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 with chest pain has a first troponin result within the normal range one hour after the pain started. Why is a repeat test arranged?
The monitor of a patient with a permanent pacemaker shows pacing spikes, but none of them is followed by a QRS complex. What does this mean?
为什么 CKD 患者常在餐时服用磷结合剂?
A patient who has taken prednisolone daily for years is vomiting and cannot keep tablets down. What should the nurse do?
许多化疗药物给药后,对体液采取特殊预防措施通常要持续多长时间?
A patient with a severe flare of ulcerative colitis develops abdominal distension, fever and tachycardia, and the stool frequency has dropped. What should the nurse suspect?
How is Helicobacter pylori infection usually treated?
A conscious patient with hypoglycaemia was given fast-acting carbohydrate. On re-check 15 minutes later the blood glucose is 3.6 mmol/L (65 mg/dL). What should the nurse do next?
Why is a blood β-hydroxybutyrate level often preferred to a urine ketone dipstick in DKA?
A patient on stable digoxin starts amiodarone. A week later, the patient has nausea and visual changes, and the digoxin level is above the range. What is the most likely explanation?
某练习动脉血气显示 pH 7.10,PaCO₂ 40 mmHg (5.3 kPa),HCO₃⁻ 12 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。
练习数值:Na⁺ 145,Cl⁻ 113,HCO₃⁻ 10 mmol/L。使用 AG = Na⁺ − (Cl⁻ + HCO₃⁻) 计算 Δ 比值 (AG − 12)/(24 − HCO₃⁻)。保留两位小数。
解读这条 II 导联心律条带。这是什么节律?点击你的答案。
这条 II 导联心电图显示心房与心室之间存在传导问题。这是什么节律?点击你的答案。
One hour after a vaginal birth, the nurse finds a soft, boggy uterus and heavy bleeding. What is the first action?
A patient is admitted with inhalational anthrax. Which precautions are needed?
答案: D · Troponin may take a few hours to rise after muscle damage
Troponin starts to rise within hours of myocardial injury, so a very early result can be normal. Protocols use serial measurements at set intervals, with the ECG and clinical picture, to diagnose or exclude MI. A rising pattern supports acute injury.
答案: A · Failure to capture
Failure to capture means the pacing stimulus does not depolarise the myocardium, so no QRS follows the spike. Causes include lead displacement, a raised threshold or battery problems. It can cause bradycardia or asystole, so the patient is assessed and the team informed urgently.
答案: C · 它们结合肾脏无法排泄的食物磷酸盐
在 CKD 中,磷酸盐潴留导致继发性甲状旁腺功能亢进、肾性骨病和血管钙化。随餐服用的磷结合剂在肠道内结合饮食中的磷酸盐。同时还需限制饮食中的磷。
答案: C · Escalate urgently for steroid by injection
Patients on long-term steroids depend on them. If tablets cannot be absorbed, they can develop an adrenal crisis. Parenteral hydrocortisone is needed, following sick-day guidance.
答案: D · 通常约 48 小时
许多细胞毒性药物在给药后的一段时间内会经尿、粪、呕吐物和其他体液排出。当地规定通常要求处理体液时戴手套和穿隔离衣约 48 小时,某些药物需要更长时间。
答案: C · Toxic megacolon
Toxic megacolon is dilatation of the inflamed colon with systemic toxicity and a high risk of perforation. Antimotility drugs and opioids are avoided, an abdominal X-ray is done and the surgical team is involved.
答案: A · A combination of antibiotics with a proton pump inhibitor
Eradication therapy combines a PPI with two antibiotics for a set course. Completing the course is important for success.
答案: A · Give another dose of fast-acting carbohydrate and recheck
If blood glucose remains below the threshold (4 mmol/L in UK guidance, 70 mg/dL in US guidance), the fast-acting treatment is repeated. Once it is above the threshold, a longer-acting carbohydrate such as a sandwich or the next meal helps prevent recurrence.
答案: D · 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 · Amiodarone has raised the digoxin level
Amiodarone reduces digoxin clearance, so the level can rise significantly, and the digoxin dose is often reduced when amiodarone is started. Nausea and visual changes are classic signs of digoxin toxicity.
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。
临床上还应检查预期代偿:按温特公式,预期 PaCO₂ 为 24–28 mmHg,所以实测 40 mmHg 提示合并呼吸性酸中毒(混合性紊乱)。上面的答案是按 ROME 法的考试分类。
答案: Δ 比值 = 0.7143
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。
低于 1:合并正常阴离子间隙酸中毒。
答案: 室上性心动过速(SVT)
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。 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)。
答案: 二度 I 型房室传导阻滞(文氏现象)
房室传导阻滞:逐个标出 P 波,检查哪些 P 波后面跟着 QRS。一度:每个 P 波都下传,PR 恒定且大于 0.20 s。二度 I 型(Mobitz I,文氏现象):PR 逐搏延长,直到一个 P 波未下传,然后周期重新开始(成组搏动)。二度 II 型(Mobitz II):下传搏动的 PR 保持恒定,P 波突然不下传;QRS 常增宽。三度(完全性)阻滞:P 波和 QRS 波群各自规则但互相独立,PR 随机变化,心房率快于逸搏率(交界性逸搏 40–60 次/分,QRS 窄;室性逸搏 20–40 次/分,QRS 宽)。2:1 阻滞仅凭一份条带无法判断是 I 型还是 II 型。
答案: B · Massage the fundus
Uterine atony is the most common cause of postpartum hemorrhage. Fundal massage helps the uterus contract; the nurse then calls for help and gives prescribed uterotonics if bleeding continues.
答案: D · Standard precautions, because it does not usually spread from person to person
Inhalational anthrax is not spread from person to person, so standard precautions are used. Contact precautions may be added for skin (cutaneous) anthrax with draining lesions.
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