IM EOR-Nephro: Renal Failure, Glomerulonephritis, Goodpastures, Nephrotic Syn, Hydronephrosis

In prerenal acute renal failure fractional excretion of sodium will be normally < ______

1

The 3 Renal causes of acute renal failure are _________________ (45%).

1. Glomerular 2. Tubular 3. Interstitial

The causes of glomerularnephritis are __________________.

1. Postreptococcal Glomerulonephritis 2. Post Infectious (i.e viral) 3. Glomerular diseases - AMCA. Wegener's, Churg-Strauss, anti-GBM, Goodpasture's syndrome, IgA nephropathy (Berger's)

There are three mechanisms of acute renal failure: 1. Prerenal - perfusional (50%) 2. Renal - glomerular, tubular, interstitial (45%) 3. Postrenal - obstructive (5%)

1. Prerenal 2. Renal 3. Postrenal

What are some possible causes of Acute Renal Failure:

1. Volume loss (blood or water) 2. Heart failure (the pump stops working = no kidney perfusion) 3. Loss of peripheral vascular resistance (think sepsis or anesthesia)

In prerenal disease, BUN/CR > _________

20:1

Oliguria is urine output less than ________ ml/day.

400 ml/day

A 25-year-old man comes to the emergency department because of severe leg cramps. He says that he has "dark urine" and that earlier in the morning he had trouble lifting a glass object. Physical examination shows tenderness in his hamstrings and quadriceps on palpation. A urine dipstick is positive for blood. Which of the following is most likely a potential complication of this patient's condition? A. Acute kidney injury B. Acute myocardial infarction C. Acute respiratory distress syndrome D. Hemothorax E. Tension pneumothorax

A (Acute kidney injury) (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 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? A. Acute kidney injury B. Acute myocardial infarction C. Acute respiratory distress syndrome D. Tension pneumothorax

A (Acute kidney injury) (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)

Which of the following is a cause of acute kidney failure due to prerenal azotemia? A. Excessive diuresis B. Urinary tract obstruction C. Radiologic contrast media D. Aminoglycosides

A (Excessive diuresis) (Prerenal azotemia is due to renal hypoperfusion which can occur with intravascular volume depletion such as excessive diuresis, hemorrhage, and gastrointestinal losses)

An elderly appearing adult male patient is transported to the emergency room with unconsciousness for an underdetermined amount of time. There is no family and the only history is provided by the paramedics. The patient arouses to verbal and painful stimuli. VS: T-97.0 degrees F rectally, P-52 bpm, R-10, BP-95/60 mmHg. Physical examination is unremarkable except for ecchymosis across his extremities. A Foley catheter is inserted draining a small amount of dark brown urine. Urine dipstick reveals 4+ positive hemoglobin and protein. Microscopic urinalysis reveals no RBCs but many renal tubular epithelial cells and renal tubular casts. Drug screen is negative, blood alcohol is 2.5 mg/dL, and creatinine is 4.9 mg/dL. What is the most likely diagnosis? A. Rhabdomyolysis causing acute renal failure B. Obstructive uropathy causing acute renal failure C. Ethanol ingestion causing acute renal failure D. Methanol ingestion causing acute renal failure

A (Rhabdomyolysis causing acute renal failure) (Since the patient was found unconscious for an undetermined amount of time and the blood alcohol is elevated the patient has been in a state of prolonged immobilization resulting in muscle ischemia resulting in myoglobinuria. This is responsible for turning the dipstick positive without the RBCs seen on the urinary microscopy. The myoglobin causes an acute tubular necrosis resulting in the sloughing of the renal tubular epithelium. Obstructive uropathy does not cause acute tubular necrosis and occurs over time. Methanol ingestion causes visual symptoms, ethylene glycol causes renal failure)

Lab results for a post-operative oliguric patient reveals an increased BUN to creatinine ratio. The patient has a low fractional excretion of sodium (less than 1%). Which of the following is the most likely diagnosis? A. prerenal azotemia B. acute tubular necrosis C. acute glomerulonephritis D. obstructive uropathy

A (prerenal azotemia) (Patients who have prerenal azotemia with otherwise normal kidneys will have severe sodium retention in order to help to save fluid. The amount of sodium in the urine is therefore very low)

A 52-year-old male with a past medical history of diabetes mellitus presents with fever and acute onset left lower quadrant abdominal pain. CT scan with contrast shows acute diverticulitis. He is started on broad-spectrum antibiotics. The next day, labs reveal a rise in creatinine from 0.7 mg/dL to 2.0 mg/dL. Urinalysis is obtained and a significant amount of muddy brown casts is found. What is the most likely diagnosis?

Acute renal failure

___________________ is a rapid but usually reversible, reduction in renal excretory function sufficient to cause azotemia, urine output may or may not be reduced.

Acute renal failure

_____________________ can develop as a result of acetaminophen overdose however this is rare.

Acute renal failure

_____________________ is suspected when urine output falls or serum BUN and creatinine rise.

Acute renal failure

Exogenous nephrotoxins, such as aminoglycosides, cause _________________, which is an intrinsic renal disease.

Acute tubular necrosis

Radiologic contrast media can be directly nephrotoxic causing _________________________, which is an intrinsic renal disease.

Acute tubular necrosis

What condition: Fractional Excretion of Sodium is going to be GREATER than 2%) + Muddy Casts + High Urine Osmolality

Acute tubular necrosis

What type of renal acute renal failure: Muddy casts

Acute tubular necrosis

What type of renal acute renal failure: ↑ Osmolality FENa > 2%

Acute tubular necrosis

Acute renal failure is a rapid but usually reversible, reduction in renal excretory function sufficient to cause ______________, urine output may or may not be reduced.

Azotemia

__________________ is retention of nitrogenous wastes

Azotemia

A 15 year old boy comes to your clinic after having a sore throat, he wasn't treated. He now has hematuria, pretibial edema and hypertension. What antibody do expect on lab findings? A. ANCA B. ASO C. ANA D. Anti GBM

B (ASO) (This patient has classic symptoms of hematuria, pretibial edema and hypertension indicative of nephritic syndrome. The history of an untreated sore throat is key to the diagnosis of post streptococcal glomerulonephritis. He would have a positive ASO titer)

A urinalysis performed during a routine physical examination on a 43 year-old male reveals 1-2 hyaline casts/HPF. The remainder of the UA is normal. Based upon these results, the physician assistant should A. collect a urine for culture and sensitivity B. do nothing, since these casts are considered normal C. refer the patient to a nephrologist D. schedule the patient for a CT scan

B (do nothing, since these casts are considered normal) (Hyaline casts are not indicative of renal disease. They can be found following strenuous exercise and with concentrated urine or during a febrile illness)

Acute renal failure is suspected when urine output falls or serum __________ and creatinine rise.

BUN

A 27 year-old patient presents with crush injuries to both lower extremities after being involved in an automobile accident. Within six hours of the accident, urine output has decreased to less than 10 cc per hour. Within 24 hours the serum creatinine increased from 0.9 mg/dl to 2.9 mg/dl and serum CPK is now 12,000 U/L. In addition to a fluid challenge with normal saline, which of the following is the most appropriate treatment as this time? A. IV calcium chloride B. Oral captopril (Capoten) C. IV sodium bicarbonate D. Oral sevelamer (Renagel)

C (IV sodium bicarbonate) (Treatment of acute renal failure due to rhabdomyolysis is best accomplished with IV fluids and forced alkaline diuresis)

What type of renal acute renal failure Waxy casts

Chronic renal disease

Serum ______________ is the most convenient marker of acute renal failure.

Creatinine

Which of the following medications is most likely to cause acute tubular necrosis? A. Trimethoprim-sulfamethoxazole (Bactrim) B. Acetaminophen C. Cephalothin (Kefzol) D. Gentamicin

D (Gentamicin) (In hospitalized patients up to 25% of patients receiving aminoglycosides sustain some degree of acute tubular necrosis. Gentamicin is one of the most toxic aminoglycosides, streptomycin is the least nephrotoxic of the aminoglycosides)

A 82-year-old man is brought to the emergency department because of muscle weakness and general discomfort. The patient is confused and says he has a headache, he feels thirsty, and that he has not urinated for the past 4 days. He lives with his son and his family, and says that he does the same thing every day, which is watching TV and stay in his room. His temperature is 39.5°C (103.1°F), pulse is 110/min, respirations are 14/min, and blood pressure is 90/65 mm Hg. Physical examination shows purple fingernails. Which of the following is the most likely cause of muscle weakness in this patient's condition? A. Botulism B. Bradycardia C. Hypercalcemia D. Hyperthermia E. Hypothermia

D (Hyperthermia) (Hyperthermia is a cause of muscle weakness when there is no history of extreme exertion, alcohol consumption, or trauma. Muscle weakness is part of the symptomatology of rhabdomyolysis, which is a condition in which damaged skeletal striated muscle breaks down rapidly) (Rhabdomyolysis is a condition in which damaged skeletal striated muscle breaks down rapidly. Breakdown products of damaged muscle cells are released into the bloodstream; some of these (e.g. myoglobin) are harmful to kidneys and lead to kidney failure. Rhabdomyolysis is characterized by muscle pain or weakness, vomiting, and confusion. 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. The muscle damage is caused by physical factors (e.g. crush injury, strenuous exercise, medications, drug abuse, and infections). When there is no history of extreme exertion, alcohol consumption, or trauma, hyperthermia is a cause of muscle weakness. Geriatric population is more susceptible to heat stroke and is related to reduced mobility, capacity for independent living, compromised end organ function (e.g. renal, hepatic), or abuse by neglect (leading to inadequate hydration, among others). Hereditary muscle condition increases risk of rhabdomyolysis. Diagnosis is made with blood tests and urinalysis. Positive urine dipstick for blood is a representation of myoglobin in the kidneys. Treatment is with intravenous fluids, dialysis, or hemofiltration)

A 35-year-old man comes to the emergency department because of dark urine. Patient denies any kidney disease and he admits that he started a new intense weight lifting program. This morning he spent 4 hours lifting heavy weights. Physical examination shows muscle weakness in all extremities. Urinalysis shows: blood++ and protein++. Urine microscopy is negative for RBCs and shows epithelial cells. Blood tests are notable for CK 1000 U/L. Which of the following is the most likely cause of this patient's dark urine? A. Creatine kinase B. Haptoglobin C. Insulin D. Myoglobin

D (Myoglobin) (Myoglobin can become lodged in the renal tubules and cause acute tubular necrosis, leading to acute kidney injury, increasing creatinine, BUN, and dark urine. This condition characterizes one of the possible complications of rhabdomyolysis, which is a condition in which damaged skeletal striated muscle breaks down rapidly)

The major causes of Acute tubular necrosis are:

Drugs and toxins -Amphotericin B ("amphoterrible") -Cisplatin -Aminoglycosides -Radiocontrast media -NSAIDs -ACE

In Acute tubular necrosis damage to the tubules means you are unable to concentrate urine which means a high _____________________.

FENa

What condition: Urinalysis: Oliguria, hematuria and RBC casts

Glomerularnephritis

What type of renal acute renal failure: RBC casts

Glomerulonephritis

_________________ are not indicative of renal disease. They can be found following strenuous exercise and with concentrated urine or during a febrile illness.

Hyaline casts

The etiology of interstitial nephritis is an ________________________.

Immune-mediated response

What condition On renal biopsy will see interstitial inflammatory cell infiltrates.

Institial nephritis

What condition: Eosinophils, WBC casts, and hematuria

Interstitial nephritis

What condition: Urinalysis shows WBC casts and eosinophils

Interstitial nephritis

What type of renal failure: Hyaline casts

Normal

To treat postrenal acute renal failure place a foley catheter to find the source of the __________________.

Obstruction

The Postrenal mechanism of acute renal failure is _________________ (5%).

Obstructive

________________ is urine output less than 400 ml/day.

Oliguria

What drugs can provoke an immune-mediated response, leading to interstitial nephritis?

PCN Sulfa NSAIDs Phenytoin

The Prerenal mechanism of acute renal failure is _________________ (50%).

Perfusional

What type of acute renal failure: Obstruction (most likely prostate)

Postrenal

What type of acute renal failure: Will typically have low or no urine output and possibly suprapubic pain

Postrenal

_____________________ azotemia is due to obstruction of urinary flow from both of the kidneys.

Postrenal

What type of acute renal failure: Urine specific gravity > 1.030 BUN/CR > 20 Urine osmolality > 500 FENA (fractional excretion of sodium) < 1

Prerenal

What type of acute renal failure: Kidney is working fine, it's the things that make the kidney perfuse that aren't working properly

Prerenal

What type of acute renal failure: Pt will be weak, decreased urine output, dizziness, sunken eyes, tachycardia, orthostatic blood pressure changes

Prerenal

__________________ azotemia is due to renal hypoperfusion which can occur with intravascular volume depletion such as excessive diuresis, hemorrhage, and gastrointestinal losses

Prerenal

__________________failure is the most common cause of Acute tubular necrosis.

Prerenal

(Proximal/distal) muscle pain is a common feature of symptomatic rhabdomyolysis.

Proximal

What type of renal acute renal failure: WBC casts

Pyelonephritis

_____________________ can be directly nephrotoxic causing acute tubular necrosis, which is an intrinsic renal disease.

Radiologic contrast media

What type of acute renal failure: Urine specific gravity < 1.010 BUN/CR < 10 Urine osmolality < 300 FENA (fractional excretion of sodium) > 1

Renal

In postrenal acute renal failure you should order a _____________ to look for tumors or hydronephrosis.

Renal US

Interstitial nephritis is diagnosed with ________________.

Renal biopsy

A diagnosis of ___________________ can be considered with an elevated creatine kinase level and evidence of renal dysfunction.

Rhabdomyolysis

Moderate to severe _____________________ may present with red to brown colored urine due to myoglobin in the urine.

Rhabdomyolysis

Statins can inhibit the electron transport chain, causing destruction of myocytes and leading to ____________________.

Rhabdomyolysis

____________________ is a condition in which damaged skeletal striated muscle breaks down releasing large amounts of myoglobin which can lead to kidney injury.

Rhabdomyolysis

Rhabdomyolysis is an adverse effect of ___________ when administered with fibrates and niacin.

Statins

_____________ (drug class) can inhibit the electron transport chain, causing destruction of myocytes and leading to rhabdomyolysis.

Statins

Immunologic and infectious diseases can provoke an immune-mediated response, leading to interstitial nephritis?

Strep SLE CMV Sjogren's Sarcoidosis

Symptomatic azotemia, with nausea, vomiting, and lethargy

Uremia

On urinalysis interstitial nephritis will have _____________ and eosinophils.

WBC casts

Acute renal failure can develop as a result of ________________________ overdose however this is rare.

acetaminophen

Treatment of acute renal failure due to rhabdomyolysis is best accomplished with IV fluids and forced ____________________.

alkaline diuresis

Exogenous nephrotoxins, such as _____________________, cause acute tubular necrosis, which is an intrinsic renal disease.

aminoglycosides

In Acute tubular necrosis damage to the tubules means you are unable to _________________ urine which means a high FENa.

concentrate

A diagnosis of rhabdomyolysis can be considered with an elevated _______________ level and evidence of renal dysfunction.

creatine kinase

Acute renal failure is suspected when urine output falls or serum BUN and ____________ rise

creatinine

Treat interstitial nephritis by discontinuing the _________________, Dialysis if needed, usually self-limiting if caught early

discontinuing the offending drug, or corticosteroids

On urinalysis interstitial nephritis will have WBC casts and ________________.

eosinophils

Acute renal failure is a rapid but usually reversible, reduction in renal _________________ function sufficient to cause azotemia, urine output may or may not be reduced.

excretory

Acute renal failure is suspected when urine output ( rise / falls) or serum BUN and creatinine rise.

falls

Hyaline casts are not indicative of renal disease. They can be found following strenuous exercise and with concentrated urine or during a _______________.

febrile illness

Rhabdomyolysis is an adverse effect of statins when administered with (two) ______________________.

fibrates and niacin

IV ____________ should be started quickly after a diagnosis of rhabdomyolysis has been made to prevent further kidney injury.

fluids

You prerenal disease with ________________and/or treat shock.

fluids and cardiac support

To treat postrenal acute renal failure place a ____________ to find the source of the obstruction.

foley catheter

Prerenal azotemia is due to renal __________________which can occur with intravascular volume depletion such as excessive diuresis, hemorrhage, and gastrointestinal losses.

hypoperfusion

In interstitial nephritis, renal biopsy will show interstitial _____________________.

inflammatory cell infiltrates

Rhabdomyolysis is a condition in which damaged skeletal striated muscle breaks down releasing large amounts of myoglobin which can lead to ____________ injury.

kidney

Rhabdomyolysis is a condition in which damaged skeletal striated muscle breaks down releasing large amounts of _______________ which can lead to kidney injury.

myoglobin

Azotemia is retention of __________________.

nitrogenous wastes

In prerenal disease, the secretion will be ____________

normal

Postrenal acute renal failure is due to obstruction, most likely from the ____________.

prostate

Moderate to severe rhabdomyolysis may present with _____________________ colored urine due to myoglobin in the urine.

red to brown

A diagnosis of rhabdomyolysis can be considered with an elevated creatine kinase level and evidence of ___________ dysfunction.

renal

Acute renal failure is suspected when urine output falls or serum BUN and creatinine (rise / falls).

rise

In prerenal disease, the ___________ will be normal

secretion

Heart failure, pulmonary edema, and hypertension are consequences of renal failure due to the retention of ____________ and water.

sodium

Hyaline casts are not indicative of renal disease. They can be found following __________________ and with concentrated urine or during a febrile illness.

strenuous exercise

In postrenal acute renal failure you should order a Renal US to look for _____________________________.

tumors or hydronephrosis

Acute renal failure is suspected when ___________ falls or serum BUN and creatinine rise.

urine output