Hematoma from poor technique or vessel injury
What it is
Causing a hematoma (localized bleeding into soft tissues) after a local anesthetic injection because the needle injures a blood vessel (artery/vein) and blood extravasates into surrounding tissues. Clinically you see rapid swelling, bruising/ecchymosis, tenderness, sometimes trismus (if deeper spaces involved). Hematoma is a known injection complication and is specifically listed among LA complications that good anatomy/technique helps minimize.
Why it happens
• Needle contact/penetration of vascular structures — classically during posterior superior alveolar (PSA) nerve block near the pterygoid plexus/posterior superior alveolar vessels, but can happen with other blocks too • Incorrect angulation or excessive depth (too posterior/superior in PSA block), bringing the needle closer to major vessels • Failure to aspirate / poor aspiration technique (increases risk of intravascular events and is a marker of sloppy technique around vessels) • Multiple penetrations / "fishing" for landmarks → more tissue/vessel trauma • Patient factors that worsen bleeding/bruising: anticoagulants/antiplatelets, vascular fragility, hypertension
The full clinical mistake entry includes
- How to avoid it — the prevention protocol
- The clinical tip experienced clinicians use
- The documented reference behind the mistake
More clinical mistakes
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