California Phlebotomy Certification Practice Exam

Which level should a phlebotomy technician collect to test a patient's lithium level following medication?

1. Trough

2. Baseline

3. Peak

4. Random

The correct answer is: Peak

The correct choice for collecting a sample to test a patient's lithium level following medication is the peak level. Peak levels refer to the highest concentration of a drug in a patient's bloodstream after administration. For lithium, which is often prescribed for bipolar disorder, monitoring peak levels is crucial because it helps ensure that the concentration in the blood is within the therapeutic range and is effective without being toxic. In practice, peak levels for lithium are typically drawn 1 to 2 hours after the dose has been administered, allowing clinicians to assess the effectiveness of the medication and make any necessary adjustments to the dosage. This timing is essential for achieving accurate and relevant results that inform patient management. Other sampling strategies, like trough levels, look at the lowest concentration of a drug just before a dose is given, which is more appropriate for ensuring that levels remain safe just prior to the next dose rather than evaluating the immediate effect of the most recent dose. Baseline could refer to the starting concentration before treatment initiation, and random samples may not provide enough contextual information regarding the timing of medication administration. Therefore, for lithium specifically, testing at peak is critical for effective monitoring and patient care.