Acute renal failure & Chronic kidney disease Flashcards
When Kidneys Fail
- Poor filtration of blood
- Waste buildup
- Electrolyte imbalances
- Acid/base balance - Blood volume/BP changes
- Decreased activation of Vit D
- Decreased erythropoietin
Prerenal Failure Causes
Due to decreased blood flow to kidney
- Hypovolemia
- Heart failure, cardiogenic shock
- Sepsis
- Medications, toxins
Reversible if caught early!
Prerenal Failure Manifestations
- Marked decrease in urinary output
- Elevation of BUN in proportion to creatinine to 20:1 (normal is 10:1)- more nitrogenous waste
BUN is not excreted as much - Azotemia: most common indicator of ARF
Intrinsic Renal Failure
Disorder within kidney structure
- Prolonged ischemia
- Injury to tubular structures
- Intratubular obstruction
- Infection
- Nephrotoxic agents
Radiocontrast Agents
Giving N-acetylcysteine reduces ARF risk by 50%
Acute Tubular Necrosis
Destruction of tubular epithelial cells
d/t sepsis, nephrotoxins, medications, obstruction, infection
- Coagulation process * rbc lysis = crystals, toxins
- Results in hypoxia & ischemia
- Often reversible!
Acute Tubular Necrosis - 3 phases
- Onset Phase (hours to days)
- Maintenance Phase
- Marked decreased GFR & urinary output
(edema, pulmonary congestion, HTN)
- Retention of urea/K+/sulfate, creatinine
CNS symptoms due to toxin build up - Recovery Phase
- Gradual increased output
Postrenal Failure
Obstruction of urine output
- Ureter (calculi, strictures)
- Bladder (tumors, neurogenic bladder)
- Urethra (BPH-common)
Treatment of all types of Renal Failure
- Prevention!
- Early diagnosis!
- Fluids – be careful!
- Electrolytes
- Calories
- Dialysis
- Continuous renal replacement therapy
Chronic Kidney Disease
Stage 1
Kidney damage
Decreased GFR
progress to…
Stage 5
Kidney failure
Minimal GFR
Chemical Changes in Renal Failure
ALL INCREASE K Cl H+ Mg NH4 PO4 PTH
ALL DECREASE
EPO
Vit D
Calcium
Clinical Manifestations of Chronic Kidney Disease
- Altered Fluid & Electrolytes
- Dehydration or fluid overload
- Sodium/salt wasting (late stage)
- Hyperkalemia (release d/t trauma, acidosis) - Altered Acid-Base Balance
- H+ ion buildup
Clinical Manifestations of Chronic Kidney Disease (3, 4, 5, 6)
- Vitamin D deficiency
- Bone Disease
- Decreased calcium absorption (d/t Vit D deficiency) increases PTH, breaking down bone - Anemia (common and early sign)
- d/t chronic blood lsoss, hemolysis, impaired erythropoietin, iron deficiency - CV Complications
- HTN (increased PVR- peripheral cascual resistance, increased RAAS)
Clinical Manifestations of Chronic Kidney Disease (7, 8, 9)
- Accumulation of nitrogenous wastes
- azotemia: elevated BUN (early sign)
- uremia - Impaired drug elimination
- Integument (d/t platelet dysfunction)
- Platelet dysfunction = bruising, pruritis
Cardiovascular Consequences of RF
Decreased blood viscosity \+ Increased blood pressure \+ Decreased oxygen supply