Nephrology Flashcards
What are indications for CRRT?
AEIOU
BUN > 100 mg/dL
Volume overload unresponsive to diuretics
Uremia/encephalopathy
Electrolyte imbalance (hyperkalemia, hypermagnesimia)
Metabolic acidosis
What agent has shown some evidence for contrast-induced nephropathy?
NAC
A study compared the use of an angiotensin receptor blocker alone or in combination with an ACEI in patients with CKD. AKI occurred in 80 of 724 (11%) patients receiving monotherapy and in 130 of 724 patients (18%) receiving combination therapy. Based on this information, what is the number of patients needed to harm?
NNT = 1/(0.18 - 0.11) = 15
How do you properly dose ESA and titrate down?
Start if Hgb < 10 g/dL and decrease dose 25% if Hb increases by 1 g/dL in 2 weeks otherwise increase by 25% if Hgb increases by 1 g/dL in 4 weeks
What is the corrected Ca equation?
Measured Ca + 0.8(4-serum albumin)
What are the goal iron studies for iron repletion?
TSAT > 30% and ferritin > 500 ng/mL
When should vitamin D be used for patients with hyperphosphatemia?
No hypercalcemia and not for secondary hyperparathyroidism
A patient with chronic kidney disease (CKD) category
G4 (estimated creatinine clearance [eCrCl]
of 25 mL/minute) has received a diagnosis of
gram-positive bacteremia, which is susceptible
only to drug X. There are no published reports on
how to adjust the dose of drug X in patients with
impaired kidney function. Review of the drug X
package insert shows that it has significant renal
elimination, with 40% excreted unchanged in the
urine. The usual dose for drug X is 600 mg/day
intravenously and is provided as 100 mg/mL in a
6-mL vial. Which is the best dose (in milliliters of
drug X) to give this patient?
Q = 1 − [Fe(1 − KF)] Q = 1 − [0.4(1 − 25/120)] Q = 1 − [0.4(0.79)] Q = 1 − 0.32 Q = 0.68 or 68% of usual dose Drug X usual dose = 600 mg Formulation = 100 mg/mL in a 6-mL vial Adjusted dose = (usual dose) × (Q) = (600 mg)(0.68) = 410 mg Volume drug = (dose)/(concentration) = (410 mg)/(100 mg/mL) = 4.1 mL
When should you consider using 24-hour urine collection instead of Cockcroft-gault?
Vegetarians or reduction in muscle mass (i.e. amputees)
A 59-year-old patient who has had category G5
CKD for 10 years is maintained on chronic hemodialysis.
He has a history of hypertension, coronary
artery disease (CAD), mild congestive heart failure
(CHF), and type 2 diabetes mellitus. Medications
are as follows: epoetin 10,000 units intravenously
three times/week at dialysis, renal multivitamin
once daily, atorvastatin 20 mg/day, insulin, and
calcium acetate 1334 mg three times/day with
meals. Laboratory values are as follows: hemoglobin
9.2 g/dL, intact parathyroid hormone (PTH)
300 pg/mL, Na 140 mEq/L, K 4.9 mEq/L, SCr 7.0
mg/dL, calcium 9 mg/dL, albumin 3.5 g/dL, and
phosphorus 4.8 mg/dL. He has a serum ferritin
concentration of 80 ng/mL and a transferrin saturation
(TSAT) of 14%. Mean corpuscular volume,
mean corpuscular hemoglobin concentration, and
white blood cell count (WBC) are all normal. He
is afebrile. Which is the best approach to managing
anemia in this patient?
Add intravenous iron
A 60-year-old (72-kg) patient with a history of
diabetes and hypertension is in the intensive care
unit after having a myocardial infarction about
1 week ago with secondary heart failure. He now
has pneumonia. He has been hypotensive for the
past 5 days. Before his admission 1 week ago, he
had an SCr of 1.0 mg/dL. His urine output has been
steadily declining for the past 3 days, despite adequate
hydration, with 700 mL of urine output in
the past 24 hours. His medications since surgery
include intravenous dobutamine, nitroglycerin,
and cefazolin. Yesterday, his BUN and SCr were
32 and 3.1 mg/dL, respectively; today, they are 41 and 3.9 mg/dL. His urine osmolality is 290
mOsm/kg. His urine sodium is 40 mEq/L, and
there are tubular cellular casts in his urine. Which
is the most likely renal diagnosis?
The BUN/SCr ratio, urine osmolality, and presence of
urinary casts all point to ATN. Prerenal and functional
AKI look similar in urinalysis. Classically, AIN has
eosinophils in the urine.
You are evaluating a study comparing epoetin and
darbepoetin in terms of their efficacy on mean
hemoglobin concentrations. Both drugs are initiated
at the recommended dose, and the hemoglobin
concentration is checked at 4 weeks. Fifty patients
are in each group. The mean hemoglobin in the
epoetin group is 12.1 g/dL, and in the darbepoetin
group, it is 12.2 g/dL. Which statistical test is best
for this comparison?
Hemoglobin represents continuous data. Because
each treatment is administered to a separate group of
patients, the data are not paired (i.e., they are unpaired).
Assuming the data are normally distributed, continuous
unpaired data should be evaluated using a t-test.
Analysis of variance can be used for continuous data,
but only when three groups of data are compared.
However, a chi-square test is used for nominal data
A 55-year-old man has a history of hypertension. His estimated glomerular filtration rate (eGFR) is 48 mL/min/1.73 m2. Urine albumin:Cr ratio (ACR) is 28 mg/g. According to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines, which of the following is this patient’s goal blood pressure?
KDIGO provides recommendations for blood pressure goals for patients with CKD based on the severity of proteinuria. This patient is considered to have normal
to mildly elevated albuminuria, with an albumin:creat-
inine ratio less than 30 mg/g. Patients with albuminuria in this category (A1) should have a goal blood pressure
of less than 140/90 mm Hg.
A 68-year-old patient has diabetes, hypertension, and an eGFR of 40 mL/min/1.73 m2. Medications include a renal multivitamin once daily, simvastatin, lisinopril, and hydrochlorothiazide. Laboratory values are as follows: hemoglobin 11.2 g/dL, immunoassay for PTH 200 pg/mL, Na 138 mEq/L, K 4.9 mEq/L, calcium 8.6 mg/dL, albumin 3.5
g/dL, phosphorus 5.8 mg/dL, and 25-hydroxyvitamin D 45 ng/mL. Which of the following is best to prevent CKD–mineral bone disorder (MBD) in this patient? A. Ergocalciferol. B. Calcium acetate. C. Calcitriol. D. Cinacalce
Although this patient’s PTH level is elevated, it may be related to hyperphosphatemia. Therefore, the first approach would be to administer a phosphate binder, such as calcium acetate, to decrease his serum phosphate concentrations. A calcium-containing phosphate binder, such as calcium acetate, is acceptable with a corrected serum calcium concentration is the low-normal range. Ergocalciferol is not necessary in this patient because the 25-hydroxyvitamin D level is greater than 30 ng/mL, indicating adequate intake. An active vitamin D, such as calcitriol, could be added if the PTH level remains elevated despite normalization of serum phosphate. Cinacalcet is reserved for patients with hyperparathyroidism despite normalization of phosphate in patients with hypercalcemia
