Unable to aspirate blood during intramuscular injection

In general, difficulty in aspirating blood during intramuscular injection may be caused by patient tension or muscle tightness, improper injection site selection, insufficient injection depth, incorrect needle insertion angle, or needle blockage or bending. Specific analysis is as follows:

1. Patient tension or muscle tightness

Patient tension or muscle tightness may also lead to difficulty in aspirating blood. It is recommended to communicate with the patient before injection to help them relax, or gently massage the injection site during injection to relieve tension and muscle tightness.

2. Improper injection site selection

If the injection site is improperly chosen—such as being too close to blood vessels or nerves—it may result in difficulty aspirating blood. It is recommended to select the correct injection site and avoid areas near blood vessels or nerves.

3. Insufficient injection depth

If the injection depth is inadequate, the needle may not reach the muscle layer, which can also cause difficulty in aspirating blood. It is recommended to increase the injection depth to ensure the needle reaches the muscle layer.

4. Incorrect needle insertion angle

Intramuscular injection requires inserting the needle into the muscle layer. An incorrect insertion angle may lead to difficulty in aspirating blood. It is recommended to re-adjust the needle angle to ensure proper insertion into the muscle layer.

5. Needle blockage or bending

Needle blockage or bending may also cause difficulty in aspirating blood. It is recommended to replace the needle with a new one to ensure it is unobstructed and not bent.

In addition, difficulty in aspirating blood during intramuscular injection may also be due to high drug viscosity or capillary rupture. If the patient experiences discomfort, they should seek medical attention promptly to avoid delaying treatment.