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。
Suspected pulmonary TB is being investigated. How are sputum samples usually collected?
A nurse finds a patient collapsed in bed and unresponsive. What should the nurse do first?
Why must Parkinson's medicines be given on time in hospital?
A patient had rapid-acting insulin before lunch, then vomited the meal 15 minutes later. What should the nurse do?
Why is thiamine given to patients with alcohol dependence admitted to hospital?
Hours after an oesophageal dilatation, a patient has chest pain, fever and crackling swelling under the skin of the neck. What should the nurse suspect?
一名服用华法林的患者 INR 远高于目标范围并有瘀斑。可能会开哪种药物来逆转其作用?
A patient with poorly controlled hyperthyroidism develops a high fever, very fast heart rate, agitation and vomiting during an infection. What is likely?
For most hospitalized adults with diabetes who are critically ill, which glucose target range is commonly recommended?
At the start of a shift, the nurse reviews four new results. Which patient needs attention first?
某练习血气显示 PaCO₂ 21 mmHg (2.8 kPa)。利用规则:在慢性呼吸性碱中毒中,PaCO₂ 每比 40 低出 10 mmHg,HCO₃⁻ 下降 5 mmol/L,以HCO₃⁻ 24 mmol/L 为起点,求预期HCO₃⁻。
某练习血气显示呼吸性酸中毒:pH 7.16,PaCO₂ 82 mmHg (10.9 kPa),HCO₃⁻ 28 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。
测量这条 II 导联心电图上的QT 间期,以秒为单位。
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。
A patient is receiving continuous tube feeds. Which action best reduces the risk of aspiration?
A team has an RN, an LPN/LVN and a nursing assistant. Which task is the best one to assign to the LPN/LVN?
答案: D · Several samples, ideally including early-morning sputum
Usually three sputum samples, including an early-morning sample, are sent for smear microscopy, culture and molecular testing. Deep coughed sputum, not saliva, is needed. Samples are collected before treatment where possible and in a way that limits exposure to others.
答案: C · Shout for help, open the airway and check breathing for up to 10 seconds
In hospital, the nurse shouts for help, opens the airway and looks for normal breathing (and a pulse if trained) for up to 10 seconds. If the patient is not breathing normally, the arrest team is called and CPR started, with a defibrillator brought as soon as possible.
答案: C · Late doses can soon cause stiffness, falls and poor swallowing
People with Parkinson's disease often take doses at exact times. A delay of even 30 minutes or so can cause rigidity, immobility, falls and unsafe swallowing. Many hospitals treat these drugs as time-critical.
答案: C · Monitor glucose closely and tell the prescriber about the hypo risk
The insulin will lower glucose without the carbohydrate it was meant to cover, so a hypo is likely. The nurse checks glucose often, offers carbohydrate the patient can keep down and escalates; IV glucose may be needed.
答案: B · To prevent Wernicke's encephalopathy
Thiamine deficiency is common in alcohol dependence and can cause Wernicke's encephalopathy (confusion, ataxia, eye signs). Thiamine is given early, ideally before or with glucose, as glucose can worsen deficiency.
答案: C · Oesophageal perforation
Chest pain, fever and surgical (subcutaneous) emphysema after instrumentation suggest oesophageal perforation, which can cause mediastinitis. The patient is kept nil by mouth and reviewed urgently; CT confirms it.
答案: A · 维生素 K
华法林抑制维生素 K 依赖的凝血因子。维生素 K(大出血时加用凝血酶原复合物)可以逆转其作用。鱼精蛋白用于逆转肝素。
答案: D · Thyroid storm
Thyroid storm is a life-threatening worsening of hyperthyroidism, often triggered by infection or surgery. It needs urgent treatment with cooling, beta-blockade and antithyroid drugs.
答案: B · About 140–180 mg/dL (7.8–10 mmol/L)
For most critically ill patients, insulin is used to keep glucose around 140–180 mg/dL (7.8–10 mmol/L). Lower targets increase the risk of hypoglycemia, and persistently higher levels increase infection and other complications.
答案: C · Sodium 119 mEq/L in a patient with new confusion and vomiting
Severe hyponatremia with confusion and vomiting suggests cerebral edema and can progress to seizures and coma. The other results are mildly abnormal and expected for those conditions, so they are less urgent.核对依据: Low blood sodium - Medical Encyclopedia · MedlinePlus (NIH) (2025); Sodium Blood Test · MedlinePlus (NIH) (2024)
答案: HCO₃⁻ = 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。
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: QT = 0.36 s
QT 与 QTc:QT 间期从 QRS 波群起点到 T 波终点。它随心率加快而缩短,因此要用以秒为单位的 R–R 间期按心率校正:Bazett QTc = QT/√RR,Fridericia QTc = QT/∛RR。多数教科书使用 Bazett 公式;它在心率快时校正过度,此时宜用 Fridericia。各参考标准的界限不同:QTc 男性高于约 0.45 s、女性高于约 0.46 s 通常称为延长,高于 0.50 s 称为明显延长。
粗略的规则:在正常心率下,QT 应小于 R–R 间期的一半(此处 R–R = 0.64 s)。
答案: 三度(完全性)房室传导阻滞
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。
II 型和三度阻滞可能突然进展,所以教科书将它们列为比 I 型更严重。
答案: A · Keep the head of the bed raised to at least 30 degrees
Raising the head of the bed to at least 30 degrees during and after feeding lowers the risk of reflux and aspiration. Lying flat greatly increases the risk.
答案: D · Giving a scheduled subcutaneous anticoagulant injection to a stable patient
LPNs/LVNs usually give scheduled injections to stable patients. A fresh postoperative assessment and teaching plans need the RN, and routine vital signs are better given to the assistant so the LPN/LVN can use their skills.
ExamProblems · examproblems.com/courses/medical-surgical-nursing