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。
Why is a non-selective beta-blocker such as propranolol usually avoided in a patient with asthma?
一名因心房颤动服用华法林的患者 INR 为 8.5,但没有出血。最可能的处理是什么?
After transsphenoidal pituitary surgery, which advice should the patient follow?
A patient on insulin has worsening chronic kidney disease and is having more hypos. What is the best explanation?
Why is thiamine given to patients with alcohol dependence admitted to hospital?
A patient with lung cancer becomes hypotensive and breathless, with distended neck veins and quiet heart sounds. What should the nurse suspect?
Which pattern is typical of relapsing–remitting multiple sclerosis?
A nurse teaches a patient with reflux disease. Which statement shows a need for further teaching?
A patient with HIV on antiretroviral therapy has an undetectable viral load. What does this mean?
Weeks after neck surgery, a patient has muscle cramps and tingling. Calcium is low, phosphate is high and parathyroid hormone (PTH) is low. Which condition fits best?
练习数值:Na⁺ 141 mmol/L,葡萄糖 31.6 mmol/L,尿素 21 mmol/L。计算血清渗透压 Osm = 2·Na⁺ + 葡萄糖 + 尿素,取最接近的整数。
某练习血气显示代谢性碱中毒,HCO₃⁻ 30 mmol/L。用预期 PaCO₂ = 0.7·HCO₃⁻ + 21 求预期PaCO₂。
测量这条 II 导联心电图上的QT 间期,以秒为单位。
识别这条 II 导联心电图上的节律。点击你的答案。
一名护理助理汇报了四位患者的情况。哪项汇报需要护士首先关注?
An older adult with type 2 diabetes is confused and very dehydrated. The glucose is 900 mg/dL (50 mmol/L), and blood and urine show no significant ketones. What is the most likely problem?
答案: B · It can cause bronchospasm by blocking beta-2 receptors
Beta-2 receptors in the airways mediate bronchodilation. Blocking them can trigger severe bronchospasm in asthma and also blunts the effect of salbutamol. Cardioselective beta-1 blockers are safer but still used with caution.
答案: D · 暂停华法林,通知开处方者,并尽快复查 INR
没有出血的极高 INR,通常的处理是暂停华法林、通知开处方者并复查 INR。根据 INR 和当地方案,也可能开具小剂量口服维生素 K(英国指南在 INR 高于 8 时给予;美国指南主要在高于 10 或出血风险高时给予)。凝血酶原复合物浓缩剂和静脉维生素 K 用于大出血。鱼精蛋白用于逆转肝素。应查明 INR 升高的原因(新药、疾病、饮食)。
答案: A · Avoid blowing the nose, straining and bending forward
Raised pressure in the head can open the repair and cause a CSF leak. Patients avoid nose blowing, straining, coughing hard and bending forward, and sneeze with the mouth open. Straws may also be avoided.
答案: C · The kidneys clear less insulin, so it lasts longer
The kidneys clear a large share of insulin. As kidney function falls, insulin stays in the blood longer and some oral agents build up, so hypos increase. Insulin doses often need to be reduced.
答案: C · 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: B · Cardiac tamponade from a pericardial effusion
Malignant pericardial effusion can compress the heart, causing hypotension, raised JVP and muffled heart sounds. It is an emergency needing urgent echocardiography and drainage (pericardiocentesis).
答案: D · Attacks of symptoms, such as visual loss or numbness, that improve between relapses
MS causes demyelination in the brain and spinal cord. Many patients first have attacks such as optic neuritis or sensory symptoms, with partial or full recovery between relapses.
答案: B · "A big meal just before bed is fine if I take my tablet."
Large late meals increase reflux even when a PPI is taken. Raising the head of the bed, losing weight and reducing alcohol are correct measures.
答案: B · The treatment is suppressing the virus very well
An undetectable viral load shows that antiretroviral therapy is suppressing viral replication. The virus remains in the body, so treatment must continue. People with a sustained undetectable viral load do not transmit HIV sexually.
答案: D · Hypoparathyroidism
Without enough PTH, calcium is not released from bone or kept by the kidney, and phosphate is not excreted, so calcium falls and phosphate rises. It can follow injury or removal of the parathyroid glands during thyroid or neck surgery.核对依据: Hypoparathyroidism · MedlinePlus (NIH) (2026); Hypocalcemia · StatPearls (NCBI Bookshelf) (2026)
答案: Osm = 335 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: PaCO₂ = 42 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。
升高是有限度的:仅靠代偿,PaCO₂ 很少超过约 55 mmHg。
答案: QT = 0.48 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 = 0.84 s)。
答案: 心室颤动
室性节律:室性心动过速是连续三个或以上宽大(0.12 s 或以上)的波群,频率超过 100 次/分,通常为 150–250 次/分,节律规则,没有相关的 P 波。心室颤动是紊乱、不规则的波形,无法辨认 P 波、QRS 波群或 T 波,也没有可计数的频率。心脏停搏是几乎平直的线,没有心室活动;平直线一定要通过检查患者、导联和增益并换一个导联来确认。在复苏指南中,室颤和无脉性室速是可电击心律,心脏停搏则不是。
在复苏指南中,室颤和无脉性室速是可电击心律。这里只是识别练习。
答案: A · 一名腹部手术后一天的患者新出现烦躁不安,心率 124 次/分
手术后新出现的烦躁不安伴心率快可能意味着出血、脓毒症或缺氧。对这名 COPD 患者,SpO₂ 90% 是预期的,6 小时 300 mL(50 mL/h)是足够的尿量。
答案: B · Hyperosmolar hyperglycemic state
Hyperosmolar hyperglycemic state occurs mainly in type 2 diabetes, with extreme glucose, severe dehydration and little or no ketosis. Treatment starts with IV fluids, as in DKA.
ExamProblems · examproblems.com/courses/medical-surgical-nursing