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• Use laboratory data into their practice
• Determine if results of test need to be reported immediately or not urgent
• Alert others to watch for symptoms to watch for or precautions to take
• recognize that abnormal results may require immediate attention and normal results may also have great diagnostic importance to rule
  out a disease.
• Use critical thinking in judging laboratory serum value is essential

Nursing Functions

• Gather information from charts
• Transcribing orders & ordering tests
• Nurses must be aware of potential problems with administering test
• Point-of-Care Testing – Sophisticated wet and dry chemistry systems (automatic analyzers) that can be used outside the
  traditional centralized laboratory.
• Hand held analyzers
• Preparation of client for laboratory test

Venous samples errors:

• Not allowing the antiseptic to dry (too wet)
• Moisture in collection tube or syringe
• Prolonged clenching fist or use of tourniquet
• Too small of gauge needle
• Use of too much suction on the syringe
• Vigorous expulsion of blood into collecting tube
• Vigorous shaking of blood specimen
• Using the arm in which there is an IV catheter
• Using the wrong color of tubes

Normal reference values and the variability of test results

• False positive and negative
• Specificity – No lab. test is 100% specific because there is always a factor that can effect a false positive reaction.
• Sensitivity – Test the degree to which a test detects disease without yielding a false-negative diagnosis.
• Conventional Measurements Vs SI
  Conventional most often used ( ml, mg)
• SI units a form of the metric system called Le Systeme Internationale d’Unites (SI). More common language all over the world

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Critical Lab Values

Points to consider

• Is  the patient having any effects from the abnormal levels?

• What care is needed for the signs or symptoms?

• What is the cause?

• How can the cause be managed?

• Critical values vary from lab to lab - you need to know the values in your institution. Examples of critical values are listed below:

Na < 120 or > 150
K   < 2.5  or > 6.5
CO₂ < 10 or > 40
PaCO2 < 20 or > 40
pH < 7.2 or > 7.53
Ca⁺⁺ < 6 or > 13
PT < 16 or > 30
INR > 3
Positive blood cultures
Hgb < 7 or > 22
Neutrophils < 7 or > 22
WBC < 2000 or > 50,000
WBC differential with any blast cells
Platelets < 30,000

Check out this site for an example of the University of Iowa's critical lab values