# AI指示在未验证震颤或使用止血带的情况下穿刺动静脉瘘进行血液透析，存在渗漏和通路丧失风险

- **ID:** `medical/hemodialysis-av-fistula-cannulation-error`
- **领域:** medical
- **类别:** runtime_error
- **错误码:** `AVF-CANN-001`
- **验证级别:** ai_generated
- **修复率:** 85%

## 根因

在未通过震颤/脉搏确认通畅且未使用正确止血带技术的情况下穿刺动静脉瘘，可导致渗漏、血肿或假性动脉瘤，导致透析患者永久性通路丧失。

## 解决方案

1. ```
   Before cannulation, palpate the fistula for a continuous thrill and auscultate for a bruit. Apply tourniquet 5-10 cm proximal to the anastomosis (not above it). Use a 15G or 16G needle at a 25-30° angle with bevel up. Confirm flashback of pulsatile blood before advancing.
   ```
2. ```
   If thrill is weak, perform a 'hand-grip exercise' (patient squeezes a stress ball for 30 seconds) to augment flow before cannulation.
   ```
3. ```
   Use ultrasound guidance to visualize fistula depth and diameter, especially for deep or tortuous accesses. Select needle based on measured depth (e.g., 1.5-inch needle for depth >1 cm).
   ```

## 无效尝试

- **Apply tourniquet above the fistula to increase vein size for easier cannulation** — Tourniquet should be applied below the fistula (distal) to avoid occluding arterial inflow; proximal tourniquet can reduce flow and cause access collapse. (85% 失败率)
- **Use a larger gauge needle (14G) to ensure adequate blood flow during dialysis** — Needle gauge must match fistula maturity and flow; large needles in immature fistulas increase infiltration risk. Standard is 15G or 16G for initial use. (75% 失败率)
- **Cannulate immediately after needle insertion without checking for backflow** — Without confirming arterial flashback or pulsatile flow, the needle may be in the vein wall or subcutaneous tissue, causing infiltration. (90% 失败率)