30 terms

Acute and Chronic Kidney Disease

RIFLE criteria
Severity classes: Risk, Injury, Failure
-defined by changes in serum creatinine
Outcome classes: Loss & ESRD
-defined by duration of loss
Acute Kidney Injury
Formerly ARF;
fxn or structural abnormality of the kidney
-manifests 48 hrs seen by blood, urine, or tissue tests
- ↑ in serum Cr of 0.3 mg/dL, or 50% ↑ of baseline, or + <0.5 mL/kg/hr urine output for ≥6 hrs) or imaging studies
Breakdown of muscle fibers that leads to the release of myoglobin into the bloodstream; an intrinsic (endogenous) cause of AKI
Acute Tubular Necrosis
Renal tubular epithelial cell injury; occurs MC in the setting of ischemia but can also be from renal toxins; MCC of intrinsic AKI (intrarenal)
Fractional Excretion of Sodium
(FENa): (Urine Na × Plasma Cr)/(Plasma Na × Urine Cr) X100 Equation with number to help determine the potential cause of AKI - whether renal failure is pre-, intra-, or post-renal; basically calculates amount of Na+ in urine
Urine Cast
Cylindrical structures produced by the kidney and present in the urine in certain disease states; made up of RBC, WBC, or kidney cells and formed in the tubules
Glomerular Filtration Rate (GFR)
volume of fluid filtered from the renal glomerular capillaries into the Bowman's capsule per unit time=([urine]×urine flow)/([plasma])
Chronic Kidney Disease
1. Presence of markers of kidney damage >3 months as define by structural or functional abnormalities of the kidney with or without ↓ GFR; manifest either by pathological abnormalities or markers of kidney damage (↑Serum Cr, ↓GFR, albuminuria)
2. or Presence of GFR<60 ml/min/1.732 for >3 months with or without other signs of damage -both definitions - kidney function progressively worsens
Renal Replacement Therapy
RRT: procedures which temporarily or permanently remedy insufficient cleansing of body fluids by the kidneys (i.e. dialysis and renal transplant)
Process for removing waste and excess H2O from blood; used to provide an artificial replacement for lost kidney fxn in pt with renal failure; hemodialysis does this with a machine while peritoneal dialysis does this with the lining of the abdomen
"Multi-organ assault" - clinical syndrome associated with fluid, electrolyte, and hormone imbalances and metabolic abnormalities which develop in parallel with ↓ renal fxn; literally means "urine in blood" and results from accumulation of unexcreted waste products and the metabolic abnormalities they induce
Arteriovenous Fistula
Permanent vascular access for hemodialysis; usually anastamosis (connection) between radial artery and adjacent veins
Pre-Renal AKI Etiology
Hypovelemia - hemorrhage, sweat, burns, D/V, diuretics, extravascular pooling
Ineffective Arterial Volume - CHF, sepsis, liver failure, arrhythmias, anaphylaxis
Arterial Occlusion - artery thomboembolism, aortic or renal artery aneurysm
• Key History: D/V, poor oral intake, HF, NSAIDs use, ACEI use, ARB use
Pre-Renal AKI sx
↓ or no urine output, pale skin, hypotension, tachycardia
Fatigue, dry mouth (mucous membranes), confusion
BUN/Cr ratio >10-20:1
Pre-Renal AKI Tx
Goal is to ↑ volume; d/c medications that interfere with renal erfusion
Avoid radiocontrast agents, restore BP, transfuse if needed, fluid bolus if ↓ volume
Intra-Renal AKI Etiology
MCC is ATN - either ischemia (MC) or toxins
Endogenous nephrotoxins - rhabdomyolysis
Exogenous nephrotoxins - abx, acyclovir, cisplatin, sulfa drugs, radio-contrast material
Acute tubulointerstitial nephritis - hypersensitivity rxn, immunologic dz, infection
Glomerular vascular inflammation - causes not discussed
• Key History: Hypotension (usually continuation of pre-renal), exposure to toxin/drug
Intra-Renal AKI sx
Signs/sx of fluid overload (SOB, DOE)
Acute tubulointerstitial nephritis - rash, fever, eosinophilia (or uria), ↑IgE
Intra-Renal AKI tx
Complex and difficult - immunosuppress for glomerulonephritis or vasculitis
Give steroids and d/c offending medications
Post-Renal AKI Etiology
Ureteral obstruction - clots, calculi, neoplasm, necrotic, papillae
Urethral obstruction - prostatitis , foreign object, neoplasm
Venous Occlusion - renal vein thrombosis, neoplasm
• Key History: Prostatic hypertrophy, prostate/cervical CA, lymphoma, retroperitoneal dz
Post-Renal AKI sx
Severe oligouria (output <450 ml/day) or anuria (<100 ml/day)
↑ BUN and ↑ Cr, pain and renal colic, hematuria, palpable masses, HTN, UTI, LUTS
Post-Renal AKI
Bladder catheter, d/c offending med (i.e. anticholinergics)
Surgical intervention - TURP, endoscopic removal, ureteral stent, nephrostomy tubes
Also surgical is internal urethrotomy and suprapubic catheter
Watch for post-obstructive diuresis
Common Medications Assoc. with AKI
Key Ones: Diuretics, NSAIDs, abx
• Antibiotics: β-lactams, vanco, gentamicin, quinolones, cephalosporins, nitrofurantoin
• Others: Contrast media, ACEI, statins
Risk Factors for Death with AKI
Male, 60 y/o, DM, HTN, CKD
Stages of Chronic Kidney Disease
I: Chronic kidney damage; normal or ↑GFR (>90); persistent albuminuria; asymptomatic

II: Mild GFR loss (60-89); persistent albuminuria; asymptomatic

III: Moderate GFR loss (30-59); anemia, metabolic acidosis, ↑K, ↓Ca, albuminemia, ↑Pi
-Consult Nephrology

IV: Severe GFR loss (15-29); uremic sx

V: ESRD (kidney failure); GFR extremely low (<15); uremic sx
Renal Laboratory and Special Test
•BUN/Cr : AKI: Pre-renal (>10-20:1), intra-renal (<10-15:1), post-renal (>20:1)
• CKD: See stages (↓GFR); GFR persistently (3 months) <60
Microaluminuria (persistently 30-300 mg/day)
• Imaging: Enlarged kidney - DM, HIV, infiltrative
Small kidney - Glomerular or interstitial disease
Different sizes - Renal artery stenosis
CKD Etiologies
in USA
• MC: DM and HTN
• Other Common: Glomerular, tubulointerstitial, vascular, and cystic diseases
CKD Management
: Antihypertensive therapy (ACEI, Arb, diuretics), smoking cessation
↓ proteinuria, low protein diet, tx of hyperlipidemia, Na+ restriction
Control hyperglycemia (tx anemia, hyperhomocysteinemia, RRT)
Risk Factors for Renal Disease Progression
• Cecil: CVD, smoking, aluminuria, hyperlipidemia, FH of CKD
Risk of CKD with DM, obesity, ↑age, minority population
•Lecturer: Unmodifiable - race, lower baseline kidney fxn, gender, age
Modifiable - ↑proteinuria, ↓serum [albumin], HTN, poor glycemic control
Also smoking, obesity, dyslipidemia
2 Major Renal Functions that Dialysis
Functions Replaced: Solute removal & fluid removal
Common Complications that Occur During Hemodialysis
-Cecil: Hypotension, muscle cramps, NV, HA, chest pain
• Lecturer: Anaphylaxis and anaphylactoid reactions
CV - hypo/hypertension, arrhythmias, DASS
Neuro - cramps, HA, RLS, DDS, seizures
Hematologic - thrombocytopenia, hemorrhage
Pulmonary - OSA, hypoxemia
Metabolic - protein, lipid, carb, vitamin
Technical - air embolus