Article
Laboratory tests are an important part of patient assessment. They provide information that healthcare professionals use alongside a patient's symptoms, medical history, physical examination, and other clinical findings. Nursing students should become familiar with common laboratory tests because they frequently appear in classroom discussions, clinical preparation, and patient-care scenarios. Understanding what a test measures is more useful than simply memorizing its abbreviation.
1. Complete blood count (CBC)
A complete blood count measures several components of the blood. It commonly includes: - Red blood cells (RBCs): Carry oxygen throughout the body. - White blood cells (WBCs): Help the body fight infections. - Hemoglobin: A protein in red blood cells that carries oxygen. - Hematocrit: The proportion of blood volume made up of red blood cells. - Platelets: Help blood clot. A CBC can help clinicians investigate concerns such as anemia, infection, and bleeding disorders. For example, a low hemoglobin result may prompt further assessment for anemia or blood loss. However, a laboratory result must always be interpreted alongside the patient's clinical condition.
2. Basic metabolic panel (BMP)
A basic metabolic panel measures substances that provide information about fluid balance, kidney function, and metabolism. It commonly includes: - Sodium - Potassium - Chloride - Bicarbonate - Blood urea nitrogen (BUN) - Creatinine - Glucose - Calcium Electrolytes such as sodium and potassium are important for normal nerve and muscle function. Abnormal potassium levels, for instance, may affect the heart's electrical activity. This is one reason healthcare professionals pay close attention to electrolyte results.
3. Blood glucose testing
Blood glucose tests measure the amount of sugar in the blood. Glucose is an important energy source, but the body must regulate its levels carefully. Testing may be used to investigate diabetes, monitor blood sugar control, or assess symptoms associated with unusually low or high glucose levels. Some tests measure glucose at a particular moment, while others, such as the hemoglobin A1c test, provide information about average blood glucose over approximately the previous two to three months.
4. Kidney function tests
The kidneys help remove waste products, regulate fluid balance, and maintain electrolyte levels. Two commonly reviewed measurements are BUN and creatinine. - BUN: Measures nitrogen in the blood from urea, a waste product formed during protein metabolism. - Creatinine: A waste product associated with normal muscle metabolism that is filtered by the kidneys. Creatinine and estimated glomerular filtration rate (eGFR) are often used together when assessing kidney function. Changes in these measurements may require further investigation. They should not be interpreted in isolation because hydration, medications, muscle mass, and other factors can influence results.
5. Liver function tests
Liver-related blood tests help clinicians assess liver injury and certain aspects of liver function. Common measurements include: - ALT - AST - Alkaline phosphatase (ALP) - Bilirubin - Albumin ALT and AST are enzymes that may rise when liver cells are damaged. Bilirubin is a substance produced during the breakdown of red blood cells, and the liver helps process it. A group of abnormal liver results does not automatically establish a diagnosis. Further assessment may be necessary.
6. Why nurses need to understand laboratory results
Nurses help monitor patients and recognize changes that may require attention. Understanding laboratory tests can support nurses in several ways: - Identifying results that require prompt communication. - Comparing current results with previous measurements. - Recognizing possible relationships between symptoms and test findings. - Monitoring patients receiving treatments that affect electrolytes or blood counts. - Explaining basic testing procedures to patients. Nurses should follow their facility's procedures for reporting critical values and escalating concerns. They should not independently diagnose conditions or change treatment based solely on a laboratory result.
7. How to study laboratory tests
Create a study table with four columns: test name, what it measures, why it is ordered, and what an abnormal result may suggest. Study a small group of tests at a time. Then use patient scenarios to connect laboratory findings with the patient's symptoms and medical history. Remember that reference ranges can differ between laboratories and patient populations. Always use the reference range provided with the actual result.
Final tip
Learn the purpose of each test before memorizing normal values. Understanding what a measurement represents makes laboratory information easier to remember and apply in nursing education. Practice question: Which blood component is primarily responsible for helping the body form clots? A. Red blood cells B. Platelets C. Hemoglobin D. White blood cells Answer: B. Platelets.
