolol
Furosemide
This patient is most likely experiencing an acute exacerbation of heart failure with reduced ejection fraction (HFrEF).
The patient’s blood urea nitrogen (BUN) and creatinine concentrations, with a BUN:creatinine ratio greater than 20, suggest that he may be experiencing prerenal acute kidney injury (AKI) due to renal hypoperfusion. Initial treatment for acute decompensated heart failure is aimed at reducing volume overload, thus decreasing preload and afterload. Loop diuretics like furosemide are considered the initial treatment of choice for increasing excretion of excess fluid.
A 19-year-old woman comes to the office because of a constant headache and decreased eyesight for 3 weeks. She also describes feeling weaker than normal, and difficulty walking. Family history includes renal cell carcinoma. Examination shows a wide-based, slow gait and decreased visual acuity. Fundoscopy shows a right sided retinal detachment. MRI is shown below. Which of the following is the most likely diagnosis?
- Von Recklinghausen disease
- Louis Bar syndrome
- Wilsons disease
- von Hippel Lindau disease
- Fredheich´s ataxia
von Hippel Lindau disease
von Hippel-Lindau (VHL) disease is an autosomal dominant familial tumor syndrome. It is caused by germline mutations in the VHL tumor suppressor gene. VHL mutations predispose to the development of a variety of tumors. The most frequent tumors are retinal and central nervous system (CNS) hemangioblastomas, clear cell renal carcinoma, phaeochromocytoma, pancreatic islet tumors and endolymphatic sac tumors.
A 65-year-old man comes to the emergency department because of nausea, vomiting, abdominal pain, and malaise. He denies fever, chest pain, dyspnea, or recent illness. Patient says that his nephew visited last week and had some “stomach bug”. His medical history includes hypertension, hyperlipidemia, sleep apnea, diabetes mellitus complicated by bilateral below-the-knee amputations, and chronic kidney disease. His temperature is 37.33°C (99.2°F), pulse is 105/min, respirations are 18/min, and blood pressure is 138/78 mm Hg. Finger blood glucose is 110 g/dL. ECG is obtained and shown below. Which of the following is the most appropriate next step in management?
- Bicarbonate
- Calcium gluconate
- Dyalisis
- Insulin
- Salbutamol
Calcium gluconate
Hyperkalemia is recognized on ECG by peaked T waves and a widened QRS complex.
A 38-year-old man is brought to the emergency department because he received electric shocks while he was working on residential powerlines. He was in ventricular fibrillation and was put back into a normal sinus rhythm via defibrillation. He is now unconscious, but stable. His airway is controlled and he is placed on telemetry to monitor for cardiac rhythm abnormalities. Physical examination shows a 3 cm full thickness burn on the right wrist and a 2 cm full thickness burn on the dorsum of the right foot. Which of the following is the most likely complication that needs to be prevented in this patient’s condition?
- AKI
- Acute myocardial infarction
- ARDS
- Hemothorax
- Tension pneumothorax
AKI
Acute kidney injury is a potential complication of rhabdomyolysis, which is a condition in which damaged skeletal striated muscle breaks down rapidly. Myoglobin can become lodged in the renal tubules and cause acute tubular necrosis, leading to acute kidney injury (which can lead to hyperkalemia) and increasing creatinine and BUN.
A 62-year-old woman comes to the office because of intermittent flank pain for 2 days. She describes the pain as “cramping” and says that is worse after drinking fluids. Medical history includes recurrent urinary tract infections. Temperature is 36.8°C (98°F), pulse is 82/min, respirations are 14/min, and blood pressure is 117/78 mm Hg. Examination reveals a left-sided flank mass. Urine dipstick is negative for leukocytes. The CT-scan is shown below. Which of the following is the most likely diagnosis?
- Bladder calculi
- PKD
- Pyelonephritis
- Renal cell carcinoma
- Ureteropelvic junction obstruction
Ureteropelvic junction obstruction
Ureteropelvic junction obstruction may be diagnosed in an adult patient with a history of genitourinary problems or procedures. In imaging studies of these patients, unilateral (usually left) hydroureteronephrosis is evident. Ureteropelvic junction obstruction may also be congenital, and is often diagnosed in utero.
A 50-year-old woman comes to the emergency department because of severe, colicky left-sided abdominal pain. Urinalysis shows microscopic hematuria. She is given intravenous fluids and ketorolac. Her temperature is 37.2°C (99°F), pulse is 70/minute, respiratory rate is 18/minute, and blood pressure is 160/90 mm Hg. Her BMI is 23 kg/m2. Her medical history is significant for celiac disease that was diagnosed 20 years ago. She avoids gluten and takes vitamins to “stay healthy”. Which of the following is most likely present in this patient?
- Vitamin C deficiency
- Hypophosphatemia
- Vitamin D excess
- Vitamin D deficiency
- Osteomalacia
Vitamin D excess
Hypervitaminosis D is usually caused by megadoses of vitamin D, including in patients who take vitamin D for repletion due to malabsorption. Chronic toxicity results in bone demineralization, pain, and nephrocalcinosis.
A 27-year-old woman comes to the office because of fatigue, joint pains, and a facial rash for 3 weeks. She states that pain and swelling in her knees makes it difficult to walk normally in the morning, however it seems to improve a little over the day. Her medical history is noncontributory. Her temperature is 37.8°C (100°F), pulse is 87/min, respirations are 18/min, and blood pressureis 152/88 mm Hg. Examination shows erythema affecting the cheeks and bridge of the nose. There are also bilateral knee effusions, and pitting peripheral edema to the ankles. Urinalysis shows abnormal levels of protein and erythrocytes. Which of the following will most likely provide a definitive diagnosis and inform treatment?
- 24 hour urine collection
- Anti-cytoplasmic antineutrophil cytoplasmic (ANCA) antibodies
- Anti nuclear antibodies
- Knee x-rays
- Renal biopsy
Renal Biopsy
Lupus nephritis is a cause of nephritic syndrome occurring in patients with systemic lupus erythematosus (SLE). Characteristic symptoms of SLE are facial rash, arthritis, and fatigue. Nephritic syndrome is characterized by the loss of both protein and erythrocytes in the urine. Renal biopsy is used for diagnosis and planning treatment.
A 28-year-old woman comes to the clinic because of left abdominal pain and a burning with urination over the past four days. She says the pain was just a nuisance at first, but now it has grown to be unbearable. She has also experienced several episodes of nausea and vomiting within the past two days. Medical history is negative for similar symptoms in the past. Her temperature is 38.9°C (102.0°F), pulse is 86/min, respirations are 18/min, and blood pressure is 108/62 mm Hg. Physical examination shows left-sided costovertebral angle tenderness. The spleen is not palpable. Complete blood count is significant for a leukocyte count of 16,000/mm³. Her urine shows gross hematuria and contains leukocyte casts on urinalysis. A computed tomography scan of her abdomen shows multiple wedge-shaped, low-attenuation areas in the left kidney. Which of the following is the most likely causative organism for this woman’s pathology?
- Campylobacter jejuni
- Enterobacter spp.
- E. coli
- Klebsiella pneumoniae
- Proteus mirabillis
E. coli
The most common organism causing pyelonephritis is E. coli.
A 63-year-old man comes to the emergency department because of severe weakness and nausea. His suffered a heart attack a month ago and has recently been placed on aspirin, carvedilol, and atorvastatin. An ECG is obtained and the readout is shown below:
- Insulin
- IV saline in conjunction with calcitonin
- Nitroglycerin
- Oral potassium chloride
- Coronary angioplasty
Insulin
Hyperkalemia can be diagnosed on ECG by looking for small P-waves and large, peaked T-waves. Insulin administration is a quick way to stave off the effects of hyperkalemia.
