Chapter 24 patho
When explaining to a class of nursing students enrolled in pathophysiology, the instructor states, "the majority of energy used by the kidney is for:
Active sodium transport mechanisms." Explanation: p. 604.
When administering a thiazide diuretic the nurse recognizes these medications exert their effects in which of these areas of the kidney?
Distal and collecting tubules Explanation:p. 606.
Recent evidence proposes use of which of these tests may become useful as a marker of glomerular filtration rate because it is more sensitive and timely than creatinine levels?
Cystatin-C Explanation: p. 614.
When caring for the client with kidney failure, the nurse anticipates that which of these laboratory test abnormalities will be present? Select all that apply.
Elevated potassium Decreased calcium Increased creatinine Explanation:p. 614.
The nurse is caring for a client with suspected dehydration. Which of these results does the nurse recognize will help confirm this diagnosis?
Elevated urine specific gravity Explanation: This tests for hydration status and functional ability of the kidneys. A normal range is 1.010 to 1.025, or 1.030 to 1.040 during dehydration (more solute concentration than water). Or it can be 1.000 during increased fluid intake. With diminished renal function you may see 1.006-1.010 and are significant when seen first in the morning (after a period of decreased water intake) indicating an issue in renal concentration ability (more water than solutes despite lack of water intake). p. 615.
The nurse is teaching a group of nursing students about the major functions of the kidney. Which of these should the nurse include in the discussion? Select all that apply.
Elimination of water Removal of waste products Removal of excess electrolytes Explanation:, p. 611.
When teaching the client with gout about the cause of the disease, which of these should the nurse relate?
Increased levels of uric acid in the blood cause gout. p. 612.
The nurse is instructing a client on the procedure for obtaining a voided urine specimen to bring the laboratory for analysis. Which is the most important information for the nurse to tell the client?
Obtain the first-voided morning specimen. Explanation: p. 615
Many substances are both filtered out of the blood and reabsorbed into the blood in the kidneys. What is the plasma level at which a specific substance can be found in the urine?
Renal threshold Explanation: 605
The nurse teaches the client with end-stage kidney disease who has developed anemia that the reason anemia has developed is which of these?
The damaged kidney is unable to produce erythropoietin. Explanation: p. 613.
A client in hospital is frustrated at the inconvenience of having to collect his urine for an entire day and night as part of an ordered 24-hour urine-collection test. The client asks the nurse why the test is necessary since the client provided a single urine sample two days prior. How could the nurse best respond?
"Often when an abnormal substance shows up in a urine test, a 24-hour urine collection is needed to determine exactly how much is present in your urine."
A patient in a hospital is frustrated at the inconvenience of having to collect his urine for an entire day and night as part of an ordered 24-hour urine collection test. He asks the nurse why the test is necessary since he provided a single urine sample two days ago. How could the nurse best respond to the patient's question?
"Often why an abnormal substance shows up in urine test, a 24-hour urine collection is needed to determine exactly how much is present in your urine." Explanation: p. 615.
A patient is scheduled for a creatinine clearance test to measure the glomerular filtration rate (GFR). The patient asks the nurse what this test is used for. Which of the following is the nurse's best response?
"This test provides a gauge of renal function." Explanation: The normal creatinine level is 0.7 mg/dL of blood for a woman and about 1.0 mg/dL for a man, and about 1.5 mg/dL for a muscular man. There is an age-related decline in creatinine clearance because muscle mass and GFR decrease with age. A normal serum creatinine reflects a normal renal function. If the value of a creatinine doubles the GFR has fallen to half of its normal state, and if it is 3 times more than normal there is about 75% loss of function, and if the value raises to 10 mg/dL or more 90% loss can be assumed. p. 614.
A new client on hemodialysis is watching his blood being filtered through a dialyzer. He asks the nurse how much blood typically passes through the kidney every minute? The nurse responds:
1000-1300 mL/minute. ( or 20-25% of CO) p. 607.
Select the percentage of cardiac output that perfuses the kidneys.
20% to 25%
A client suffering from a previous myocardial infarction (MI) has symptomology indicating ineffective renal blood vessel dilation, resulting in increased sodium retention. Which hormone level may have been affected by the MI?
ANP p. 611.
The nurse is caring for a critically ill client who requires measurement of hourly urine output. When assessing the urine output of the previous shift, the nurse recognizes that which of these volumes reflects a minimum, normal urinary output?
60 ml/hour Explanation: p. 604.
Urine is a amber, light-yellow fluid that is 5% dissolved solid. What percent of it is water?
95 Explanation: Urine is amber-colored fluid that is about 95% water and 5% dissolved solids. The kidneys normally produce 1.5 L or urine each day. Normal urine has metabolic wastes and few or no plasma proteins, blood cells, or glucose molecules. Urine tests can be performed on a single urine specimen or a 24-hour urine specimen. First-voided morning specimens are useful for qualitative protein and specific gravity testing. A freshly voided specimen is also the most reliable. Urine tests that have been left standing may hold lysed RBCs , disintegrating casts, and rapidly multiplying bacteria. p. 615.
A client is experiencing an increase in urinary output. The nurse determines this is a result of:
A decrease in antidiuretic hormone Explanation: Less ADH means the membrane is permeable so more urination occurs. p. 609.
When caring for the client in a shock state, the nurse recognizes that which of these compensatory substances may produce vasoconstriction of renal vessels? Select all that apply.
Angiotensin II Antidiuretic hormone Endothelins Explanation: p. 609.
Following an automobile accident where the patient had a traumatic amputation of their lower leg and lost >40% of their blood volume, they are currently not producing any urine output. The nurse bases this phenomena on which of the following humoral substances responsible for causing severe vasoconstriction of the renal vessels?
Angiotensin II and ADH. Explanation: The Renin-angiotensin-aldosterone mechanism regulates hort and long term blood pressure. Renin is an enzyme that is tsored and secreted by the juxtaglomerular cells of the kidney, and is released in response to a decrease in renal blood flow or a change in the composition in the distal tubular fluid, or sympathetic nervous system stimulation. Renin acts by converting angiotensinogen to angiotensin I. Angiotensin I (some vasocontrictor properties) leaves the kidneys and enters the circulation. There it is converted to Angiotensin II by the angiotensin-converting enzyme. ANgiotensin II is a potent vasoconstrictor and acts directly on the kidneys to decrease SALT and WATER excretion, this enzyme also stimualtes the secretion of aldosterone by the adrenal gland which exerts a long-term effect on maintenance of blood pressure by increasing the reabsorption of Na in the distal tubule. Renin also acts via Angiotensin II to prodoce constriction of the efferent arteriole as a means of preventing a serious decrease in Glomerular filtration pressure. The glomerular filtration pressure is 2-3 times higher than other cap beds in the body. Relaxation of the afferent arteriole increases the filtration pressure and GFR by increasing glomerular blood flow; relaxation of the efferent arteriole decreases resistance to outflow of blood, decreasing glomerular pressure and GFR. The symapthetic nervous system innervate both the afferent and efferent arterioles which are also sensitive to vasoactive hormones like ANgiotensin II. When sympathetic system is stimulated (shock) the constriction of the afferent arteriole causes a decrease in renal BL flow and thus one in GFR, Therefore urine output can fall to almost 0. p. 604.
It is known that high levels of uric acid in the blood can cause gout, while high levels in the urine can cause kidney stones. What medication competes with uric acid for secretion in to the tubular fluid, thereby reducing uric acid secretion?
Aspirin Explanation: p. 612.
Which substance, released by the atria, causes vasodilation of the afferent and efferent arterioles, which results in an increase in renal blood flow and glomerular filtration rate (GFR)?
Atrial natriuretic peptide (ANP) Explanation: Increased evels of this inhibit the reabsoprtion of sodium and water in the renal tubules, as well as inhibiting renin secretion, therefore angiotensin II formation (vasoconstrictor) thus reducing the reabsoprtion of sodium. The decreased sodium reabsorption increases urine output and helps return BV to normal. ANP levels become high when atria are stretched in congestive heart failure, which helps to decrease vascular volume by increasing urine output. p. 611.
An adult has a serum sample taken to evaluate the BUN-creatinine ratio. Select the result that indicates a normal test.
BUN 10 mg/dL to creatinine 1 mg/dL Explanation: Blood Urea Nitrogen (BUN) is related to GFR but is also influenced by protien intake, GI bleeding, and hydration status. Urea is formed as a by-product of protein metabolism is mainly eliminated by the kidneys. In GI bleeding the BL is broken down by intestinal flora, and the nitogenous waster is absorbed into the portal vein and transported to the liver where it is converted to urea. During dehydration elevated BUN results from an increased concentration. About 2/3rds of renal function must be lost before sign. rise in BUN level occurs. A BUN-creatine ratio is a useful diagnostic for renal insufficiency, anything from 15:1 and greater respresents prerenal conditions like congestive heart failure and upper GI bleeding that increase BUN but NOT creatinine. A ratio less than 10:1 occurs in peaple with liver disease who eat a low-protein diet or chronic dialysis because BUN is more readily dialyzable then creatinine. p. 614.
The physician has prescribed a thiazide diuretic for a client. The nurse anticipates that the medication will:
Block the tubular reabsorption of sodium Explanation: p. 607.
When caring for a client with dehydration, the nurse anticipates the client will have an alteration in which of these substances in the blood?
Blood urea nitrogen Explanation: p. 614.
A nurse is evaluating a patient's morning laboratory values. Which of the following results requires that the nurse notify the health care provider?
Creatinine: 10.6 mg/dL Explanation: This indicates 90% loss of GFR or renal function. p. 614.
A client has just been admitted to the emergency department after sustaining severe injuries and massive blood loss following a motor vehicle accident. The nurse predicts that the client's glomerular filtration rate will
Decrease Explanation: Under conditions of decreased perfusion or increased sympathetic nervous system stimulation, BL flow is redistibuted from the cortex to the medulla. This causes a decrease in glomerular filtration while maintaining urine-concentrating ability of the kidneys, which is an important factor during conditions like shock. p. 600.
Which of the following occurrences is most likely to cause increased urination?
Decrease in anti-diuretic hormone Explanation: p. 608.
The nurse is caring for a client who has sustained a cervical spinal cord injury with resulting muscle wasting due to immobility. Which of these alterations in the laboratory tests does the nurse recognize is consistent with decreased muscle mass?
Decreased creatinine levels p. 614.
A nurse is caring for a patient with end-stage renal failure who has symptoms of anemia. The nurse anticipates administering which of the following interventions to increase red blood cell production?
Epoetin alfa Explanation: p. 613.
The nurse is caring for a client with a condition of deficiency of antidiuretic hormone (ADH). When assessing the client, which of these findings does the nurse anticipate?
Excessive urine output Explanation: ADH helps maintain ECF by controlling the permeability of the medullary colelcting tubules. Osmopreceptors in the hypothalamus sense an increase in osmolality of ECF and stimulate the release of ADH (aka vasopressin) from the posterior pituitary galnds. Adh then binds to receptors on tubular celss causes the water channels to move into the luminal side of the tubular membrance, produncung an increase in water permeability. At the basolateral side the water exits the tubular cells into the hyperosmotic interstitium of the medullary area, where it then enters the peritubular capillaries for return to the vascular syste,.The water channels may play a role in inherited and acquired disorders if water reaborption by the kidney, such as diabetes insipidus. p. 607.
Select the option that identifies the function of the kidneys in maintaining normal composition of internal body fluids.
Filtration and reabsorption of physiologically essential substances Explanation: p. 599.
Urine specific gravity is normally 1.010 to 1.025 with adequate hydration. When there is loss of renal concentrating ability due to impaired renal function, low concentration levels are exhibited. When would the nurse consider the low levels of concentration to be significant?
First void in morning Explanation: , p. 615.
The nurse is caring for a client with a disease causing excess antidiuretic hormone. When performing the assessment, the nurse should focus on which of these consequences of excess ADH?
Fluid volume excess Explanation:p. 608.
Which condition causes an elevation in the level of blood urea nitrogen (BUN)?
Gastrointestinal bleeding Explanation:p. 612.
When caring for the client with proteinuria, the nurse recognizes dysfunction in which of these structures of the kidney allows protein to leak into the urine?
Glomerulus Explanation: This a condition in which alot protein is excreted in the urine. In healthy people less than 150 mg/dL is lost a day. Microalbuminuria occurs long before this condition, and a dipstick test can be done for this. A 24-hour test is recommended for both. p. 615
Which of the following statements about mesangial cells within the glomerulus is accurate? Mesangial cells: Select all that apply.
Have phagocytic properties that remove macromolecular materials. Enlarge (hyperplasia) in response to glomerular diseases. Explanation:The mesangial cells lie in between the tufts of capillaries in the glomerulus and provide support to it. They also produce an intracellular substance similar to the basement membrane. The substance covers the endothelial cells where they are not covered by the basement membrane. They also contribute to contractile properties, contribute to reg. BL flow through the glomerulus, phagocytize and remove macromolecular materials from the inter-capillary spaces, and they can profilerate.
A 62-year-old woman with high blood pressure is to begin long-term treatment with a thiazide diuretic that she thinks she'll need to take for some time. What should the nurse expect to happen to her potassium and calcium levels?
Her potassium level will drop, but her calcium level may rise. Explanation: p. 606.
The nurse is teaching a group of nursing students about antidiuretic hormone. The nurse should include which of these points about the site of ADH production in the discussion?
Hypothalamus Explanation: p. 607.
To treat enuresis in a young girl, her pediatrician prescribes desmopressin, an antidiuretic hormone (ADH) nasal spray, before bedtime. Which rationale for this treatment is the most likely?
It removes water from the filtrate and returns it to the vascular compartment. Explanation p. 607.
Which type of nephron is primarily responsible for concentrating urine?
Juxtamedullary nephrons Explanation: p. 601-602.
The nurse recognizes that ADH, antidiuretic hormone, exerts its effects in which of these locations?
Loop of Henle Explanation: p. 606.
A nurse educator is explaining the importance of maintaining GFR for the maintenance of homeostasis. Which play an essential role in maintaining a constant GFR?
Macula densa Explanation: p. 610.
The nurse is administering a potent loop diuretic which blocks reabsorption of certain electrolytes. The nurse applies principles of pathophysiology when monitoring the client for deficiency of which of these substances in the blood?
Magnesium Explanation: p. 606.
The nurse is explaining the role of endothelial cells in synthesizing vasoactive substances, one of which nitric oxide. What affect does nitric oxide have on renal blood flow?
Opens the renal vessels to increase blood flow Explanation: p. 602-603.
The nurse and nursing student are caring for a client with a condition causing deficiency of ADH. The nurse recognizes that the student understands the origin of this process when the student states ADH is produced in which of these areas?.
Pituitary gland Explanation: p. 607
A nursing student studying pharmacology is learning how angiotensin converting enzyme inhibitors (ACE) work. The student is correct when the student states the mechanism of action of ACE inhibitors is which of these?
Prevent conversion of angiotensin I to II Explanation:p. 610.
The anemia that occurs with end-stage kidney disease is often caused by the kidneys themselves. What loss of function in the kidney results in anemia of end-stage kidney disease?
Produce erythropoietin Explanation: About 85-95% of erythropoietin is is formed in the kidneys, and its synthesis is stimulated by hypoxia which can be from anemia, high-altitudes, cardiac pulmonary disease, or impaired oxygenation of tissues. Thus those with chronic kidney disease have anemia because they cannot make eythropoientin and need a recombinant drug to stimulate erythropoiesis. p. 613.
The nurse is teaching a group of nursing students about the formation of urine in the nephron. Which of these components does the nurse teach are components of the nephron? Select all that apply.
Proximal convoluted tubule Loop of Henle Distal convoluted tubule Collecting tubule Explanation: p. 601.
Damage to which of the following areas of a nephron would most likely result in impaired secretion and reabsorption?
Proximal tubule Explanation: This drains Bowman's capsule. About 65% of all reabsorpative and secretory processes occur here. There is complete reabsorption of glucose, amino acids, lactate, and water-soluble vitamins here, as well as most of the electrolytes Na+,K+, and Cl-. When blood glucose is elevated in uncontrolled diabetes mellitus the amount that is secreted is surpassing what is being reaborbed (about 320mg/min). p. 603.
When teaching a pharmacology class the nurse relates that 65 percent of all reabsorptive and secretory processes that occur in the tubular system take place in which of these areas?
Proximal tubules Explanation:p. 605.
A patient is diagnosed with gouty arthritis. To prevent the buildup of uric acid and recurrence of gout attacks, the nurse teaches the patient to avoid eating foods containing which of the following compounds?
Purine Explanation: p. 612.
An elderly man is brought into the clinic by his daughter who states, "My father hasn't been himself lately. Now I think he looks a little yellow." What test would the nurse expect to have ordered to check this man's creatinine level?
Serum creatinine Explanation:p. 614.
The nurse is caring for a client with Addison's disease who has an absence of aldosterone. When reviewing the client's diagnostic test results, which of these consequences of low aldosterone levels does the nurse anticipate?
Serum potassium of 7.3 mEq/L Explanation: p. 612.
The nurse is analyzing the results of a client's urinalysis. Which of these findings does the nurse follow up on because they are abnormal?
Specific gravity 1.034 This indicates dehydration.
The nurse is caring for a client with kidney disease who has an estimated glomerular filtration rate of 75 ml/minute. The nurse interprets this data in which of the following way?
The client has reduced glomerular filtration reflecting damage to the kidney. Explanation: p. 604.
A medical client's routine urinalysis includes the following data: Casts: positive Red blood cells: negative Crystals: negative White blood cells: negative Epithelial cells: few Which interpretation of these findings is the most plausible?
The client's urine contains excessive protein Explanation: Casts are molds of distal nephron lumen and they are made of a gel-like substance. The hyaline casts develop when protein concentration of the urine is high (nephrotic syndrome),urine osmalality is high, and urine pH is low. Casts should be negative possibly a little hyaline cast presnt; RBCs negative or rare; crystals neg; WBCs neg or rare; epithelial cells=few. p. 615.
The nurse is teaching an anatomy and physiology class to a group of nursing students. When discussing the juxtamedullary nephrons it is correct to relate which of these functions to the students?
The juxtamedullary nephrons function is to concentrate urine. p. 602.
Which function of the kidneys helps to maintain the pH balance in the body?
The kidneys conserve base bicarbonate and eliminate hydrogen ions. Explanation: p. 607.
The nurse is caring for a client who has produced an average of 20 ml/hour for the previous day. The nurse recognizes this compares in which way to the normal urine output?
The kidneys should produce about 1.5 liters of urine each day. Explanation: p. 615.
While assessing a patient with urosepsis, the ICU nurse notes the patient's BP is 80/54; HR 132; RR 24; pulse Ox 89% on 6 lpm O2. Over the last hour, the patients urine output is 15 mL. When explaining to a new graduate nurse, the nurse will emphasize that the patients status may relate to:
The patients sympathetic nervous system has been stimulated which has resulted in vasoconstriction of the afferent arteriole which causes a decrease in renal blood flow. Explanation: p. 609.
In the presence of aldosterone in the distal tube, what action would occur?
The urine would be nearly sodium free. Explanation: p. 606.
The nurse is teaching a group of nursing students about the mechanism of action of common diuretics. Which of these best reflects the mechanism of these drugs?
They block the reabsorption of sodium and chloride in the nephron. Explanation: Thiazide diuretics are used widely in hypertension and act by blocking sodium chloride reabsorption in the distal and collecting tubules, and by enhancing the active reabsorption of Ca into the blood via the calcium-sodium exchange transport mechanism. It is for this reason that diuretics are useful in reducing calcium kidney stones in persons with hypercalciruria. p. 606.
The nurse is administering the diuretic furosemide (Lasix) to a client with heart failure. The nurse recognizes that this exerts its action in which of these areas in the kidney?
Thick ascending loop of Henle Explanation: p. 606.
Gout and the development of kidney stones are often attributed to high levels of what compound?
Uric acid Explanation: Uric acid is a product of purine metabolism, and excessively high levels can develop gout or kidney stones. Uric acid uses the same transport mechanisms as drugs like aspirin, suflinpyrozone, probenecid. Thus a small does of aspirin will compete with uric acid for secretion into the tubular fluid and reduce uric acid secretion, but a LARGER dose competes with uric acid for re-absorption and increases the uric acid excretion in the urine. Thus aspiring is NOT a recommended treatment for those with gouty arthritis. Thiazide and loop diuretics (furosemide and ethracrynic acid) also can cause gouty arthritis and hyperuricemia (most likley through a decrease in ectracellualr fluid volume and more uric acid absorption). p. 612.
The nurse administers the drug vasopressin to a patient with a pituitary disorder. Based on knowledge of pathophysiology, the nurse anticipates the client will react in which of these ways?
Water will be retained and decreased urine output will result. Explanation: p. 609.
The client with chronic kidney disease asks the nurse why he must take active vitamin D (calcitriol) as a medication. Which of these is the most appropriate response by the nurse?
With renal disease vitamin D is unable to be transformed to its active form. Explanation: Activation of vitamin D occurs in the kidneys, and the vitamin acts by increasing clacium absoprtion from the GI tract to help regulate calcium deposition in bone. iT has weak stimulatory effect on renal calcium absorption. People with end-stage-renal disease are unable to transform vitamin D to its active form so they need to take it in its active form to maintain the mineralization of their bones. p. 613.
A client arrives in the emergency department semi-comatose. Her breath has a "fruity" smell. Their initial blood glucose level is >600. Her mouth and mucous membranes are dry. The healthcare providers suspect the client may be experiencing hyperglycemic hyperosmolar syndrome. In this situation, the nurse can expect the client's lab results to reflect:
an increase in glomerular filtration rate [GFR].
A client has been prescribed a drug that is not removed quickly by renal filtration. The drug likely has this quality because it is:
bound to plasma proteins. Explanation: The kidneys can eliminate drugs that are weak acids or bases, aka not bound to a protein. p. 612.
The nurse is reviewing the results of a renal client's laboratory results. This client's urine specific gravity allows the nurse to assess the kidneys' ability to:
concentrate urine. Explanation: p. 615.
A client with a history of renal insufficiency is experiencing a flare-up of his arthritis and he has increased his daily dose of ibprofen (an NSAID). Knowing the effect that ibprofen has on prostaglandin synthesis, the nurse should anticipate:
decrease renal blood flow resulting in decrease in urine output. Explanation: p. 609.
A client with a history of renal insufficiency is experiencing a flare-up of his arthritis and he has increased his daily dose of ibprofen (an NSAID). Knowing the effect that ibprofen has on prostaglandin synthesis, the nurse should anticipate:
decrease renal blood flow resulting in decrease in urine output. Explanation: p. 609.
The mesagial are is very narrow and has only a small number of cells BUT mesangial ________________ and increased mesangial matrix develop in many forms of glomerular disease.
hyperplasia
In the emergency department, a client arrives following a car accident. His pulse is 122; BP 88/60; respiration is 18 bpm. Urine output is 4 mL over the first hour on arrival. When in shock, this lower urine output is primarily due to:
innervation of the sympathetic nervous system causing constriction of the afferent arteriole. Explanation: p. 604.
A client with Addison disease has been admitted to regulate fluid and electrolyte imbalances. The nurse can anticipate that the client's blood work will show:
serum potassium levels have increased. Explanation :Aldosterone is absent in this disease, and so potassium secretion is deacreased thus the blood levels of it fall. Aldosterone works by secreting potassium. p. 612.
A client with a diagnosis of heart failure has begun showing signs of renal failure. This occurs because:
the kidneys receive a high proportion of cardiac output to maintain GFR and waste-product removal. Explanation: p. 607.