Nephrology Lecture #3

What is the classic triad for pyelonephritis?

Fever, flank pain, nausea or vomiting

What should be suspected in patients with flank pain and UTIs?

Pyelonephritis

What type of bacteria are most common causing agents for pyelonephritis?

Gram negative bacteria

- E. coli

Costovertebral angle tenderness is usually pronounced

Pyelonephritis

A 32-year-old woman presents to urgent care with a 2-day history of fever, chills, and right-sided flank pain. She also reports nausea and two episodes of vomiting. She denies vaginal discharge or abdominal cramping. On physical exam, her temperature is 101.8°F (38.8°C), heart rate is 102 bpm, and blood pressure is 110/70 mmHg. Costovertebral angle tenderness is noted on the right side.

1.) What is the diagnosis?

2.) What labs should you order? What would you find on those labs?

3.)What imaging?

4.) How do you treat this?

1.) Pyelonephritis

2.)

CBC - Leukocytosis

Urinalysis

- Nitrite production if E. coli

- Presence of WBC casts

3.)

Renal ultrasound or CT

Perinephric stranding CT is imaging study of choice

----> Findings include perinephric fat stranding and focal wedge-like regions appear swollen and demonstrate reduced enhancement compared with normal kidney

4.) Outpatient treatment - Fluoroquinolones or single dose of ceftriaxone + oral antibiotics

What would you find on a renal ultrasound of pyleonephritis?

Particulate matter/debris in collecting duct, gas bubbles, focal/segmental hypoechoic regions

Your patient has an uncomplicated case of pyelonephritis, how do you treat it?

Fluorquinolones

Ceftriaxone + oral antibiotics

Your patient is admitted to the hospital for pyelonephritis, how do you treat it?

Parenteral antibiotic therapy

--> Cipro, ceftriaxone, piperacillin-tazobactam - standard spectrum IV antibiotics

--> Zosyn, imipenem, meropenem for patients at risk for MDR gram neg

You are treating your hospitalized patient for pyelonephritis, how long does it take them to respond to treatment?

48-72 hours

A 28-year-old woman who is 24 weeks pregnant presents to the emergency department with fever, chills, right-sided flank pain, and nausea with vomiting for the past 2 days. On exam, her temperature is 102.2°F (39°C), pulse is 110 bpm, and she has pronounced right costovertebral angle tenderness. Urinalysis shows positive nitrites, leukocyte esterase, and pyuria.

How should you manage this patient?

1.) Patient should be admitted and treated initially with parental therapy

-> Broad spectrum beta lactams (Ceftriaxone or zosyn)

--> Switch to oral antibiotics

-------> Beta lactams (penicillins, cephalosporins, carbapenems).

This patient would not receive Bactrim because she is in her second trimester, but if she were past the second trimester then should would receive Bactrim

Solve the riddle.

I am a rare variant of pyelonephritis. I can massively destruct the kidney by granulomatous tissue. I am here as a result of infected renal stones. What am I?

xanthogranulamatous pyelonephritis

A 54-year-old woman presents with fatigue, malaise, low-grade fever, and left-sided abdominal pain that has been gradually worsening over several weeks. She also reports poor appetite and unintentional weight loss. Her medical history includes recurrent urinary tract infections and a known staghorn calculus in the left kidney. On physical exam, she has mild left costovertebral angle tenderness. A CT scan of the abdomen shows an enlarged kidney with multiple low-density round lesions, described as having a "bear's paw" appearance.

What is the diagnosis?

How do you treat this?

1.) Xanthogranulamatous pyelonephritis

2.) Refer to urology. Radical nephrectomy - Kidney is completely destroyed

Bear paw sign

Xanthogranulamatous pyelonephritis

More then __________% of nephrolithiasis will be become recurrent.

50

What are the 5 types of nephrolithiasis stones?

1.) Calcium oxalate

2.) Calcium phosphate

3.) Uric acid

4.) Struvite

5.) Cystine

What percentage of renal stones are calcium?

80% are calcium oxalate

What is the number one risk for calcium nephrolithiasis?

Dehydration is the #1 risk factor, this is why you need to increase fluid intake to produce at least 2.5 liters of urine a day

What are the risk factors for calcium nephrolithiasis?

Hypercalinuria

Hyperoxaluria

Hypocitrauria

A 40-year-old man presents to the emergency department with sudden-onset, severe left flank pain radiating to the groin. He describes the pain as sharp and intermittent, and he is visibly uncomfortable, frequently shifting positions. He reports associated nausea and hematuria, but denies fever or dysuria. He has no significant past medical history but admits to frequently working outdoors in hot weather and rarely drinks water. A non-contrast CT of the abdomen and pelvis reveals a 3 mm left distal ureteral stone.

What is the most likely composition of the stone?

A. Uric acid stone

B. Cystine stone

C. Struvite stone

D. Calcium oxalate stone

D. Calcium oxalate stone

What acid urine pH level can lead to uric acid nephrolithiasis?

Less then 5.5

A 52-year-old man presents with sudden onset of right flank pain that radiates to the groin. He describes it as sharp and cramping. He has a history of gout and reports consuming a high-protein diet. He denies fever but has mild nausea. Urinalysis reveals hematuria, and urine pH is 5.0. A non-contrast CT confirms the presence of a renal calculus. The stone is radiolucent on X-ray.

What is likely the cause of his kidney stone?

How do you treat it?

1.) Uric acid

2.) Alkalinization of urine to a target pH (6.5-7.0), potassium citrate 40-60mEq daily

What are some risk factors for uric acid nephrolithiasis?

1.) Disorders leading to acidic urine pH

2.) Disorders leading to purine or urate production

3.) Drug, diet, toxin induced purine or urate overproduction

A 27-year-old woman at 24 weeks' gestation presents to the emergency department with a 2-day history of fever, chills, right-sided flank pain, and dysuria. On exam, her temperature is 102.4°F (39.1°C), pulse is 110/min, and she has costovertebral angle tenderness on the right. Urinalysis shows pyuria, positive nitrites, and leukocyte esterase. A urine culture is pending.

What is the most appropriate next step in management?

A) Discharge home with oral nitrofurantoin

B) Start intravenous ceftriaxone and admit for inpatient management

C) Start trimethoprim-sulfamethoxazole and discharge home

D) Begin oral ciprofloxacin and observe in outpatient clinic

B) Start intravenous ceftriaxone and admit for inpatient management

Can later switch to beta lactams. If past second trimester can switch to oral Bactrim

Approximately 80% of renal stones are ____________.

Calcium

How does calcium nephrolithiasis occur?

Supersaturation of urine, forms crystals, and aggregates into detectable stone.

What is the number 1 risk factor for calcium nephrolithiasis?

Dehydration

To avoid calcium stones you should increase fluid intake to produce at least __________ liters of urine in a day.

2.5

What are the risk factors for calcium nephrolithiasis?

Hypercalcinura - Too much calcium

Hyperoxaluria

Hypocitrauria

How do you treat uric acid nephrolithiasis?

Alkalinization of urine to a target pH (6.5-7.0)

Potassium citrate 50-60Eq

Xanthium oxidase inhibitors - Allopurinol 300mg daily

Staghorn calculus that fills entire renal collecting system

struvite nephrolithiasis

A 36-year-old man presents to the emergency department with sudden-onset severe left flank pain that radiates to his groin. He is pacing around the room, appears uncomfortable, and rates his pain as 9/10. He reports associated nausea but no fever or dysuria. He mentions working outdoors and drinking very little water throughout the day. A non-contrast CT scan of the abdomen and pelvis reveals a 4 mm calculus in the left ureter. Urinalysis shows microscopic hematuria.

What is the diagnosis?

How do you treat it?

1.) Calcium nephrolithiasis

2.) High fluid intake to pass the stone

What is a risk factor for struvite nephrolithiasis?

UTIs

A 65-year-old woman presents to the urology clinic with intermittent right flank discomfort but denies hematuria or dysuria. Her history is significant for a neurogenic bladder requiring chronic catheterization. A recent non-contrast CT scan of the abdomen reveals a large staghorn calculus occupying the right renal pelvis and extending into multiple calyces.

What is the diagnosis?

How did she likely get this condition? Be specific!

If you did a urinalysis what you find?

What would the urine pH be?

How do you treat this?

1.) This patient has struvite nephrolithiasis. It is more common in women than men since women are more prone to UTIs

2.) She likely got it from recurrent UTI caused by urease-producing organisms such as E. Coli, Klebsiella, proteus, pseudomonas, mycoplasma

3.) Urine would contain magnesium ammonium phosphate.

4.) Urine pH is elevated which decreases the solubility of phosphate and allows stone formation to occur.

5.) Antibiotics to prevent recurrent UTIs + Percutaneous nephrolithonotomy.

_________ is caused by a rare genetic metabolic defect (autosomal dominant), resulting in abnormal excretion of cystine.

Cystine nephrolithiasis

What type of stone do you suspect when its the patient's first kidney stone in childhood or adolescence (median onset is 12)?

Cystine Nephrolithiasis

A 13-year-old boy presents to the emergency department with severe flank pain and hematuria. His parents report that he has had similar episodes in the past, starting around age 10. He has no significant past medical history, but his father reports that several family members have a history of kidney stones beginning in their teens. A non-contrast CT scan of the abdomen reveals multiple bilateral radiopaque renal calculi. Urinalysis reveals hexagonal crystals.

How do you treat this condition?

1.) Aggressive hydration (3-4 L day)

Urinary alkalinization

---> Potassium citrate 60-80mEq/day

Thiobased drugs

Surgical intervention

A 38-year-old man presents to the emergency department with sudden onset of severe left-sided flank pain that started 3 hours ago. He describes the pain as sharp, constant, and radiating to his left groin and lower abdomen. He is visibly uncomfortable and frequently shifts positions on the stretcher. He also reports nausea and has vomited twice since the pain began. He denies fever or dysuria but mentions increased urinary urgency over the past day.

On physical exam, he is afebrile with normal vital signs. Abdominal exam reveals left costovertebral angle tenderness without rebound or guarding. Urinalysis shows microscopic hematuria.

What is best diagnostic imaging test to order for this patient?

The patient has nephrolithiasis order a Non-contrast CT scan. It can detect obstruction, stone size and location

You order a non-contrast CT scan for your patient with nephrolithiasis? What is the best position to put them in to differentiate location of the stone?

Prone position on a non-contrast CT scan

A 28-year-old woman at 22 weeks gestation presents to the emergency department with severe, intermittent right-sided flank pain that began 6 hours ago. She reports associated nausea but no vomiting. She denies fever or chills. Her prenatal course has been uncomplicated so far.

On physical exam, she has right costovertebral angle tenderness. Vitals are normal. Urinalysis shows microscopic hematuria. Serum creatinine is within normal limits.

What scan do you order for her?

What is her diagnosis?

1.) Ultrasound since she is pregnant

2.) Nephrolithiasis

Which imaging is used to detect large radioopaque stones such as calcium, struvite, and cystine?

KUB

You can use urine pH from a urinalysis to help you determine which type of nephrolithiasis a patient has.

What is the pH of someone with uric acid stone?

What is the pH of someone with struvite or calcium phosphate stone?

What is the pH of someone with calcium oxalate stone?

1.) pH less then 5.5 for uric acid

2.) pH greater then 7.2 for struvite and calcium phosphate

3.) Normal pH for calcium oxalate

A 45-year-old man presents to the ED with sudden onset of right flank pain that began this morning. He describes the pain as sharp and radiating to his groin. He has had two episodes of vomiting and reports urgency when urinating. He denies fever or dysuria. Urinalysis reveals microscopic hematuria and a urine pH of 5.0.

A KUB is unremarkable, but the patient continues to have severe pain despite analgesics.

What is the appropriate next diagnostic step?

1.) Non-contrast CT this patient has nephrolithiasis

Any obstructing stone with _______________ is a medical emergency

associated infection

A 52-year-old woman presents to the emergency department with severe left flank pain, fever, and nausea. She notes the pain began abruptly 6 hours ago and has worsened. She reports chills and urinary urgency. Her temperature is 102.4°F (39.1°C), heart rate 118 bpm, blood pressure 88/54 mmHg, and respiratory rate 22 breaths/min.

Physical examination reveals left costovertebral angle tenderness. Urinalysis shows positive nitrites, leukocyte esterase, and microscopic hematuria. A non-contrast CT of the abdomen reveals a 7 mm obstructing stone in the proximal left ureter with evidence of hydronephrosis.

What is the next best step in management?

This patient has a fever, tachycardia, and hypotension due to an obstructing stone. This is clear evidence that this patient has acute nephrolithiasis with infection. This a medical emergency and you need to admit and consult urology to prompt drainage of the kidney + administer antibiotics.

A 48-year-old woman presents to the emergency department with sudden onset of severe left-sided flank pain, nausea, and chills. She reports a subjective fever earlier today. On exam, she is febrile to 102.1°F (38.9°C), heart rate is 120 bpm, and blood pressure is 90/55 mmHg. She appears uncomfortable and is constantly shifting positions. There is significant left costovertebral angle tenderness.

Urinalysis is positive for nitrites, leukocyte esterase, and microscopic hematuria. A non-contrast CT scan shows a 9 mm obstructing stone in the left proximal ureter with hydronephrosis.

What is the most appropriate next step in management?

A. Administer aggressive IV fluids to promote diuresis and stone passage

B. Begin IV antibiotics and reassess in 24 hours

C. Consult urology for urgent drainage and start IV antibiotics

D. Insert Foley catheter to reduce bladder pressure and promote passage

C. Consult urology for urgent drainage and start IV antibiotic

Note that forced diuresis will NOT push stones down the ureter and may make the problem worse

A 34-year-old man presents to the urgent care clinic with right-sided flank pain that started 12 hours ago. He describes the pain as sharp, intermittent, and radiating to the groin. He has no fever, chills, or urinary symptoms. He is hemodynamically stable and in moderate discomfort.

A non-contrast CT reveals a 4 mm stone in the distal right ureter with no signs of hydronephrosis. Urinalysis is positive for microscopic hematuria, and renal function is normal.

What is most appropriate treatment?

This is nephrolithiasis. For stones less then 5 mm in size can treat with alpha blockers (tamsulosin 0.4mg daily)

A 56-year-old man presents to the ED with worsening left-sided flank pain for the past 3 days. He has had intermittent nausea and difficulty urinating. He denies fever or chills. Non-contrast CT of the abdomen and pelvis reveals a 17 mm renal stone located near the left renal calyx, with moderate hydronephrosis. Urinalysis shows microscopic hematuria. Renal function is stable.

Which of the following is the most appropriate treatment for this patient?

A. Tamsulosin and trial of passage over 4 weeks

B. Extracorporeal shock wave lithotripsy (ESWL)

C. Percutaneous nephrolithotomy (PCNL)

D. Ureteroscopic stone extraction with laser fragmentation

What is your patient education?

C. Percutaneous nephrolithotomy (PCNL) this is remove large stones 15-20 mm in size near the renal calyces.

1.)

Increased fluid intake --> void volume of 2.5 L/day

Limit sodium intake to less then 3500mg

Limit animal protein

_____________ is nephrolithiasis surgery that involves basket extraction or laser fragmentation by endoscopy.

Ureteroscopic stone extraction

__________________ is a type of nephrolithiasis surgery where external energy sources causes stone fragmentation.

Extracorporeal shock wave lithotripsy (ESWL)

Describe what extracorporeal shockwave lithotripsy is and when would you use it?

Its a noninvasive procedure that breaks down stones in parts of urinary system through shock waves. Stones can pass through their own after EWSL.

What is the most common cause of AKI, especially in hospitalized patients?

Acute Tubular Necrosis

_______________ occurs when the tubular cells are exposed to a toxic substance.

Toxic ATN

______________ occurs when there is decreased renal blood flow and the tubular cells do not get enough oxygen, a condition that they are highly sensitive to due to their very high metabolism.

Ischemic ATN

A 65-year-old man is admitted to the ICU following repair of a ruptured abdominal aortic aneurysm. On postoperative day 2, his urine output has significantly declined. He reports feeling nauseated and "foggy." Vitals are stable. Labs reveal:

BUN: 58 mg/dL

Creatinine: 4.2 mg/dL (baseline: 1.0 mg/dL)

Urinalysis: muddy brown granular casts, no RBCs or WBCs

FeNa: elevated

What is the most likely diagnosis?

How do you diagnosis this?

What would his blood potassium and phosphate levels be?

How do you treat this patient?

1.) Acute tubular necrosis

2.) Kidney biopsy

3.) Elevated

4.) Supportive care, assess dialysis need.

What would you find in urine microscopy of acute tubular necrosis?

1.) Granular (muddy brown) cast

2.) Renal tubular epithelial cell cast

Oval fat bodies in urine

Nephrotic spectrum disease

Hypoalbumin

oval fat bodies in urine

Peripheral edema

hyperlipidemia

Nephrotic spectrum disease

What is the most common cause of nephrotic syndrome in developed countries?

Diabetes mellitus

A 6-year-old boy is brought to the clinic by his parents due to generalized swelling that began around his eyes and has progressed to his legs and abdomen over the past week. His parents note that he has become more fatigued and short of breath, especially when lying flat. They deny fever or recent illness.

On exam, the child appears puffy with periorbital edema, pitting edema of the lower extremities, and mild abdominal distention. Lung auscultation reveals decreased breath sounds at the bases bilaterally. Urinalysis shows +4 proteinuria, no hematuria. Serum labs reveal:

Albumin: 1.9 g/dL

Total cholesterol: 320 mg/dL

Creatinine: Normal

What is the most likely diagnosis?

How do you diagnose this?

How do you treat it?

1.) Nephrotic syndrome

2.) Kidney Biopsy

3.) Treatment depends on the underlying cause.

What is the most common cause of proteinuric renal disease in children in 80% of cases?

Minimal Change Disease

Is minimal change disease nephrotic spectrum or nephritic specrum disease?

NEPHROTIC!!

A 4-year-old boy is brought to the pediatrician by his parents because of puffiness around his eyes and swelling in his legs for the past week. He recently recovered from a mild upper respiratory infection. His appetite has decreased, and he seems more tired than usual. Physical exam reveals periorbital and pedal edema, a distended abdomen, and normal blood pressure.

Urinalysis reveals +4 proteinuria, no hematuria. Serum albumin is 1.7 g/dL, and total cholesterol is 350 mg/dL. Renal function is normal. No RBC casts are seen on microscopy.

What is the most likely diagnosis?

How would you diagnose this?

What is the treatment?

1.) Minimal Change Disease

2.) Kidney biopsy

3.)

Prednisone 4-8 weeks

What would you find on a minimal change disease biopsy in light microscopy and electron microscopy?

Light microscopy

- Glomeruli are normal

Electron microscopy

- Effacement of the epithelial cell (podocyte) foot proceesses

Focal segmental glomerulosclerosis is a type of _____________syndrome.

nephrotic

What would you find on a kidney biopsy of focal segmental glomerulosclerosis?

Sclerosis of segments of some glomeruli

Positive IgM and C3

Foot processes effacement

A 28-year-old African American man presents to the clinic with progressive swelling of his legs and shortness of breath over the past month. He denies recent illness, sore throat, or rash. He has no significant past medical history but reports occasional use of anabolic steroids and has a strong family history of kidney disease.

On physical examination, he has bilateral pitting edema in the lower extremities and mild periorbital swelling. Blood pressure is 148/92 mmHg. Labs reveal:

Serum albumin: 2.1 g/dL

Cholesterol: 310 mg/dL

Creatinine: 2.0 mg/dL

Urinalysis: 4+ protein, no hematuria

24-hour urine protein: 5.5 g/day

A renal biopsy shows segmental sclerosis of some glomeruli, positive IgM and C3, and effacement of foot processes on electron microscopy.

What is the diagnosis?

How do you treat it?

Focal segmental glomerulosclerosis

Treat proteinuria/HTN with ACEi/ARB or mineralcorticoid receptor antagonist.

Prednisone

What is the most common cause of nephrotic syndrome in adults?

Membranous nephropathy

A 62-year-old man is referred to nephrology for evaluation of new-onset lower extremity edema and frothy urine over the past few weeks. He denies fever, rash, arthralgia, or recent illness. He has a 30-pack-year smoking history and is up to date with cancer screening except for recent imaging. Physical exam reveals bilateral pitting edema and mild ascites. Blood pressure is 142/88 mmHg.

Labs reveal:

Urinalysis: 4+ protein, no hematuria

Serum albumin: 2.3 g/dL

Total cholesterol: 295 mg/dL

Creatinine: 1.1 mg/dL

Antibody workup: negative ANA, ANCA, and anti-dsDNA

Renal biopsy shows diffuse thickening of the glomerular basement membrane on light microscopy, and subepithelial deposits with spike and dome appearance on silver stain.

What is the most likely diagnosis?

Membranous nephropathy

____________ is an autoimmune disease with reactivity against podocyte antigens. May be due to secondary cause associated with infections, cancer, SLE, and certain drugs.

Membranous nephropathy

Spike and dome on kidney biopsy

Membranous nephropathy

Elevated levels of PLA2R antibodies

Membranous nephropathy

A 60-year-old man is referred to the nephrology clinic for evaluation of new-onset lower extremity edema and foamy urine. He has no known history of diabetes or hypertension. He denies fever, joint pain, or recent infections. On physical exam, he has bilateral pitting edema of the legs and mild periorbital puffiness. Vital signs are normal.

Labs reveal:

Urinalysis: 4+ protein, no blood

Serum albumin: 2.0 g/dL

Total cholesterol: 312 mg/dL

Creatinine: 1.2 mg/dL

Renal biopsy: thickened glomerular basement membrane with subepithelial immune deposits and a "spike and dome" appearance

What is the diagnosis?

How do you treat it?

1.) Membranous nephropathy

2.)

Spontaneous remission may occur

Treat with immunosuppressive agents - reserve for those with highest risk of progression to ESRD

A 36-year-old African American man presents to the clinic with complaints of swelling in his legs and increasing fatigue over the past month. He was recently diagnosed with HIV but has not started antiretroviral therapy. He denies fever, rash, or hematuria. Vitals are within normal limits. On physical exam, he has bilateral lower extremity pitting edema.

Labs show:

BUN: 32 mg/dL

Creatinine: 2.6 mg/dL (baseline unknown)

CD4 count: 110 cells/mm³

Urinalysis: 4+ proteinuria, no RBCs or casts

Renal biopsy: collapsing focal segmental glomerulosclerosis with microcystic tubular dilation

What is the most likely diagnosis?

How do you treat it?

1.) HIV associated nephropathy

2.)

Antiretroviral therapy

ACEi or ARB

A 55-year-old African American man with a 15-year history of poorly controlled hypertension presents for routine evaluation. He denies any urinary symptoms but reports fatigue and mild ankle swelling. He is not currently on any antihypertensive medications. Blood pressure today is 176/98 mmHg.

Which of the following is the most likely cause of this patient's kidney dysfunction?

How do you treat it?

1.) Hypertensive nephrosclerosis

2.) ACEi/ARB

What is hypertensive nephropathy?

It is when the nephrotic tissue hardens and thickens

What is the most common cause of ESRD in the US?

diabetic nephropathy

What would you find on a kidney biopsy of diabetic nephropathy?

1.) Diffuse glomerulosclerosis

2.) Kimmelstiel-Wilson nodules

A 58-year-old man with a 15-year history of type 2 diabetes mellitus presents for follow-up. He has no current complaints. His blood pressure is 138/86 mmHg, and his HbA1c is 7.4%. Routine labs show a serum creatinine of 1.1 mg/dL. Urinalysis reveals no hematuria, but urine albumin-to-creatinine ratio (UACR) is 120 mg/g.

What is the most appropriate next step in the management of this patient's kidney disease?

A. Start loop diuretic and schedule renal biopsy

B. Begin SGLT2 inhibitor and ACE inhibitor

C. Repeat urine study in 3 months and observe

D. Refer for dialysis planning

The patient has diabetic nephropathy

B. Begin SGLT2 inhibitor and ACE inhibitor