内外科护理:心血管与呼吸
方法
- 说出问题所在:泵衰竭、动脉阻塞、节律、血栓、气道狭窄、感染或设备问题。
- 先检查危险征象:低氧、低血压、胸痛、新出现的意识模糊、冰冷无脉搏的肢体。
- 让氧疗与患者相匹配:大多数人为 94–98%,有 CO₂ 潴留风险者为 88–92%。
- 把每种药物与其检测和风险联系起来:华法林与 INR,肝素与 aPTT 和血小板,利尿剂与血钾。
- 选择安全的第一步措施,然后升级处理并重新评估。
公式表、每个专题的关键方法步骤和 16 道练习题,完整解答附在最后。
A peripheral cannula site is red, warm, tender and swollen along the vein. What should the nurse do?
A 74-year-old with atrial fibrillation, hypertension and diabetes asks why she needs an anticoagulant when she feels well. Which reply is best?
Why is pyridostigmine often taken about 30–60 minutes before meals by patients with myasthenia gravis?
An 84-year-old man became more confused a week after starting oxybutynin. Infection has been ruled out. What should the nurse suspect?
How can low-dose opioids help a patient with breathlessness from advanced cancer?
A patient with three fractured ribs is taking shallow breaths because of pain. Why is effective analgesia a priority?
Which rule is essential for safe use of patient-controlled analgesia (PCA)?
Why must blood samples for a cross-match be labelled at the bedside immediately after they are taken?
一名意识清醒的患者血糖为 54 mg/dL(3.0 mmol/L),已摄入 15 g 速效碳水化合物。应在何时复测血糖?
A nursing student has a positive interferon-gamma release assay (IGRA) for tuberculosis, no symptoms and a normal chest X-ray. What does this most likely mean?
某练习血气显示 PaCO₂ 55 mmHg (7.3 kPa)。利用规则:在慢性呼吸性酸中毒中,PaCO₂ 每比 40 高出 10 mmHg,HCO₃⁻ 升高 3.5 mmol/L,以HCO₃⁻ 24 mmol/L 为起点,求预期HCO₃⁻。
某练习血气显示代谢性碱中毒,HCO₃⁻ 35 mmol/L。用预期 PaCO₂ = 0.7·HCO₃⁻ + 21 求预期PaCO₂。
这条 II 导联心电图显示心房扑动。测量扑动波间期,求出心房率(单位:次/分)。
这条 II 导联心电图显示房室传导阻滞,所以心房和心室以不同的频率搏动。测量 P–P 间期,求出心房率(单位:次/分,1500 法,取整数)。
An older adult asks for something to help them sleep. Which drug is most likely to cause confusion and falls in this age group?
A patient has peripheral arterial disease with a non-healing ulcer on the toe. Which advice about leg position is correct?
答案: D · Remove the cannula, document and monitor the site
Redness, pain, warmth and swelling along the vein indicate phlebitis. The cannula is removed, the site is observed for infection and the event is documented. Regular visual phlebitis scoring and removing cannulas that are no longer needed reduce the risk.
答案: A · Her risk of stroke is high, and an anticoagulant lowers it
In AF, blood stasis in the left atrium causes clots that can travel to the brain. Scores such as CHA₂DS₂-VASc (age, hypertension, diabetes, female sex and others) estimate stroke risk; her score is high. Anticoagulation reduces stroke risk but does not change the rhythm.
答案: D · To improve the strength of chewing and swallowing at mealtimes
Pyridostigmine inhibits acetylcholinesterase, so more acetylcholine is available at the neuromuscular junction. Timing it before meals gives the best muscle strength for chewing and swallowing, which lowers the risk of aspiration.
答案: A · Anticholinergic side effects of the drug
Anticholinergic drugs such as oxybutynin can cause confusion and worsen cognition in older people. The prescriber should review the medicine and the patient's overall anticholinergic burden.
答案: C · They reduce the feeling of breathlessness
In palliative care, low-dose opioids reduce the sensation of breathlessness and the anxiety it causes. Fans, positioning, relaxation and treating reversible causes are also used.
答案: C · Shallow breathing can lead to atelectasis and pneumonia
Uncontrolled chest wall pain prevents deep breaths and coughing, leading to atelectasis, sputum retention and pneumonia, particularly in older adults. Multimodal analgesia, sometimes with regional blocks, and physiotherapy are used.
答案: C · Only the patient should press the button
If the patient becomes too sedated, they stop pressing the button, which protects them. When others press it, this safety mechanism is lost and overdose can occur.
答案: D · To prevent "wrong blood in tube" errors that can cause fatal reactions
A sample labelled with the wrong patient's details can lead to incompatible blood being issued. Labelling at the bedside after positive identification is a key transfusion safety step.
答案: C · 约 15 分钟后
15 法则是指摄入 15 g 速效碳水化合物,15 分钟后复测,如果血糖仍低于 70 mg/dL(3.9 mmol/L)则重复。然后再吃点心或正餐有助于预防复发。核对依据: Low blood sugar - self-care · MedlinePlus (NIH) (2026)
答案: D · Latent TB infection, which is not contagious
A positive IGRA with no symptoms and a normal chest X-ray indicates latent TB infection, which cannot spread to others. Treatment of latent TB is often offered to prevent later active disease. The IGRA is much less likely than the skin test to give a false-positive result after BCG vaccination.核对依据: Tuberculosis Screening · MedlinePlus (NIH) (2026); PPD skin test · MedlinePlus (NIH) (2025)
答案: HCO₃⁻ = 29.25 mmol/L
预期代偿:代谢性酸中毒时,温特公式预测 PaCO₂ = 1.5·HCO₃⁻ + 8 ± 2 mmHg;实测值高于该范围提示合并呼吸性酸中毒,低于该范围提示合并呼吸性碱中毒。阴离子间隙 AG = Na⁺ − (Cl⁻ + HCO₃⁻),正常约为 8–12 mmol/L,用于区分高阴离子间隙与正常阴离子间隙代谢性酸中毒;低白蛋白会掩盖升高的间隙(白蛋白低于 4.0 的部分,每 g/dL 加 2.5)。Δ 比值 (AG − 12)/(24 − HCO₃⁻) 约在 0.8 到 2 之间符合单纯高间隙酸中毒(有些教材用 1 代替 0.8),低于此范围提示合并正常间隙酸中毒,高于 2 提示合并代谢性碱中毒。
答案: PaCO₂ = 45.5 mmHg
预期代偿:代谢性酸中毒时,温特公式预测 PaCO₂ = 1.5·HCO₃⁻ + 8 ± 2 mmHg;实测值高于该范围提示合并呼吸性酸中毒,低于该范围提示合并呼吸性碱中毒。阴离子间隙 AG = Na⁺ − (Cl⁻ + HCO₃⁻),正常约为 8–12 mmol/L,用于区分高阴离子间隙与正常阴离子间隙代谢性酸中毒;低白蛋白会掩盖升高的间隙(白蛋白低于 4.0 的部分,每 g/dL 加 2.5)。Δ 比值 (AG − 12)/(24 − HCO₃⁻) 约在 0.8 到 2 之间符合单纯高间隙酸中毒(有些教材用 1 代替 0.8),低于此范围提示合并正常间隙酸中毒,高于 2 提示合并代谢性碱中毒。
升高是有限度的:仅靠代偿,PaCO₂ 很少超过约 55 mmHg。
答案: 心房率 = 300 bpm
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。
答案: 心房率 = 100 bpm
房室传导阻滞:逐个标出 P 波,检查哪些 P 波后面跟着 QRS。一度:每个 P 波都下传,PR 恒定且大于 0.20 s。二度 I 型(Mobitz I,文氏现象):PR 逐搏延长,直到一个 P 波未下传,然后周期重新开始(成组搏动)。二度 II 型(Mobitz II):下传搏动的 PR 保持恒定,P 波突然不下传;QRS 常增宽。三度(完全性)阻滞:P 波和 QRS 波群各自规则但互相独立,PR 随机变化,心房率快于逸搏率(交界性逸搏 40–60 次/分,QRS 窄;室性逸搏 20–40 次/分,QRS 宽)。2:1 阻滞仅凭一份条带无法判断是 I 型还是 II 型。
三度阻滞,伴窄 QRS 交界性逸搏(通常为 40–60 次/分)。
答案: A · Diphenhydramine
Diphenhydramine is strongly anticholinergic and can cause confusion, urinary retention and falls in older adults. It is on lists of drugs to avoid in this group.
答案: C · Keep the legs level or slightly lowered, not raised
In arterial disease, gravity helps blood reach the feet, so legs are not elevated. Elevation and compression suit venous disease, and crossing the legs reduces flow further.
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