Key Questions Flashcards
-A hypertensive patient develops chronic renal failure from progressive nephrosclerosis. Which of the following should you expect to occur as a result?
A)A decrease in the fractional excretion of sodium
B)An increase in the free water clearance
C)A decrease in net acid excretion
D)A decrease in the excretion of creatinine
E)No change in the anion gap
Correct D
-The excretion of creatinine, which is neither reabsorbed nor secreted in any significant amount, is dependent on filtration, which is in turn dependent on renal plasma flow. The decrease in renal plasma flow that accompanies chronic renal failure results in a decrease in creatinine excretion and an increase in plasma creatinine concentration.
-A 33-year-old male is brought to the emergency department with pain in his lower abdomen that radiates to his inner thigh and scrotum. He is afebrile. The urinalysis shows 3+ blood, no protein, and 20 to 40 RBCs/hpf.
A tender testicle
High urine calcium
Low urine osmolality
Right lower quadrant tenderness
Urinary RBC casts
Urine leukocytes
Urine muddy-brown granular casts
-Ca++-oxalate stone
A 30-year-old woman comes to the emergency department because of a 3-day history of a burning sensation with urination, flank pain, and fever. She has a history of recurrent urinary tract infections. Temperature is 38.3°C (100.9°F ) and pulse is 110/min. On examination there is left costovertebral angle tenderness. Urinalysis reveals a pH of 8.5 and is positive for blood, leukocyte esterase, and nitrite. X-ray of the abdomen is shown.–>Staghorn calculi
Enterococcus faecalis
Escherichia coli
Proteus mirabilis
Pseudomonas aeruginosa
Staphylococcus saprophyticu
P.mirabilis
-alkaline urine pH suggests that this UTI is due to an organism that makes urease.
-are gram-negative, as suggested by the positive urine nitrite test.
A 4-year-old child is brought to her pediatrician by her parents. Over the past several days, they have noticed swelling of her eyelids, and she has vomited twice in the past two days. She has no significant past medical history. Her vital signs are a temperature of 98.6°F, blood pressure of 97/62 mm Hg, and pulse of 76 bpm. Laboratory testing reveals an albumin of 2.2 gm/dL and total cholesterol of 243 mg/dL. A urine dipstick is positive for protein and negative for red blood cells and white blood cells. She is admitted to the hospital. Of the following, which would further testing most likely reveal?
A.Urine osmolality of 500mOsm/kg
B.Urine output of 300 mL in one day
C.4.0 g/day of protein in the urine
D.Red blood cell casts
E.Leukocyte esterase positivity in the urine
C correct
-Vignett describes nephrotic syndrome.
37-year-old female presents to an acute care clinic. Over the past several days, she has noticed swelling of her eyelids and she has experienced nausea and vomiting several times in the past two days. She has no significant past medical history. Her vital signs are a temperature of 98.6°F, blood pressure of 97/62 mm Hg, and pulse of 91 bpm. Laboratory testing reveals an albumin of 2.2 gm/dL and total cholesterol of 243 mg/dL. A urinalysis is positive for protein, negative for red blood cells, and white blood cells. She is admitted to the hospital. Overnight testing reveals 4.1 g/24 hrs of protein in the urine. A renal biopsy is performed. Immunofluorescence staining reveals granular IgG positivity, and electron microscopy reveals subepithelial immune complexes. Of the following, what is the diagnosis?
A.Minimal change disease
B.Focal segmental glomerulosclerosis
C.Membranous glomerulonephropathy
D.Postinfectious glomerulonephritis
E.Type I membranoproliferative glomerulonephritis
C corrects answer** (has sub-epithelial deposits)**
-FSGS has NO immune deposits.
A pathologist is examining a kidney biopsy and notes that some of the glomeruli have sclerosis of a portion of the glomerulus. Of the following, what feature was most likely identified in the patient prior to the biopsy?
A.Blood pressure of 171/93 mm Hg
B.Proteinuria of 2.5 g/day
C.Tinnitus
D.Red blood cell casts
E.Increased serum concentration of lipoprotein(a)
E.
A 7-year-old girl is brought to the clinic because of a 5-month history of fatigue and diffuse muscle weakness. Her mother reports that the patient has been drinking more water lately and urinates frequently. Family history is remarkable for an inherited kidney defect in the patient’s father. She is small for her age (5th percentile). Blood pressure is 70/50 mm Hg. Serum studies show:
Na+: 142 mEq/L
K+: 2.8 mEq/L
Cl–: 90 mEq/L
HCO3–: 34 mEq/L
Creatinine: 0.9 mg/dL
Glucose: 100 mg/dLRenin: 60 ΜU/mL (normal: 21-41 ΜU/mL)
Urinalysis reveals osmolality of 130 mOsm/kg and calcium clearance of 500 mg/day (normal: 100-300 mg/day).
The patient’s underlying pathology is most similar to the mechanism of action of which of the following drugs?
Acetazolamide
Amiloride
Furosemide
Hydrochlorothiazide
Spironolactone
Triamterene
Furosemide.
-Look at values
Thiazide dosent promote Ca++ excretion
-Bartter syndrome is a rare inherited cause of hypokalemia due to mutations in the Na+/K+/2Cl– transporters in the thick ascending loop of Henle.
Bartter syndrome causes tubular effects similar to furosemide, including increased urine calcium excretion and impaired ability to concentrate urine.
Altitude sickness
-Altitude sickness is associated with **cerebral edema **and respiratory alkalosis and can present with headache, vomiting, and confusion.
-Acetazolamide is a carbonic anhydrase inhibitor that causes HCO3– wasting, metabolic acidosis, and subsequent diuresis.
A 58-year-old man begins taking furosemide because of worsening pedal edema and dyspnea due to dilative cardiomyopathy. At a follow-up examination 2 weeks later, he reports feeling better. Laboratory tests show a venous pH of 7.48, venous partial pressure of carbon dioxide of 48 mm Hg, and serum bicarbonate of 35 mEq/L.
Which of the following is an effect of furosemide that best explains the patient’s abnormal laboratory values?
Decreased aldosterone
Decreased renin synthesis
Increased minute ventilation
Increased proximal tubule ammoniagenesis
increased sodium delivery to the distal nephron
Respiratory alkalosis with metabolic compensation
-increased sodium delivery to the distal nephron
-Loop diuretics cause metabolic alkalosis by stimulating renal hydrogen ion excretion. This occurs in two ways. Loop diuretics inhibit the Na+/K+/2Cl– loop transporters, causing sodium chloride diuresis. The increased sodium delivery to the distal nephron stimulates the distal sodium channels (aldosterone sensitive) to reabsorb more sodium. This stimulates the cells to secrete hydrogen ions and potassium, partly explaining the metabolic alkalosis (and hypokalemia) induced by loop diuretics. In addition, the volume depletion caused by loop diuretics leads to secondary hyperaldosteronism, leading to an additional aldosterone-mediated hydrogen ion loss in the same cells. The resulting alkalosis inhibits alveolar ventilation, which causes the PCO2 to rise, that is, a respiratory compensation.
A 73-year-old man comes to the clinic with a painful, swollen right great toe. He also has hypertension and congestive heart failure and was started on multiple medications for these disorders at the last clinic visit.
Which of the following medications is the most likely cause of his new symptoms?
Digoxin
Enalapril
Furosemide
Metoprolol
Spironolactone
Verapamil
Furosemide
-Gout is often, but not always, associated with elevated serum uric acid levels (hyperuricemia). Elevated uric acid can be associated with several medications, including thiazide and loop diuretics like furosemide (see table). These drugs decrease urinary uric acid excretion and so raise the serum uric acid level. Furosemide is a potent loop diuretic that is commonly used to treat heart failure.
Diagnosis and Relation to Renal system:
-Failure of normal bone resorption due to defective osteoclasts thickened,dense bones that are prone to fracture.Mutations (eg,carbonic anhydrase II) impairability of osteoclast to generate acidic environment necessary for bone resorption.Overgrowth of cortical bone fills marrow space–> pancytopenia ,extramedullary hematopoiesis (hepatosplenomegaly)
-Cranial nerve impingement and palsies due to narrowed foramina.
-X-rays show diffuse symmetric sclerosis(bone-in-bone,“stonebone app).
Osteopetrosis.
It relates renal system in that carbonic anhydrase deficency is associated with Renal Tubular acidosis.
A 22-year-old woman presents to her family physician because of increasing fatigue and pale appearance. She reports that her urine appears brown each morning. There is no history of major medical illness. Laboratory studies show RBC of 3 million/mm3 and hemoglobin 10 g/dL.
Which of the following best describes the most likely mechanism of erythrocyte injury in this condition?
-A defective cytoskeleton-membrane tethering protein
-Complement-mediated hemolysis
-Increased oxidative injury by H2O2 due to decreased NADPH
-Phagocytosis of RBCs due to complement fixation
-Phagocytosis of RBCs, which have surface-bound IgG
-Point mutation in the hemoglobin β-chain
-PNH is caused by complement-mediated lysis of RBCs. This is due to an acquired mutation of the PIGA gene within myeloid stem cells, required to make functioning glycosylphosphatidylinositol anchors for CD55 (decay accelerating factor) and CD59 (MAC inhibitory protein). These proteins, when attached to the cell membrane, protect cells against complement-mediated attack, so the absence of the anchoring protein makes RBCs subject to complement-mediated attack. In PNH, hemolysis of RBCs occurs at night as the carbon dioxide level rises during sleep, lowering pH levels (mild respiratory acidosis) and facilitating complement-mediated lysis of RBCs. As a result, the first morning void reveals dark urine with progressive clearing during the day.
Left and Right Hb dissociation curve with O2sat?
Left: Hb affinity towards O2 increases–>dosent release O2. (decr 2-3BPG, alkaline pH (Furosemide use), Low Temp., CO toxicity,vasodilators by forming MetHb–>reverse it with methylene blue.
*Right: *promotos decr Hb affinity towards O2–>promotes un-binding (incr 2-3BPG,exercise–>lactic acidosis Decr pH, Elvated Temp.,
A 7-month-old boy is brought to the emergency department with a 4-hour history of vomiting and irritability. His mother reports that these episodes began 1 month ago. Solid food and fruit juice were added to his diet around the same time after being exclusively breastfed. Prior to this episode he had met all developmental milestones. On physical examination, his weight and height are at the 30th percentile, down from the 40th percentile at his 6-month checkup. He appears lethargic and diaphoretic. The abdominal examination is normal. The vomitus is nonbloody and nonbilious.
Which of the following abnormalities is most likely to be present in this patient?
Biliary obstruction
Hypoglycemia
Hypothyroidism
Intestinal intussusception
Low serum vitamin D
-Hereditary fructose intolerance presents upon introduction of fructose into the diet with irritability, vomiting, failure to thrive, lethargy, and diaphoresis.
-hypoglycemia due to an inhibition of hepatic gluconeogenesis and glycogenolysis. As fructose is ingested, it is rapidly converted into fructose-1-phosphate by fructokinase in the liver. Hereditary fructose intolerance is caused by a deficiency in aldolase B, responsible for the conversion of fructose-1-phosphate into glyceraldehyde and dihydroxyacetone phosphate(metabolites of Glycolyisis) The increased fructose-1-phosphate damages the liver, depletes phosphate, and inhibits hepatic gluconeogenesis and glycogenolysis, leading to hypoglycemia.
-Intestinal intussusception causes vomiting with pain. It occurs when the intestine folds into the section in front of it, leading to obstruction. It causes severe, crampy, progressive abdominal pain with vomiting in infants up to 3 years old. There is often a right-sided abdominal mass.
-Biliary atresia causes extrabiliary obstruction in young infants. There is jaundice, acholic stools, and dark urine reflecting the increased conjugated bilirubin.
-Hypothyroidism in infancy is caused by congenital thyroid dysgenesis or enzymatic defects in thyroid synthesis. It causes lethargy and slow bone growth, but may also show coarse facial features, poor appetite, diminished reflexes, and a hoarse cry with eventual intellectual disability.
-Rickets caused by low serum vitamin D is seen mostly in developing countries and is marked by delayed growth, parietal and frontal bossing, soft skull bones, and other bone deformities not present in this patient.
Patient exposed to fires what type of poisoning should you suspect?
Cyanide
A 47-year-old man is brought to the emergency department immediately after being evacuated from his apartment because of a fire. He reports headache, weakness, and vertigo. Physical examination is significant for confusion. Arterial blood gas analysis shows a pH of 7.2. Carboxyhemoglobin is normal. He is not responsive to supplemental oxygen.
Which of the following best characterizes the most likely diagnosis in this patient?
-Anion-gap acidosis
-Decreased venous oxygen saturation
-Increased arterial-venous oxygen gradient
-Respiratory acidosis
-Cyanide poisoning presents with central nervous system symptoms, acidosis, and increased methemoglobin.
Cyanide inhibits the electron transport chain, which results in an increase in anaerobic metabolism and subsequent increase in lactic acid production.
Increased serum lactic acid results in an anion-gap metabolic acidosis, due to increased anion in serum.
-High Anion Gap Metabolic Acidosis
-Decreased venous oxygen saturation can be seen in various conditions, either caused by increased peripheral oxygen utilization or decreased cardiac output.
-An* increased arterial-venous oxygen gradient would be seen in conditions that have increased oxygen utilization in the periphery such as in sepsis.
-Respiratory acidosis* is caused by lung disease resulting in increased dead space, reduced minute ventilation, or increased carbon dioxide production.
A 30-year-old woman is brought to the emergency department after collapsing on her front lawn. Her medical history is unknown. On arrival in the emergency department, pulse is 108/min, blood pressure is 98/54 mm Hg, and oxygen saturation is 92% on room air. Laboratory analysis shows:
Serum:
Na+: 140 mEq/L
K+: 3.4 mEq/L
*Cl–: 116 mEq/L
HCO3–: 15 mEq/**L
Arterial blood:
pH: 7.32
pCO2: 30 mm Hg
Which of the following is the most likely explanation for these laboratory abnormalities?
Bulimia
Diabetic ketoacidosis
Diarrhea
Furosemide
Heroin overdose
-normal anion gap metabolic acidosis presents with low pH, low bicarbonate, and low pCO2 combined with a normal anion gap.
Diarrhea can cause normal anion gap metabolic acidosis and hypokalemia via gastrointestinal HCO3– and potassium loss.
-Bulimia would lead to a metabolic alkalosis, as the GI loss of hydrochloric acid due to vomiting leads to a transient increase in pH.
-Diabetic ketoacidosis leads to a high anion gap metabolic acidosis, due to increased unmeasured anions (ketones).
-Loop diuretics such as furosemide can lead to metabolic alkalosis due to volume depletion, renal loss of hydrogen ions, and secondary hyperaldosteronism.
-Heroin overdose would lead to a respiratory acidosis due to narcotic-induced hypoventilation.
-Spironolactone is a potassium-sparing diuretic that may cause a normal anion gap metabolic acidosis and hyperkalemia.
Diagnosis
Infection od Campylobacter Jejuni and developed LMN lesions bilateral?
-patient has presented with ascending weakness that is consistent with Guillain-Barré syndrome (GBS). GBS is a demyelinating disease of peripheral nerves, suggested on the electromyography/nerve conduction testing here. Patients also develop acute, progressive, symmetric, ascending muscle weakness/paralysis with lack of reflexes in the involved extremities as a result of the ascending paralysis.
GBS causes an ascending paralysis resulting in symmetric weakness with absent reflexes.
A patient may develop hypoventilation and respiratory acidosis leading to respiratory arrest.
Respiratory acidosis is demonstrated by low pH, high PCO2, and high bicarbonate.