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 patient stops ramipril because of a troublesome dry cough. Which drug class is a common alternative?
Four surgical patients need VTE prevention. For which patient is mechanical prophylaxis alone most appropriate?
Why is pyridostigmine often taken about 30–60 minutes before meals by patients with myasthenia gravis?
A patient who has taken prednisolone daily for years is vomiting and cannot keep tablets down. What should the nurse do?
Which description fits a category (stage) 4 pressure ulcer?
A patient arrives in recovery with a temperature of 35.2 °C and is shivering. What is the most appropriate action?
A patient with COPD and known carbon dioxide retention needs a nebulised bronchodilator. How should it usually be given?
A patient starting a DOAC is taught about missed doses. Which statement shows a need for further teaching?
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?
一名患者的万古霉素谷浓度为 28 mcg/mL;开医嘱者设定的目标为 15–20 mcg/mL。下一次给药时间到了。最好的措施是什么?
某练习动脉血气显示 pH 7.22,PaCO₂ 40 mmHg (5.3 kPa),HCO₃⁻ 16 mmol/L。原发性紊乱是代谢性酸中毒。代偿到什么程度?点选你的答案。
某练习血气显示代谢性碱中毒,HCO₃⁻ 46 mmol/L。用预期 PaCO₂ = 0.7·HCO₃⁻ + 21 求预期PaCO₂。
在这条规则的 II 导联心电图上测量 QT 间期和 R–R 间期,然后用 Bazett 公式 QTc = QT/√RR(均以秒计)计算经心率校正的QTc。答案以秒表示,保留三位小数。
依次按五个步骤解读这条 II 导联心电图:心率、节律、P 波、PR 间期、QRS 时限。你在哪一步发现第一个异常?点击它。
An older patient becomes confused over a few hours, with attention that comes and goes. What does this suggest?
A patient with untreated hyperthyroidism has surgery and develops a temperature of 40 °C, a heart rate of 160/min and severe agitation. What is most likely happening?
答案: A · An angiotensin II receptor blocker such as losartan
Angiotensin receptor blockers (ending in -sartan) block the effects of angiotensin II without inhibiting ACE, so bradykinin does not build up and cough is much less common. They share other effects, such as raising potassium, and ACE inhibitors and ARBs are not normally combined.
答案: C · A patient who had a brain haemorrhage two days ago
When bleeding risk is high, such as after recent intracranial haemorrhage, mechanical methods (intermittent pneumatic compression) are used instead of anticoagulants until it is safe. The other patients are at high VTE risk and would usually receive pharmacological prophylaxis unless contraindicated.
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 · Escalate urgently for steroid by injection
Patients on long-term steroids depend on them. If tablets cannot be absorbed, they can develop an adrenal crisis. Parenteral hydrocortisone is needed, following sick-day guidance.
答案: A · Full-thickness loss with exposed bone, tendon or muscle
Category 4 has full-thickness loss with exposed bone, tendon or muscle and often undermining or tunnelling. Category 3 reaches the fat but does not expose bone, tendon or muscle.
答案: D · Start active warming and monitor the temperature
Hypothermia increases the risk of bleeding, infection and cardiac events, and shivering increases oxygen use. Active warming with warmed fluids if needed is started, and the patient stays in recovery until temperature is acceptable.
答案: B · Driven by compressed air, with oxygen given separately if needed
Nebulisers driven by high-flow oxygen can raise PaCO2 in patients at risk. Air-driven nebulisers are used, with supplementary oxygen via nasal cannulae to keep saturation in the target range.
答案: A · "If I forget a dose, I'll take two the next day to catch up."
Doubling up on an anticoagulant increases the bleeding risk. Patients follow the specific missed-dose advice for their drug and never take a double dose.
答案: A · 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 · 暂停该剂量,通知开医嘱者并检查肾功能
谷浓度高于目标意味着药物在蓄积,这会增加肾损害的风险。护士应暂停该剂量并通知开医嘱者,后者将调整剂量或间隔。同时检查肾功能。
答案: 未代偿
解读血气(ROME):先看 pH:低于 7.35 为酸血症,高于 7.45 为碱血症。然后找出能解释它的指标。PaCO₂(正常 35–45 mmHg,4.7–6.0 kPa)是呼吸方面的指标,在呼吸性紊乱中与 pH 反向(Opposite)变化;HCO₃⁻(正常 22–26 mmol/L)是代谢方面的指标,与 pH 同向变化(Respiratory Opposite, Metabolic Equal,即呼吸性相反,代谢性相同)。另一个指标显示代偿情况:正常表示未代偿;沿着使 pH 回升的方向异常、而 pH 仍然异常,表示部分代偿;pH 正常而两个指标都异常,表示完全代偿。各实验室的范围略有差异;这些是练习用数值。
临床上还应检查预期代偿:按温特公式,预期 PaCO₂ 为 30–34 mmHg,所以实测 40 mmHg 提示合并呼吸性酸中毒(混合性紊乱)。上面的答案是按 ROME 法的考试分类。
答案: PaCO₂ = 53.2 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: QTc = 0.48 s
QT 与 QTc:QT 间期从 QRS 波群起点到 T 波终点。它随心率加快而缩短,因此要用以秒为单位的 R–R 间期按心率校正:Bazett QTc = QT/√RR,Fridericia QTc = QT/∛RR。多数教科书使用 Bazett 公式;它在心率快时校正过度,此时宜用 Fridericia。各参考标准的界限不同:QTc 男性高于约 0.45 s、女性高于约 0.46 s 通常称为延长,高于 0.50 s 称为明显延长。
超过男性(约 0.45 s)和女性(约 0.46 s)的通常上限:延长。(480 ms)
答案: P 波
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。
答案: A · Delirium, which needs the cause found quickly
Delirium starts suddenly, over hours or days, and attention fluctuates. It often has a treatable cause such as infection, hypoxia or medication, so it is a priority to assess.
答案: C · Thyroid storm
Thyroid storm is a life-threatening surge of thyroid hormone, with fever, tachycardia and agitation or confusion. It needs urgent treatment; myxedema coma is the opposite extreme of hypothyroidism.
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