# AI tells anaphylaxis patient to inject epinephrine into the upper arm or buttock, but the thigh muscle (vastus lateralis) is the recommended site for self-injection

- **ID:** `emergency/epinephrine-injection-site`
- **Domain:** emergency
- **Category:** life_safety
- **Error Code:** `EPI-INJECT-ERR-005`
- **Verification:** ai_generated
- **Fix Rate:** 92%

## Root Cause

The AI incorrectly recommends injection sites based on common vaccine administration (deltoid) or outdated first-aid advice, ignoring that the thigh provides faster absorption and is easier for self-injection.

## Workarounds

1. **For EpiPen or generic auto-injector, remove safety cap, place orange tip against outer thigh (mid-anterior lateral aspect), and push firmly until click. Hold for 3 seconds. Example: 'Inject into the outer middle third of the thigh.'** (95% success)
   ```
   For EpiPen or generic auto-injector, remove safety cap, place orange tip against outer thigh (mid-anterior lateral aspect), and push firmly until click. Hold for 3 seconds. Example: 'Inject into the outer middle third of the thigh.'
   ```
2. **If no auto-injector, use a manual syringe with 1-inch needle for adults (shorter for children). Inject at 90-degree angle into vastus lateralis muscle (outer thigh).** (85% success)
   ```
   If no auto-injector, use a manual syringe with 1-inch needle for adults (shorter for children). Inject at 90-degree angle into vastus lateralis muscle (outer thigh).
   ```
3. **Practice with trainer devices (e.g., EpiPen trainer) to locate the correct site; inject into a foam pad simulating thigh to build muscle memory.** (90% success)
   ```
   Practice with trainer devices (e.g., EpiPen trainer) to locate the correct site; inject into a foam pad simulating thigh to build muscle memory.
   ```

## Dead Ends

- **** — User injects into deltoid (upper arm), but muscle is too small; may hit bone or subcutaneous tissue, delaying absorption. (80% fail)
- **** — User injects into buttock, but the gluteal muscle is not recommended due to risk of sciatic nerve damage and slower absorption via fat layers. (70% fail)
- **** — User attempts to inject into thigh but misses the vastus lateralis (outer thigh), injecting into quadriceps which is acceptable but less ideal. (50% fail)