# AI instructs to dilute IV vancomycin with 50mL D5W for a 1.5g dose, ignoring concentration limits for phlebitis risk

- **ID:** `medical/iv-antibiotic-dilution-error`
- **Domain:** medical
- **Category:** data_error
- **Error Code:** `IV-DILUTION-007`
- **Verification:** ai_generated
- **Fix Rate:** 90%

## Root Cause

Vancomycin concentration should not exceed 5 mg/mL for peripheral IV administration; 1.5g in 50mL yields 30 mg/mL, causing high osmolarity and severe phlebitis; proper dilution requires at least 300mL.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| vancomycin 1.5g vial | active | — | — |
| D5W 250mL bag | active | — | — |
| ISMP guidelines 2023 | active | — | — |

## Workarounds

1. **Dilute 1.5g vancomycin in 300mL NS or D5W to achieve 5 mg/mL; use `python -c "print(f'Required volume: {1500/5} mL')"`** (95% success)
   ```
   Dilute 1.5g vancomycin in 300mL NS or D5W to achieve 5 mg/mL; use `python -c "print(f'Required volume: {1500/5} mL')"`
   ```
2. **If fluid restriction needed, consider central line with concentration up to 10 mg/mL (150mL); document in EHR with pump rate calculation** (85% success)
   ```
   If fluid restriction needed, consider central line with concentration up to 10 mg/mL (150mL); document in EHR with pump rate calculation
   ```
3. **Use premixed vancomycin bags (1g/200mL or 1.5g/300mL) from pharmacy to eliminate dilution errors** (92% success)
   ```
   Use premixed vancomycin bags (1g/200mL or 1.5g/300mL) from pharmacy to eliminate dilution errors
   ```

## Dead Ends

- **** — Central line reduces phlebitis risk but does not eliminate need for proper dilution; concentrated solution still causes precipitation or red man syndrome (70% fail)
- **** — Slow infusion does not reduce osmolarity damage; phlebitis occurs due to high concentration regardless of rate (90% fail)
- **** — Volume still insufficient (1.5g/100mL = 15 mg/mL, 3x limit); NS vs D5W does not change concentration requirement (80% fail)