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。
After coronary artery bypass surgery through a median sternotomy, which instruction is usually given for the first several weeks?
A patient with lung cancer develops swelling of the face and arms, distended neck and chest veins and breathlessness that is worse when bending forward. What is the most likely cause?
Before checking a capillary glucose, why should the patient wash their hands with soap and water?
A patient with suspected meningitis has a GCS of 9 and pupils that have become unequal. A doctor plans an immediate lumbar puncture. What is the main concern?
A patient on enteral feeding develops diarrhoea. What should the nurse review first?
A patient with lung cancer becomes hypotensive and breathless, with distended neck veins and quiet heart sounds. What should the nurse suspect?
A patient who injects drugs has a fever, a new heart murmur and small dark lines under the nails. What is the likely diagnosis?
Why should chronic hypernatraemia be corrected gradually?
为什么对血清白蛋白低的患者,必须谨慎解读偏低的总钙?
A patient's bedside glucose meter shows "HI" (above its measuring range). The patient is drowsy. What should the nurse do?
某练习血气显示 PaCO₂ 22 mmHg (2.9 kPa)。利用规则:在慢性呼吸性碱中毒中,PaCO₂ 每比 40 低出 10 mmHg,HCO₃⁻ 下降 5 mmol/L,以HCO₃⁻ 24 mmol/L 为起点,求预期HCO₃⁻。
在海平面,某练习血气取自吸入 21% 氧气时,显示 PaO₂ 65 mmHg (8.7 kPa),PaCO₂ 39 mmHg (5.2 kPa)。用 PAO₂ = FiO₂·(760 − 47) − PaCO₂/0.8 求A–a 梯度。
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)。
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 patient has a nasogastric tube on suction. Which task can the nurse delegate to a nursing assistant?
A patient on airborne precautions for suspected tuberculosis must go to the radiology department. What should the patient wear during transport?
答案: B · Avoid heavy lifting and pushing up with the arms
The sternum is wired and takes weeks to heal. Patients are advised to avoid heavy lifting, pulling and pushing with the arms, and to support the chest with a pillow when coughing. Walking is encouraged as part of cardiac rehabilitation.
答案: B · Superior vena cava obstruction
A tumour in the mediastinum can compress the superior vena cava, causing swelling of the face, neck and arms, dilated veins on the chest and breathlessness. It is an oncological emergency. The patient is sat upright and given oxygen if hypoxic, and treatment may include a stent, steroids or radiotherapy.
答案: C · Sugar on the skin can give a falsely high reading
Traces of sugar on the fingers can falsely raise the reading. Hands are washed and dried before testing. The side of the fingertip is used, and lancets are single use.
答案: A · Raised pressure in the skull, so the procedure could cause herniation
Reduced consciousness and unequal pupils suggest raised ICP. A lumbar puncture in this situation may cause brain herniation, so imaging comes first, and antibiotics are not delayed. The nurse should raise this concern.
答案: A · The medicine chart, including laxatives and antibiotics
Diarrhoea on enteral feeds is often caused by drugs such as antibiotics, laxatives and liquid medicines containing sorbitol, or by infection such as C. difficile. The feed is not stopped automatically; the cause is investigated.
答案: D · Cardiac tamponade from a pericardial effusion
Malignant pericardial effusion can compress the heart, causing hypotension, raised JVP and muffled heart sounds. It is an emergency needing urgent echocardiography and drainage (pericardiocentesis).
答案: C · Infective endocarditis
Infective endocarditis causes fever and a new or changing murmur, sometimes with splinter haemorrhages. Several sets of blood cultures are taken before long-course IV antibiotics.
答案: C · Lowering the sodium too fast can cause cerebral oedema
In chronic hypernatraemia, brain cells adapt by holding extra solutes. If sodium falls too quickly, water moves into brain cells and causes cerebral oedema, so correction is controlled.
答案: D · 许多钙与白蛋白结合,因此即使离子钙正常,总钙也会下降
约 40–45% 的钙与血浆蛋白结合,主要是白蛋白。白蛋白低时,总钙下降,而离子钙可能正常。校正钙或实测离子钙才能反映真实情况。核对依据: Hypocalcemia (StatPearls) · StatPearls (NCBI Bookshelf) (2026)
答案: B · Send a venous sample to the lab and inform the provider at once
"HI" means the glucose exceeds the meter's range, so the true value is unknown and may be very high, as in DKA or HHS. A laboratory sample is sent, the provider is informed promptly, and the patient is assessed for dehydration and ketones.核对依据: Blood Glucose Test · MedlinePlus (NIH) (2024); Diabetic ketoacidosis - Medical Encyclopedia · MedlinePlus (NIH) (2025)
答案: HCO₃⁻ = 15 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: A–a 梯度 = 35.98 mmHg
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: 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: 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 · Giving mouth care
Mouth care is routine and important because the patient cannot eat or drink. Checking position, irrigating the tube and assessing drainage need nursing skills and judgement.
答案: A · A surgical mask
A patient with an airborne infection wears a surgical mask outside the isolation room to contain respiratory particles. Staff caring for the patient wear fit-tested respirators, and the receiving department is told in advance.
ExamProblems · examproblems.com/courses/medical-surgical-nursing