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。
Why must intravenous potassium chloride never be given as a rapid push or undiluted?
一名因心房颤动服用华法林的患者被开具克拉霉素。哪项措施最恰当?
A urine dipstick is positive for nitrites. What does this suggest?
A patient with SIADH needs IV fluid. Which fluid is most likely to worsen the hyponatraemia?
How should pancreatic enzyme replacement capsules usually be taken?
对于循环不良患者足跟上稳定、干燥、完整的黑色焦痂,通常推荐哪种处理?
What is the most common cause of hypernatraemia in frail older inpatients?
After a high spinal cord injury, a patient has low blood pressure with a slow heart rate and warm, dry skin. What is most likely?
Why is a blood β-hydroxybutyrate level often preferred to a urine ketone dipstick in DKA?
The nurse teaches a patient who is starting warfarin. Which statement shows a need for further teaching?
某练习血气显示代谢性酸中毒,HCO₃⁻ 6 mmol/L。用温特公式求预期PaCO₂(范围的中心),单位 mmHg。
某练习血气显示代谢性酸中毒:pH 7.27,PaCO₂ 27 mmHg (3.6 kPa),HCO₃⁻ 12 mmol/L。把实测的PaCO₂与温特公式比较。点选你的解读。
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。
一位处于监护中的患者被发现无反应、呼吸不正常,且摸不到颈动脉搏动。监护仪显示这种有组织的心律。这种情况叫什么?点击你的答案。
Straight after birth, what is the first priority for a healthy-looking newborn?
A nursing assistant has twice not reported abnormal vital signs to the RN. What is the RN’s best action?
答案: B · A sudden high potassium level can cause cardiac arrest
Rapid or concentrated IV potassium can cause cardiac arrest. It is given diluted, by infusion, at controlled rates (often with a pump and ECG monitoring for higher rates). Concentrated ampoules are tightly controlled in hospitals because of fatal errors.
答案: C · 询问是否应提前检查 INR,因为它可能升高
包括克拉霉素等大环内酯类、某些氟喹诺酮类和复方磺胺甲噁唑在内的几种抗生素,可使 INR 升高并增加出血风险。需要更密切地监测 INR,并可能需要调整剂量。未经建议停用或加倍华法林是不安全的。
答案: D · Bacteria that convert nitrate are present
Many urinary pathogens convert dietary nitrate to nitrite, so a positive nitrite test supports a bacterial UTI. A negative result does not rule infection out. Leucocytes on the dipstick show white cells.
答案: D · 5% glucose (dextrose, D5W)
5% glucose (5% dextrose, D5W) provides free water once the glucose is metabolised. In SIADH, this water is kept, so sodium falls further. Hypotonic fluids are avoided. Hypertonic saline is used for severe symptomatic hyponatraemia.
答案: A · With every meal and snack
Pancreatic enzymes digest fat, protein and carbohydrate, so they are taken with meals and snacks. The dose is adjusted to reduce steatorrhoea and support weight gain.
答案: C · 保持完整,足跟减压并转诊评估
缺血足跟上稳定、干燥的焦痂起着生物屏障的作用,通常不应清创。应给足跟减压并评估循环。如果它变软、松软、发红或渗液,应怀疑感染并寻求专科评估。
答案: D · Not drinking enough water
Hypernatraemia usually reflects water deficit, often in patients who are confused, unable to drink independently or losing fluid through fever or diarrhoea. Supporting fluid intake prevents it.
答案: A · Neurogenic shock
Neurogenic shock from cervical or high thoracic injury causes vasodilation and bradycardia because sympathetic outflow is lost. Hypovolaemic shock usually causes tachycardia and cool, pale skin.
答案: C · It measures the main ketone in DKA, and the dipstick may miss it
In DKA, β-hydroxybutyrate is the main ketone, but most urine dipsticks detect acetoacetate, so they can underestimate ketosis. Blood β-hydroxybutyrate gives a current value that is also useful to monitor recovery.核对依据: Diabetic ketoacidosis - Medical Encyclopedia · MedlinePlus (NIH) (2025)
答案: A · "If I miss a dose, I will take two tablets the next day"
Doubling a missed warfarin dose can raise the INR and cause bleeding; the patient should follow the prescriber's instructions, usually taking the missed dose the same day or skipping it. A steady vitamin K intake, regular INR checks and telling other providers are correct.核对依据: Warfarin (drug information) · MedlinePlus (NIH) (2026)
答案: PaCO₂ = 17 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。
答案: 适当的代偿
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: QTc = 0.44 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。
在通常上限之内(男性约 0.45 s,女性约 0.46 s)。(440 ms)
答案: 无脉性电活动(PEA)
无脉性电活动(PEA):PEA 无法从心电图条带上看出。监护仪显示有组织的电活动(VF、VT 或心搏停止以外的心律),但患者摸不到脉搏,因此要通过检查患者来识别。在成人复苏指南中,PEA 和心搏停止是不可电击的心脏骤停心律:进行高质量心肺复苏,尽快使用肾上腺素,并寻找可逆原因(5H 和 5T,如低血容量、缺氧、张力性气胸和心脏压塞)。VF 和无脉性 VT 是可电击心律。
PEA 在床旁识别,绝不能仅凭心电图条带。这是考试练习,不是临床指南。
答案: B · Dry and warm the baby while checking that it is breathing
Breathing and keeping warm come first. Drying stimulates breathing and reduces heat loss; skin-to-skin contact helps. Weighing and routine injections can wait.
答案: B · Talk to the assistant privately, restate what must be reported and follow up closely
The RN gives direct, private feedback, restates the reporting limits and increases supervision. If the problem continues, it is escalated to the manager according to policy.
ExamProblems · examproblems.com/courses/medical-surgical-nursing