2021-CH-3cf8f2529acc5a86

Which description about pulmonary embolism is wrong?

• A. Pulmonary embolism (PE) is stratified into massive, submassive, and low risk based on the presence of hypotension, right ventricular dysfunction or dilation, or the absence of these, respectively; this stratification is based on increasing mortality risk. ✓
• B. Certain imaging features (eg, right ventricle/left ventricle ratio, septal bowing) at CT angiography and echocardiography are associated with worse 30-day outcomes.
• C. In patients with massive PE, more aggressive treatment including systemic thrombolysis, catheter-directed therapy, and/or surgical embolectomy is warranted to rapidly restore pulmonary blood flow and prevent death.
• D. Oxygen saturation of less than 90% is associated with a greater 30-day mortality risk.

本題為 NEGATIVE 題，測驗急性肺栓塞（Acute Pulmonary Embolism, PE）的風險分級（risk stratification）與對應的臨床及影像特徵。考生最容易忽略選項中關於風險排序的文字細節。Massive、submassive 到 low-risk PE 的順序代表的是死亡風險遞減，而非遞增。

官方正解為 A。因為本題是選出錯誤的敘述（NEGATIVE 題）。選項 A 的前半部對於分級條件的描述是正確的（Massive PE 表現為低血壓；Submassive PE 為血壓正常但有 RV dysfunction/dilation；Low-risk 兩者皆無）。但選項最後提到「this stratification is based on increasing mortality risk」是錯誤的。從 massive、submassive 到 low risk，其死亡率風險是從高到低，因此應該是「decreasing mortality risk」（死亡風險遞減），故選項 A 為錯誤敘述。

區分 Massive 與 Submassive PE 的最關鍵臨床指標是「血壓」。若患者有低血壓（hypotension, SBP < 90 mmHg）即為 Massive PE；若血壓正常，但影像上有 RV strain（如 RV/LV ratio > 1 或 septal bowing），則為 Submassive PE。常混淆的點是誤以為單憑影像上嚴重的血管阻塞（如 saddle embolus）或嚴重的 RV strain 就能稱作 massive PE，但實際上 massive PE 的定義嚴格依賴於 hemodynamics（血流動力學）。

[REF-SUPPORTED] 題目選項的文字幾乎直接節錄自 Radiology 2017 年的文獻《Stratification, Imaging, and Management of Acute Massive and Submassive Pulmonary Embolism》。該文獻明確指出這三類分級是基於「decreasing mortality risk」。[STANDARD TEACHING] 這些分級標準與處置原則也完全符合現行臨床 PE 治療指引與放射科教學標準。

• Stratification, Imaging, and Management of Acute Massive and Submassive Pulmonary Embolism [review article]
• 2019 ESC Guidelines for the diagnosis and management of acute pulmonary embolism [society guideline PDF]
• Guidelines on the diagnosis and management of acute pulmonary embolism [guideline]
• Prognostic Role of Echocardiography Among Patients With Acute Pulmonary Embolism and a Systolic Arterial Pressure of 90 mm Hg or Higher [cohort study]
• Simplification of the pulmonary embolism severity index for prognostication in patients with acute symptomatic pulmonary embolism [prognostic study]
• Importance of computed tomography pulmonary angiography for predict 30-day mortality in acute pulmonary embolism patients [cohort study]
• 📝 The official answer A is supported under the 2017 source-era classification because the listed order massive -> submassive -> low risk corresponds to decreasing, not increasing, mortality risk.
• 📝 Current ESC guidance uses a newer risk scheme and explicitly stratifies PE by estimated risk of early death rather than relying on massive/submassive terminology as the preferred formal framework.
• 📝 RV hypokinesis on echocardiography, increased RV/LV ratio on CT, and septal deviation/bowing are all associated with adverse or worse short-term outcomes, supporting option B.
• 📝 Arterial oxyhemoglobin saturation below 90% is incorporated into PESI/sPESI-based prognostic assessment and is associated with higher 30-day mortality risk, supporting option D.
• 📝 For high-risk PE, systemic thrombolysis is the recommended reperfusion therapy; surgical embolectomy or catheter-directed treatment are mainly alternatives when thrombolysis is contraindicated or has failed.

修訂指示：In `/solver_output/options_review/2/explanation`, `/solver_output/knowledge_connections`, and `/solver_output/reference_alignment`, replace the unqualified current-guideline wording with versioned wording that anchors the item to the 2017/AHA-style massive-submassive-low-risk framework, and clarify that in high-risk/massive PE systemic thrombolysis is the standard first-line reperfusion therapy while catheter-directed therapy or surgical embolectomy are alternatives when thrombolysis is contraindicated or has failed.

審核摘要：No question flaw or unresolved source conflict was found. Human review is only needed if the item bank requires all PE teaching language to be normalized to current ESC terminology rather than preserving legacy source-era nomenclature.

驗證建議：Re-check PMID 28628412 for the source-faithful wording of the item, then verify the wording update against the 2019 ESC acute PE guideline for current risk nomenclature and acute-phase treatment recommendations, especially the placement of systemic thrombolysis versus catheter/surgical reperfusion.

QA 信心：91% HIGH

• ✅ Logic direction and stem interpretation：The draft correctly recognizes this as a NEGATIVE stem and audits for the wrong statement rather than the true statement. It also identifies that the error in option A is the mortality-risk direction attached to the listed order.
• ✅ Correct answer validity and mechanistic explanation：Option A is the keyed wrong answer under the source-era massive/submassive/low-risk framework: the listed sequence runs from higher to lower early mortality risk, not lower to higher. The explanation of hypotension/RV dysfunction as the basis of the older classification is broadly correct.
• ✅ Complete and specific option-by-option coverage：All four options are reviewed individually, each is labeled correctly, and the explanations are specific enough to distinguish why A is false while B-D are acceptable.
• ✅ Cross-option consistency and absence of internal contradiction：The draft is internally consistent: A is the only rejected option, B and D are presented as prognostic markers, and C is treated as a management statement for hemodynamically unstable PE without contradicting the overall answer.
• ✅ Feature weighting and whether the decisive feature is presented correctly：The decisive feature is the wording switch from decreasing to increasing mortality risk in option A. The draft emphasizes that exact feature rather than being distracted by otherwise correct classification criteria.
• ⚠️ Unsafe heuristics or over-generalized rules：Two teaching shortcuts are too broad for board-style memorization: the knowledge summary presents the older massive/submassive rule as if it were the complete current standard, and the option C explanation risks implying that systemic thrombolysis, catheter-directed therapy, and surgical embolectomy are co-equal default first-line choices for all massive PE.
• ❌ Reference alignment and guideline / version correctness：The `reference_alignment` field over-claims by saying the scheme and management are fully aligned with current guidelines. Current ESC guidance published in 2019 uses high-, intermediate-high, intermediate-low, and low-risk terminology and does not treat massive/submassive as the preferred formal classification; it also places systemic thrombolysis as recommended first-line reperfusion for high-risk PE, with surgical or catheter-directed therapy mainly when thrombolysis is contraindicated or has failed.
• ✅ Anki fidelity, compression quality, and structural completeness：`anki_summary.front` exactly matches the stem, `anki_summary.answer` exists and matches official answer A plus the core explanation, and the card remains concise without dropping the decisive concept.