Albumin, Urine and Albumin to Creatinine Ratio (ACR)
Synonym/Acronym
Microalbumin, micral; ACR
Rationale
To assist in the identification and management of early diabetes in order to avoid or delay onset of diabetic associated kidney disease.
Patient Preparation
There are no food, fluid, activity, or medication restrictions unless by medical direction. Either a random or a 24-hr urine collection may be ordered. As appropriate, provide the required urine collection container and specimen collection instructions.
Normal Findings
Method: Immunoturbidometry for albumin, spectrophotometry for Cr.
| Albumin Creatinine Ratio (ACR) | | Conventional Units | SI Units (Conventional Units x 0.113) | | Normal | Less than 30 mg/g creatinine | Less than 3.4 mg/mmol creatinine | | Clinically significant albuminuria | 30–299 mg/g creatinine | 3.4–33.8 mg/mmol creatinine | | Overt albuminuria | Greater than 300 mg/g creatinine | Greater than or equal to 33.9 mg/mmol creatinine | | Laboratory reports include the measured levels of random urine albumin and creatinine, and reporting units may vary between laboratories; reference ranges are often listed as “not established.” |
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Study type: Urine from a random or timed specimen collected in a clean plastic collection container; related body system: Endocrine and Urinary systems.
Chronic kidney disease (CKD) is a significant health concern worldwide. International research has been undertaken to evaluate the risk factors common to cardiovascular disease, diabetes, and hypertension; these three diseases are all associated with CKD. Albuminuria, which can result from increased glomerular permeability to proteins, is considered an independent risk factor predictive of kidney or cardiovascular disease. The National Kidney Foundation and American Society for Clinical Pathology recommend using timed or random urine albumin (formerly microalbumin) and eGFR together to screen for CKD. The tests are sometimes ordered together in a bundle called the Kidney Profile:
- The urine albumin assesses for kidney damage. Urine creatinine is also measured in order to report the albumin/creatinine ratio (ACR).
- The eGFR assesses for kidney function. Either serum creatinine and/or cystatin C levels are required for the estimation formulas. For detailed information regarding eGFR, refer to the study titled “Creatinine, Blood and Estimated Glomerular Filtration Rate (eGFR).”
The term albuminuria, formerly known as microalbuminuria, describes concentrations of albumin in urine that are greater than normal but are undetectable by the dipstick used in routine urinalysis or by traditional spectrophotometry methods. Albuminuria precedes the nephropathy associated with diabetes and is often elevated years before the creatinine clearance test shows abnormal values. Studies have shown that the median duration from onset of albuminuria to development of nephropathy is 5 to 7 yr. For additional information regarding screening guidelines and management of diabetes, refer to the studies titled “Glucose 1-5 Anhydroglucitol, and Fructosamine” and “Glucose Tolerance Tests.”
The random urine ACR is frequently used as a quick and reliable screen for diabetes and hypertension. A first morning void specimen is best if a random urine albumin will be tested. The American Diabetes Association (ADA) recommends periodic measurement of urine albumin as requested by the health-care provider (HCP) with serum creatinine (Cr) and estimated glomerular filtration rate (eGFR). Timed collections are often impractical and don’t provide improved accuracy of results so random samples are almost universally requested. Due to biological variability in excretion of urinary albumin and other factors that may independently cause increased urine albumin levels (e.g., congestive heart failure, exercise within 24 hr of testing, fever, hydration level, hyperglycemia [marked], hypertension [marked], infection, and menstruation), two of three specimens tested within a 3- to 6-month period should be abnormal before making a determination for significant albuminuria. Guidelines for frequency of testing are based on the type of diabetes being treated and level of the patient’s ability to meet treatment goals.
Factors That May Alter the Results of the Study
- Drugs and other substances that may decrease urine albumin levels include captopril, dipyridamole, enalapril, furosemide, indapamide, perindopril, quinapril, ramipril, and simvastatin.
Other Considerations
- All urine voided for the timed collection period must be included in the collection, or else falsely decreased values may be obtained. Compare output records with volume collected to verify that all voids were included in the collection.
Increased In
Conditions resulting in increased renal excretion or loss of protein.
Decreased In
N/A
Potential Nursing Problems: Assessment & Nursing Diagnosis
| Problems | Signs and Symptoms |
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| Glucose (deficit—related to liver disease [hepatitis, cirrhosis, cancer, tumor], alcoholic liver damage, drug reactions to beta blockers and sulfonylureas, andrenergic response, dietary or medication imbalance in response to insulin or oral hypoglycemic, hyperinsulinemic disorder) | Tremor, diaphoresis, tiredness, decreased concentration, elevated blood pressure, palpitations, headache, polyphagia, restlessness, lethargy, altered mental status, combativeness, altered speech, altered coordination, hunger, irritability, dizziness, nervousness, blurred vision; confusion, tachycardia | | Glucose (excess—related to diabetes, hyperosmolar nonketotic syndrome, sedentary lifestyle, excess body mass, insulin sensitivity, metabolic syndrome secondary to alterations in the adiponectin gene, pancreatic insufficiency, excessive dietary intake, glucokinase mutations, pregnancy, glucocorticoid imbalance, increased epinephrine levels secondary to stress/trauma, excess glucose secondary to TPN administration) | Fatigue, mild dehydration, elevated blood glucose, weight loss, weakness, polyuria, polydipsia, polyphagia, blurred vision, headache, paresthesia, poor skin turgor, dry mouth, nausea, vomiting, abdominal pain, hypotension, tachycardia, Kussmaul respirations |
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Before the Study: Planning and Implementation
Teaching the Patient What to Expect
- Discuss how this test can assist in evaluating for early kidney disease associated with diabetes.
- Emphasize that good glycemic management delays the onset and slows the progression of diabetic retinopathy, nephropathy, and neuropathy.
- Explain that a urine sample is needed for the test. Information regarding urine specimen collection is presented with other general guidelines in Appendix A: Patient Preparation and Specimen Collection.
Potential Nursing Actions
- Include on the timed collection container’s label urine total volume, test start and stop times/dates, and any medications that may interfere with test results.
After the Study: Implementation & Evaluation Potential Nursing Actions
Avoiding Complications
- Emphasize, as appropriate, that good management of glucose levels delays the onset and slows the progression of diabetic retinopathy, nephropathy, and neuropathy.
- Explain that unmanaged diabetes can cause multiple health issues, including diabetic kidney disease, amputation of limbs, and ultimately in death.
Treatment Considerations
- Emphasize the importance of adhering to the HCP-recommended therapeutic regime to manage diabetes.
- Discuss the advantages that attendance in support group meetings has to learn how to manage the disease process from other people with diabetes.
General
- Use the appropriate general strategy appropriate for management of glucose excess.
- Ensure the patient understands how to perform glucose self-checks and provide education for deficits in learning.
- Discuss the lifestyle alterations necessary to support positive health management secondary to disease process.
- Monitor and trend results: hemoglobin (Hgb) A1c, BUN, Cr, glucose, electrolytes, arterial pH, magnesium, urine albumin and ACR, urine ketones, WBC count, amylase, Hgb/Hct, CRP, liver enzymes, and serum insulin levels.
Glucose Excess
- Explain that glucose should be checked before meals and at bedtime; prescribed insulin or oral drugs should be administered.
- Advise the patient to report signs and symptoms of elevated glucose.
- Facilitate the HCP’s ordered therapy for glucose management (e.g., sliding scale method for determining insulin dose).
- Closely manage insulin drip in cases of liable glucose excess.
- Monitor for fluid volume deficit associated with osmotic response to elevated glucose.
- Ensure airway remains open with adequate ventilation provide assistance as necessary.
- Encourage activity commensurate with the patient’s physical abilities
Glucose Deficit
- Advise the patient to report signs and symptoms of decreased glucose.
- Facilitate ingestion of about 20 g of oral carbohydrates in alert patients. Repeat blood glucose check in 15 min and retreat for levels less than 70 mg/dL. Follow organizational protocols.
- Facilitate administration of intravenous glucose in unconscious patient followed by oral carbohydrate ingestion once alert. Follow organizational protocols.
- Ensure airway remains open with adequate ventilation provide assistance as necessary.
- Teach the patient to carry a carbohydrate food as an intervention for hypoglycemic episodes.
Nutritional Considerations
- Collaborate with the HCP and registered dietitian to support medical nutritional therapy.
- Instruct the patient, as appropriate, in nutritional management of diabetes.
- Discuss foods that can be used to treat hypoglycemia: milk, fruit juice, granola bars, cheese and crackers, regular soda, graham crackers, hard candies.
- Explain that abnormal findings may be associated with diabetes.
- Explain that there is no “diabetic diet”; however, a variety of dietary patterns are beneficial for people with diabetes and many meal-planning approaches with nutritional goals are endorsed by the ADA.
- Discuss the reasons why patients who adhere to dietary recommendations report a better general feeling of health, better weight management, better management of glucose and lipid values, and improved use of insulin.
- Facilitate consultation with a registered dietitian who is a certified diabetes educator.
Clinical Judgement
- Consider ways to assist in adaptation to therapeutic nutritional choices to improve glucose homeostasis.
Follow-Up and Desired Outcomes