{
  "id": "medical/incorrect-use-of-iv-heparin-nomogram-in-obese-patient",
  "signature": "AI applies a standard weight-based heparin nomogram without adjusting for obesity, leading to supratherapeutic aPTT and increased bleeding risk",
  "signature_zh": "AI在肥胖患者中应用标准体重肝素列线图而未进行调整，导致aPTT过高和出血风险增加",
  "regex": "(?i)(heparin|UFH).*(obese|obesity|BMI|weight-based|nomogram).*(overdose|supratherapeutic|bleeding|aPTT)",
  "domain": "medical",
  "category": "protocol_error",
  "subcategory": null,
  "root_cause": "Standard heparin nomograms use actual body weight for dosing, but in obese patients (BMI > 30), the volume of distribution for heparin is not linearly proportional to weight, and using actual weight can lead to overdosing; many nomograms recommend using adjusted body weight or a fixed maximum dose.",
  "root_cause_type": "generic",
  "root_cause_zh": "标准肝素列线图使用实际体重给药，但在肥胖患者（BMI > 30）中，肝素的分布容积与体重不成线性比例，使用实际体重可能导致过量给药；许多列线图建议使用调整体重或固定最大剂量。",
  "versions": [
    {
      "version": "CHEST Guidelines for Antithrombotic Therapy 2023",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "ACCP Heparin Dosing Nomograms 2022",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "Ideal body weight can underdose heparin, leading to subtherapeutic aPTT and increased risk of thrombosis.",
      "fail_rate": 0.7,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Heparin clearance is not linearly proportional to weight in obesity; doses >20,000 units/day can accumulate and cause bleeding.",
      "fail_rate": 0.8,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "This reactive approach delays correction and increases the risk of bleeding before the first aPTT is checked.",
      "fail_rate": 0.6,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "Use an obesity-adjusted dosing nomogram that calculates initial bolus and infusion rate using adjusted body weight (ABW = IBW + 0.4 × (actual weight - IBW)) for patients with BMI > 30.",
      "success_rate": 0.9,
      "how": "Use an obesity-adjusted dosing nomogram that calculates initial bolus and infusion rate using adjusted body weight (ABW = IBW + 0.4 × (actual weight - IBW)) for patients with BMI > 30.",
      "condition": "",
      "sources": []
    },
    {
      "action": "Implement a maximum initial infusion rate of 18 units/kg/hour based on actual body weight, with a hard cap of 2000 units/hour for patients >110 kg, as recommended by some institutional protocols.",
      "success_rate": 0.85,
      "how": "Implement a maximum initial infusion rate of 18 units/kg/hour based on actual body weight, with a hard cap of 2000 units/hour for patients >110 kg, as recommended by some institutional protocols.",
      "condition": "",
      "sources": []
    },
    {
      "action": "Require a pharmacist review of the heparin order for any patient with BMI > 35 before administration, using a clinical decision support alert.",
      "success_rate": 0.88,
      "how": "Require a pharmacist review of the heparin order for any patient with BMI > 35 before administration, using a clinical decision support alert.",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [
    "Use an obesity-adjusted dosing nomogram that calculates initial bolus and infusion rate using adjusted body weight (ABW = IBW + 0.4 × (actual weight - IBW)) for patients with BMI > 30.",
    "Implement a maximum initial infusion rate of 18 units/kg/hour based on actual body weight, with a hard cap of 2000 units/hour for patients >110 kg, as recommended by some institutional protocols.",
    "Require a pharmacist review of the heparin order for any patient with BMI > 35 before administration, using a clinical decision support alert."
  ],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": "https://journal.chestnet.org/article/S0012-3692(23)00657-8/fulltext",
  "official_doc_section": null,
  "error_code": "HEPARIN-OBESITY-DOSING-ERROR",
  "verification_tier": "ai_generated",
  "confidence": 0.84,
  "fix_success_rate": 0.86,
  "resolvable": "true",
  "first_seen": "2025-02-18",
  "last_confirmed": "2024-06-01",
  "last_updated": "2024-06-01",
  "evidence_count": 1,
  "tags": [],
  "locale": "en",
  "aliases": []
}