Ch. 26 Acute Renal Failure & Chronic Kidney Disease Flashcards
What four things happen when kidneys fail?
Poor filtration of blood
Blood volume/BP changes
Decreased activation of vitamin D
Decreased erythropoietin
What results from poor filtration of blood?
Waste buildup
Electrolyte imbalances
Acid/base imbalances
What causes prerenal failure?
Due to decreased blood flow to kidney
- hypovolemia
- heart failure
- cardiogenic shock
- sepsis
- medications/toxins
What are the manifestations of prerenal failure?
Marked decrease in urinary output
Elevation of BUN in proportion to creatinine (15:1 or 20:1)
Azotemia
What is a normal proportion of BUN (blood urea nitrogen) to creatinine?
10:1
What is the most common indicator of acute renal failure?
Azotemia
What is azotemia?
The buildup of nitrogenous waste in the blood.
What is intrinsic renal failure?
A disorder within the kidney structure.
What are some causes of intrinsic renal failure?
Prolonged ischemia Intratubular obstruction Infection Injury to tubular structures Nephrotoxic agents
What is acute tubular necrosis?
Destruction of tubular epithelial cells
How does acute tubular necrosis happen?
Sepsis, nephrotoxins, medication, obstruction, infection
Coagulation process and red blood cell lysis = crystals and toxins
Results in hypoxia and ischemia
Often reversible!
What are the three phases of acute tubular necrosis?
Onset phase
Maintenance phase
Recovery phase
What occurs during the onset phase of acute tubular necrosis, and how long does it take?
Development of acute tubular necrosis up to the time of ischemia (hours to days)
What occurs during the maintenance phase of acute tubular necrosis?
Marked decrease in GFR and urinary output. Retention of urea, K+, sulfate, creatinine
Why do CNS symptoms occur during the maintenance phase of acute tubular necrosis?
Due to the buildup of toxins in the blood during acute tubular necrosis.
What are the results of the marked decrease in GFR that occurs during the maintenance phase of acute tubular necrosis?
Edema, pulmonary congestion, HTN
What occurs during the recovery phase of acute tubular necrosis?
Gradual increased output
What is postrenal failure?
Obstruction of urine output.
What are the treatments for renal failure?
Fluids (careful) Electrolytes Calories Dialysis Continuous renal replacement therapy
What are causes of postrenal failure in the ureter?
Calculi, strictures
What are the causes of postrenal failure in the bladder?
Tumors, neurogenic bladder
What are the causes of postrenal failure in the urethra?
Benign prostatic hypertrophy
What chemicals increase during renal failure?
K Cl H g NH4 PO4 PTH (parathyroid hormone)
What chemicals decrease during renal failure?
Ca
EPO
Vitamin D
What are the clinical manifestations of chronic kidney disease?
Altered fluid and electrolytes Altered acid-base balance Bone disease Vitamin D deficiency Anemia CV complications Accumulation of nitrogenous wastes Impaired drug elimination Integumentary changes
What are the alterations in fluid and electrolytes that occur during chronic kidney disease
Dehydration or fluid overload
Sodium/salt wasting (late stage)
Hyperkalemia (release d/t trauma, acidosis)
Why does chronic kidney disease cause altered acid-base balance?
Hydrogen ions build up
How does chronic kidney disease cause bone disease?
Vitamin D deficiency
Decreased calcium absorption (d/t vitamin D deficiency) increases parathyroid hormone, breaking down bone
How does chronic kidney disease cause anemia?
Due to chronic blood loss, hemolysis, impaired erythropoietin, iron deficiency
What are the cardiovascular complications that result from chronic kidney disease?
HTN (intreased peripheral vascular resistance, increased RAAS)
What is an early sign of accumulation of nitrogenous wastes in the blood due to chronic kidney disease?
Elevated BUN
What is the effect of chronic kidney disease on the integument?
Platelet dysfunction = bruising, pruritis
What are two types of dialysis?
Hemodialysis
Peritoneal dialysis
What are ways to manage chronic kidney disease?
Dialysis
Dietary management
Transplantation
What is hemodialysis/how does it work?
Takes blood out of the body, runs it through a machine, and puts it back in the body. It allows all molecules (except for blood cells and plasma proteins) to move from blood to dialysate and back.
How often does hemodialysis need to be done?
2-4 times a week for 3-4 hours
What are the side effects of hemodialysis?
Hypotension Chest pain Nausea, vomiting Cramps "restless leg" Dialysis disequilibrium syndrome (DDS)
