Fundamentals of Care: Laboratory Values

The nurse volunteering at the health screening clinic reinforces instructions to a 22-year-old client that diet and exercise should be used as tools to keep the total cholesterol level under at least which level?

✅ 200 mg/dL. 📋Rationale: The cholesterol level should be at least less than 199 mg/dL. The client should be counseled to keep the total cholesterol level under 200 mg/dL. This will aid in prevention of atherosclerosis, which can lead to a number of cardiovascular disorders later in life.

Which laboratory results indicate a therapeutic drug level? Refer to chart. Select all that apply.

✅ Carbamazepine (Tegretol) 10 mcg/mL ✅ Gentamicin (Garamycin) 8 mcg/mL ✅ Theophylline 10 mcg/mL 📋Rationale: Options 1, 3, and 5 are the only therapeutic drug levels; all the rest are abnormal (too high). Therapeutic drug levels are as follows: carbamazepine is 5 to 12 mcg/mL; digoxin is 0.5 to 2 ng/mL; gentamicin is 5 to 10 mcg/mL; phenytoin is 10 to 20 mcg/mL; theophylline is 10 to 20 mcg/mL; and tobramycin is 5 to 10 mcg/mL.

An adult client has had serum electrolytes drawn. The nurse receiving the results by telephone from the laboratory should be most concerned with which result?

✅ Potassium 5.4 mEq/L 📋Rationale: The normal serum electrolyte ranges for adults are sodium, 135 to 145 mEq/L; potassium, 3.5 to 5.0 mEq/L; chloride, 98 to 107 mEq/L; and bicarbonate (venous), 22 to 29 mEq/L. The only abnormal value identified above is the serum potassium, which would be the one of most concern to the nurse.

A client is seen in the urgent care center for complaints of chest pain 2 days ago. Since that time, the client has not been feeling well and fatigues easily. The nurse reviews the results of the laboratory tests. An elevation of which laboratory test indicates a myocardial infarction occurred at the time of chest pain 2 days ago?

✅ Troponin I 📋Rationale: When a myocardial infarction occurs, the heart muscle is damaged and enzymes (cardiac markers) are released into the bloodstream. Laboratory testing can detect elevations to support the diagnosis. Troponin I levels elevate as early as 3 hours after myocardial injury and may remain elevated for 7 to 10 days. The myoglobin level can rise as early as 2 hours after a myocardial infarction, with a rapid decline in the level seen after 7 hours. The CK level begins to rise within 6 hours of muscle damage, peaks at 18 hours, and returns to normal in 2 to 3 days. However, factors such as skeletal and cardiac muscle damage, as well as central nervous system damage, can lead to the elevation, so the total CK level is not specific enough. BNP is the primary marker for identifying heart failure.

A client has been diagnosed as having syndrome of inappropriate antidiuretic hormone (SIADH) secretion following cranial surgery. The nurse interprets that this complication is not resolving if which urine specific gravity measurement is obtained?

✅1.030 📋Rationale: The normal range for urine specific gravity, the comparison of urine concentration to water is from 1.016 to 1.022. Elevations may occur with SIADH because the kidneys are stimulated to reabsorb water, thus causing a higher concentration of the urine. The client retains water in the circulating blood volume leading to hyponatremia and low sodium levels, which cause decreased mental alertness and functioning. Specific gravities of 1.016, 1.018, and 1.020 are all within the normal range.

A client with a history of seizure disorder is having a routine serum phenytoin level drawn. The nurse who receives a telephone report of the results notes that the client's blood level of the medication is within the normal range if which value is reported?

✅15 mcg/mL. 📋Rationale: The therapeutic range for serum phenytoin level is 10 to 20 mcg/mL. If the level is below the therapeutic range, the client could experience seizure activity. If the level is too high, the client is at risk for phenytoin toxicity.

A client has been admitted for urinary tract infection and dehydration. The nurse determines that the client has received adequate volume replacement if the blood urea nitrogen (BUN) level drops to which value?

✅15 mg/dL 📋Rationale: The normal blood urea nitrogen value for the adult is 10 to 20 mg/dL. Thus the value of 15 mg/dL is correct. Values of 29 and 35 mg/dL reflect continued dehydration. Option 1 " 6 mg/dL "reflects a lower than normal value, which may occur with fluid overload, among other conditions.

A client has been treated for dehydration and pneumonia. The nurse evaluates that the client has been successfully treated if the blood urea nitrogen (BUN) level is which value?

✅19 mg/dL. 📋Rationale: The normal BUN for the adult is 8 to 25 mg/dL. Thus, option 2 is correct. Values such as those in options 3 and 4 are high and reflect continued dehydration. Option 1 reflects a lower than normal value, which can occur with fluid overload.

The nurse is assigned to a hospitalized client with chronic pancreatitis. The nurse reviews the client's record and expects to note a serum amylase level that is most like which value?

✅300 units/L 📋Rationale: The normal serum amylase level is 25 to 151 units/L. In chronic cases of pancreatitis, the rise in the serum amylase level usually does not exceed three times the normal value. In acute pancreatitis, the value may exceed five times the normal value. Therefore, 300 units/L is correct because the remaining options are normal values. Chronic pancreatitis is inflammation of the pancreas that occurs long term. It is a progressive destructive disease and is often caused by alcoholism or chronic biliary tract disease including cholecystitis and cholelithiasis.

The nurse is monitoring the laboratory results of a client preparing to receive chemotherapy. The nurse determines that the white blood cell count (WBC) is normal if which result is present?

✅5000 mm³ (5 × 10⁹/L) 📋Rationale: The normal WBC count ranges from 5000 to 10,000 mm³ (5 to 10 × 10⁹/L). Normal WBC Range:

A client who takes theophylline for chronic obstructive pulmonary disease (COPD) is seen in the urgent care center for respiratory distress. Just before initiating treatment for the respiratory distress, a sample for a theophylline level is drawn. The nurse notes the therapeutic range for the serum theophylline level is 10 to 20 mcg/mL and determines that the client may not be taking the medication as prescribed if which result is obtained?

✅6 mcg/mL. 📋Rationale: A therapeutic range for a medication is (the level at which the medication is enough to produce the desired physiological effect without any symptoms of excess or toxicity). A level of 6 mcg/mL is below the therapeutic range, indicating the client may not be taking the medication as frequently as prescribed. With a low level, the client may experience frequent exacerbations of the disorder. If the level is within the therapeutic range as indicated by the results of 11 and 15 mcg/mL, the client is most likely compliant with medication therapy. An elevated level such as 25 mcg/mL is greater than normal, and the client may be taking too great or frequent a dose than prescribed or physiologically does not metabolize the medication normally. Theophylline is metabolized in the liver.

The nurse is caring for a client recovering from hepatitis. The nurse recognizes the need to report which laboratory test result to the primary health care provider?

✅Alanine aminotransferase (ALT) that is significantly elevated. 📋Rationale: As tissues in the body are injured, enzymes present in the cells are released and can be monitored through blood tests. It is important to recognize which enzymes are found in which tissues. ALT is found predominantly in the liver, and an elevated level would indicate significant liver damage. The WBC count may be slightly elevated with the hepatitis. Antigens and delta antigen HBsAg, are agents that trigger cell damage; antigens do not result from the damage.

A client is admitted to the hospital with a diagnosis of malnutrition. The nurse is told that blood will be drawn to determine whether the client has a protein deficiency. Which laboratory data indicate that the client is experiencing a protein deficiency? Select all that apply.

✅Albumin 2.2 g/dL ✅Transferrin, 90 mg/dL ✅Prealbumin 10 mg/dL 📋Rationale: Serum albumin, prealbumin, and transferrin are measures of visceral protein and provide objective data for determining protein deficiency in malnutrition. Albumin reflects protein over the last few weeks and is affected by the fluid status of the client. Normal albumin levels are 3.5 to 5.0 g/dL. Prealbumin is more sensitive and represents more recent protein levels since it has a half-life of 2 days. Normal prealbumin levels are 15 to 36 mg/dL. Serum transferrin is an iron transport protein that can be measured directly or calculated as an indirect measurement of total iron-binding capacity. It is a more sensitive indicator of protein status than albumin. When the serum transferrin level is less than 100 mg/dL, the level of visceral protein depletion is severe. Serum calcium and sodium levels reflect the levels of these electrolytes and are not related to protein levels.

The nurse is reviewing the results of a client's serum laboratory studies. Which result indicates a deficiency of protein intake?

✅Albumin, 2.6 mg/dL 📋Rationale: Albumin is a type of protein, and decreased serum levels (option 1) can indicate a number of problems, including malnutrition and decreased fluid intake, or liver dysfunction. The normal albumin level is 3.5 to 5 g/dL. The triglycerides, blood glucose, and hemoglobin levels are all within normal ranges. Triglycerides are one of the fatty acids, and glucose is the most elemental form of carbohydrate. Hemoglobin carries oxygen in the red blood cells.

The nurse is providing directions to a client about how to test a stool for occult blood. The nurse cautions that which could cause a false-negative result?

✅Ascorbic acid. 📋Rationale: Ascorbic acid can interfere with results of occult blood testing, yielding false-negative results. Colchicine and iodine can cause false-positive results. Acetylsalicylic acid would either have no effect or cause a positive result by inducing bleeding from the gastrointestinal tract.

A child is receiving edetate calcium disodium (calcium EDTA) for the treatment of lead poisoning. Which laboratory result would be important to monitor during treatment?

✅Blood urea nitrogen (BUN) level. 📋Rationale: Edetate calcium disodium is used to treat lead poisoning. The medication combines with the lead to form a stable substance that is excreted through the kidneys. An adverse effect of edetate calcium disodium is nephrotoxicity. Urine flow and the BUN are assessed before the start of therapy. Potassium, RBC and WBC levels are not related to adverse effects of the medication. Lead poisoning can lead to anemia with low RBC.

The nurse reviews the client's laboratory results. Which abnormal findings should the nurse report? Select all that apply.

✅Calcium 8.2 mg/dL ✅Potassium 6 mEq/L ✅Magnesium 2.9 mg/dL ✅Phosphorus 5.2 mg/dL 📋Rationale: The laboratory results reveal hypocalcemia (normal is 8.6 to 10 mg/dL), hyperkalemia (normal is 3.5 to 5.0 mEq/L), hypermagnesemia (normal is 1.6 to 2.6 mg/dL), and hyperphosphatemia (normal is 2.7 to 4.5 mg/dL). The sodium level is the only one within the normal range.

The nurse reviews the client's laboratory data. Which data warrant notification of the registered nurse and an immediate call to the primary health care provider? Refer to chart. Laboratory Test Client Results Sodium 138 mEq/L Potassium 4.3 mEq/L Calcium 7.2 mg/dL Magnesium 2 mg/dL

✅Calcium Level 📋Rationale: The normal range for calcium is 9 to 10.5 mg/dL. A calcium value of 7.2 mg/dL represents hypocalcemia and should be reported immediately to the primary health care provider because it may lead to a decrease in heart rate and contractility. The sodium, potassium, and magnesium laboratory results are within normal limits. Abnormal results must be reported to avoid adverse consequences of electrolyte disturbances.

Several laboratory tests are prescribed for a client, and the nurse reviews the results of the tests. Which laboratory results warrant a call to the primary health care provider (PHCP)? Select all that apply.

✅Calcium, 7 mg/dL ✅Magnesium, 1 mg/dL ✅White blood cells (WBC), 3000 mm³ 📋Rationale: The PHCP should be notified of significantly abnormal laboratory results that are helpful with diagnosing the medical problem, warrant further testing, and/or may put the client at risk for complications. The blood calcium is 7mg/dL, which is significantly low (normal calcium, 8.6 to 10.0 mg/dL). The blood magnesium is 1 mg/dL, which is also significantly low (normal magnesium, 1.6 to 2.6 mg/dL). The WBC count is somewhat decreased at 3000 cells/mm³, (normal WBC, 4,500 to 11,000 mm³.) These laboratory results should be called to the PHCP. The TSH of 0.4 microunits/mL is normal (0.2 to 5.4 microunits/mL). The BUN of 10 mg/dL is normal (5 to 20 mg/dL). The serum creatinine of 1 mg/dL is normal (0.6 to 1.3 mg/dL). These values should be noted.

Which laboratory result would verify the diagnosis of bacterial meningitis?

✅Cloudy cerebrospinal fluid with high protein and low glucose levels. 📋Rationale: A diagnosis of meningitis is made by testing the cerebrospinal fluid (CSF) obtained by lumbar puncture. In the case of bacterial meningitis, findings usually include increased pressure, cloudy cerebrospinal fluid, a high protein level, and a low glucose level.

The nurse working the 3:00 to 11:00 pm shift notes that a client with coronary artery disease (CAD) has a prescription for serum lipid levels to be drawn in the morning. The nurse places the client on which dietary preparation to ensure accurate test results?

✅Fasting for 12 hours 📋Rationale: To obtain an accurate cholesterol level, a client must fast 12 hours before the tests. Having an early meal tray delivered before the laboratory test or adding a snack at bedtime will interfere with the accuracy of the test results. Placing the client nothing by mouth (NPO) for 24 hours represents an unnecessary time period.

A primary health care provider is caring for a client who is human immunodeficiency virus (HIV) positive and has delivered a newborn baby. The nurse anticipates which interventions should be employed for the newborn to decrease the risk of HIV. Select all that apply.

✅HIV testing of the newborn within 48 hours. ✅Anti-retroviral prophylaxis for newborns testing HIV positive. ✅Periodic testing for HIV at set intervals until the age of 6 months. 📋Rationale: There are known methods to decrease the risk of transmission of HIV from a positive mother to the infant including caesarian section delivery and treatment of the mother with antiretroviral medications. A newborn of a mother who is HIV positive should be tested within 48 hours of delivery and then at set intervals until the age of 6 months. The infant may test positive due to transmission of maternal antibodies and not be truly HIV positive. Antiretroviral prophylaxis for newborns testing HIV positive is started and continues for 6 weeks. Breastfeeding is not recommended for the HIV positive mother. Airborne precautions are not indicated for the newborn.

The nurse is reviewing the complete blood count (CBC) laboratory results of a female adult client suspected of having iron deficiency anemia. The nurse reviews the results and determines that which results are consistent with this diagnosis? Select all that apply.

✅Hemoglobin (Hgb) 8.8 g/dL ✅Hematocrit (Hct) 30% ✅Decreased mean corpuscular volume (MCV) 66 fL 📋Rationale: Iron deficiency anemia is a low red blood cell count caused by inadequate iron intake or absorption from the diet or blood loss. The low Hgb and Hct indicate an anemia. The normal hemoglobin level for an adult female is 12 to 16 g/dL, and the normal hematocrit is 37% to 47%. The low MCV (normal 80 to 95 fL) indicates a microcytic anemia (red blood cells smaller than normal), which is consistent with iron deficiency anemia. The platelet count and the WBC count are within the normal ranges. The normal platelet count is 150,000 to 400,000 mm³. The normal WBC count is 5,000 to 10,000 mm³.

The nurse is reviewing the laboratory results of a client scheduled for surgery. Which laboratory result should indicate to the nurse that the surgery might be postponed?

✅Hemoglobin, 8.4 g/dL. 📋Rationale: Routine screening tests include a complete blood cell count, serum electrolyte analysis, coagulation studies, and serum creatinine tests. The complete blood count includes the hemoglobin analysis. All these values are within normal range, except the hemoglobin. If a client has a low hemoglobin level, the surgery may be postponed.

Which cardiovascular sign should the nurse expect to note in a client with a diagnosis of hypocalcemia?

✅Hypotension. 📋Rationale: Cardiovascular manifestations that occur with hypocalcemia include decreased heart rate, diminished peripheral pulses, and hypotension. On the ECG, the nurse should note a prolonged ST segment and a prolonged QT interval.

A client is admitted to the hospital with a diagnosis of suspected myocardial infarction (MI). The nurse is reviewing the laboratory results performed on the client. Which documented laboratory result specifically indicates the presence of an MI?

✅Increased creatine kinase (CK-MB) 📋Rationale: The creatine kinase (CK-MB) is most specific in determining the presence of an MI. The creatinine kinase (CK-MM) reflects injury to the skeletal muscle. The WBC count is most likely elevated in the client with an MI as a reaction to the stress of having the heart muscle injury. The blood urea nitrogen is unrelated to this disorder, but the client may be dehydrated or have some renal impairment.

A hospitalized client with heart disease who is taking digoxin has a digoxin level prescribed. The level is elevated above normal. Based on this finding the nurse plans to notify the registered nurse and primary health care provider (PHCP) and anticipates which additional interventions will be prescribed? Select all that apply.

✅Monitor the potassium level. ✅Place the client on cardiac monitor. ✅Monitor the blood urea nitrogen (BUN) and creatinine. 📋Rationale: Digoxin is a cardiac glycoside that is used as a second-line medication to treat heart failure. It affects the electrical and mechanical actions of the heart and can reach toxic levels easily. An elevated digoxin level is digoxin toxicity. Digoxin toxicity with cardiac dysrhythmias is enhanced by hypokalemia so the electrolytes, especially potassium, should be monitored. Digoxin is excreted through the kidneys so renal function should be determined by the BUN and creatinine levels. The client should be placed on a cardiac monitor so the client can be assessed for dysrhythmias. A repeat digoxin level is not needed because digoxin has a long half-life and the result would not be noticeably different so soon. An additional dose should not be given due to the elevated digoxin level.

A licensed practical nurse (LPN) is assisting in the care of a client receiving a continuous intravenous (IV) infusion of heparin sodium for deep vein thrombosis (DVT). The LPN notes that the result of a newly drawn activated partial thromboplastin time (aPTT) level is 90 seconds. The client's baseline before the initiation of therapy was 30 seconds. The LPN should take which action?

✅Notify the RN about the value immediately. 📋Rationale: The normal aPTT varies between 20 and 36 seconds, depending on the type of activator used in testing. When a client receives intravenous heparin, the range of the aPTT is ordered by the primary health care provider but is greater than the normal range. Heparin treatment for DVT often involves a protocol to follow determined by the results of aPTT. If the aPTT is within the desired level, the rate is maintained and an aPTT is not ordered again until the next morning. The LPN should report the findings immediately to the RN, who will take further action to follow up on the elevated value. Checking for pain from the DVT, checking for additional heparin, and delaying reporting the aPTT are not appropriate actions.

A client with a history of seizure disorder is receiving phenytoin (Dilantin) in the hospital. The client has a seizure and the nurse reviews the laboratory results of the phenytoin level of 18 mcg/mL. The therapeutic level is 10 to 20 mcg/mL. The nurse understands from reviewing the medication level that which is the correct situation?

✅Phenytoin alone is not effectively controlling seizures. 📋Rationale: The therapeutic range for serum phenytoin level is 10 to 20 mcg/mL. The client has been receiving phenytoin in the hospital, and the blood level is within the therapeutic range. The client needs an additional medication or a different medication since the seizures are not controlled with a therapeutic level of phenytoin. There are no data in the question to suggest the client is allergic to phenytoin. The dosage is therapeutic so it should not be increased or decreased.

A client is receiving standard oral anticoagulant therapy with warfarin. The result of a newly drawn international normalized ratio is 3.8 seconds. The client needs to have an invasive procedure done on the next day. Which medication will likely be ordered to reverse the anticoagulant effect?

✅Phytonadione (Vitamin K) 📋Rationale: A client who is prescribed warfarin will need to have the medication reversed if an invasive procedure is planned. Vitamin K1 or phytonadione is administered to reverse warfarin. Naloxone reverses narcotics. Protamine reverses heparin. Calcium chloride will not reverse warfarin.

The nurse is reading a client's urinalysis report. The nurse interprets which item found on the report to be considered abnormal? Select all that apply.

✅Positive protein. ✅Leukocyte esterase positive. ✅White blood cells, 10 per high power screen. 📋Rationale: A urinalysis tests the urine specimen at hand for appearance, concentration, and content and is a broad screening for abnormalities. Presence of protein is abnormal and could indicate a kidney problem. Leukocyte esterase is an enzyme produced by white blood cells and may indicate infection. The number of white blood cells should only by 0 to 2 and a count of 10 could indicate infection. The pH of 6 is normal since urine has a normal pH range of 4.5 to 8. A specific gravity of 1.018 is normal, with normal ranging from 1.010 to 1.025.

The nurse is monitoring a client who is attached to a cardiac monitor and notes the presence of U waves. The nurse checks the client and then reviews the results of the client's recent electrolyte results. The nurse expects to note which electrolyte value?

✅Potassium 3.0 mEq/L. 📋Rationale: The U wave is a very small wave that may be present following the T wave on a heart monitor strip. It is thought to represent repolarization of the Purkinje fibers. It is present in some clients who have hypokalemia. A serum potassium level below 3.5 mEq/L is indicative of hypokalemia. In hypokalemia, the electrocardiogram (ECG) changes that occur include inverted T waves, ST segment depression, heart block, and prominent U waves. The normal sodium level is 135 to 145 mEq/L. The normal potassium level is 3.5 to 5.0 mEq/L.

A client with diabetes mellitus has a glycosylated hemoglobin A (HbA1c) level of 8%. Which instruction does the nurse plan to reinforce to the client based on this test result?

✅Prevent hyperglycemia. 📋Rationale: Elevations of the HbA1c value indicate a need for teaching related to the prevention of hyperglycemic episodes. The HbA1c value measures the amount of glucose that has become permanently bound to the red blood cells. Elevations in blood glucose levels will cause elevations in the amount of glycosylation. Thus, this test is useful for detecting clients who have periods of hyperglycemia that are undetected in other ways. Values, expressed as a percentage of the total hemoglobin and based on the primary health care provider's preference, include the following: diabetic client with good control, 7.5% or less; diabetic client with fair control, 7.6% to 8.9%; and diabetic client with poor control, 9% or greater. Some primary health care providers prefer levels lower than these noted. Avoiding infection relates to a low white blood cell count rather than the HbA1c level. Taking in enough fluids relates to an increased hematocrit level rather than the HbA1c level. Increasing iron relates to a low red blood cell count and hemoglobin level rather than the HbA1c level. HbA1c relates to glucose.

The nurse is reviewing the laboratory results from the lumbar puncture performed on a client with a diagnosis of meningitis. Which findings are indicative of a bacterial infection? Select all that apply.

✅Protein level of 20 mg/dL ✅Increased white blood cells ✅A cerebrospinal fluid (CSF) pressure of 250 mm H2O 📋Rationale: If a bacterial infection of cerebrospinal fluid is present, test results will indicate a cloudy appearance, pressure greater than 200 mm H2O, protein greater than 15 mg/dL, increased white blood cells, and reduced glucose level. Clear cerebrospinal fluid (CSF) is normal. An increased glucose level of CSF is not associated with infection in CSF.

The nurse is reading a computer printout of the results of a cerebrospinal fluid (CSF) analysis performed on an adult client who underwent lumbar puncture. The nurse knows that a reported value of 0 is normal for which substance in CSF?

✅Red blood cells (RBCs) 📋Rationale: The adult with normal CSF has no red blood cells in the CSF. The client may have small numbers of white blood cells (0 to 3 cells/mm³). Protein (15 to 45 mg/dL) and glucose (40 to 80 mg/dL) normally are present in CSF.

The nurse caring for a male client with a diagnosis of gastrointestinal (GI) bleeding reviews the client's laboratory results and notes a hematocrit level of 30%. Which action should the nurse take?

✅Report the abnormally low level. 📋Rationale: A hematocrit level of 30% is a low level and should be reported to the registered nurse and primary health care provider because it indicates blood loss. The normal hematocrit level in a male client ranges from 39% to 52%, depending on age.

A nurse about to give a daily dose of digoxin and notes that a serum digoxin level drawn earlier in the day measured 2.7 ng/mL. The nurse should take which actions? Select all that apply.

✅Report the finding to the registered nurse. ✅Gather data from the client related to signs of toxicity. 📋Rationale: The normal therapeutic range for digoxin is 0.5 to 2 ng/mL. A value of 2.7 ng/mL exceeds the therapeutic range and could be toxic to the client. The nurse should gather data about signs of digoxin toxicity (nausea/vomiting, seeing yellow rings) and then notify the registered nurse who will then contact the primary health care provider. The dose of digoxin should not be administered or recorded as normal. Foods high in potassium should not be administered without knowing the serum potassium level.

The nurse is assisting in monitoring a client who may be started on parenteral nutrition (PN). The nurse reviews the client's laboratory results and determines that the client is at risk of severe malnutrition if the report indicates which critical level?

✅Serum albumin 2.8 g/dL 📋Rationale: Parenteral nutrition is used when a client has a non-functioning gastrointestinal system or is unable to eat enough to meet nutritional needs. The serum albumin level is a measurement of protein and a critical indicator of the need for PN. The client whose albumin level is 2.8 g/dL is at severe risk for malnutrition. The normal serum albumin level in the adult is 3.4 to 5 g/dL. The sodium, hemoglobin, and WBC count are within normal limits and are not directly related to malnutrition.

A CD4+ count has been prescribed for a child with human immunodeficiency virus (HIV) infection. The mother asks the nurse about the purpose of the test and why the test needs to be done if it is already known that the child has HIV. The nurse should reinforce which information to the mother? Select all that apply.

✅The CD4+ count is used to determine the child's immune status. ✅The CD4+ count is used to identify the risk for disease progression. ✅The CD4+ count identifies the need for Pneumocystis jiroveci pneumonia prophylaxis after 1 year of age. ✅The CD4+ count is measured at ages 1 and 3 months, every 3 months until the age of 2 years, and at least every 6 months thereafter. ✅More frequent monitoring of CD4+ counts is indicated when pneumonia prophylaxis and antiretroviral therapy are administered. 📋Rationale: The CD4+ count is the measurement of a specific subset of T lymphocytes used to monitor clients who are HIV positive.CD4+ counts are used to assess a young child's immune status, risk for disease progression, and need for pneumonia prophylaxis after 1 year of age. These counts are measured at ages 1 and 3 months, every 3 months until the age of 2 years, and at least every 6 months thereafter. More frequent monitoring of CD4+ counts is indicated when pneumonia prophylaxis and antiretroviral therapy are administered. The CD4+ is not used by itself to specifically diagnose the HIV-positive client.

A client with diabetes mellitus calls the clinic nurse to report that the blood glucose level is 150 mg/dL. After obtaining further data from the client, the nurse determines that the client ate lunch approximately 2 hours ago. How should the nurse interpret the data?

✅The blood glucose level is slightly higher than the normal value. 📋Rationale: Normal fasting blood glucose values range from 70 to 110 mg/dL, depending on primary health care provider preference. The 2-hour postprandial blood glucose level should be less than 140 mg/dL. In this situation, the blood glucose value was 150 mg/dL 2 hours after the client ate, which is slightly elevated above normal.

The nurse is explaining to a client the reason a peak and trough has been prescribed because the client is receiving an antibiotic. Which reason for the blood levels should be included in the teaching plan?

✅To determine if the dose of the antibiotic is effective against the organism causing the infection. 📋Rationale: The peak and trough levels are blood concentrations of the prescribed antibiotic. The peak is the high point of the antibiotic level in the blood and is drawn 30 to 60 minutes after administration of the medication. The trough is the low point of the antibiotic level in the blood and is drawn 30 minutes before the next scheduled dose. The peak and trough level of an antibiotic are prescribed to determine if the dose of the medication is at a level that will kill the pathogen causing the infection. The blood urea nitrogen and creatinine levels are indicative of renal function. A test dose or skin test of a medication could be used in advance to determine if the client is allergic. Most often, observation of symptoms after medication administration is how allergies are determined. Whether a symptom is caused by the medication is not determined by the peak and trough. However, the prescriber can use the levels to see how the dose and frequency are excreted by the body. The goal is to prescribe the smallest dose that is effective.

A client is suspected of having a myocardial infarction. The nurse should expect elevations in which laboratory values to support the diagnosis? Select all that apply.

✅Troponin I ✅Creatinine phosphokinase MB (CPK-MB) 📋Rationale: When a myocardial infarction occurs, the heart muscle is damaged and enzymes (cardiac markers) are released into the bloodstream. Laboratory testing can detect elevations to support the diagnosis. Troponin I levels elevate as early as 3 hours after myocardial injury and may remain elevated for 7 to 10 days. The CPK-MB reflects the isoenzyme from cardiac muscle, which is the level that increases with myocardial infarction. TSH is not affected with heart damage and is elevated with clients who are hypothyroid. The CPK-MM reflects the isoenzyme from skeletal muscle. The CPK-BB reflects the isoenzyme from the brain.

The nurse is reviewing the laboratory studies of a client receiving epoetin alfa. When should the nurse expect to note a therapeutic effect of this medication on the hemoglobin and hematocrit?

✅Two months after therapy. 📋Rationale: Epoetin alfa stimulates erythropoiesis. Initial effects are noted within 1 to 2 weeks, and hematocrit levels reach normal levels in 2 to 3 months. Therefore, this medication is not intended for clients who require immediate correction of severe anemia, and it is not a substitute for emergency transfusions.

The nurse is caring for a client with a diagnosis of gout. Which laboratory value should the nurse expect to note in the client?

✅Uric acid level of 8.4 mg/dL 📋Rationale: Gout is arthritis caused by high uric acid levels. Uric acid levels are measured in clients with suspected gout. Normal uric acid levels are 2.8 to 6.8 mg/dL in females and 3.5 to 7.8 mg/dL in males. Calcium, potassium, and phosphorus levels are not used in diagnosing gout and are normal.

The nurse is reviewing laboratory results and notes that the client's international normalized ratio (INR) is 2.2. The nurse should realize this test is performed to monitor the effectiveness of which medication?

✅Warfarin 📋Rationale: The prothrombin time and INR are names for a laboratory assay that measures the extrinsic pathway of coagulation including liver function making vitamin K. The effectiveness of warfarin is monitored by the INR. Heparin is an anticoagulant that is monitored by the partial thromboplastin time (PTT). Dabigatran is an anticoagulant used for clients with atrial fibrillation and does not require laboratory testing. Dipyridamole is a medication that will cause a decrease in platelet agglutination (stickiness) and does not require any laboratory monitoring.

A client is admitted to the hospital with a fever and extreme weakness. Which laboratory studies are likely to be elevated if the client is experiencing an infection? Select all that apply.

✅White blood cell count (WBC) ✅Erythrocyte sedimentation rate (ESR) 📋Rationale: The laboratory tests that display changes with infection are the WBC count, which will increase to fight infections, and the ESR, which is a general test showing elevation when inflammation or infection occurs. The hematocrit, hemoglobin, and red blood cell count are not directly affected by infection.