Alanine Aminotransferase

Synonym/Acronym:
ALT.

Rationale
To assess liver function related to liver disease and/or damage.

Patient Preparation
There are no food, fluid, activity, or medication restrictions unless by medical direction.

Normal Findings
Method: Spectrophotometry.

AgeConventional and SI Units
Newborn7–41 units/L
Child, Adult
 Male19–36 units/L
 Female24–36 units/L
Greater than 90 yr
 Male6–38 units/L
 Female5–24 units/L
Values may be slightly elevated in older adults due to the effects of medications and the presence of multiple chronic or acute diseases with or without muted symptoms.

Critical Findings and Potential Interventions
N/A

Overview

(Study type: Blood collected in a gold-, red-, red/gray-, or green-top [heparin] tube; related body system: Digestive system.) ALT is an enzyme produced by the liver. The highest concentration of ALT is found in liver cells; moderate amounts are found in kidney cells; and smaller amounts are found in heart, pancreas, spleen, skeletal muscle, and red blood cells. When liver damage occurs, serum levels of ALT may increase as much as 50 times normal, making this a sensitive test for evaluating liver function. ALT is part of a group of tests known as LFTs, or liver function tests, used to evaluate liver function: ALT; albumin; alkaline phosphatase; aspartate aminotransferase (AST); bilirubin, direct; bilirubin, total; and protein, total.

Indications

  • Compare serially with AST levels to track the course of liver disease.
  • Monitor liver damage resulting from hepatotoxic drugs.
  • Monitor response to treatment of liver disease, with tissue repair indicated by gradually declining levels.

Interfering Factors

Factors that may alter the results of the study

  • Drugs and other substances that may increase ALT levels by causing cholestasis include anabolic steroids, dapsone, estrogens, ethionamide, oral contraceptives, sulfonylureas, and zidovudine.
  • Drugs and other substances that may increase ALT levels by causing hepatocellular damage include acetaminophen (toxic), acetylsalicylic acid, anticonvulsants, asparaginase, cephalosporins, chloramphenicol, clofibrate, cytarabine, danazol, enflurane, erythromycin, ethambutol, ethionamide, ethotoin, florantyrone, foscarnet, gentamicin, gold salts, halothane, ibufenac, indomethacin, interleukin-2, isoniazid, lincomycin, low-molecular-weight heparin, metahexamide, metaxalone, methoxsalen, methyldopa, naproxen, nitrofurans, oral contraceptives, probenecid, procainamide, and tetracyclines.
  • Drugs and other substances that may decrease ALT levels include cyclosporine, interferons, metronidazole (affects enzymatic test methods), and ursodiol.

Potential Medical Diagnosis: Clinical Significance of Results

Increased In:

Related to release of ALT from damaged liver, kidney, heart, pancreas, red blood cells, or skeletal muscle cells.

  • Acute pancreatitis
  • AIDS (related to hepatitis B co-infection)
  • Biliary tract obstruction
  • Burns (severe)
  • Chronic alcohol misuse
  • Cirrhosis
  • Fatty liver
  • HELLP syndrome of pregnancy (hemolysis, elevated liver enzymes, low platelet count)
  • Hepatic cancer
  • Hepatitis
  • Infectious mononucleosis
  • Muscle injury from intramuscular injections, trauma, infection, and seizures (recent)
  • Muscular dystrophy
  • Myocardial infarction
  • Myositis
  • Pancreatitis
  • Pre-eclampsia
  • Shock (severe)

Decreased In:

  • Pyridoxal phosphate deficiency (related to a deficiency of pyridoxal phosphate that results in decreased production of ALT)

Nursing Implications

Potential Nursing Problems Assessment and Nursing Diagnosis

ProblemsSigns and Symptoms
Fluid volume (water) Deficit: (related to vomiting, decreased intake, compromised kidney function, overly aggressive diuresis) Deficit: Decreased urinary output, fatigue, sunken eyes, dark urine, decreased blood pressure, increased heart rate, and altered mental status
Excess: Fluid overload, abdominal ascites (overload related to overly aggressive fluid resuscitation; ascites related to hypoalbumenia, imbalanced aldosterone, altered [low] serum osmotic pressure)Excess: Fluid resuscitation—edema, shortness of breath, rales, rhonchi, and diluted laboratory valuesAbdominal ascites—increasing abdominal girthFluid resuscitation and abdominal ascites—increased weight
Gastrointestinal (GI) problems (related to altered motility, irritation of the GI tract, taste alterations, pancreatic and gastric secretions)Nausea, vomiting, abdominal distention, unexplained weight loss, steatorrhea, diarrhea, visible abdominal distention, ascites, diminished or absent bowel sounds
Insufficient nutrition (related to metabolic imbalances, excess alcohol use, anorexia)Increased liver function tests; hyperglycemia with polyuria, weight loss, weakness, nausea, vomiting; hypocalcemia with confusion, intestinal cramping, diarrhea; hypertriglyceridemia; altered thiamine with weakness, confusion
Pain (related to organ inflammation and surrounding tissues, excessive alcohol intake, infection)Emotional symptoms of distress, crying, agitation, facial grimace, moaning, verbalization of pain, rocking motions, irritability, disturbed sleep, diaphoresis, altered blood pressure and heart rate, nausea, vomiting, self-report of pain, upper abdominal and gastric pain after eating fatty foods or alcohol intake with acute pancreatic disease, pain that may be decreased or absent in chronic pancreatic disease

Before the Study: Planning and Implementation

Teaching the Patient What to Expect

  • Inform the patient this test can assist with evaluation of liver function and help identify liver disease.
  • Explain that a blood sample is needed for the test.

After the Study: Potential Nursing Actions

Avoiding Complications

  • The patient with cirrhosis should be carefully observed for the development of ascites, in which case fluid and electrolyte balance requires strict attention.

Treatment Considerations

  • Fluid Volume Deficit: Collaborate with health-care provider (HCP) regarding administration of IV fluids to support optimal hydration. Monitor laboratory values that reflect alterations in fluid status: potassium, BUN, Cr, calcium, Hgb, and Hct. Administer replacement electrolytes, as ordered, to manage underlying cause of fluid alteration; monitor urine characteristics and respiratory status. Trend vital signs and daily weight, and perform strict intake and output.
  • Fluid Volume Overload: Measure abdominal girth and trend size. Monitor and trend laboratory values: albumin, protein, and globulin. Assess for dehydration and increase fluids if present (fluid shifts from intravascular to extravascular can result in concerns related to hydration status). Administer ordered diuretics. Trend vital signs and daily weight, and perform strict intake and output.
  • GI Problems: Perform nasogastric intubation to remove gastric secretions and decrease pancreatic secretions, which may result in autodigestion. Monitor nasogastric tube for patency and amount of drainage, and assess bowel sounds frequently. Measure abdominal girth to monitor degree of abdominal distention.
  • Pain: Collaborate with the patient and HCP to identify the best pain management modality. Refrain from activities that may increase pain. Apply heat or cold to the best effect in managing pain, and monitor pain severity.

Nutritional Considerations

  • Increased ALT levels may be associated with liver disease. In general, patients should be encouraged to eat a well-balanced diet that includes foods high in fiber. Dietary recommendations will vary depending on the condition and its severity. For example, a soft foods diet is recommended if esophageal varices develop, fat substitutes are recommended if bile duct disease is diagnosed, and salt intake should be limited if ascites develop.
  • Administer ordered enteral or parenteral nutrition; monitor laboratory values (albumin, protein, potassium) and collaborate with HCP on replacement strategies; correlate laboratory values with IV fluid infusion, and collaborate with the HCP and pharmacist to adjust to patient needs; ensure adequate pain control, and monitor vital signs for alterations associated with metabolic imbalances.

Followup Evaluation and Desired Outcomes

  • Acknowledges contact information provided for the Centers for Disease Control and Prevention (www.cdc.gov/diseasesconditions)
  • Understands information regarding causative factors of pancreatitis and liver disease, the disease process, and proactive lifestyle changes to better manage health.
  • Accepts the importance of adhering to the medication regimen as prescribed to limit pancreatic secretions and decrease pain.

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