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 on furosemide has a serum potassium of 3.0 mmol/L (3.0 mEq/L). Which symptoms may this cause?
A ventilated patient with severe ARDS is to be turned prone. What is the main reason, and the key nursing risk?
Which picture fits Brown-Séquard syndrome?
A patient taking an SGLT2 inhibitor is booked for major surgery. Which statement is correct?
After a percutaneous liver biopsy, how is the patient usually positioned at first?
Shortly after a spinal anaesthetic, a patient says their arms feel weak and it is hard to breathe, and the BP is falling. What is most likely?
过敏性休克的一线药物治疗是什么?
A patient with back pain develops numbness around the anus and genitals and new difficulty passing urine. Which condition should be suspected?
一名因房颤服用华法林的患者 INR 为 1.4。这意味着什么?
A patient with chronic kidney disease stage 4 has a high phosphate, a low-normal calcium and a very high parathyroid hormone (PTH). What does this show?
练习数值:Na⁺ 128 mmol/L,葡萄糖 14.5 mmol/L,尿素 9.4 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。
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。
这条 II 导联心电图显示房室传导阻滞,所以心房和心室以不同的频率搏动。测量 P–P 间期,求出心房率(单位:次/分,1500 法,取整数)。
When making patient assignments, what should the charge nurse consider first?
A chemical cleaning fluid splashes into a patient’s eye. What should the nurse do first?
答案: A · Muscle weakness, cramps and an irregular pulse
The adult reference range is about 3.5–5.0 mmol/L, so 3.0 mmol/L is low. Hypokalaemia causes weakness, cramps, constipation and arrhythmias, with flattened T waves and U waves on the ECG. Tingling lips and hand spasm suggest low calcium.
答案: D · It improves oxygenation; risks are pressure injury and tube displacement
Prone positioning improves ventilation–perfusion matching and oxygenation and improves survival in severe ARDS. Turning needs a trained team. Risks include accidental extubation or line removal and pressure damage to the face, chest and knees, so careful positioning and skin checks are essential.
答案: B · Weakness on the same side and loss of pain on the opposite side
Damage to one side of the spinal cord, often from a stab wound, causes motor loss and loss of proprioception on the same side, and loss of pain and temperature on the opposite side. The pain fibres cross soon after entering the cord.
答案: C · It is usually paused in the days before surgery
Fasting, surgery and dehydration increase the risk of euglycaemic DKA with SGLT2 inhibitors. Guidance usually advises stopping them in the days before major surgery and restarting when the patient is eating and drinking normally.
答案: C · On the right side, to press on the puncture site
Lying on the right side presses the liver capsule against the chest wall and helps stop bleeding. The nurse monitors pulse and BP closely for haemorrhage, which is the main risk.
答案: A · A high spinal block
If local anaesthetic spreads upwards, it can affect the arms, breathing muscles and cardiac nerves, causing hypotension and bradycardia. It is an emergency; help is called, and breathing and circulation are supported.
答案: B · 肌内注射肾上腺素
肌注肾上腺素于大腿(成人通常为 0.5 mg,即 1 mg/mL 溶液 0.5 mL;美国指南为 0.3–0.5 mg)是一线治疗,必要时 5 分钟后重复。抗组胺药和激素不是一线治疗。
答案: D · Cauda equina syndrome
Saddle anaesthesia, bladder or bowel dysfunction and leg symptoms with back pain suggest cauda equina syndrome. It needs an emergency MRI and surgical review to prevent permanent loss of function.
答案: D · 抗凝不足,更容易发生血栓和卒中
INR 低于目标范围意味着对于这一适应证来说血液凝固过于容易。应通知开医嘱者,并复核剂量和可能的原因,如漏服或药物相互作用。
答案: D · Secondary hyperparathyroidism from CKD
In CKD, phosphate retention and reduced activation of vitamin D lower calcium, which stimulates the parathyroid glands. The result is high PTH with high phosphate, causing bone disease. Phosphate binders, diet and active vitamin D are used.
答案: Osm = 280 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: 停顿 = 1.52 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: 心房率 = 83 bpm
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。
二度 II 型:每 2 个 QRS 波群对应 3 个 P 波,PR 恒定。
答案: B · Matching each patient’s needs to staff competence
Assignments are based mainly on patient acuity and needs and on each staff member’s skills and scope. Geography and continuity of care help, but they come after safety.
答案: D · Flush the eye with plenty of water or saline straight away
Chemical eye injuries are treated by immediate, continuous irrigation with large amounts of water or saline. Delay, rubbing or a patch allows more damage.
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