Patho chapter 26
_____ failure, the most common form of acute renal failure, is characterized by a marked decrease in renal blood flow.
Prerenal
Define Uremia
Presence of excessive amounts of urea in the blood
The normal glomerular filtration rate, which varies with age, gender, and body size, is approximately _____ mL/minute (1.73 mL/minute per square millimeter) for normal young healthy adults.
120 to 130
Define Axotemia
Accumulation of nitrogenous wastes in the blood
Name the most common intrarenal cause of renal failure and describe its different forms.
Acute tubular necrosis (ATN) is characterized by the destruction to tubular epithelial cells with acute suppression of renal function. ATN can be caused by a variety of conditions, including acute tubular damage due to ischemia, sepsis, nephrotoxic effects of drugs, tubular obstruction, and toxins from a massive infection. Tubular epithelial cells are particularly sensitive to ischemia and are vulnerable to toxins. The tubular injury that occurs in ATN frequently is reversible.
Sexual dysfunction in people with chronic kidney disease is thought to be multifactorial. What are thought to be causes of sexual dysfunction in people with chronic kidney disease?
Antihypertensive drugs, psychological factors, and uremic toxins. The cause of sexual dysfunction in men and women with chronic kidney disease is unclear. The cause probably is multifactorial and may result from high levels of uremic toxins, neuropathy, altered endocrine function, psychological factors, and medications (e.g. antihypertensive drugs).
Why is chronic kidney disease considered to have an insidious progression?
As kidney structures are destroyed, the remaining nephrons undergo structural and functional hypertrophy, each increasing its function as a means of compensating for those that have been lost. In the process, each of the remaining nephrons must filter more solute particles from the blood. It is only when the few remaining nephrons are destroyed that the manifestations of kidney failure become evident.
Define Creatinine
By-product of muscle metabolism
Define Uremic Encephalopathy
Decreased central nervous system activity
Dietary restrictions placed on people with chronic kidney disease include limiting protein in their diet. The recommended sources of protein for people with chronic kidney disease include what source of protein?
Milk. At least 50% of the protein intake for clients with chronic kidney disease should consist of proteins with high biologic value, such as those in eggs, lean meat, and milk, which are rich in essential amino acids.
Define Prostatic hyperplasia
Most common cause of postrenal failure
Define Isosthenuria
Polyuria with urine that is almost isotonic with plasma
What are the clinical manifestations of chronic kidney disease?
The manifestations of chronic kidney disease (CKD) include an accumulation of nitrogenous wastes; alterations in water, electrolytes, and acid-base balance; mineral and skeletal disorders; anemia and coagulation disorders; hypertension and alterations in cardiovascular function; gastrointestinal disorders; neurologic complications; disorders of skin integrity; and disorders of immunologic function. The point at which these disorders make their appearance and the severity of the manifestations are determined largely by the extent of renal function that is present and the coexisting disease conditions.
Chronic kidney disease impacts many systems in the body. What is the number one hematologic disorder caused by chronic kidney disease (CKD)?
The number one hematologic disorder that accompanies chronic kidney disease is anemia.
Describe the progression of acute tubular necrosis (ATN).
The onset or initiating phase, which lasts for hours or days, is the time from the onset of the precipitating event until tubular injury occurs. The maintenance phase of ATN is characterized by a marked decrease in the glomerular filtration rate (GFR), causing sudden retention of endogenous metabolites, such as urea, potassium, sulfate, and creatinine that normally are cleared by the kidneys. Fluid retention gives rise to edema, water intoxication, and pulmonary congestion. If the period of oliguria is prolonged, hypertension frequently develops and, with it, signs of uremia. The recovery phase is the period during which repair of renal tissues take place. Its onset usually is heralded by a gradual increase in urine output and a fall in serum creatinine, indicating that the nephrons have recovered to the point at which urine excretion is possible.
Define Hemodialysis
Use of artificial kidney to filter blood
The causes of acute renal failure commonly are categorized as _____, _____, or ______.
prerenal, intrinsic, postrenal
In chronic renal failure, the kidneys lose the ability to regulate _____ excretion.
sodium
The term renal _____ is used to describe the skeletal complication of chronic kidney disease.
osteodystrophy
Because of their high metabolic rate, the _____ cells are most vulnerable to ischemic injury.
tubular epithelial
Increased excretion of low-molecular-weight globulins is a marker of ____ disease, and excretion of ____ a marker of chronic kidney disease.
tubulointerstitial, albumin
Anorexia, nausea, and vomiting are common in patients with _____, along with a metallic taste in the mouth that further depresses the appetite.
uremia
The _____ state includes signs and symptoms of altered fluid, electrolyte, and acid-base balance; and alterations in regulatory functions.
uremic
_____ commonly is an early manifestation of chronic renal failure.
Hypertension
How is chronic kidney disease classified?
Glomerular filtration rate (GFR) is used to classify chronic kidney disease into five stages, beginning with kidney damage with normal or elevated glomerular filtration rate (GFR), progressing to chronic kidney disease, and potentially, to kidney failure.
____ represents a rapid decline in kidney function sufficient to increase blood levels of nitrogenous wastes and impair fluid and electrolyte balance.
Acute renal failure
Acute renal failure occurs at a high rate in seriously ill people who are in intensive care units. What is the most common indicator of acute renal failure?
Azotemia and a decrease in the glomerular filtration rate. The most common indicator of acute renal failure is axotemia, an accumulation of nitrogenous wastes (urea nitrogen, uric acid, and creatinine) in the blood and a decrease in the glomerular filtration rate.
People with chronic kidney disease have impaired immune responses to infection because of high levels of urea and metabolic wastes in the blood. What is one thing that is missing in an immune response in people with chronic kidney disease?
Failure to mount a fever with infection. Many persons with chronic kidney disease fail to mount a fever with infection, making the diagnosis more difficult.
The parents of a hospitalized 4-year-old boy have just been told that their son has a chronic renal disease. The nurse is planning discharge teaching for this family. The parents inquire about treatment for their son and if kidney transplantation could occur. What would be the nurse's best response?
Chronic kidney disease is a progressive disorder that can be slowed by adherence to dietary restrictions and medication regimen. The disorder usually progresses to the point where the child needs either hemodialysis or peritoneal dialysis or a kidney transplant. All forms of renal replacement therapy are considered safe in the pediatric population, and renal transplantation is considered the best treatment for a child.
Define Oliguria
Decreased urine production
The parents of a hospitalized 4-year-old boy have just been told that their son has a chronic renal disease. The nurse is planning discharge teaching for this family. What would the nurse know to include in the discharge teaching for this child and his family?
Description of the disease process; prognosis, manifestations of the disease, including physical growth and developmental delays; medication regimen, including side effects; and dietary restrictions including protein, caloric, sodium, and fluid restrictions.
Define Salt Wasting
Impaired tubular reabsorption of sodium
Define Osteitis fibrosa
Increased bone resorption and formation
In hemodialysis, access to the vascular system is most commonly through what?
Internal arteriovenous fistula. Access to the vascular system is accompanied through the external arteriovenous shunt (i.e. tubing implanted into an artery and a vein) or, more commonly, through an internal arteriovenous fistula (i.e. anastomosis of a vein to an artery, usually in the forearm).
How does renal disease cause cardiovascular disease?
People with chronic kidney disease (CKD) tend to have an increased prevalence of left ventricular ejection fraction, as in systolic dysfunction, and impaired ventricular filling, as in diastolic failure. Multiple factors lead to development of left ventricular dysfunction, including extracellular fluid overload, shunting of blood through an ateriovenous fistula for dialysis, and anemia. Coupled with the hypertension that often is present, they cause increased myocardial work and oxygen demand, with eventual development of heart failure. Congestive heart failure and pulmonary edema tend to occur in the late stages of kidney failure. Coexisting conditions that have been identified as contributing to the burden of cardiovascular disease include hypertension, anemia, diabetes mellitus, dyslipidemia, and coagulopathies. Anemia, in particular, has been correlated with the presence of left ventricular hypertrophy.
Uremia pericarditis is a disorder that accompanies chronic kidney disease (CKD). What are its presenting signs and symptoms?
Pericardial friction rub, chest pain with respiratory accentuation, and fever without infection. Uremic pericarditis resembles viral pericarditis in its presentation. This includes all potential complications, up to and including cardiac tamponade. The presenting signs include mild to severe chest pain with respiratory accentuation and a pericardial friction rub. Fever is variable in the absence of infection and is more common in dialysis than uremic pericarditis. Shortness of breath and thromboangiitis are not indicative of uremic pericarditis.
____ failure results from obstruction of urine outflow from the kidneys.
Postrenal
Neuromuscular disorders can be triggered by chronic kidney disease (CKD). For those clients on dialysis, approximately two-thirds suffer from what peripheral neuropathy?
Restless leg syndrome is a manifestation of peripheral nerve involvement and can be seen in as many as two-thirds of patients on dialysis.
The glomerular filtration rate is considered to be the best measure of renal function. What is used to estimate the glomerular filtration rate?
Serum creatinine. In clinical practice, glomerular filtration rate is usually estimated using the serum creatinine concentration.
Acute tubular necrosis is the most common cause of intrinsic renal failure. One of the causes of ATN is ischemia. What are the most common causes of ischemic ATN?
Severe hypovolemia, Burns, and overwhelming sepsis. Ischemic acute tubular necrosis occurs most frequently in persons who have major surgery, severe hypovolemia, overwhelming sepsis, trauma, and burns.
How is anemia related to chronic kidney disease?
The anemia of chronic kidney disease (CKD) is due to several factors including chronic blood loss, hemolysis, bone marrow suppression due to retained uremic factors, and decreased red cell production due to impaired production of erythropoietin and iron deficiency. The kidneys are the primary site for the production of the hormone erythropoietin, which controls red blood cell production. In renal failure, erythropoietin production usually is insufficient to stimulate adequate red blood cell production by the bone marrow.
Neuropathy is caused by ______ and _____ of nerve fibers, possibly caused by uremic toxins.
atrophy, demyelination
Prerenal failure is manifested by a sharp decrease in urine output and a disproportionate elevation of _____ in relation to serum creatinine levels.
blood urea nitrogen
The acidosis that occurs in persons with kidney failure seems to stabilize as the disease progresses, probably as a result of the tremendous buffering capacity of _____.
bone
A major concern in the treatment of acute renal failure is identifying and correcting the _____.
cause
Regardless of cause, _____ represents a loss of functioning kidney nephrons with progressive deterioration or glomerular filtration, tubular reabsorptive capacity, and endocrine functions of the kidneys.
chronic kidney disease
In clinical practice, glomerular filtration rate is usually estimated using the serum _____ concentration.
creatinine
Normal aging is associated with a decline in the _____ and subsequently with reduced homeostatic regulation under stressful conditions.
glomerular filtration rate
Chronic renal failure can produce _____ or fluid _____, depending on the pathology of the kidney disease.
dehydration, overload
