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 repair of an abdominal aortic aneurysm, which regular assessment helps detect a blocked graft or clots in the legs?
A ventilated patient with severe ARDS is to be turned prone. What is the main reason, and the key nursing risk?
An 85-year-old care home resident becomes newly confused and is falling more often. A UTI is one possibility. Why?
An 89-year-old with stage 5 CKD and severe heart failure, who has capacity, decides not to start dialysis. What is the nurse's best response?
Which group of findings suggests obstruction of the bile duct?
A patient taking IV antibiotics has three unexplained loose stools in 24 hours. What should the nurse do first?
After a needlestick injury from a patient known to have HIV, why must the nurse report it immediately?
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?
A patient starts lisinopril (an ACE inhibitor). Which laboratory values should the nurse expect to be monitored?
A patient's potassium is 7.2 mEq/L, and the monitor shows wide QRS complexes. Several treatments are prescribed. Which should be given first?
某练习血气显示 PaCO₂ 32 mmHg (4.3 kPa)。利用规则:在急性呼吸性碱中毒中,PaCO₂ 每比 40 低出 10 mmHg,HCO₃⁻ 下降 2 mmol/L,以HCO₃⁻ 24 mmol/L 为起点,求预期HCO₃⁻。
练习数值:Na⁺ 138,Cl⁻ 114,HCO₃⁻ 14 mmol/L,白蛋白 22 g/L。求经白蛋白校正的阴离子间隙 AGc = AG + 0.25·(40 − 白蛋白)。
解读这条 II 导联心律条带。这是什么节律?点击你的答案。
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 severe neutropenia needs a room. Which roommate is the safest choice?
A patient in labor is receiving oxytocin, and the fetal monitor shows repeated late decelerations. What should the nurse do first?
答案: D · Checking leg pulses, colour, warmth and sensation
After aortic surgery, distal pulses, skin colour, temperature, capillary refill, movement and sensation are checked often and compared with baseline. Loss of pulses, pallor or pain suggests graft occlusion or emboli and must be reported at once. Urine output is also monitored for renal perfusion.
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: C · Older adults often show infection as confusion
In older adults, infections such as UTI may present with delirium, falls or reduced mobility rather than dysuria or fever. Other causes of delirium must also be considered, and urine tests alone can mislead.
答案: C · Respect the decision and support symptom-focused care
A competent patient can refuse dialysis. The nurse makes sure the choice is informed, respects it and supports conservative kidney management, with symptom control, advance care planning and palliative care input.
答案: A · Jaundice, dark urine, pale stools and itching
When bile cannot reach the gut, conjugated bilirubin enters the blood and urine (dark urine), stools lose their colour, and bile salts in the skin cause itching. Causes include gallstones and pancreatic cancer.
答案: A · Isolate the patient and send a stool sample for testing
Unexplained diarrhoea in a patient on antibiotics should be treated as possible C. difficile. The patient is isolated promptly, a stool sample is sent and the antibiotics are reviewed with the medical team.
答案: B · Post-exposure prophylaxis works best when started as soon as possible
HIV post-exposure prophylaxis should be started as soon as possible after exposure, ideally within hours. Occupational health or the emergency department will assess the risk and arrange follow-up testing.
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: C · Potassium and creatinine
ACE inhibitors reduce aldosterone, so potassium can rise, and they lower the filtration pressure in the kidney, so creatinine can rise. Both are checked before and soon after starting or increasing the dose.核对依据: Hyperkalemia · StatPearls (NCBI Bookshelf) (2025)
答案: D · IV calcium gluconate (or chloride)
With ECG changes, IV calcium is given first to stabilize the cardiac membrane within minutes. It does not lower potassium, so insulin with glucose (and sometimes albuterol/salbutamol) follows to shift potassium into cells, then binders, diuretics or dialysis remove it.核对依据: High potassium level - Medical Encyclopedia · MedlinePlus (NIH) (2025)
答案: HCO₃⁻ = 22.4 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: AGc = 14.5 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。
校正后高于约 12:阴离子间隙升高。
答案: 交界性心律
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: 双腔(房室)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: C · A patient after a knee replacement with no signs of infection
A neutropenic patient cannot fight infection well, so the roommate must not have a transmissible infection. A clean postoperative patient is the safest choice; ideally the neutropenic patient has a single room.
答案: D · Stop the oxytocin infusion
Late decelerations point to reduced blood flow through the placenta. Stopping oxytocin reduces contractions; the nurse then turns the patient onto her side, gives IV fluids as prescribed and informs the provider.
ExamProblems · examproblems.com/courses/medical-surgical-nursing