A hematoma quickly appears after a PSA nerve block. Which of the following may have caused the hematoma?

When a hematoma quickly appears after a PSA (posterior superior alveolar) nerve block, it may indicate that the needle inadvertently punctured the pterygoid plexus of veins. The pterygoid plexus is a network of veins located in the infratemporal fossa, which is in close proximity to the area being anesthetized during the PSA block. If the needle inadvertently enters this plexus, blood can rapidly escape into the surrounding soft tissue, leading to a hematoma.

This occurrence is somewhat common in the context of a PSA nerve block due to the vascular nature of the pterygoid plexus. It underscores the importance of proper technique and anatomical knowledge during the administration of anesthetic blocks, as the presence of a hematoma can also lead to complications such as pain, dysfunction, or a diffusion of local anesthetic.

In contrast, while the deposition of the anesthetic solution into blood vessels can also lead to complications, it is less likely to result in a quickly formed hematoma compared to direct penetration of a venous plexus like the pterygoid. Similarly, puncturing the parotid gland mainly risks causing complications related to the facial nerve or salivary flow and would not typically lead to