Question

A patient needs two small sutures near the base of his right ring finger. The nurse practitioner draws up lidocaine as a local anesthetic. The NP knows that she must first:

a. Inject a small amount of lidocaine into the subcutaneous tissue
b. Aspirate first to check for needle placement and ensure blood return
c. Aspirate first to check for needle placement and ensure no blood return.
d. Aspirate first to check for infection

Answer 1

The nurse practitioner should first aspirate the syringe to ensure no blood return, confirming correct needle placement and avoiding intravascular injection. Lidocaine acts as an effective local anesthetic by blocking voltage-gated sodium channels, preventing nerve signal transmission and resulting in an absence of pain.

Step-by-step explanation:

When administering lidocaine as a local anesthetic, a nurse practitioner (NP) must ensure the correct procedure is followed to provide effective and safe pain relief for the patient. The correct first step before injecting an anesthetic into the subcutaneous tissue is to aspirate first to check for needle placement and ensure no blood return.

This step is crucial because it confirms that the needle is not in a blood vessel which would be indicated by the appearance of blood in the syringe upon aspiration. Injecting lidocaine directly into a blood vessel could lead to systemic anesthetic effects and cause complications. Lidocaine works as a local anesthetic by blocking voltage-gated sodium channels which are essential for the initiation and propagation of nerve impulses. When these channels are blocked, neurons in the affected area cannot generate or transmit pain signals leading to the absence of pain. This mechanism of action makes lidocaine an effective local anesthetic for procedures like suturing.