一位頭部外傷病人的顱內壓（ICP）為 18 mmHg，平均動脈壓（MAP）為 70 mmHg。護理師對此結果的最佳解釋為何？
A client with a head injury has an intracranial pressure (ICP) of 18 mmHg and a mean arterial pressure (MAP) of 70 mmHg. Which is the best interpretation of these findings?
- AThe client is at risk for cerebral ischemia病人有腦缺血的風險正確答案
- BThe intracranial pressure is critically low顱內壓顯著偏低
- CThe cerebral perfusion pressure is within normal limits腦灌流壓在正常範圍內
- DThe findings are expected for a client with a head injury這些發現符合頭部外傷病人的預期狀況
- A病人有腦缺血的風險
這題需要計算腦灌流壓（CPP）並評估其臨床意義。CPP = MAP - ICP。在此案例中，CPP = 70 - 18 = 52 mmHg。正常 CPP 的範圍是 60 至 100 mmHg。當 CPP 低於 60 mmHg 時，大腦血流量會顯著減少，導致腦缺血（Cerebral Ischemia）和進一步的腦損傷。雖然 ICP 18 mmHg 僅輕微高於正常上限（10-15 mmHg），但因為病人的 MAP 較低（70 mmHg），導致計算出來的灌流壓不足。護理師必須理解，單看 ICP 或 MAP 都不夠全面，必須結合兩者評估腦部的血液供應風險。因此，解釋為缺血風險（A）是最精確的。這屬於 Reduction of Risk Potential 中監測與解釋複雜診斷數據的能力。
- A · 正確答案病人有腦缺血的風險
當 CPP 低於 60 mmHg，腦組織會因為血流不足而缺氧，增加腦缺血風險，這是此數據呈現出的核心威脅。
- B顱內壓顯著偏低
顱內壓（ICP）正常值約為 5-15 mmHg。18 mmHg 屬於輕微升高而非過低，選項與數值解釋完全相反。
- C腦灌流壓在正常範圍內
正常的腦灌流壓（CPP）應維持在 60-100 mmHg。此病人 CPP 僅 52 mmHg，不足以維持腦部灌流，並非在正常範圍內。
- D這些發現符合頭部外傷病人的預期狀況
雖然頭部外傷常伴隨 ICP 升高，但 CPP 過低是必須立即處理的異常狀態，不能僅視為「預期中」而不採取行動。
美國 NCLEX 非常強調 CPP = MAP - ICP 的公式計算與臨床應用；台灣護理養成中雖有提及，但在臨床上護理師較少獨立計算 CPP 並據此調整照護，通常由醫師在 ICU 設置目標值。
English explanation
This question requires calculation of cerebral perfusion pressure (CPP) and assessment of its clinical significance. CPP = MAP - ICP. In this case, CPP = 70 - 18 = 52 mmHg. The normal range for CPP is 60 to 100 mmHg. When CPP falls below 60 mmHg, cerebral blood flow decreases significantly, leading to cerebral ischemia and further brain injury. Although the ICP of 18 mmHg is only mildly above the normal upper limit (10-15 mmHg), because the patient's MAP is low (70 mmHg), the resulting perfusion pressure is inadequate. The nurse must understand that evaluating ICP or MAP in isolation is not sufficient; both must be combined to assess the risk to cerebral blood supply. Therefore, interpreting the findings as risk for ischemia (A) is the most accurate option. This falls under the Reduction of Risk Potential domain, requiring the ability to monitor and interpret complex diagnostic data.
最近修訂：2026-10-05