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。
How big should a suction catheter be compared with the tracheostomy or endotracheal tube?
A 74-year-old with atrial fibrillation, hypertension and diabetes asks why she needs an anticoagulant when she feels well. Which reply is best?
Why is levodopa combined with carbidopa (or benserazide)?
一名卒中并右侧肢体无力的患者准备从床转移到椅子上。哪种方法最安全?
手术后哪个时期最可能发生伤口裂开?
A patient with diabetes on continuous enteral feeding and an insulin regimen has the feed stopped for a procedure. What is the main concern?
A patient with dysphagia after a stroke has been cleared for a modified diet. How should they be positioned for meals?
During CPR for asystole, when should adrenaline (epinephrine) be given according to standard adult guidelines?
A patient with iron-deficiency anemia started oral iron. Which result is usually the earliest sign that treatment is working?
静脉输注硫酸镁期间,哪项评估最能早期发现中毒?
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。
练习数值:Na⁺ 136,Cl⁻ 105,HCO₃⁻ 16 mmol/L,白蛋白 18 g/L。求经白蛋白校正的阴离子间隙 AGc = AG + 0.25·(40 − 白蛋白)。
在这条规则的 II 导联心电图上测量 QT 间期和 R–R 间期,然后用 Bazett 公式 QTc = QT/√RR(均以秒计)计算经心率校正的QTc。答案以秒表示,保留三位小数。
这条 II 导联心电图显示二度房室传导阻滞 I 型(文氏现象)。共有多少个每组的 P 波数,包括未下传的那一个(n:(n − 1) 阻滞中的 n)?
Two hours after birth, the nurse finds the uterus firm but above the umbilicus and pushed to the right. What should the nurse do first?
Which patient finding after a total knee replacement needs the nurse’s action first?
答案: A · No more than half the internal diameter of the tube
A catheter no larger than half the internal diameter of the tube lets air enter around it, reducing negative pressure in the lungs, atelectasis and hypoxaemia. Catheter size is often calculated from the tube size.
答案: A · Her risk of stroke is high, and an anticoagulant lowers it
In AF, blood stasis in the left atrium causes clots that can travel to the brain. Scores such as CHA₂DS₂-VASc (age, hypertension, diabetes, female sex and others) estimate stroke risk; her score is high. Anticoagulation reduces stroke risk but does not change the rhythm.
答案: D · To stop levodopa being converted to dopamine outside the brain
Carbidopa blocks the enzyme that converts levodopa to dopamine in the periphery. More levodopa reaches the brain, so a lower dose works, and side effects such as nausea and low blood pressure are reduced.
答案: B · 把椅子放在左侧,并向椅子方向转身
向较强的一侧转移更安全,这样患者可以用健侧腿负重并转身。拉扯无力的手臂可引起肩关节半脱位和疼痛。应遵循物理治疗师的建议并使用合适的辅助器具。
答案: A · 术后约 5–10 天
伤口裂开最常发生在第 5–10 天左右,此时伤口依赖缝线和早期胶原。危险因素包括肥胖、营养不良、糖尿病、感染、使用类固醇、吸烟、咳嗽和用力。
答案: B · Hypoglycaemia if insulin continues without the feed
When feed stops but insulin continues, blood glucose can fall sharply. The insulin plan is reviewed with the team, glucose is checked frequently, and a glucose infusion may be needed.
答案: C · Sitting fully upright, and staying upright for a time after eating
Sitting upright during and after meals reduces the risk of aspiration. The patient should also be supervised and given the consistency recommended by the speech and language therapist.
答案: A · As soon as IV or IO access is obtained, then every 3–5 minutes
In non-shockable rhythms, adrenaline is given as soon as possible and repeated every 3–5 minutes while CPR continues. In shockable rhythms it is given after the third shock in UK/European guidelines (after the second shock in AHA guidelines).
答案: D · A rise in the reticulocyte count
Once iron is available, the marrow releases more young red cells, so the reticulocyte count rises within about 1–2 weeks. The hemoglobin rises more slowly over weeks, and iron stores take months to refill.核对依据: Reticulocyte Count · MedlinePlus (NIH) (2024)
答案: B · 膝反射、呼吸频率和尿量
膝反射消失是镁中毒的早期预警征象,出现在呼吸减慢之前。镁由肾脏清除,因此尿量下降会增加风险。静脉注射葡萄糖酸钙可拮抗镁中毒。核对依据: Magnesium Toxicity · StatPearls (NCBI Bookshelf) (2026); Magnesium Toxicity · StatPearls (NCBI Bookshelf)
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: AGc = 20.5 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: QTc = 0.424 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。
在通常上限之内(男性约 0.45 s,女性约 0.46 s)。(424 ms)
答案: 每组的 P 波数 = 3
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。
3:2 文氏阻滞。
答案: A · Help the patient empty her bladder
A uterus that is high and displaced to one side usually means a full bladder. A full bladder stops the uterus contracting well, so the nurse helps the patient void and reassesses.
答案: D · Sudden calf pain and swelling in the operated leg, with new breathlessness
Calf pain and swelling suggest deep vein thrombosis, and new breathlessness raises concern for a pulmonary embolism. This needs immediate assessment and escalation; the other findings are expected.
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