Acute Kidney pt. 1 - Clin Med

What does this refer to

• Components

  • Kidneys, ureters, bladder, and urethra

• Functions

  • Serves as the body’s water treatment plan by collecting body waste products and expelling them as urine

• Filters electrolyte

  • Cortex

  • Medulla

  • Pelvis

The Renal System

What does this refer to

• Cortex

• Medulla

• Renal artery

• Renal calyx

• Renal pelvis

• Renal vein

• Ureters

Major Structures of the Kidney

What does this refer to

Nephrons

What does this refer to

• Maintaining fluid and acid-base balance

• Regulating electrolyte concentration

• Detoxifying the blood and eliminating wastes

• Regulating blood pressure

• Aiding red blood cell (RBC) production (erythropoiesis)

• Regulating vitamin D and calcium formation

Vital Functions of the Kidneys

What does this refer to

• Produced by pituitary gland

• Alters the collecting tubules’ permeability to water

Antidiuretic hormone (ADH)

What does this refer to

• Produced and released by the adrenal cortex

• Regulates water reabsorption by the distal tubules

• Changes urine concentration by increasing sodium reabsorption

• Helps control secretion of potassium by the distal tubules

Aldosterone

What does this refer to

• Assists with converting vitamin D to its active form

Calcitriol

What does this refer to

• Stimulates red blood cell production

Erythropoietin

What does this refer to

• Affects heart function and blood pressure by metabolizing catecholamines

Renalase

What does this refer to

• Helps regulate blood pressure through angiotensin conversion

Renin

What does this refer to

• Secrete hydrogen ions

• Reabsorb sodium and bicarbonate ions

• Acidify phosphate salts

• Produce ammonia

Kidney Actions to Regulate Acid-Base Balance

What does this refer to

• Glomerular filtration

• Tubular reabsorption

• Tubular secretion

Waste Collection

What does this refer to

• Rate at which glomeruli filter blood

• Normal is between 107 and 139 mL/minute for males and 87 and 107 mL/minute for females

• Depends on:

  • Permeability of capillary walls

  • Vascular pressure

  • Filtration pressure

• Most accurate measure is creatinine clearance

Glomerular Filtration Rate

What does this refer to

• Nephrotic syndrome

• Nephritic syndrome

• Acute interstitial nephritis (AIN)

• Acute tubular necrosis (ATN)

• Rhabdomyolysis

Acute Disorders

What does this refer to

• Definition

  • Sudden interruption of renal function

• Causes

  • Obstruction

  • Poor circulation

  • Kidney disease

• Classification

  • Prerenal

  • Intrarenal

  • Postrenal

• Phases

  • Oliguric-Urine output of <400mL/24h

  • Diuretic

  • Recovery

Acute Kidney Injury

What does this refer to

• Inadequate perfusion.

• Decreased blood pressure.

• Obstructed blood flow to the kidneys.

Pre-renal

What does this refer to

• Renal cell damage

• Inflammation

• Infection

• Drugs

• Autoimmune drugs

Intra-renal

What does this refer to

• Obstruction

• BPH

• Kidney stones

• Bladder injury

• Bladder tumor

Post-renal

What does this refer to

• A 6-year-old boy is brought to the emergency department by his mother due to swelling around his eyes and legs.

• The mother reports that the patient recently recovered from an upper respiratory tract infection.

• Physical exam is significant for periorbital and lower extremity edema.

• Laboratory testing is significant for hypoalbuminemia and normal complement levels.

• Urinalysis demonstrates 4+ protein.

• A presumptive diagnosis of minimal change disease is made and the patient is started on steroid therapy.

Nephrotic syndrome

What does this refer to

• Type of kidney disease that results in proteinuria, peripheral edema, hyperlipidemia, and hypoalbuminemia

Nephrotic Syndrome

What does this refer to

• 3 cases/100,000 adults diagnosed annually in the US

• 2-7 cases/100,000 children < 16 yo diagnosed annually in the US

EpidemiologyNephrotic Syndrome

What does this refer to

• Primary

  • Focal segmental glomerulosclerosis (MC cause)

  • Membranous nephropathy

  • Minimal change disease

• Secondary

  • Diabetic nephropathy

  • SLE

  • Amyloidosis

EtiologyNephrotic Syndrome

What does this refer to

Minimal-Change Disease

What does this refer to

• Glomerulus becomes permeable to large molecules

• Loss of albumin (proteinuria) results in hypoalbuminemia and edema

• Associated with a hypercoagulable state

  • Pathophysiology unclear but may be due to loss of antithrombin and plasminogen proteins

• Increased lipid synthesis secondary to proteinura

PathogenesisNephrotic Syndrome

What does this refer to

• Edema

• Frothy urine

• Ascites

• Weight gain

• Fatigue

• Shortness of Breath

Clinical historyNephrotic Syndrome

What does this refer to

• HTN

• Edema – anasarca in severe cases

• Leukonychia

Physical examNephrotic Syndrome

What does this refer to

• Primary v Secondary Nephrotic Syndrome

• IgA nephropathy

• Rapid progressive glomerulonephritis

• Nephritic syndrome

• Exacerbation of chronic glomerulonephritis

Differential diagnosisNephrotic Syndrome

What does this refer to

Rapidly Progressive Glomerulonephritis

What does this refer to

WorkupNephrotic Syndrome

What does this refer to

• Formed by the breakdown of lipid-rich epithelial cells

• They are hyaline casts with fat globule inclusions, yellowish-tan in color.

• If cholesterol or cholesterol esters are present, they are associated with the "Maltese cross" sign under polarized light

• They are pathognomonic for high urinary protein nephrotic syndrome.

DiagnosticsNephrotic Syndrome

What does this refer to

Nephrotic Syndrome

What does this refer to

• Consult/referral with Nephrology

• Treat underlying disease/cause

• Sodium restriction

• Fluid restriction

• Control diabetes

Clinical interventionNephrotic Syndrome

What does this refer to

• 1st line Loop diuretics – Furosemide (Lasix)

• ACE-I or ARBs

  • ARBs may have a little more impact on proteinuria

    • Losartan (Cozaar) or Irbesartan (Avapro)

• Corticosteroids

  • Peds – Prednisolone (typically every other day x 4 weeks)

• Statins (↑ lipids)

  • Choice drug based on treatment guidelines

Clinical pharmacotherapeuticsNephrotic Syndrome

What does this refer to

• Nutritional Deficiencies

  • Calcium

  • Vitamin D

• Complications

  • Peritonitis

  • Opportunistic infection

  • Coagulation disorders

PrognosisNephrotic Syndrome

What does this refer to

• Primary prevention:

  • Promote rapid treatment for strep infections or other infections in body

  • Prevent high-risk lifestyle, needle use, drugs, HIV prevention

  • Achieve target BP for pts

  • Achieve target Glucose control

  • Restrict excessive salt

  • Maintain healthy weight

  • Quit smoking

• Secondary prevention

  • Consume less protein

  • Restrict salt

Health MaintenanceNephrotic Syndrome

What does this refer to

• A 26-year-old man presents with hematuria, periorbital edema, and jaundice.

• He has a medical history of opioid use disorder with prior hospitalizations for heroin overdose.

• He is on methadone but is non-adherent.

• His blood pressure is 155/102 mmHg.

• Physical examination is significant for scleral icterus, hepatomegaly, and palpable purpura.

• Serology shows decreased C3 and C4 levels and elevated anti-hepatitis C antibodies.

• Urinalysis demonstrates dysmorphic red blood cells and red blood cell casts

Nephritic syndrome

What does this refer to

• Immunologic mechanism (IgA)

  • Triggers inflammation and proliferation of glomerular tissue

• Acute Clinical Picture

  • Sudden onset of HTN, azotemia, hematuria, proteinuria, and red blood cell (RBC) casts in the urine

Nephritic Syndrome

What does this refer to

• Represents 25-30% of ESRD

• 25% present with Acute Nephritic Syndrome

• PSGN MC in Africa, the Caribbean, India, Pakistan, Malaysia, Papua New Guinea, and South America

• Post-infectious - Occur at any age

  • MC children 5-15yo

  • Only 10% occur in patients > 40yo

• Acute GN

  • M > F

EpidemiologyNephritic Syndrome

What does this refer to

• IgA Nephropathy (Berger’s disease) MC cause

  • After URI or GI infection

• Post-infectious

  • Streptococcal

    • Post-streptococcal Glomerulonephritis (PSGN)

  • Staphylococcal

• Membranoproliferative glomerulonephritis

  • Hep C

• Rapidly progressive GN

EtiologyNephritic Syndrome

What does this refer to

• Middle age Male (most likely diabetic)

• Post-staphylococcal infection

  • Recent history of a visceral abscess or skin infection

    • Methicillin-resistant Staphylococcus aureus (MRSA)

  • Hematuria is almost always present

Clinical historyNephritic Syndrome

What does this refer to

• Onset and duration of the illness?

  • Symptom onset is usually abrupt

• Acute post-infectious glomerulonephritis (GN)

  • Latent period of up to 3 weeks occurs before sx

    • May vary → typically 1-2 weeks for post-pharyngitis cases

    • 2-4 weeks for post-dermal infection

• Onset of nephritis within 1-4 days of streptococcal infection suggests preexisting renal disease

Clinical historyNephritic Syndrome

What does this refer to

• Hematuria - universal finding (microscopic or gross hematuria)

• HTN

• Gross hematuria - 30% of pediatric patients

  • Smoky-, coffee-, or cola-colored urine

• Oliguria

• Edema (peripheral or periorbital)

  • Mild (involving only the face)

  • Severe, bordering on a nephrotic appearance

• Headache 2⁰ hypertension

• SOB-DOE 2⁰ heart failure or pulmonary edema

• Flank pain secondary to stretching of the renal capsule

Clinical historySx of Acute gn

What does this refer to

• Triad of sinusitis, pulmonary infiltrates, and nephritis, suggesting granulomatosis with polyangiitis (Wegener granulomatosis)

• Nausea and vomiting, abdominal pain, and purpura, observed with Henoch-Schönlein purpura (HSP)

Symptoms specific to underlying systemic disease that can precipitate acute GN

What does this refer to

• Hemoptysis, occurring with Goodpasture syndrome or idiopathic progressive glomerulonephritis

• Skin rashes, observed with hypersensitivity vasculitis or SLE; also possibly due to the purpura that can occur in hypersensitivity vasculitis, cryoglobulinemia, and Henoch-Schönlein purpura

Underlying systemic disease that can precipitate acute GN

What does this refer to

Physical examNephritic Syndrome

What does this refer to

• Renal Syndromes that mimic Acute GN

  • Anaphylactoid purpura with nephritis

  • Chronic GN with an acute exacerbation

  • Idiopathic hematuria

  • Familial nephritis

• AKI

• Goodpasture Syndrome

• Non-Infectious GN

Differential DiagnosisNephritic Syndrome

What does this refer to

• CBC w. diff

• CMP

• Erythrocyte sedimentation rate (ESR)

• Complement levels (↓ C3, C4, CH50)

• Strep titer (ASO) +

• Renal biopsy

  • Crescent shape of glomerulus

WorkupNephritic Syndrome

What does this refer to

• Protein < 3.5g/day

• Blood

• Red blood cells (RBCs)

• White blood cells (WBCs)

• Dysmorphic RBCs

• Acanthocytes (abnormal RBC)

• Cellular (ie, RBC, WBC) casts

• Granular casts

Workup – UrinalysisNephritic Syndrome

What does this refer to

• Type II hypersensitivity

• Anti-glomerular basement membrane disease (Anti-GBM) antibodies against α3-chain of collagen type IV

  • Antibodies to the alveolar basement membrane result in hemoptysis and lung disease

• Pauci-immune processes

  • Granulomatosis with polyangiitis

  • Microscopic polyangiitis

Rapidly progressive gnGoodpasture syndrome etiology

What does this refer to

• Post-infectious often self-resolving

• Treat underlying disease (hepatitis)

• 1st line tx – corticosteroids (Prednisone, dexamethasone)

• IgA nephropathy

  • ACE-I or ARB for proteinuria and HTN

  • +/- corticosteroids

• Edema/volume overload

  • Loop diuretics

  • BB or CCB for HTN

• Rapidly Progressive AGN

  • Corticosteroids + cyclophosphamide

TreatmentNephritic Syndrome

What does this refer to

• Most epidemic cases result in full recovery

• Sporadic cases of acute nephritis often progress to a chronic form

  • Occurs in as many as 30% of adult patients and 10% of pediatric patients.

• May progress to nephrotic syndrome

• GN is the most common cause of chronic renal failure (25%)

• Proteinuria may be present 6 months – 1 year after onset of nephritis

PrognosisNephritic Syndrome

What does this refer to

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