Acute Kidney Injury, Chronic Kidney Disease and Renal Failure Flashcards
Define renal failure and understand types of renal failure
renal failure is a condition in which kidneys fail to remove metabolic end products from the blood and regulate the fluid, electrolytes, and pH balance of the extracellular fluids.
acute kidney injury is abrupt in onset and is often reversible if recognized early and treated appropriately
in contrast, chronic kidney disease (CKD) is the end result of irreparable damage to the kidneys. it develops slowly, usually over the course of a number of years. 88% of the nephrons need to be nonfunctioning before the symptoms of CKD are manifested.
Understand AKI - 3 different types
causes of AKI - prerenal, intrarenal, and postrenal
prerenal: most common form of AKI, characterized by a marked decrease in renal blood flow. it is reversible if the cause of the decreased renal flow can be identified and corrected before kidney damage occurs. manifested by a sharp decrease in urine output and a disproportionate elevation of blood urea nitrogen (BUN) in relation to serum creatinine levels. a disproportionate elevation in the ratio of BUN to serum creatinine, from a normal value of 10:1 ratio > 15:1 to 20:1
intrarenal: results from conditions that cause damage to structures within the kidney.
major causes of intrarenal failure - ischemia associated w/ prerenal AKI, toxic insult to the tubular structures of nephron, and intratubular obstruction.
postrenal: results from obstruction of urine outflow from kidneys. bc of increased urine not being able to be excreted due to obstruction, retrograde pressure occurs throughout the tubules and nephrons, which ultimately damages the nephrons
Understand CKD and Clinical Manifestations
CKD defined as either kidney damage of a GFR less than 60 mL/min/1.73 m2 for 3 months or longer.
hypertension and diabetic kidney disease are the two main causes of CKD in the US.
guidelines define kidney failure “as either A GFR of less than 15 or a need to start renal replacement therapy (dialysis or transplantation)”
these guidelines point out that kidney failure is not synonymous with end-stage renal disease (ESRD)
regardless of cause, CKD represents a loss of functioning kidney nephrons with progressive deterioration of glomerular filtration, tubular reabsorptive capacity, and endocrine functions of the kidney
microalbuminuria, which is an early sign of diabetic kidney disease, refers to albumin excretion that is above the normal range
the accumulation of nitrogenous wastes in the blood, or azotemia, is an early sign of kidney failure, usually occurring before other symptoms become evident. urea is one of the first nitrogenous wastes to accumulate in the blood, and the BUN level becomes increasingly elevated as CKD progresses.
uremia, which literally means “urine in the blood,” is the term used to describe the clinical manifestations of kidney failure. uremia differs from azotemia, which merely indicates the accumulation of nitrogenous wastes in the blood and can occur without any symptoms.
K+, Anemia, Coagulopathies, Drug Metabolism
approximately 90% of potassium excreted is through the kidneys. hyperkalemia usually does not develop until the kidney function in severely compromised.
chronic anemia is the most profound hematologic alteration that accompanies CKD.
the kidneys are the primary site for the production of the hormone erythropoietin, which controls red blood cell production. in renal failure, erythropoietin production is usually insufficient to stimulate adequate red blood cell production by the bone marrow. among the causes of iron deficiency in people with CKD are anorexia and dietary restrictions that limit intake and the blood loss that occurs during dialysis.
bleeding disorders manifested by epistaxis, menorrhagia, gastrointestinal bleeding, and bruising of skin & subcutaneous tissues. although platelet production is often normal in CKD, platelet function is impaired. people w/ CKD also have greater susceptibility to thrombotic disorders.
people w/ CKD tend to have an increase prevalence of left ventricular dysfunction, with both depressed left ventricular ejection fraction, as in systolic dysfunction, and impaired ventricular filling, as in diastolic failure.
CKD and its treatment can interfere w/ absorption, distribution, and elimination of drugs.
there are two broad categories of dialysis: hemodialysis and peritoneal dialysis.
a living donor kidney functions, on average, 12 to 20 years, and a deceased donor kidney from 8 to 12 years. patients who get a kidney transplant before dialysis live an average of 10 to 15 years longer than if they stayed on dialysis.
Treatment for Renal Failure
a major component in the treatment of CKD is nutritional management
