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 choosing between a mechanical and a biological heart valve asks about the main difference. Which answer is accurate?
A nurse has four cardiac patients. Which one should be seen first?
A patient has just started haemodialysis. What usually happens to their protein needs?
The nurse has four patients with diabetes. Which one needs to be seen first?
A patient takes co-codamol at home (a combination tablet sold under different names in different countries). Why should the nurse check this before giving regular paracetamol (acetaminophen)?
A nurse teaches a patient after a colonoscopy with polyp removal. Which statement shows a need for further teaching?
一名患者有绞痛样腹痛、腹胀、呕吐,两天未排便排气。可能的问题是什么?
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?
When do the blood counts usually reach their lowest point (nadir) after many standard chemotherapy regimens?
Ten days after chemotherapy, a patient has a platelet count of 9 × 10³/µL and reports a sudden severe headache and blurred vision. What is the priority?
某练习动脉血气显示 pH 7.32,PaCO₂ 38 mmHg (5.1 kPa),HCO₃⁻ 19 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。
某练习血气显示呼吸性酸中毒:pH 7.19,PaCO₂ 74 mmHg (9.9 kPa),HCO₃⁻ 27 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 导联心电图显示心房扑动。测量扑动波间期,求出心房率(单位:次/分)。
这位患者装有起搏器。请解读这条 II 导联心电图条带。点击你的答案。
A patient with diabetes is unresponsive and has a blood glucose of 40 mg/dL (2.2 mmol/L). What should the nurse do first?
Using ESI, a stable adult with abdominal pain will need blood tests and a CT scan, but has a heart rate of 130/min. Which statement is correct?
答案: B · Mechanical valves last longer but need lifelong anticoagulation
Mechanical valves are very durable but are thrombogenic, so lifelong warfarin is needed. Biological (tissue) valves usually do not need long-term anticoagulation but wear out over time and may need replacement. Age, lifestyle and bleeding risk guide the choice.
答案: D · A patient with angina whose chest pain has not eased with rest and who is sweating
Chest pain that does not settle with rest, especially with sweating, suggests an acute coronary syndrome and needs immediate assessment and a 12-lead ECG. A controlled heart rate in AF, a very small weight change and a question about eating are not urgent.
答案: A · They increase, because dialysis removes amino acids
Before dialysis, a moderate protein intake may be advised. Dialysis removes amino acids and protein, so needs rise, and malnutrition is a common risk. A renal dietitian sets individual targets.
答案: C · A patient with a glucose of 2.8 mmol/L (50 mg/dL) who is sweaty and confused
Hypoglycaemia with confusion can rapidly lead to seizures and loss of consciousness, so it is treated at once. A moderately high glucose without symptoms, diet questions and routine tests can wait.
答案: C · It already contains paracetamol, so overdose could occur
Co-codamol combines codeine and paracetamol. Giving extra paracetamol can exceed the maximum daily dose and cause liver damage, so all sources of paracetamol are counted.
答案: B · "Severe abdominal pain is normal for a week afterwards."
Mild bloating and cramps from the air used are expected. Severe or worsening pain, fever, a distended abdomen or heavy rectal bleeding can mean perforation or haemorrhage and must be reported straight away.
答案: D · 肠梗阻
肠梗阻引起腹胀、绞痛、呕吐和停止排便排气。患者通常需禁食,并留置鼻胃管进行胃减压。
答案: D · 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: A · About 7–14 days after treatment
Chemotherapy damages dividing marrow cells, but mature neutrophils and platelets already in the blood survive for a while, so counts usually fall to a nadir about 7–14 days later, depending on the drug. Infection and bleeding risks are highest then.
答案: B · Assess neurological status and report it at once as possible brain bleeding
Platelet counts usually reach their lowest point (nadir) about 7–14 days after chemotherapy. With a count below 10 × 10³/µL, a sudden severe headache or visual change may signal intracranial bleeding, which is an emergency. The nurse assesses neurological status and reports it immediately.核对依据: Bleeding and Bruising (Thrombocytopenia) and Cancer Treatment · National Cancer Institute (NIH) (2022); Pancytopenia · StatPearls (NCBI Bookshelf) (2023)
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。
答案: 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: 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: 心室起搏心律
起搏心律:起搏器脉冲表现为一条细而垂直的起搏钉样信号。心室钉样信号之后的 QRS 是增宽的(0.12 s 或以上),因为冲动是从导线经心肌传播,而不是经传导系统;右心室起搏时,在 II 导联上通常以负向为主。P 波之前的钉样信号表示心房起搏;双腔(房室)起搏器则表现为心房钉样信号加 P 波,再经过程控的房室延迟,出现心室钉样信号和增宽的 QRS。夺获是指每个钉样信号之后都跟着一次除极。夺获失败是指钉样信号之后没有 P 波或 QRS;感知不良(钉样信号无视患者自己的心搏)和起搏不良(该出现钉样信号时没有)是另外两种典型的故障。
起搏产生的 QRS 本来就是增宽的;不要称它为束支传导阻滞或室性心律。
答案: D · Give IV dextrose or glucagon as prescribed
An unconscious patient must not be given anything by mouth because of aspiration risk. IV dextrose or glucagon raises the glucose quickly.
答案: A · The nurse should consider level 2 because of the danger-zone vital sign
In ESI, a patient who needs two or more resources is level 3, but danger-zone vital signs such as a very fast heart rate should make the nurse consider level 2.
ExamProblems · examproblems.com/courses/medical-surgical-nursing