Interpreting Laboratory Values in the Rehabilitation Setting

Written By: Sam Savage

Published Date: March 2, 2007 Last Edited: March 2, 2007

By Flanagan, Jane; Melillo, Karen Devereaux; Abdallah, Lisa; Remington, Ruth

Treating patients in rehabilitation settings is becoming increasingly complex for a variety of reasons, such as the presence of several comorbid conditions, increased age, and earlier discharge from acute care facilities. As a result, careful monitoring and assessment by nurses is essential. Laboratory testing can improve the assessment when nurses are able to recognize when and what should be reported and what types of treatments may be needed. Understanding what laboratory findings should be monitored and what added assessment criteria are necessary can be daunting. Therefore, this article reviews critical laboratory and other assessment findings in light of common health problems faced by patients in rehabilitation settings. A case study is used to highlight the importance of laboratory testing.

KEY WORDS

assessment

electrolytes

nutrition

Nurses in rehabilitation settings face multiple challenges, including caring for patients with increasingly complex problems. Laboratory values can provide critical information regarding the patient’s condition, but interpreting the findings can be overwhelming. Common problems experienced by adults in the rehabilitation setting include dehydration, fluid overload, bleeding disorders, malnutrition, infection, and drug toxicities. Therefore, the most critical laboratory values that most often reflect serious problems in the adult will be considered in light of these potential health problems. Several important points to remember with regard to laboratory values are outlined in Figure 1.

Laboratory Values

Nurses working in rehabilitation settings care for patients who experience a number of problems, such as traumatic brain injury, major cardiac events, fractures, burns, elective orthopedic surgeries, and many other conditions. Because of advances in healthcare, people are living longer and overall healthier lives. With this improved life expectancy, patients in the rehabilitation setting may not only be older but have increasingly complex medical histories. For example, an older patient may be recovering from a stroke and also have underlying medical problems such as diabetes and heart disease necessitating chronic medical management.

For the nurse in the rehabilitation setting, small changes in a person’s physical condition, especially in the older adult, may warrant notifying a physician. Subtle changes such as confusion, loss of appetite, and alterations in elimination are not normal for the older population and instead serve as cues of a new problem or a change in an underlying chronic disease. Age-related physiological changes can also affect some laboratory values and must be recognized (Amelia, 2004; Clark & Halm, 2003).

Some general considerations for interpreting and reporting laboratory values are highlighted in Figures 2 and 3.

Sodium and Potassium: Two Important Electrolytes

Two critically important electrolyte values are sodium (Na) and potassium (K). Working together on the cellular level as the sodium- potassium pump, these values are integral to the overall water balance of the body. Regulation of potassium is through the kidneys and of sodium through the adrenal glands. It therefore stands to reason that problems with either organs, such as Cushing’s disease or chronic renal failure, will cause disturbances in the fluid and electrolyte balance in the body (Kraft, Btaiche, Sacks, & Kudsk,2005).

When considering laboratory values of patients in the rehabilitation setting, it is important to remember that a person with a history of medical problems is more prone to and more sensitive to changes in fluid and electrolyte balance. These include problems of the cardiac, respiratory, endocrine, orthopedic, vascular, gastrointestinal, and urinary systems. Often underlying medical conditions directly correspond to problems with fluid and electrolyte balance; however, problems can also arise as a result of a side effect of medical management (Kraft et al., 2005). An example of a condition causing fluid and electrolyte disturbance is congestive heart failure, which can cause a fluid overload in the body through a poorly functioning heart, as occurs with mitral valve regurgitation. Likewise, the medical management of this problem, which may include drugs such as digoxin and furosemide, may also cause dehydration and lower the potassium level.

The nurse in a rehabilitation setting should always be concerned about sodium and potassium levels. Any changes in a person’s clinical condition, in association with a variation in electrolyte values above or below the normal parameter, should be reported to the doctor immediately.

The Complete Blood Cell Count

The complete blood cell count (CBC) can provide information about the patient’s general health and concerns such as excessive bleeding, hydration status, infection, and anemia. The major components of whole blood are erythrocytes or red blood cells (RBCs), leukocytes or white blood cells (WBCs), and platelets (PLTs).

The RBC count is made up of hemoglobin (Hb) and reticulocytes, which are immature RBCs. Th Hb is a measure of the iron-rich protein that carries oxygen in the blood. Often reported with the Hb is the hematocrit (Hct), a measure of the percentage of blood volume that is composed of RBCs (George-Gay & Parker, 2003).

Decreases in any component of the RBC can represent rapid blood loss as a result of hemolysis or destruction of the blood cell, sometimes caused by medications, or of decreased cell production, as in anemia. In the next section fluid volume overload and dehydration are discussed in detail, but it is important to note that the Hct can be falsely low because of hemodilution when a person has fluid volume overload and can be falsely elevated when a person is dehydrated because of hemoconcentration (George-Gay & Parker, 2003). Correction of the underlying problem will provide a more accurate Hct result. The nurse should assess for and report findings related to recent changes in a person’s medical or surgical history, skin color (pallor, jaundice), pruritus, blood pressure, pulse rate and respirations, intake and output, weight, and Hct.

Fluid Overload

When a patient’s serum sodium level is low, it is known as hyponatremia. Although often asymptomatic initially, the patient may eventually complain of a headache, nausea and vomiting, and generalized malaise and muscle weakness. Most importantly in the rehabilitation setting, the nurse may observe confusion, a symptom that is often attributed to hospitalization, medications, and old age (Amelia, 2004). Therefore, in this setting hyponatremia often is overlooked. Daily weights, intake and output, jugular ” vein pressure, respiration, skin appearance, mental status, and blood pressure are helpful in evaluating hyponatremia.

Hyponatremia is complex and can be the result of several underlying conditions. There are three types of hyponatremia: hypovolemic, normovolemic, and hypervolemic. Less commonly in the adult population, normovolemic hyponatremia can be a result of syndrome of inappropriate antidiuretic hormone, or psychogenic polydipsia, a syndrome in which there is excessive water intake. Hypovolemic hyponatremia is defined as true volume depletion and is caused by excessive fluid loss through sweating, burns, diuretics, vomiting, and diarrhea. The third and most common type of hyponatremia is hypervolemic (Kugler & Hustead, 2000).

Hypervolemic hyponatremia occurs when there is retention of water in the body and low serum sodium. Hypervolemia can be caused by several underlying chronic medical conditions, such as diabetes, kidney disease, hypothyroidism, and cardiac and liver failure, and as a result of some medications such as first-generation sulfonylureas and diuretics (Kugler & Hustead, 2000). Assessment findings in hypervolemic hyponatremia include changes in mental status, restlessness, anxiety, decreased urine output, weight gain, edema in the dependent extremities, increased blood pressure, jugular vein distention, dyspnea and orthopnea, and, on auscultation, abnormal lung sounds such as crackles. In addition to a low sodium count, laboratory findings include a low Hb and Hct.

Treatment may vary, depending on the cause, but often diuretics help alleviate the imbalance (Kugler & Hustead, 2000). Other considerations in the treatment plan for hyponatremia include careful monitoring of vital signs, daily weightlifting, intake and output measurement, and assessment of signs and symptoms of hypernatremia.

The normal changes associated with aging can make assessment related to hydration status more challenging (Amelia, 2004; Larson, 2003). Skin turgor can be altered by decreased elasticity and therefore may not be an accurate indicator of dehydration. Mental status changes can be the result of other underlying conditions, including infection or preexisting dementia. Certain medications may alter the mucosa of the mouth, causing dryness. Physical symptoms such as nocturia, psychological symptoms associated with depression, and the decreased thirst and desire for fluids (and food) common in older adults can all present challenges to the nurse’s assessment (Larson). An initial assessment of the person with frequent reassessment can enable the nurse to detect changes early.

Dehydration

There are three types of hypernatremia: hypovolemic, normovo\lemic, and hypervolemic. Hypervolemic hypernatremia is less common and can occur as a result of less common chronic medical conditions such as Cushing’s disease or as a result of excessive salt intake. Excessive intake of hypertonic fluids via tube feedings or intravenous fluids may also result in hypervolemic hypernatremia in the rehabilitation setting (Kugler & Hustead, 2000).

Hypovolemic hypernatremia is the more commonly seen condition and is the result of dehydration or inadequate fluid replacement in combination with free water loss (Amelia, 2004; Kugler & Hustead, 2000). Hypovolemic hypernatremia occurs when there is a deficient water intake. This is usually the result of an impaired thirst mechanism or a lack of access to adequate fluid intake, two common problems among older adults (Kugler & Hustead). Free water loss can occur with fever, sweating, diarrhea, and hyperventilation.

In a patient experiencing dehydration, the nurse may observe a change in mental status including irritability initially and later, confusion, lethargy, weakness, fatigue, dizziness, weight loss (3% or greater), decreased urine output, increased urine concentration, poor skin turgor, dry skin and mucous membranes, and thirst. Muscle cramping may occur initially, followed by hyperreflexia, increased pulse rate, and decreased jugular venous pressure and blood pressure. In addition to elevated serum sodium, the patient may have elevated Hb and Hct (Clark & Baldwin, 2004; Foreman, Mion, Trygstad, & Fletcher, 2003; Larson, 2003). Treatment includes intravenous infusion of 0.9% sodium chloride or normal saline (which is the normal concentration of sodium chloride in the blood plasma) and monitoring of intake, output, vital signs, and daily weight (Kugler & Hustead, 2000).

Hypokalemia: Causes and Treatment

Normal potassium (K) levels can vary depending on the laboratory, and as with all electrolytes, little variation from the norm is acceptable and should be reported immediately to the healthcare provider. This is particularly true in patients who have been or are being treated for cardiac disease, renal disease, diabetes, Cushing’s disease, gastrointestinal disturbances necessitating suctioning, or problems with diarrhea.

Vomiting, diarrhea, suctioning (gastrointestinal), diuretics, and insulin can all cause hypokalemia. The patient experiencing hypokalemia may complain of muscle weakness. Potassium is vital to cardiac functioning, and therefore fluctuations such as a flattening of the T wave and later ST depression are reflected in the electrocardiogram. If this technology is unavailable, there are other symptoms to note, such as a decrease in both blood pressure and bowel sounds (Fishbach, 2004).

If the patient is on digoxin, it is important to note that kidney function diminishes with age, and as a result there may be a decreased ability to clear digoxin from the body. In addition, a person who is on digoxin may often be on diuretics, which may cause further depletion of potassium even if the person is taking potassium supplements (Harrington, 2005). These two situations may result in digoxin toxicity, which is evidenced by such signs and symptoms as nausea, vomiting, visual changes, blurred vision, anorexia, palpitations, and, in older adults, mental status changes. It is therefore particularly important to monitor both digoxin and potassium levels carefully and frequently, especially if drugs are newly initiated or if the person has concurrent kidney disease.

Treatment for hypokalemia is through supplementation, usually given orally in the rehabilitation setting, but it may need to be given intravenously in severe cases. Orally, potassium may be given in pill or diluted liquid form. Intravenously, it must always be diluted and never infused rapidly. It is infused at a rate of no more than 10-20 mEq/hr for intermittent potassium dosing. Higher infusion rates are reserved for more critical situations, and when this occurs, the patient may need to be transferred to a hospital because continuous cardiac monitoring is recommended. In these cases and at these dosages it is also recommended that potassium be given by central line to minimize phlebitis (Kraft, Btaiche, Sacks, & Kudsk, 2005). It is extremely important to remember that the patient must have urinary output of 20-30 cc per hour before being given any type of potassium supplementation.

Hyperkalemia: Causes and Treatment

Burns, necrotizing tissue, Addison’s disease, hypoxia, acidosis, overuse of salt substitutes, and potassium replacement can cause hyperkalemia (National Institutes of Health, 2005). The patient experiencing hyperkalemia may complain of numbness and tingling in hands and feet along with diarrhea, and the nurse caring for the person may note a slowed pulse rate or bradycardia, an irregular rhythm confirmed by electrocardiogram, and signs such as apathy, confusion, and hyperactive bowel sounds. Untreated hyperkalemia can result in cardiac arrest.

Before reporting or treating an abnormal potassium value, it is essential to determine whether the sample was drawn adequately. Because potassium is mostly intracellular, it is released into serum when the cell wall is broken, which can result even from difficulty obtaining the specimen. This can result in hemolysis, causing a falsely elevated level. The laboratory should be called to verify the adequacy of the sample. If the serum level is elevated, the treatment of hyperkalemia initially involves Kayexalate enemas (Harrington, 2005). If the condition is severe or the person does not respond quickly enough, intravenous insulin and glucose may be necessary; the insulin binds to the potassium, thus decreasing the concentration in the blood. Glucose is given to stabilize the blood sugar *” level. These treatments often necessitate transfer to an acute care facility.

Nutritional Concerns

Considered part of liver function tests, prealbumin is an important laboratory value in the adult because it provides a window into nutritional status. Malnutrition is a multifaceted problem and can be the result of limited income, social isolation, decreased appetite, chronic illness, depression, and physiological changes (DiMaria-Ghalili & Amelia, 2005).

During hospitalization, and even in the rehabilitation setting, dietary intake can be poor. This places the patient at risk for low protein intake, which can delay wound healing and can be associated with skin breakdown, infection, and an increased risk of morbidity. It is essential for nurses to know how to screen for and when to report nutrition concerns (DiMaria-Ghalili & Amelia, 2005; Lawrence & Amelia, 2004; Stechmiller, 2003). Prealbumin is the preferred laboratory test to screen for nutrition problems. It is not affected by hydration status, but it is low in patients with malignant conditions and temporarily in the postoperative period or when inflammation is present. Prealbumin levels of 5.0 mg/dl or less indicate poor prognosis, and additional treatments including intravenous hyperalimentation may be needed (Beck, 2002; Stechmiller, 2003). Nutritional screening by nursing in the rehabilitation setting is essential, and several good tools for nurses are available, such as those provided by the Hartford Institute for Geriatric Nursing (Lawrence & Amelia, 2004). All nutritional concerns should be conveyed to the physician and a nutritionist for appropriate intervention.

Medications, Dehydration, Malnutrition, and the Aging Kidney

Blood urea nitrogen (BUN) and creatinine are laboratory values usually considered together and provide the nurse with a picture of the filtering function of the kidneys and the degree of bodily hydration. The normal range for BUN is 7-20 mg/dl, and for creatinine it is 0.6-1.2 mg/dl. The ratio of BUN to creatinine normally is 20:1 (Larson, 2003). Increases in the BUN and creatinine are caused by dehydration (too little water in the tissues), any condition that decreases blood flow to the kidneys, blood in the intestinal tract, or a large meal of cooked meat. Malnutrition, kidney diseases, liver disease, and sickle cell anemia cause increases in the BUN and creatinine.

With decreases in muscle mass as a person ages, creatinine production slows, as does the ability to excrete creatinine; therefore, a creatinine level in an older adult that is within the normal laboratory range may actually reveal impairment. Because lean body mass declines with aging, the total production of creatinine also declines, and as a result static measurements may overestimate renal function in older adults. Therefore, creatinine clearance provides a more accurate picture of renal function, which is important when one is considering hydration status and the potential for drug toxicity (Melillo, 1993). One formula commonly used to estimate creatinine clearance based on serum creatinine is the Cockcroft-Gault equation: creatinine clearance (ml/min) = {[140 (-) age (years)] (x) weight (kg)}/[72 (x) serum creatinine concentration (mg/dl)]. For women, multiply the result by 0.85 (Larson, 2003).

Hypotension in itself can be a precipitating factor for diminished renal function, but it can also be a symptom of dehydration, along with poor skin turgor, low urine output, and complaints of thirst. However, thirst often tends to be diminished in older adults. It has been suggested that skin turgor assessment in the older adult should be tested on the inner aspect of the thigh or over the sternum (Larson, 2003). Dehydration is treated with fluid replacement starting with oral rehydration and advancing to intravenous treatments as indicated. Assessing skin turgor and measuring intake, output, vital signs, and daily weights will determine effectiveness of the plan. Because a common presentation in older adults with dehydration is altered mental status and lethargy, improvement in energy and mental status would also indicate effectiveness of the plan (Beer\s & Berkow, 2000).

Two common medications that can cause altered renal function are angiotensin-converting enzyme inhibitors and nonsteroidal antiinflammatory drugs. Lithium and some antibiotics and cardiac antiarrhythmic medications can also be detrimental to kidney function; therefore, creatinine clearance must be monitored in these situations as well (Larson, 2003).

Drug Toxicity

Drug levels in the rehabilitation setting are obtained for several reasons: when a drug is newly prescribed and it is necessary to know whether the therapeutic range has been reached, when an underlying medical condition may place the person at risk for toxicity, and when one drug may potentiate the action of another. The latter can be a common problem among older adults because of polypharmacy (Fishbach, 2004). In general, drug levels are drawn when the drug has a narrow therapeutic range or when the person has preexisting medical conditions such as renal failure or age-related changes such as decreased renal or liver function that may alter the drug level.

Some commonly used medications necessitating routine drug level measurements include anticonvulsants, antibiotics, antiarrhythmics, bronchodilators, and cardiotonics, all of which have narrow therapeutic ranges. Therapeutic drug levels can be monitored for many other drugs if toxicity is suspected. The frequency of testing depends on the medication itself, its potential for toxicity, underlying preexisting medical conditions, and changes in a person’s medical condition, appearance, signs, and symptoms; more frequent testing may be needed when the desired therapeutic response is not achieved (Fishbach, 2004). Any drug level below or above the therapeutic range should be reported immediately, along with changes in mental status, vision or hearing disturbances, weight changes, gastrointestinal distress, or changes in vital signs.

Liver function tests (LFTs) are a group of blood tests that measure substances in the blood that indicate how well the liver is working. LFTs include alanine transaminase, aspartate transaminase, alkaline phosphatase (ALP), gamma-glutamyl transpeptidase, total and direct bilirubin and albumin, and total protein. The liver produces bilirubin, and elevations of this value and the ALP usually are associated with blockages in the bile duct, such as gallstones, but can be associated with rumors or chronic alcoholism (National Institutes of Health, 2005).

The rehabilitation nurse should be concerned with liver disorders such as hepatitis or cirrhosis and with illicit drug use and overconsumption of alcohol, which are sometimes overlooked in older adults (Masters, 2003). In older adults the ALP may be slightly elevated, yet overall LFTs may be unchanged. Newly elevated LFTs warrant further assessment of the skin and sciera of the eyes to determine whether jaundice is present. Other assessment criteria should include checking for pruritus and increases in abdominal girth. The presence or absence of these findings should be reported along with elevated LFT results.

Treatment varies greatly depending on the causative agent and may include anything from discontinuation of the liver toxic substance, to surgery to remove a blockage, to palliative care to ease the suffering. The toxic substance may include an infectious agent, a prescribed drug, or substance abuse.

Bleeding Problems and Anticoagulation

Blood clots are a risk after many surgeries, trauma, or recovery periods necessitating prolonged inactivity. To reduce the incidence of such complications prophylactic anticoagulation therapy is used. This entails frequent monitoring of the platelets, prothrombin time (PT), or international normalized ratio (INR). With anticoagulation therapy, the therapeutic range rather than a normal value is the goal (Warkentin & Greinacher, 2004). For example, a person can have a normal PT or INR but not be in therapeutic range if he or she is on warfarin. Some situations necessitating prophylactic anticoagulation therapy are obesity and cardiac or orthopedic surgery. Each of these situations warrants a different therapeutic range for the INR or PT.

Heparin is no longer a preferred agent for prophylactic therapy because of the risk of heparin-induced thrombocytopenia, which can cause deep vein thrombosis, pulmonary embolism, myocardial infarction, skin necrosis, end organ damage, and death. Instead, low molecular weight heparin or warfarin sodium is used for prophylactic anticoagulation therapy (Warkentin & Greinacher, 2004).

All patients on warfarin or low molecular weight heparin should have frequent monitoring as follows. All results should be reported to the medical group managing prophylactic therapy as soon as they are obtained (Warkentin & Greinacher, 2004).

* Low molecular weight heparin: at least every-other-day platelet count monitoring until day 14, or until low molecular weight heparin is stopped.

* Warfarin: PT or INR daily until therapeutic range is achieved, then two or three times per week, then once per month during treatment (Hirsh, Fuster, Ansell, & Halperin, 2003).

It is important to note that the platelets, PT, and INR are measures of clotting, which depends on vitamin K and protein made by the liver. Liver cell damage and bile flow obstruction can interfere with proper blood clotting.

Along with calcium, vitamin K, and fibrinogen, platelets aid in blood dotting. A normal platelet count is approximately 150,00- 400,000, and platelet counts less than this can be considered thrombocytopenia. When platelets drop below 30,000, it is critical because the person’s ability to clot or heal after injury is seriously compromised (George-Gay & Parker, 2003). Although there are several blood disorders that result in thrombocytopenia, it is more commonly the result of certain medications, such as chemotherapy, and autoimmune disorders such as lupus. Any low platelet count should be reported along with the previous result of a platelet count (if known) and symptoms of bleeding difficulties such as petechiae (painless, round, reddened pinpoints on the skin), ecchymosis (purple, blue, or yellow-green bruises), nosebleeds, malaise, fatigue and general weakness, temperature, and abnormal vital signs.

Rarely, people can have problems with elevated platelet production, which can be a benign condition occurring in the absence of other medical problems or a result of a blood disorder. With elevated platelet production, two seemingly opposite conditions are possible (Fishbach, 2004). Despite the elevated production of platelets, bleeding can occur because the platelets may lack adhesive properties, or as a result of an elevated number of platelets, adhesions may occur and result in a vascular clot. The latter situation is urgent and may warrant transfer to an acute care facility. Any symptoms associated with emboli should be reported immediately. These include chest pain, shortness of breath, changes in vital signs, confusion, and calf area irritation, swelling, redness, or tenderness.

Infection

The WBC is the measure of white blood cells in the whole blood. There are five types of WBCs, which together are known as the differential: neutrophils, eosinophils, monocytes, lymphocytes, and basophils. In general, WBC elevations are an indication of infection, but confusion may be the only presenting symptom initially (Foreman et al., 2003). A low WBC can indicate some types of cancers or blood disorders. Therefore, increases or decreases should be reported to the provider immediately, along with changes in the person’s general condition, respiratory status, skin, body temperature, other vital signs, aches, night sweats, gastrointestinal distress, urine output, weakness, or generalized malaise.

The urinalysis is a routine test used to screen for myriad health problems. A positive urinalysis may be significant for problems such as infection, diabetes, renal failure, fever, vomiting, excessive sweating, dehydration, poor nutrition, anorexia, cirrhosis, hepatitis, gallstones, liver tumors, and hyperthyroidism (National Institutes of Health, 2005).

In some situations, such as diabetes, a patient may have a positive chemical urinalysis, and ketones or glucose may be present (Haas, 2005). It is therefore important to know the patient’s history, but typically any variation from a normal urinalysis warrants reporting to the primary provider, who may initiate treatment or perform additional testing. Along with reporting the positive urinalysis, the nurse should record the patient’s self- report of overall health, past medical history, and current medications and assess the patient’s appearance, temperature, vital signs, intake, output, and any odors or complaints such as urinary frequency and burning.

A urine culture and sensitivity may be ordered in conjunction with the urinalysis. It is important that this sample be obtained as cleanly as possible; if a catheter is in place, a sterile specimen can be obtained. Institutions and manufacturers of specimen kits will provide instructions for sample collection, and they should be followed closely. The tests are sent to bacteriology laboratories, and results usually take several days. The results will report the presence of specific bacteria and indicate the antibiotics to which the strain is sensitive or resistant. Similarly, other specimens such as blood, sputum, and stool may be obtained for bacteriology, with findings reported in the same manner as urine culture and sensitivity.

Conclusions

In the rehabilitation setting, laboratory values can provide the nurse with critical information about the health status of their patients. Seldom will the findings alone provide the whole picture. Because of age-related changes, symptoms in older adults may not be the same as those in a younger person. For example, a change in mental status may be the only warning of an infection or dehydration. It is therefore important to \assess the patient frequently and be able to readily detect changes in the usual pattern. The nurse must also know when and what to report to the primary provider.

Small and subtle changes keenly observed make the difference in early diagnosis and treatment of health problems in the rehabilitation setting. The nurse’s knowledge of the patient and the patient’s history, medications, and unique variations is essential to providing optimal care.

Case Study

Mrs. R is an 84-year-old woman admitted to the rehabilitation setting after a 3-week stay at an acute care hospital. Her admitting diagnosis is traumatic brain injury and fractured left hip after a fall at home. Until this event, she had been living at home with her husband and was healthy, with only a history of atrial fibrillation. She now presents with confusion. The following laboratory findings are important for you to know about.

* CBC: Elevations in the WBC could be a sign of infection.

* Electrolytes and creatinine clearance: These provide information about hydration status, which could be altered and lead to confusion.

* Platelets, PT, and INR: If she is on anticoagulation, this will provide information about whether Mrs. R’s drug level is in therapeutic range. This is particularly important because of her fracture history, traumatic brain injury, and atrial fibrillation history. All three conditions place her at risk for a blood clot, and a presenting sign can be increased confusion.

* Urinalysis, culture, and sensitivity: Even though she is not known to be a diabetic, she could have unknown diabetes, be newly diagnosed while hospitalized, or develop diabetes caused by medications such as prednisone. Also, she may have a urinary tract infection, which would be noted on a culture and sensitivity.

* Have any drug levels been drawn? If the patient is on antibiotics, it indicates a history of infection (that may or may not be improving). Confusion can be a sign of infection.

* Prealbumin level: This will provide a window on her nutritional status, and poor nutrition can contribute to confusion.

* LFT: An elevated LFT may indicate an underlying alcohol or drug dependency problem.

Other considerations in the treatment plan for hyponatremia include careful monitoring of vital signs, daily weightlifting, intake and output measurement, and assessment of signs and symptoms of hypernatremia.

References

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Stechmiller, J. (2003). Early nutrition screening of older adults: Review and nutritional support. Journal of Infusion Nursing, 26(3), 170-177.

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Jane Flanagan, PhD APRN BC * Karen Devereaux Melillo, PhD APRN BC FAANP * Lisa Abdallah, PhD RN * Ruth Remington, PhD APRN BC

About the Authors

Jane Flanagan, PhD APRN BC, is an assistant professor at Connell School of Nursing, Boston College. Address correspondence to her at 140 Commonwealth Avenue, Chestnut Hill, MA 02467, or [email protected].

Karen Devereaux Melillo, PhD APRN BC FAANP, is a professor and chair at the Department of Nursing School of Health and Environment, University of Massachusetts, Lowell, MA.

Lisa Abdallah, PhD RN, is an assistant professor at the Department of Nursing School of Health and Environment, University of Massachusetts, Lowell, MA.

Ruth Remington, PhD APRN BC, is an assistant professor at the Department of Nursing School of Health and Environment, University of Massachusetts, Lowell, MA.

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