Chapter 25: Kidney Clinical Assessment and Diagnostic Procedures

Loss of albumin from the vascular space may result in which condition? a. Peripheral edema b. Extra heart sounds c. Hypertension d. Hyponatremia

ANS: A Decreased albumin levels in the vascular space result in a plasma-to-interstitium fluid shift, creating peripheral edema. A decreased albumin level can occur as a result of protein-calorie malnutrition, which occurs in many critically ill patients in whom available stores of albumin are depleted. A decrease in the plasma oncotic pressure results, and fluid shifts from the vascular space to the interstitial space.

A patient has been admitted with acute kidney injury. The nurse knows the most important consideration for evaluating the patient's fluid status is what parameter? a. Daily weights b. Urine and serum osmolality c. Intake and output d. Hemoglobin and hematocrit levels

ANS: A One of the most important assessments of kidney and fluid status is the patient's weight. In the critical care unit, weight is monitored for each patient every day and is an important vital signs measurement.

When calculating the anion gap, what is the predominant cation? a. Sodium b. Potassium c. Chloride d. Bicarbonate

ANS: A The anion gap is a calculation of the difference between the measurable extracellular plasma cations (sodium and potassium) and the measurable anions (chloride and bicarbonate). In plasma, sodium is the predominant cation, and chloride is the predominant anion.

A patient is admitted in acute heart failure secondary to renal insufficiency. The patient reports that over the past few weeks, his urine output has decreased, and he has developed peripheral edema and ascites. A diagnosis of renal failure is made. The nurse would expect to see elevated values in which laboratory results? (Select all that apply.) a. Blood urea nitrogen (BUN) b. Creatinine c. Glucose d. Hemoglobin and hematocrit e. Protein

ANS: A, B, D With kidney dysfunction, the blood urea nitrogen (BUN) is elevated because of a decrease in the glomerular filtration rate and resulting decrease in urea excretion. Elevations in the BUN can be correlated with the clinical manifestations of uremia; as the BUN rises, symptoms of uremia become more pronounced. Creatinine levels are fairly constant and are affected by fewer factors than BUN. As a result, the serum creatinine level is a more sensitive and specific indicator of kidney function than BUN. Creatinine excess occurs most often in persons with kidney failure resulting from impaired excretion. Decreased hematocrit value can indicate fluid volume excess because of the dilutional effect of the extra fluid load. Decreases also can result from anemias, blood loss, liver damage, or hemolytic reactions. In individuals with acute kidney failure, anemia may occur early in the disease.

Which findings may be present in the patient with significant fluid volume overload? (Select all that apply.) a. S3 or S4 may develop. b. Distention of the hand veins will disappear if the hand is elevated. c. When testing the quality of skin turgor, the skin will not return to the normal position for several seconds. d. Tachycardia with hypotension may be present. e. Dependent edema may be present.

ANS: A, E A gallop and dependent edema are indicative of fluid excess; the other signs are indicative of fluid volume deficit

What causes the presence of myoglobin in urine? (Select all that apply.) a. Bleeding b. Traumatic damage to the skeletal muscle c. Asthmatic attack d. Rhabdomyolysis e. Cocaine abuse

ANS: A, B, D, E Although a few red blood cells (RBCs) in the urine are normal, discernibly bloody urine usually indicates bleeding within the urinary tract or kidney trauma. The presence of myoglobin can make the urine appear red. Microscopic examination of the urine fails to reveal RBCs, with myoglobin being present instead. Myoglobin in the urine may result from skeletal muscle damage (eg, traumatic crush injury) or rhabdomyolysis. Rhabdomyolysis may develop in patients admitted to a critical care unit for many reasons, including traumatic injury, cocaine abuse, status epilepticus, heat prostration, or collapse during intense physical exercise (eg, running a marathon race on a hot day).

A patient is admitted in acute heart failure secondary to renal insufficiency. The patient reports that over the past few weeks, his urine output has decreased, and he has developed peripheral edema and ascites. Which diagnostic tests would provide the best information about the internal kidney structures, such as the parenchyma, calyces, pelvis, ureters, and bladder? a. Kidney-ureter-bladder (KUB) b. Intravenous pyelography (IVP) c. Renal ultrasonography (ECHO) d. Renal angiography

ANS: B Intravenous pyelography allows visualization of the internal kidney parenchyma, calyces, pelvis, ureters, and bladder. Kidney-ureter-bladder flat-plate radiography of the abdomen determines the position, size, and structure of the kidneys, urinary tract, and pelvis. It is useful for evaluating the presence of calculi and masses and is usually followed by additional tests. In ultrasonography, high-frequency sound waves are transmitted to the kidneys and urinary tract, and the image is viewed on an oscilloscope. This noninvasive procedure identifies fluid accumulation or obstruction, cysts, stones or calculi, and masses. It is useful for evaluating the kidneys before biopsy. Angiography is injection of contrast into arterial blood perfusing the kidneys. It allows for visualization of renal blood flow and may also visualize stenosis, cysts, clots, trauma, and infarctions.

A patient has been on complete bed rest for 3 days. The practitioner has left orders to get the patient out of bed for meals. The patient complains of feeling dizzy and faint while sitting at the bedside. The nurse suspects that the patient is experiencing what problem? a. Orthostatic hypertension b. Orthostatic hypotension c. Hypervolemia d. Electrolyte imbalance

ANS: B Orthostatic hypotension produces subjective feelings of weakness, dizziness, or faintness. Orthostatic hypotension occurs with hypovolemia or prolonged bed rest or as a side effect of medications that affect blood volume or blood pressure.

Percussion of kidneys is usually done to assess what parameter? a. Size and shape of the kidneys b. Presence of pain in the renal area c. Presence of a fluid wave d. Patient's overall fluid status

ANS: B Percussion is performed to detect pain in the area of a kidney or to determine excess accumulation of air, fluid, or solids around the kidneys. Percussion of the kidneys also provides information about kidney location, size, and possible problems.

A patient was admitted with acute kidney failure. Which urinalysis value reflects a decreased ability of the kidneys to concentrate urine? a. pH of 5.0 b. Specific gravity of 1.000 c. No casts d. Urine sodium of 140 mEq/24 h

ANS: B Specific gravity measures the density or weight of urine compared with that of distilled water. The normal urinary specific gravity is 1.005 to 1.025. For comparison, the specific gravity of distilled water is 1.000. Because urine is composed of many solutes and substances suspended in water, the specific gravity should always be higher than that of water.

A patient was admitted with acute heart failure a few days ago. Today the patient's urine has a specific gravity of 1.040. What could be the potential cause for this value? a. Volume overload b. Volume deficit c. Acidosis d. Urine ketones

ANS: B Specific gravity ranges from 1.003 to 1.030. Possible causes for increased values include volume deficit, glycosuria, proteinuria, and prerenal acute kidney injury (AKI). Possible causes for decreased values include volume overload and interrenal AKI.

A patient has been admitted in acute heart failure. Which parameter would indicate to the nurse that the patient is fluid overloaded? a. Central venous pressure of 4 mm Hg b. Pulmonary artery occlusion pressure (PAOP) of 18 mm Hg c. Cardiac index of 2.5 L/min/m2 d. Mean arterial pressure of 40 mm Hg

ANS: B The pulmonary artery occlusion pressure (PAOP) represents the left atrial pressure required to fill the left ventricle. When the left ventricle is full at the end of diastole, this represents the volume of blood available for ejection. It is also known as left ventricular preload and is measured by the PAOP. The normal PAOP is 5 to 12 mm Hg. In fluid volume excess, PAOP rises. In fluid volume deficit, PAOP is low.

A patient was admitted with acute heart failure who has been receiving diuretic therapy. The nurse suspects the patient is hypovolemic. What auscultatory parameter would confirm the nurse's suspicion? a. Hypertension b. Third or fourth heart sound c. Orthostatic hypotension d. Vascular bruit

ANS: C A drop in systolic blood pressure of 20 mm Hg or more, a drop in diastolic blood pressure of 10 mm Hg or more, or a rise in pulse rate of more than 15 beats/min from lying to sitting or from sitting to standing indicates orthostatic hypotension. The drop in blood pressure occurs because a sufficient preload is not immediately available when the patient changes position. The heart rate increases in an attempt to maintain cardiac output and circulation.

A patient is admitted in acute heart failure secondary to renal insufficiency. The patient reports that over the past few weeks, his urine output has decreased, and he has developed peripheral edema and ascites. The nurse suspects the main cause of ascites is what condition? a. Hypervolemia b. Dehydration c. Volume overload d. Liver damage

ANS: C Individuals with kidney failure may have ascites caused by volume overload, which forces fluid into the abdomen because of increased capillary hydrostatic pressures. However, ascites may or may not represent fluid volume excess. Severe ascites in persons with compromised liver function may result from decreased plasma proteins. The ascites occurs because the increased vascular pressure associated with liver dysfunction forces fluid and plasma proteins from the vascular space into the interstitial space and abdominal cavity. Although the individual may exhibit marked edema, the intravascular space is volume depleted, and the patient is hypovolemic.

A patient is admitted with renal failure. The patient's weight upon admission was 176 lb, and the next day it is 184 lb. What is the approximate amount of fluid retained with this weight gain? a. 800 mL b. 2200 mL c. 3600 mL d. 8000 mL

ANS: C One liter of fluid equals 1 kg, which is 2.2 lb; 8 lb equals 3.6 kg, which is 3.6 L; 3.6 L is equal to 3600 mL.

A patient was admitted with heart failure. The nurse is assessing the patient for peripheral edema. The nurse presses two fingers over the tibial area, and it takes 1 minute before the indention disappears. What would the nurse note in the medical record? a. +1 pitting edema b. +2 pitting edema c. +3 pitting edema d. +4 pitting edema

ANS: C The pitting edema scale includes +1 = 2-mm depth; +2 = 4-mm depth (lasting up to 15 seconds); +3 = 6-mm depth (lasting up to 60 seconds); and +4 = 8-mm depth (lasting longer than 60 seconds).

As serum osmolality rises, intravascular fluid equilibrium will be maintained by the release of what substance? a. Ketones b. Glucagon c. Antidiuretic hormone d. Potassium

ANS: C When the serum osmolality level increases, antidiuretic hormone is released from the posterior pituitary gland and stimulates increased water resorption in the kidney tubules. This expands the vascular space, returns the serum osmolality level back to normal, and results in more concentrated urine and an elevated urine osmolality level.

The patient complains of a metallic taste and loss of appetite. The nurse is concerned that the patient has developed what problem? a. Glycosuria b. Proteinuria c. Myoglobin d. Uremia

ANS: D A history of recent onset of nausea and vomiting or appetite loss caused by taste changes (uremia often causes a metallic taste) may provide clues to the rapid onset of kidney problems. Glycosuria is the presence of glucose in the urine. Proteinuria is the presence of protein in the urine. Myoglobin is the presence of red blood cells in the urine.

A patient was admitted with multiple trauma who has been volume resuscitated. The nurse suspects the patient is fluid overloaded. Which assessment findings would confirm the nurse's suspicion? a. Venous filling of the hand veins greater than 5 seconds b. Distended neck veins in the supine position c. Presence of orthostatic hypotension d. Presence of a third heart sound

ANS: D Auscultation of the heart requires not only assessing rate and rhythm but also listening for extra sounds. Fluid overload is often accompanied by a third or fourth heart sound, which is best heard with the bell of the stethoscope.

In a patient with a distended abdomen, differentiating ascites from solid bowel contents is accomplished by performing what assessment? a. Auscultation of bowel sounds b. Palpation of the liver margin c. Measuring abdominal girth d. Eliciting a fluid wave

ANS: D Differentiating ascites from distortion by solid bowel contents is accomplished by producing what is called a fluid wave. The fluid wave is elicited by exerting pressure to the abdominal midline while one hand is placed on the right or left flank. Tapping the opposite flank produces a wave in the accumulated fluid that can be felt under the hands.