After greeting the patient, a phlebotomy technician is preparing to perform a blood draw on a patient in an inpatient facility. Which of the following actions should the technician take next?

Choice A Reason:
The right antecubital fossa is not the optimal site for blood collection in this case because the presence of a shunt in the right forearm can complicate the procedure and potentially damage the shunt, which is a critical access point for dialysis treatments.

Choice B Reason:
The right hand should also be avoided for blood collection due to the shunt placement in the right forearm. Using the same arm as the shunt for venipuncture could lead to complications such as infection, clotting, or accidental damage to the shunt.

Choice C Reason:
The left antecubital fossa might seem like a viable option; however, with an IV placed in the left hand, it is generally recommended to avoid using the same limb for blood collection to prevent contamination of the sample and reduce the risk of infection at the IV site.

Choice D Reason:
Capillary collection from the left hand is the most appropriate choice in this scenario. It avoids the arm with the shunt and the IV, reducing the risk of complications. Capillary blood collection is a suitable alternative when venipuncture sites are limited, and it can provide an adequate sample for a CBC.

Choice A Reason:
Asking "When was your last dose of lithium?" is crucial for therapeutic drug monitoring (TDM). TDM is used to tailor dosages and maintain therapeutic levels in a patient’s bloodstream, especially for drugs with narrow therapeutic indices like lithium. The timing of the last dose can significantly affect blood levels, and knowing this information helps in interpreting the results accurately.

Choice B Reason:
While knowing the fasting status of a patient may be relevant for certain tests, it is not typically critical for TDM unless the medication being monitored is affected by food intake. Lithium levels are not significantly influenced by fasting, so this question is less relevant than knowing the timing of the last dose.

Choice C Reason:
Inquiring about the last alcoholic beverage is important if alcohol could interfere with the medication's metabolism or the test's accuracy. However, for lithium TDM, alcohol consumption is not as directly relevant as the timing of the last dose. Alcohol does not typically alter lithium levels unless it affects the patient's hydration status.

Choice D Reason:
Asking if the patient has finished drinking the glucose solution would be pertinent if conducting a glucose tolerance test. However, this is not relevant for TDM of lithium, as the glucose solution does not interfere with lithium levels or the TDM process.

In conclusion, for therapeutic drug monitoring, particularly for lithium, the most critical question is regarding the timing of the last dose. This information is essential to ensure that the blood levels reflect the peak or trough concentration, depending on what is being measured, and to avoid misinterpretation that could lead to inappropriate dosing adjustments.