Unit 6 - Renal - Unit 20 - Kidney Disorders and Therapeutic Management

16. What is a continuous venovenous hemodialysis filter permeable to? a. Electrolytes b. Red blood cells c. Protein d. Lipids

ANS: A A continuous venovenous hemodialysis filter is permeable to solutes such as urea, creatinine, uric acid, sodium, potassium, ionized calcium, and drugs not bound by proteins.

19. Which of the following diuretics maybe combined to work on different parts of the nephron? a. Loop and thiazide diuretics b. Loop and osmotic diuretics c. Osmotic and carbonic anhydrase inhibitor diuretics d. Thiazide and osmotic diuretics

ANS: A A thiazide diuretic such as chlorothiazide (Diuril) or metolazone (Zaroxolyn) may be administered and followed by a loop diuretic to take advantage of the fact that these medications work on different parts of the nephron. Sometimes a thiazide diuretic is added to a loop diuretic to compensate for the development of loop diuretic resistance.

22. A patient with renal failure reports all of the following during the medical history. Which is most likely to have precipitated the patient's renal failure? a. Recent computed tomography of the brain with and without contrast b. A recent bout of congestive heart failure after an acute myocardial infarction c. Twice-daily prescription of Lasix 40 mg by mouth d. A recent bout of benign prostatic hypertrophy and transurethral resection of the prostate

ANS: A Intravenous contrast media can be nephrotoxic, especially with the patient's pre-existing cardiac disease. The other choices, although possible causes, are less likely than the intravenous contrast media.

24. A patient in acute renal failure presents with a potassium level of 6.9 mg/dL. He has had no urine output in the past 4 hours despite urinary catheter insertion and Lasix 40 mg intravenous push. Vital signs are as follows: HR, 76 beats/min; respiratory rate, 18 breaths/min; and BP, 145/96 mm Hg. He is given 100 mL of 50% dextrose in water and 20 U of regular insulin intravenous push. A repeat potassium level 2 hours later shows a potassium level of 4.5 mg/dL. What order would now be expected? a. Sodium Kayexalate 15 g PO b. Nothing; this represents a normal potassium level c. Lasix 40 mg IVP d. 0.9% normal saline at 125 mL/hr

ANS: A This patient appears to be in acute anuric renal failure. The potassium was not eliminated from the body; it was simply shifted intracellularly. Soon the potassium will return to the bloodstream, and the Kayexalate will help permanently remove it from the body. Lasix is not expected to work in the presence of anuria. The patient's vital signs do not support hypovolemia. In the presence of anuria, a large fluid infusion can precipitate congestive heart failure.

7. To remove fluid during hemodialysis, a positive hydrostatic pressure is applied to the blood and a negative hydrostatic pressure is applied to the dialysate bath. This process is known as a. ultrafiltration. b. hemodialysis. c. reverse osmosis. d. colloid extraction.

ANS: A To remove fluid, a positive hydrostatic pressure is applied to the blood, and a negative hydrostatic pressure is applied to the dialysate bath. The two forces together, called transmembrane pressure, pull and squeeze the excess fluid from the blood. The difference between the two values (expressed in millimeters of mercury [mm Hg]) represents the transmembrane pressure and results in fluid extraction, known as ultrafiltration, from the vascular space.

1. Which of the following conditions is associated between kidney failure and respiratory failure? (Select all that apply.) a. ARDS b. Lower GFR c. Increased urine output d. Decreased urine output e. Decreased blood flow to the kidneys

ANS: A, B, D, E Mechanical ventilation for respiratory failure can alter kidney function. Positive-pressure ventilation reduces blood flow to the kidney, lowers the glomerular filtration rate, and decreases urine output. Kidney failure increases inflammation, causes the lung vasculature to become more permeable, and contributes to the development of acute respiratory distress syndrome.

2. To prevent catheter-associated UTI (CAUTI), the nurse should (Select all that apply.) a. insert urinary catheters using aseptic techniques. b. change the urinary catheter daily. c. review the need for the urinary catheter daily and remove promptly. d. flush the urinary catheter q8 hours to maintain patency. e. avoid unnecessary use of indwelling urinary catheters.

ANS: A, C, E The key components of CAUTI prevention are to avoid unnecessary use of urinary catheters, insert urinary catheters using aseptic technique, adopt evidence-based standards for maintenance of urinary catheters, review the need for the urinary catheter daily, and remove the catheter promptly.

12. A patient has acute kidney injury (previously known as acute tubular necrosis). The following blood work was noted: complete blood count shows a white blood cell count of 11,000 mm3, a hemoglobin of 8 g/dL, and a hematocrit of 30%. His chemistry panel shows serum potassium, 4.5 mg/dL; serum sodium, 135 mg/dL; serum calcium, 8.5 mg/dL; BUN, 20 mg/dL; and creatinine, 1.5 mg/dL. What laboratory value(s) need(s) to be treated most immediately and why? a. Administration of 5% dextrose in water and insulin because the patient is hyperkalemic and needs this level reduced b. Administration of Epogen to treat anemia c. Administration of a broad-spectrum antibiotic to treat the elevated blood cell count d. Administration of a calcium supplement for low calcium

ANS: B A patient showing signs of anemia per his hematocrit and hemoglobin must be treated. Epogen is used because it helps stimulate erythrocyte production by the bone marrow.

8. Which electrolytes pose the most potential hazard if not within normal limits for a person with renal failure? a. Phosphorous and calcium b. Potassium and calcium c. Magnesium and sodium d. Phosphorous and magnesium

ANS: B Although most electrolytes, such as potassium, become increasingly elevated in patients with acute renal failure, calcium levels are reduced. In each case, these conditions produce life-threatening cardiac dysrhythmias.

9. A patient has been hospitalized for a subtotal gastrectomy. After the procedure, an infection developed that eventually had to be treated with gentamicin, an aminoglycoside antibiotic. After 3 days of administration, oliguria occurred, and subsequent laboratory values indicated elevated BUN and creatinine levels. The patient is transferred to the critical care unit with acute kidney injury (previously known as acute tubular necrosis). Which dialysis method would be most appropriate for the patient's condition? a. Peritoneal dialysis b. Hemodialysis c. Continuous renal replacement therapy d. Continuous venovenous hemodialysis (CVVH)

ANS: B As a treatment, hemodialysis literally separates and removes from the blood the excess electrolytes, fluids, and toxins by use of a hemodialyzer. Although hemodialysis is efficient in removing solutes, it does not remove all metabolites. Furthermore, electrolytes, toxins, and fluids increase between treatments, necessitating hemodialysis on a regular basis.

13. The patient is a gravida 6, para 1. She is admitted after a cesarean section after an amniotic embolus. Her heart rate (HR) is more than 150 beats/min with a systolic BP less than 80 mm Hg. Her temperature is 38°C, and her condition has caused her to develop prerenal azotemia. The patient was fluid resuscitated through a double-lumen catheter, which was placed into her right femoral access, and started on vasopressors with a fair response (BP, 80/50 mm Hg; HR, 122 beats/min). Because of her diagnosis and a concern regarding fulminating sepsis, the patient was begun on CVVH. Which of the statements best describes CVVH? a. Complete renal replacement therapy requiring large volumes of ultrafiltrate and filter replacement b. Complete renal replacement therapy that allows removal of solutes and modification of the volume and composition of extracellular fluid to occur evenly over time c. Involves the introduction of sterile dialyzing fluid through an implanted catheter into the abdominal cavity, which relies on osmosis, diffusion, and active transport to help remove waste from the body d. Complete renal replacement therapy that allows an exchange of fluid, solutes, and solvents across a semipermeable membrane at 100 to 300 mL/hr

ANS: B Continuous venovenous hemodialysis is indicated when the patient's clinical condition warrants removal of significant volumes of fluid and solutes. Fluid is removed by ultrafiltration in volumes of 5 to 20 mL/min or up to 7 to 30 L/24 hr. Removal of solutes such as urea, creatinine, and other small non-protein-bound toxins is accomplished by convection. The replacement fluid rate of flow through the continuous renal replacement therapy circuit can be altered to achieve desired fluid and solute removal without causing hemodynamic instability.

26. Which of the following medications is considered a loop diuretic? a. Acetazolamide (Diamox) b. Furosemide (Lasix) c. Mannitol d. Metolazone (Zaroxolyn)

ANS: B Loop diuretics include furosemide (Lasix), bumetanide (Bumex), and torsemide (Torsemide). Furosemide is the most frequently used diuretic in critical care patients. It may be administered orally, as an intravenous (IV) bolus, or as a continuous IV infusion. Diamox is a carbonic anhydrase inhibitor diuretic. Mannitol is an osmotic diuretic, and Zaroxolyn is a thiazide diuretic.

3. Which of the following IV solutions is recommended for treatment of prerenal failure? a. Dextrose in water b. Normal saline c. Albumin d. Lactated Ringer solution

ANS: B Prerenal failure is caused by decreased perfusion and flow to the kidney. It is often associated with trauma, hemorrhage, hypotension, and major fluid losses. If contrast dye is used, aggressive fluid resuscitation with normal saline (NaCl) is recommended.

2. Which of the following laboratory values is the most help in evaluating a patient for acute renal failure? a. Serum sodium b. Serum creatinine c. Serum potassium d. Urine potassium

ANS: B Serum creatinine is the most reliable predictor of kidney function. In the acutely ill patient, small changes in the serum creatinine level and urine output may signal important declines in the glomerular filtration rate and kidney function.

11. The most common site for short-term vascular access for immediate hemodialysis is the a. subclavian artery. b. subclavian vein. c. femoral artery. d. radial vein.

ANS: B Subclavian and femoral veins are catheterized when short-term access is required or when a graft or fistula vascular access is nonfunctional in a patient requiring immediate hemodialysis. Subclavian and femoral catheters are routinely inserted at the bedside. Most temporary catheters are venous lines only. Blood flows out toward the dialyzer and flows back to the patient through the same catheterized vein. A dual-lumen venous catheter is most commonly used.

23. An alert and oriented patient presents with a pulmonary artery wedge pressure of 4 mm Hg and a cardiac index of 0.8. The BUN is 44 mg/dL, creatinine is 3.2 mg/dL, and BP is 88/36 mm Hg. Urine output is 15 mL/hr. Lungs are clear to auscultation with no peripheral edema noted. Which of the following treatments would the physician most likely order? a. Lasix 40 mg intravenous push b. 0.9% normal saline at 125 mL/hr c. Dopamine 15 g/kg/min d. Transfuse 1 U of packed red blood cells

ANS: B The patient's hemodynamic parameters are most consistent with hypovolemia. The renal failure would then most probably be prerenal from inadequate blood flow. The treatment of choice for hypovolemia is fluid resuscitation. Important criteria when calculating fluid volume replacement include baseline metabolism, environmental temperature, and humidity. The rate of replacement depends on cardiopulmonary reserve, adequacy of kidney function, urine output, fluid balance, ongoing loss, and type of fluid replaced.

18. To control azotemia, the recommended nutritional intake of protein is a. .5 to 1.0 g/kg/day. b. 1.2 to 1.5 g/kg/day. c. 1.7 to 2.5 g/kg/day. d. 2.5 to 3.5 g/kg/day.

ANS: B The recommended energy intake is between 20 and 30 kcal/kg/day, with 1.2 to 1.5 grams/kg of protein per day to control azotemia (increased blood urea nitrogen level).

14. The patient is a gravida 6, para 1. She is admitted after a cesarean section after an amniotic embolus. Her heart rate (HR) is more than 150 beats/min with a systolic BP less than 80 mm Hg. Her temperature is 38°C, and her condition has caused her to develop prerenal azotemia. The patient was fluid resuscitated through a double-lumen catheter, which was placed into her right femoral access, and started on vasopressors with a fair response (BP, 80/50 mm Hg; HR, 122 beats/min). Because of her diagnosis and a concern regarding fulminating sepsis, the patient was begun on CVVH. Identify three complications of CVVH therapy. a. Fat emboli, increased ultrafiltration, and hypertension b. Hyperthermia, overhydration, and power surge c. Air embolism, decreased inflow pressure, and electrolyte imbalance d. Blood loss, decreased outflow resistance, and acid-base imbalance

ANS: C Air embolism, decreased inflow pressure, electrolyte imbalances, blood leaks, access failure, and clotted hemofilter are just a few complications that can occur with continuous venovenous hemodialysis.

25. A patient with chronic renal failure receives hemodialysis treatments 3 days a week. Every 2 weeks, the patient requires a transfusion of 1 or 2 U of packed red blood cells. What is the probable reason for this patient's frequent transfusion needs? a. Too much blood phlebotomized for tests b. Increased destruction of red blood cells because of the increased toxin levels c. Lack of production of erythropoietin to stimulate red blood cell formation d. Fluid retention causing hemodilution

ANS: C In chronic renal failure, the kidneys do not produce sufficient amounts of erythropoietin in response to normal stimuli such as anemia or hypotension. The other choices are not reasons for frequent blood transfusions in this patient.

1. An elderly patient is in a motor vehicle accident and sustains a significant internal hemorrhage. Which category of renal failure is the patient at the greatest risk of developing? a. Intrinsic b. Postrenal c. Prerenal d. Acute tubular necrosis

ANS: C Any condition that decreases blood flow, blood pressure, or kidney perfusion before arterial blood reaches the renal artery that supplies the kidney may be anatomically described as prerenal acute kidney injury (AKI). When arterial hypoperfusion caused by low cardiac output, hemorrhage, vasodilation, thrombosis, or other cause reduces the blood flow to the kidney, glomerular filtration decreases, and consequently urine output decreases. Any condition that produces an ischemic or toxic insult directly at parenchymal nephron tissue places the patient at risk for development of intrarenal AKI. Any obstruction that hinders the flow of urine from beyond the kidney through the remainder of the urinary tract may lead to postrenal AKI. When the internal filtering structures are pathologically affected, the condition was previously known as acute tubular necrosis.

5. Which of the following IV solutions is contraindicated for patients with kidney or liver disease or in lactic acidosis? a. D5W b. 0.9% NaCl c. Lactated Ringer solution d. 0.45% NaCl

ANS: C Lactated Ringer solution is contraindicated for patients with kidney or liver diseases or in lactic acidosis.

20. What is the dose for low-dose dopamine? a. 1 to 2 mcg/kg/min b. 1 to 2 mg/kg/min c. 2 to 3 mcg/kg/min d. 2 to 3 mg/kg/min

ANS: C Low-dose dopamine (2-3 mcg/kg/min), previously known as renal-dose dopamine, is frequently infused to stimulate blood flow to the kidney. Dopamine is effective in increasing urine output in the short term, but tolerance of the dopamine renal receptor to the medication is theorized to develop in the critically ill patients who are most at risk for acute kidney injury.

6. To assess whether or not an arteriovenous fistula is functioning, what must be done and why? a. Palpate the quality of the pulse distal to the site to determine whether a thrill is present; auscultate with a stethoscope to appreciate a bruit to assess the quality of the blood flow. b. Palpate the quality of the pulse proximal to the site to determine whether a thrill is present; auscultate with a stethoscope to appreciate a bruit to assess the quality of the blood flow. c. Palpate gently over the site of the fistula to determine whether a thrill is present; listen with a stethoscope over this site to appreciate a bruit to assess the quality of the blood flow. d. Palpate over the site of the fistula to determine whether a thrill is present; check whether the extremity is pink and warm.

ANS: C The critical care nurse frequently assesses the quality of blood flow through the fistula. A patent fistula has a thrill when palpated gently with the fingers and a bruit when auscultated with a stethoscope. The extremity should be pink and warm to the touch. No blood pressure measurements, intravenous infusions, or laboratory phlebotomy is performed on the arm with the fistula.

17. A patient has sepsis and is placed on broad-spectrum antibiotics. Her temperature is 37.8°C. Her BUN level is elevated. She continues on vasopressor therapy. What other steps should be taken to protect the patient from inadequate organ perfusion? a. Increase net ultrafiltrate of fluid. b. Discontinue vasopressor support. c. Assess the patient for blood loss and hypotension. d. Notify the physician of access pressures.

ANS: C The patient should be assessed for blood loss or response to blood products and medications. The nurse should use ordered vasopressor support and decrease the net ultrafiltrate to zero.

4. One therapeutic measure for treating hyperkalemia is the administration of dextrose and regular insulin. How do these agents lower potassium? a. They force potassium out of the cells and into the serum, lowering it on a cellular level. b. They promote higher excretion of potassium in the urine. c. They bind with resin in the bowel and are eliminated in the feces. d. They force potassium out of the serum and into the cells, thus causing potassium to lower.

ANS: D Acute hyperkalemia can be treated temporarily by intravenous administration of insulin and glucose. An infusion of 50 mL of 50% dextrose accompanied by 10 units of regular insulin forces potassium out of the serum and into the cells.

15. The patient is a gravida 6, para 1. She is admitted after a cesarean section after an amniotic embolus. Her heart rate (HR) is more than 150 beats/min with a systolic BP less than 80 mm Hg. Her temperature is 38°C, and her condition has caused her to develop prerenal azotemia. The patient was fluid resuscitated through a double-lumen catheter, which was placed into her right femoral access, and started on vasopressors with a fair response (BP, 80/50 mm Hg; HR, 122 beats/min). Because of her diagnosis and a concern regarding fulminating sepsis, the patient was begun on CVVH. Why would this therapy be chosen for this patient? a. Hyperdynamic patients can better tolerate abrupt fluid and solute changes. b. It is the treatment of choice for patients with diminished renal perfusion who are unresponsive to diuretics. c. It is indicated for patients who require large-volume removal for severe uremia or critical acid-base imbalances. d. It is indicated for hemodynamically unstable patients, who are often intolerant of the abrupt fluid and solute changes that can occur with hemodialysis.

ANS: D Continuous venovenous hemodialysis is indicated for patients who require large-volume removal for severe uremia or critical acid-base imbalances or for those who are resistant to diuretics.

10. A patient has been hospitalized for a subtotal gastrectomy. After the procedure, an infection developed that eventually had to be treated with gentamicin, an aminoglycoside antibiotic. After 3 days of administration, oliguria occurred, and subsequent laboratory values indicated elevated BUN and creatinine levels. The patient is transferred to the critical care unit with acute kidney injury (previously known as acute tubular necrosis). The fluid that is removed each hour is not called urine; it is known as a. convection. b. diffusion. c. replacement fluid. d. ultrafiltrate.

ANS: D The fluid that is removed each hour is not called urine; it is known as ultrafiltrate. Typically, some of the ultrafiltrate is replaced through the continuous renal replacement therapy circuit by a sterile replacement fluid. Diffusion is the movement of solutes along a concentration gradient from a high concentration to a low concentration across a semipermeable membrane. Convection occurs when a pressure gradient is set up so that the water is pushed or pumped across the dialysis filter and carries the solutes from the bloodstream with it.

21. Laboratory results come back on a newly admitted patient. They are as follows: serum BUN, 64 mg/dL; serum creatinine, 2.4 mg/dL; urine osmolality, 210 mOsm/kg; specific gravity, 1.002; and urine sodium, 96 mEq/L. The urine output has been 120 mL since admission 2 hours ago. These values are most consistent with which of the following diagnoses? a. Prerenal failure b. Postrenal failure c. Oliguric renal failure d. Acute kidney injury (AKI)

ANS: D Urinary sodium less than 10 mEq/L (low) suggests a prerenal condition. Urinary sodium greater than 40 mEq/L (in the presence of an elevated serum creatinine and the absence of a high salt load) suggests intrarenal damage has occurred. The urine output does not seem to suggest oliguria. The other options do not fit the data as presented.