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。
How should a patient breathe in when using a dry powder inhaler?
Which method best confirms that an endotracheal tube is in the trachea?
A nurse is teaching a patient going home after a mild concussion. Which statement shows a need for further teaching?
At bedtime, a patient was given their rapid-acting insulin by mistake instead of their long-acting insulin. What should the nurse do?
Aspirate from a nasogastric tube has a pH of 7. What should the nurse do?
Two days after a PEG insertion, a patient reports pain on feeding, and feed is leaking around the site. What should the nurse do?
Which of these is a non-drug measure that can help relieve pain?
An older patient's blood pressure is 142/80 mmHg lying and 116/72 mmHg after standing for three minutes, and they feel dizzy. What does this show?
A patient with hyperkalemia is prescribed an oral potassium binder such as patiromer or sodium zirconium cyclosilicate. How does this drug lower potassium?
A patient on digoxin has a calcium of 12.1 mg/dL (3.0 mmol/L) and new nausea and a slow pulse. Why is the calcium result important?
练习数值:Na⁺ 151 mmol/L,葡萄糖 27.2 mmol/L,尿素 9.7 mmol/L。计算血清渗透压 Osm = 2·Na⁺ + 葡萄糖 + 尿素,取最接近的整数。
某练习血气显示呼吸性酸中毒:pH 7.23,PaCO₂ 81 mmHg (10.8 kPa),HCO₃⁻ 33 mmol/L。利用规则“HCO₃⁻ 每 10 mmHg 升高 1 mmol/L(急性)或 3.5 mmol/L(慢性)”进行分类。点选你的答案。
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。
请解读这条 II 导联心电图条带。仅凭这一条心电图条带,你能为哪种解读辩护?点击你的答案。
A nurse sees a nursing assistant leave a confused patient’s bed in the highest position after care. What should the nurse do?
A day after a femur fracture, a young patient becomes confused and breathless, with small red spots on the chest. What should the nurse suspect?
答案: B · Quickly and deeply, after breathing out away from the device
Dry powder inhalers have no propellant, so a fast, deep inhalation is needed to disperse the powder. The patient breathes out away from the device first, because moist breath can clump the powder. Very weak or breathless patients may not manage this.
答案: A · A sustained waveform on capnography
A sustained exhaled carbon dioxide waveform confirms tracheal placement. Misting and chest movement can be misleading, and skin colour changes late. A chest X-ray shows the depth of the tube but does not prove it is in the trachea.
答案: D · "A few drinks tonight will help me relax and sleep."
After a head injury, alcohol and sedatives should be avoided because they can mask drowsiness and confusion. A responsible adult should stay with the patient, and worsening headache, repeated vomiting, confusion or drowsiness mean they must return.
答案: D · Tell the prescriber and check glucose often overnight
Rapid-acting insulin without a meal can cause hypoglycaemia. The nurse informs the prescriber, monitors glucose closely, offers carbohydrate, follows advice about the missed basal dose and reports the incident.
答案: B · Do not use it; re-test later or arrange an X-ray as per policy
A pH above 5.5 may mean the tube is in the lung or oesophagus, or the stomach acid is reduced by drugs or feed. Nothing is given until position is confirmed according to local policy.
答案: C · Stop the feed at once and seek urgent medical advice
Pain on feeding, external leakage or new bleeding soon after PEG insertion may mean feed is leaking into the peritoneum. Feeding and medicines are stopped immediately and senior review is arranged to exclude peritonitis.
答案: D · Repositioning and distraction
Positioning, heat or cold where safe, relaxation, distraction and explanation can all reduce pain alongside analgesics.
答案: B · Postural hypotension
A fall in systolic pressure of 20 mmHg or more (here 26 mmHg) on standing, especially with symptoms, indicates postural hypotension. Causes include medicines, dehydration and autonomic problems.
答案: D · It binds potassium in the gut so it leaves in the stool
Potassium binders exchange potassium in the gut for another ion, so potassium is removed from the body in the stool. They act over hours, so they are not used alone for emergencies; calcium protects the heart, and insulin with glucose shifts potassium into cells quickly.核对依据: High potassium level · MedlinePlus (NIH) (2025)
答案: B · High calcium increases the risk of digoxin toxicity
Hypercalcemia, like hypokalemia and hypomagnesemia, makes the heart more sensitive to digoxin and raises the risk of toxic arrhythmias. Nausea and bradycardia suggest toxicity, so the nurse holds the dose and reports the findings.
答案: Osm = 339 mOsm/kg
衍生数值:计算所得的血清渗透压为 2·Na⁺ + 葡萄糖 + 尿素,各值均以 mmol/L 计(葡萄糖和 BUN 以 mg/dL 计时为 2·Na⁺ + 葡萄糖/18 + BUN/2.8);正常约为 275–295 mOsm/kg。P/F 比值是 PaO₂ 除以以小数表示的 FiO₂。海平面的肺泡氧分压为 PAO₂ = FiO₂·(760 − 47) − PaCO₂/0.8 mmHg,A–a 梯度为 PAO₂ − PaO₂。
答案: 慢性基础上的急性
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 = 0.465 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。(465 ms)
答案: 2:1 房室传导阻滞(类型未定)
2:1 房室传导阻滞:每个 QRS 对应两个 P 波时,没有两个下传的 P 波连续出现,所以无法看出在未下传的 P 波之前,PR 间期是逐渐延长(I 型)还是保持恒定(II 型)。仅凭一条心电图条带,只能称为 2:1 房室传导阻滞;更长的条带或传导比例的改变才能决定类型。QRS 较窄时更可能是 I 型,QRS 增宽时更可能是 II 型,但两者都不能证明。
QRS 较窄时更可能是 I 型,QRS 增宽时更可能是 II 型,但只有更长的条带或传导比例的改变才能决定。
答案: A · Lower the bed now and remind the assistant why it matters
A high bed increases the risk of a serious fall, so the nurse corrects it at once and gives brief, clear feedback. Leaving it or delaying feedback leaves the patient at risk.
答案: B · Fat embolism syndrome
Fat embolism syndrome usually appears 24–72 hours after a long bone fracture, with breathing problems, confusion and a petechial rash. It needs oxygen and urgent escalation.
ExamProblems · examproblems.com/courses/medical-surgical-nursing