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 pulse oximeter on a patient's finger gives an unreliable, flickering reading. Which factor is the most likely cause?
After a faulty gas heater was found at home, a patient has headache, nausea and confusion. SpO₂ is 99% on air. What is the priority treatment?
A patient has just started levetiracetam. Which side effect should the nurse teach them to report?
A patient with a cervical spinal cord injury is helped to sit up for the first time. They become dizzy and pale, and the BP falls from 110/70 to 78/46 mmHg. What should the nurse do?
Which finding suggests a deep tissue pressure injury?
A patient with gastric outlet obstruction has vomited repeatedly for several days. Which blood picture is most likely?
一名心力衰竭患者两天内体重增加 2 kg。这最可能说明什么?
A patient with stress incontinence is taught self-care. Which statement shows a need for further teaching?
实验室打电话到病房报告钾的危急值 6.9 mEq/L。护士应怎么做?
A woman with preeclampsia is receiving IV magnesium sulfate. Her urine output has fallen and her creatinine is rising. Why is this a concern?
某练习血气显示代谢性酸中毒,HCO₃⁻ 10 mmol/L。用温特公式求预期PaCO₂(范围的中心),单位 mmHg。
在海平面,某练习血气取自吸入 21% 氧气时,显示 PaO₂ 70 mmHg (9.3 kPa),PaCO₂ 54 mmHg (7.2 kPa)。用 PAO₂ = FiO₂·(760 − 47) − PaCO₂/0.8 求A–a 梯度。
解读这条 II 导联心律条带。这是什么节律?点击你的答案。
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。
在大规模伤亡现场进行 START 分诊时,一名伤员在被要求时能走到指定区域。该伤员被归入哪一类?
A patient is going home on a new oral anticoagulant. There is only a short time for teaching. Which topic is most important?
答案: C · Cold hands with poor peripheral circulation
Poor perfusion (cold, shock, vasoconstriction), movement, dark nail varnish or bright ambient light can make readings unreliable. The nurse checks the waveform, warms the hand or uses an ear probe, and compares the reading with the clinical picture.
答案: C · High-concentration oxygen via a non-rebreather mask
Carbon monoxide binds haemoglobin far more strongly than oxygen, causing tissue hypoxia, while pulse oximetry can look normal. High-concentration oxygen speeds CO removal. Carboxyhaemoglobin is measured on a blood gas, and others in the home may also be at risk.
答案: A · Changes in mood, such as irritability, low mood or anger
Levetiracetam is widely used and has few drug interactions, but it can cause mood changes, irritability, depression and, rarely, suicidal thoughts. Patients and families should report these. Gum overgrowth is linked to phenytoin.
答案: A · Lower the patient back towards lying, then raise them gradually later
Loss of sympathetic tone causes orthostatic hypotension after high spinal injuries. The patient is reclined, and later raised gradually, often with compression stockings, an abdominal binder and sometimes medicines.
答案: A · Intact skin that is purple or maroon over a bony area
A deep tissue injury appears as persistent purple, maroon or dark discolouration, or a blood-filled blister, from pressure and shear on underlying tissue. It may quickly turn into a deep wound.
答案: B · Low chloride, low potassium and metabolic alkalosis
Loss of gastric acid causes a hypochloraemic metabolic alkalosis. Hypokalaemia follows from vomiting and kidney potassium loss as the body tries to save volume. Treatment includes IV saline with potassium.
答案: A · 液体潴留
心衰患者体重骤增通常意味着液体超负荷。每天称重是监测液体平衡最简单的方法。
答案: C · "I'll drink as little as possible so I don't leak."
Restricting fluids concentrates urine, irritates the bladder and risks dehydration and infection. Pelvic floor exercises, weight loss and reducing caffeine are recommended measures.
答案: A · 复述该数值,评估患者并通知医疗人员
复述口头报告的结果可防止差错。危急值应毫不延迟地报告给医疗人员,护士应评估患者,包括心律。可能需要重新采样,但不得延误反应。
答案: B · Magnesium is excreted by the kidneys, so it can build up to toxic levels
Magnesium is cleared by the kidneys, so falling urine output and rising creatinine raise the risk of toxicity. The nurse checks deep tendon reflexes, respiratory rate and level of consciousness, reports the findings and keeps calcium gluconate available as the antidote.核对依据: Magnesium Toxicity (StatPearls) · StatPearls (NCBI Bookshelf) (2026)
答案: PaCO₂ = 23 mmHg
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 = 12.23 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: 一度房室传导阻滞
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: QRS 时限
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: C · 绿色(轻伤)
能行走的伤员被标为绿色,并最先被引导离开。之后要重新评估他们,因为有些人的伤情可能会加重。
答案: C · Signs of bleeding and when to seek help
The main risk of anticoagulants is bleeding, so the patient must know the signs, such as black stools or blood in the urine, and when to seek help. Other topics can follow later.
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