Final answer:
The correct action when a needle becomes disengaged from the adapter during venipuncture is to terminate the procedure, dispose of the needle safely, and start over with new equipment after informing the patient.
Step-by-step explanation:
If the needle becomes disengaged from the adapter during a venipuncture, the proper course of action is to stop the procedure immediately and safely discard the disengaged needle using proper sharp disposal protocols. Then, you should prepare a new venipuncture needle and adapter, inform the patient about the mishap, ensure they are comfortable and stable, and proceed with the venipuncture again if necessary. At all times, adhere to safety guidelines to prevent needlestick injuries and maintain infection control.