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。
Which investigation is usually used to confirm a deep vein thrombosis in the leg?
During CPR on an adult, a nurse notices a colleague compressing at about 140/min and leaning on the chest between compressions. Which correction is most appropriate?
An older patient with a long-term catheter has bacteria in the urine but no symptoms. What is usually appropriate?
A patient with Addison's disease has been vomiting for a day. They are confused, with BP 78/40 mmHg, sodium 126 mmol/L and potassium 6.0 mmol/L. What is the priority?
How is the height of an epidural sensory block usually checked?
Which medicine commonly needs enteral feeds paused before and after each dose because the feed reduces its absorption?
一名患者新出现意识混乱,呼吸频率 24 次/分,收缩压 95 mmHg。你首先应怀疑什么?
一名头部外伤患者出现血压升高、心率减慢和呼吸不规则。这提示:
为什么肝衰竭患者即使没有服用华法林,INR 也可能升高?
A patient with diabetes and chronic kidney disease had a CT scan with IV contrast. Two days later, the creatinine has risen from 1.4 to 2.0 mg/dL (124 to 177 µmol/L). Which action is most appropriate?
练习数值:Na⁺ 131 mmol/L,葡萄糖 13.6 mmol/L,尿素 7.3 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 7.34,PaCO₂ 62 mmHg (8.3 kPa),HCO₃⁻ 32 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。
这条 II 导联心电图条带显示窦性心律伴一次停顿。测量 停顿,即跨越停顿的 R–R 间期,单位为秒。
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。
Which two patients can most safely share a room?
A patient with Guillain-Barré syndrome has weakness that is spreading up from the legs. Which assessment has the highest priority?
答案: D · Compression duplex ultrasound
Compression ultrasound shows whether a deep vein is compressible and whether flow is normal; a vein containing clot does not compress. A low clinical probability with a negative D-dimer can rule out DVT without imaging.
答案: D · Slow to 100–120/min and allow full chest recoil
High-quality adult CPR uses a rate of 100–120/min, a depth of 5–6 cm, full recoil after each compression and minimal interruptions. Leaning prevents the chest from re-expanding, so the heart fills less. Compressors should swap about every 2 minutes to avoid fatigue.
答案: A · No antibiotics, as long as there are no symptoms
Nearly all long-term catheters become colonised. Treating asymptomatic bacteriuria does not improve outcomes and promotes resistance. Antibiotics are reserved for symptomatic infection.
答案: A · IV hydrocortisone straight away, plus IV fluids
An adrenal crisis is life-threatening. IV or IM hydrocortisone is given immediately, without waiting for tests, together with IV saline and checks of glucose and electrolytes. Vomiting prevents tablets from being absorbed.
答案: D · Testing sensation to cold with ice or a cold spray
The level at which the patient no longer feels cold shows the upper extent of the sensory block. Motor block is assessed with a scale such as Bromage. A rising block or new weakness is reported.
答案: B · Phenytoin
Enteral feeds bind phenytoin and lower its levels, risking seizures. Feeds are usually paused around doses, as advised by the pharmacist, and drug levels are monitored.
答案: C · 脓毒症
这三项体征构成 qSOFA 标准,提示脓毒症预后不良的风险很高。应紧急上报并启动脓毒症处理流程。
答案: A · 颅内压增高(库欣三联征)
库欣三联征(高血压伴脉压增大、心动过缓和呼吸不规则)是颅内压增高的晚期征象,需要紧急处理。
答案: C · 肝脏合成大多数凝血因子,因此合成减少
肝脏合成大多数凝血因子,包括依赖维生素 K 的因子。在严重肝病中,它们的合成减少,因此 INR 升高。INR 升高是反映肝衰竭严重程度的指标之一。核对依据: Prothrombin Time Test and INR (PT/INR) · MedlinePlus (NIH) (2024)
答案: D · Report it, monitor urine output and hold metformin until reviewed
A creatinine rise of 0.3 mg/dL or more within 48 hours meets the criteria for AKI, and contrast is a recognized risk factor, especially in CKD and diabetes. The nurse reports it, monitors fluid balance and holds metformin until kidney function is reviewed, as metformin can accumulate.核对依据: Acute Kidney Injury · StatPearls (NCBI Bookshelf) (2026); Abdominal CT scan · MedlinePlus (NIH) (2024); Acute kidney failure · MedlinePlus (NIH) (2026)
答案: Osm = 283 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
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: 停顿 = 1.92 s
窄 QRS 心动过速与停顿:室上性心动过速(SVT)是规则的心动过速,约 150–250 次/分钟,QRS 波群较窄;P 波通常看不到,因为它们隐藏在 QRS 波群或 T 波中。成人静息时的窦性心动过速通常低于约 150 次/分钟,且每个 QRS 前都有可见的 P 波;伴 2:1 传导的心房扑动常在约 150 次/分钟,并显示锯齿波。窦性停搏是指窦房结暂时停止发放冲动:出现既无 P 波也无 QRS 的停顿,其长度不是 P–P 周期的整数倍(恰好两个或三个周期的停顿则提示窦房传导阻滞)。
停顿中没有出现 P 波,且停顿不是 P–P 周期的整数倍:窦性停搏。恰好两个或三个周期的停顿则提示窦房传导阻滞。
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。
答案: A · Two patients who both have C. difficile infection
Cohorting patients with the same organism is acceptable when single rooms are not available. The other pairs would expose a vulnerable patient to an infection.
答案: B · Breathing strength, such as vital capacity and the ability to cough
Guillain-Barré syndrome causes ascending weakness that can involve the respiratory muscles. Falling vital capacity or a weak cough can mean the patient needs ventilation, so breathing is monitored closely.
ExamProblems · examproblems.com/courses/medical-surgical-nursing