{
  "id": "medical/iv-pump-rate-miscalculation-obesity",
  "signature": "AI calculates IV heparin infusion rate using actual body weight instead of adjusted body weight for an obese patient, causing supratherapeutic aPTT",
  "signature_zh": "AI使用实际体重而非调整体重计算肥胖患者的静脉肝素输注速率，导致aPTT过高",
  "regex": "(heparin|unfractionated heparin|UFH).*(actual body weight|ABW|weight based).*(obese|BMI|overweight)",
  "domain": "medical",
  "category": "medication_error",
  "subcategory": null,
  "root_cause": "Heparin dosing for obese patients (BMI >30) should use adjusted body weight (ABW = IBW + 0.4*(actual weight - IBW)) or fixed-dose nomograms; using actual body weight results in supratherapeutic aPTT (>100 sec) and increased bleeding risk (major bleed rate 5-10%).",
  "root_cause_type": "generic",
  "root_cause_zh": "肥胖患者（BMI>30）的肝素剂量应使用调整体重（ABW = IBW + 0.4*(实际体重 - IBW)）或固定剂量方案；使用实际体重会导致aPTT过高（>100秒）和出血风险增加（大出血率5-10%）。",
  "versions": [
    {
      "version": "CHEST Antithrombotic Guidelines 2021",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "Epic Willow v2023",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "Heparin Nomogram v2.0 (institutional)",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "IBW underestimates volume of distribution for heparin, leading to subtherapeutic aPTT and increased risk of clot progression. Adjusted body weight is evidence-based.",
      "fail_rate": 0.8,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Even reduced bolus with actual weight leads to high infusion rates; steady-state levels become toxic. Must use ABW for both bolus and infusion.",
      "fail_rate": 0.75,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Fixed-dose nomograms are validated for non-obese patients only. For BMI >30, use obesity-specific nomogram (e.g., CHEST guideline).",
      "fail_rate": 0.85,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "Calculate adjusted body weight: IBW (males = 50 + 2.3*(height_in_inches - 60); females = 45.5 + 2.3*(height_in_inches - 60)). Then ABW = IBW + 0.4*(actual weight - IBW). Use ABW for heparin bolus (80 units/kg) and infusion (18 units/kg/hr). Verify with nomogram.",
      "success_rate": 0.92,
      "how": "Calculate adjusted body weight: IBW (males = 50 + 2.3*(height_in_inches - 60); females = 45.5 + 2.3*(height_in_inches - 60)). Then ABW = IBW + 0.4*(actual weight - IBW). Use ABW for heparin bolus (80 units/kg) and infusion (18 units/kg/hr). Verify with nomogram.",
      "condition": "",
      "sources": []
    },
    {
      "action": "Use electronic health record (EHR) calculator that auto-calculates ABW when BMI >30. Example Epic SmartPhrase: .HEPARINOBESE. Ensure pharmacy verifies before dispensing.",
      "success_rate": 0.9,
      "how": "Use electronic health record (EHR) calculator that auto-calculates ABW when BMI >30. Example Epic SmartPhrase: .HEPARINOBESE. Ensure pharmacy verifies before dispensing.",
      "condition": "",
      "sources": []
    },
    {
      "action": "Implement protocol: For BMI >30, use fixed-dose heparin nomogram (e.g., 5000 units bolus + 1000 units/hr infusion) with aPTT monitoring at 6 hours. Adjust per aPTT response.",
      "success_rate": 0.85,
      "how": "Implement protocol: For BMI >30, use fixed-dose heparin nomogram (e.g., 5000 units bolus + 1000 units/hr infusion) with aPTT monitoring at 6 hours. Adjust per aPTT response.",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [
    "计算调整体重：IBW（男性=50+2.3*(身高英寸-60)；女性=45.5+2.3*(身高英寸-60)）。然后ABW=IBW+0.4*(实际体重-IBW)。使用ABW计算肝素负荷剂量（80单位/公斤）和输注速率（18单位/公斤/小时）。与方案验证。",
    "使用电子病历计算器，当BMI>30时自动计算ABW。例如Epic SmartPhrase：.HEPARINOBESE。确保药房在发放前验证。",
    "实施方案：对于BMI>30，使用固定剂量肝素方案（例如5000单位负荷+1000单位/小时输注），6小时监测aPTT。根据aPTT反应调整。"
  ],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": "https://www.chestnet.org/guidelines/pulmonary-vascular/antithrombotic-therapy",
  "official_doc_section": null,
  "error_code": "ANTICOAG-042",
  "verification_tier": "ai_generated",
  "confidence": 0.86,
  "fix_success_rate": 0.87,
  "resolvable": "true",
  "first_seen": "2024-06-15",
  "last_confirmed": "2024-06-01",
  "last_updated": "2024-06-01",
  "evidence_count": 1,
  "tags": [],
  "locale": "en",
  "aliases": []
}