A Venturi mask entrains a set amount of room air, giving a fixed oxygen percentage regardless of the patient's breathing pattern. This makes it useful for patients at risk of hypercapnia.
答案
C · Venturi mask
4.临床护理
答案: D · Anticoagulant proteins are lost in the urine and clotting factors rise
为什么是这个答案
Loss of proteins such as antithrombin in the urine, together with increased hepatic production of clotting factors, creates a hypercoagulable state. Some patients need anticoagulation.
答案
D · Anticoagulant proteins are lost in the urine and clotting factors rise
节律标准(II 导联):窦性心律每个 QRS 之前都有直立的 P 波,PR 恒定为 0.12–0.20 s,QRS 狭窄:60–100 次/分为正常窦性心律,低于 60 为窦性心动过缓,高于 100 为窦性心动过速。心房颤动:无 P 波,基线呈颤动,R–R 绝对不规则。心房扑动:约 250–350 次/分的锯齿状扑动波,伴固定的传导比例,如 2:1 或 4:1。一度房室传导阻滞:窦性心律,PR 恒定且大于 0.20 s。交界性心律:窄 QRS,40–60 次/分,P 波缺失或倒置(PR 低于 0.12 s,或 P 波在 QRS 之后)。室性早搏(PVC)是提前出现的宽大(0.12 s 或以上)、形态怪异的 QRS,没有 P 波,T 波方向相反,通常有完全性代偿间歇;二联律是指每隔一个搏动就有一个室性早搏。
五个步骤
1. 心率:R–R = 22 个小格,1500 ÷ 22 ≈ 68 次/分。
2. 节律:规则,每个 R–R 均为 0.88 s。
3. P 波:直立,每个 QRS 之前各有一个,形态一致。
4. PR 间期:0.12 s,恒定,在 0.12–0.20 s 范围内。
5. QRS:0.08 s,狭窄(低于 0.12 s)。
解读
正常窦性心律
答案
正常窦性心律
12.心电图节律条带解读
答案: PR 间期
每条心电图的五个步骤:1. 心率(300 法或 1500 法;若不规则则用 6 秒法);2. 节律:R–R 间期是否相等;3. P 波:是否存在、在 II 导联直立、每个 QRS 之前各有一个且形态一致;4. PR 间期:0.12–0.20 s 且恒定;5. QRS 时限:低于 0.12 s。五个步骤做完之后才命名节律。正常窦性心律五项全部符合:60–100 次/分,规则,每个 QRS 之前有直立 P 波,PR 0.12–0.20 s,QRS 低于 0.12 s。
五个步骤
1. 心率:R–R = 18 个小格,1500 ÷ 18 ≈ 83 次/分。
2. 节律:规则,每个 R–R 均为 0.72 s。
3. P 波:直立,每个 QRS 之前各有一个,形态一致。
4. PR 间期:0.28 s,恒定,长于 0.20 s。
5. QRS:0.08 s,狭窄(低于 0.12 s)。
第一个异常的步骤
PR 间期 → 一度房室传导阻滞
答案
PR 间期
13.优先排序与委派
答案: D · Raise the head of the bed, give oxygen and call for urgent help
为什么是这个答案
Sudden breathlessness and chest pain after surgery suggest a pulmonary embolism. The nurse supports breathing with positioning and oxygen and escalates at once; walking or leg massage could make things worse.
答案
D · Raise the head of the bed, give oxygen and call for urgent help
14.优先排序与委派
答案: A · Trachea shifted away from the affected side, with low blood pressure
为什么是这个答案
In tension pneumothorax, trapped air pushes the mediastinum to the other side, reducing venous return and blood pressure. It is life-threatening and needs immediate decompression.
答案
A · Trachea shifted away from the affected side, with low blood pressure
15.感染控制与患者安全
答案: D · The patient may climb over them or get trapped in gaps
为什么是这个答案
Confused patients may climb over rails and fall from a greater height or become trapped between the rail and mattress. Alternatives such as low beds and close observation are often safer.
答案
D · The patient may climb over them or get trapped in gaps
16.感染控制与患者安全
答案: A · Explain the risks, agree on ways to reduce them, respect the decision and document
为什么是这个答案
A competent patient can accept a risk. The nurse explains the danger, offers measures such as a low bed, non-slip footwear, a clear path and a call light, respects the choice and documents the discussion.
答案
A · Explain the risks, agree on ways to reduce them, respect the decision and document
17.实验室检查值与电解质
答案: C · In the afternoon and evening
为什么是这个答案
A morning dose of prednisone raises glucose mainly in the afternoon and evening, with a smaller effect overnight. Glucose monitoring and insulin plans often target these times, and doses are adjusted when the steroid is tapered.核对依据:Blood Glucose Test · MedlinePlus (NIH) (2024)
答案
C · In the afternoon and evening
18.实验室检查值与电解质
答案: C · Lithium 1.8 mEq/L with a new coarse tremor
为什么是这个答案
A lithium level of 1.8 mEq/L with a coarse tremor suggests toxicity, which can progress to confusion and seizures. The digoxin, phenytoin and valproate levels are within commonly cited ranges and the patients are stable.