Introduction to Lab Values NCLEX^® Review

This Lab Values NCLEX^® Review should hopefully provide a nice review of the many kinds of lab values and ranges to keep in mind when practicing and preparing for your exam.

Complete Blood Count Lab Values

The complete blood count lab (CBC) is one of the most used types of lab tests in daily practice. This lab defines the number of cells present in the blood which may reveal the concentration of red blood cells, white blood cells, platelets, hemoglobin, and hematocrit. These values can help clinicians understand the presence of blood loss, anemia, infection, or medication overdose.

• Hemoglobin:
  • 12.0-16.0 g/dL (women)
  • 13.5-17.5 g/dL (men)
• Hematocrit:
  • 41%-53% (men)
  • 36%-46% (women)
• RBC: 4.5-5.5 million
• WBC: 5,000-10,000
• Platelet: 150,000-400,00

Metabolic Panel Lab Values

The metabolic panel (BMP or CMP) is often used to evaluate a client’s fluids, electrolytes, glucose, renal function, and liver function. These tests are useful when monitoring certain disease states as well as for side effects of medications in use.

• Potassium: 3.5-5.0 mEq/L
• Sodium: 136-145 mEq/L
• Glucose:
  • Fasting: 70-110 mg/dL
  • 2-h postprandial: < 120 mg/dL
• Calcium: 8.4-10.2 mg/dL
• Phosphorus: 3.0-4.5 mg/dL
• Magnesium: 1.5-2.0 mEq/L
• Chloride: 95-105 mEq/L
• BUN: 5-20
• Serum creatinine: 0.6-1.2 mg/dL
• Albumin: 3.5-5.5 g/dL
• Bilirubin: 0.1-1.0 mg/dL
• Liver Function Tests (LFTs):
  • ALP: 40-120 u/L
  • ALT: 7-56 u/L
  • AST: 10-40 u/L

Arterial Blood Gases (ABGs) Lab Values

Arterial blood gases are important lab values to understand, especially when evaluating clients in critical condition. These labs determine the acidity and alkalinity of the blood and can help in the diagnosis of many different types of conditions.

• pO2: 80-100%
• O2 saturation: 95-100%
• pH: 7.35-7.45
• PaCO2: 35-45 mmHg
• HCO3: 22-26 mEq/L

Coagulation Levels Lab Values

Coagulation levels are very commonly ordered for clients on anticoagulation therapy like warfarin, direct oral anticoagulants, heparin, and in clients at risk for developing a clot.

These values are crucial when clinicians attempt to dose clients with the correct number of anticoagulants as overdosing can lead to serious bleeding and potentially death. Underdosing can also lead to an increased risk of clot formation causing myocardial infarction, stroke, or pulmonary embolism.

• INR:
  • Not on warfarin: < 1
  • On warfarin: 2-3
• aPTT (activated partial thromboplastin time):
  • Not on heparin 30-40 seconds
  • On heparin aPTT 1.5-2.5 times normal range

Lipid Panel Lab Values

Lipid panels are a key part of ambulatory care when the goal is to establish adequate lipid levels to reduce the risk of clients having a serious atherosclerotic disease such as heart disease and stroke. Something key to note is that HDL values are better when higher while the other values should be lower.

• HDL: > 40 mmol/L
• LDL: < 110 mmol/L
• Triglycerides (TGs): < 90 adults mmol/L
• Total Cholesterol: < 170 mmol/L

Hemoglobin A1C Lab Values

A1C proves to be a very important lab value to understand for clients with diabetes or at risk for diabetes. A1C is defined as glycosylated hemoglobin which represents the amount of glucose that consistently binds to hemoglobin over approximately three months.

• Normal: < 5.7%
• Prediabetes: > 5.7% – < 6%
• Diabetes: > 6.5%

Drug Level Ranges Lab Values

Drug level monitoring is often utilized when administering certain drugs that are dangerous when either overdosed or underdosed. Here are some common drugs that generally require monitoring to reduce the risk of serious adverse events.

• Acetaminophen: 10-25 μg/mL
• Digoxin: 0.8-2 ng/mL
• Lidocaine: 1.5-5m μg/mL
• Lithium:
  • 0.6-1 mEq/L
  • Acute mania: 0.8-1.2 mEq/L
  • Elderly: 0.4-0.8 mEq/L
• Phenobarbital:
  • Adults: 10-40 μg/mL
  • Infants/children: 15-30 μg/mL
• Phenytoin: 10-20 μg/mL
• Theophyline:
  • Adults: 5-15 μg/mL
  • Children: 5-10 μg/mL
  • Neonatal apnea: 6-11 μg/mL
• Vancomycin: 10-20 mg/L

Practice questions for Lab Values NCLEX^® Review:

NCLEX^® Lab Values Conclusion

Memorizing the many lab values that may appear in practice can often prove to be a very challenging and extensive process. However, it is something that will improve with practice and over-time.

It’s nevertheless important to do your best to become comfortable with these values as they will likely present on the NCLEX^® exam and will be a frequent requirement of your daily practice. Hopefully, this Lab Values NCLEX^® Review will aid you in your studies and your future practice.

References:

1. Laboratory tests normal reference ranges in adults. In: Post T, ed. UpToDate. Waltham, MA.: UpToDate; 2020. www.uptodate.com. Accessed May 5th, 2020.
2. Client education: Complete blood count (CBC) (Th Basics). In: Post T, ed. UpToDate. Waltham, MA.: UpToDate; 2020. www.uptodate.com. Accessed May 5th, 2020.
3. Laboratory evaluation of the immune system. In: Post T, ed. UpToDate. Waltham, MA.: UpToDate; 2020. www.uptodate.com. Accessed May 5th, 2020.
4. Nbme.org. 2020. [online] Available at: https://www.nbme.org/sites/default/files/2020-01/LabReferenceValues.pdf Accessed 11 May 2020.
5. Heart.org. 2020. Available at: https://www.heart.org/-/media/files/health-topics/cholesterol/chlstrmngmntgd_181110.pdf Accessed 11 May 2020.
6. Diabetes.org. 2020. Diagnosis ADA. Available at: https://www.diabetes.org/a1c/diagnosis> Accessed 11 May 2020.
7. Emedicine.medscape.com. 2020. Therapeutic Drug Levels: Therapeutic Drug Levels. Available at: <https://emedicine.medscape.com/article/2172048-overview Accessed 11 May 2020.