# AI为有严重造影剂过敏史的患者开具CT增强扫描，未安排预处理用药

- **ID:** `medical/contrast-allergy-history-missed`
- **领域:** medical
- **类别:** data_error
- **错误码:** `CONTRAST-ALLERGY-002`
- **验证级别:** ai_generated
- **修复率:** 85%

## 根因

对既往有碘造影剂过敏反应的患者跳过预处理（如泼尼松、苯海拉明）可能引发危及生命的过敏反应；电子病历中的过敏警报常被忽视。

## 版本兼容性

| 版本 | 状态 | 引入 | 弃用 |
|------|------|------|------|
| iohexol 350mgI/mL | active | — | — |
| ACR manual on contrast media v2023 | active | — | — |
| EHR allergy module v5.2 | active | — | — |

## 解决方案

1. ```
   Order premedication: prednisone 50mg PO at 13h, 7h, 1h before scan + diphenhydramine 50mg IV 1h before; use `python -c "print('Premed: pred 50mg PO at t-13, t-7, t-1; benadryl 50mg IV at t-1')"`
   ```
2. ```
   If urgent scan needed, use emergency premedication (methylprednisolone 40mg IV + diphenhydramine 50mg IV) 1h prior
   ```
3. ```
   Consider alternative imaging without contrast (e.g., non-contrast CT, MRI with gadolinium if no contraindication)
   ```

## 无效尝试

- **** — Low-osmolar reduces but does not eliminate risk in patients with prior severe reaction; premedication still indicated (80% 失败率)
- **** — Anaphylaxis can occur within minutes regardless of infusion rate; reactive monitoring is insufficient (85% 失败率)
- **** — Non-ionic contrast still carries risk; premedication protocol applies to all iodinated contrast agents (75% 失败率)