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。
监护仪显示心室颤动。患者无反应,呼吸不正常。关键的治疗是什么?
Which instruction from the registered nurse to a healthcare assistant (unlicensed assistive personnel) caring for a patient with COPD is most appropriate?
一名原发性肾上腺皮质功能减退的患者发热。关于类固醇替代治疗,通常的病日建议是什么?
Two days after surgery, an 80-year-old woman is quiet, sleepy, slow to answer and eating little. Her daughter says she is "not herself". What should the nurse suspect?
In the UK National Early Warning Score (NEWS2), what does an aggregate score of 5 or more usually trigger?
An hour after a line flush, a patient receiving parenteral nutrition has rigors and a temperature of 39.1 °C. What should the nurse suspect and do?
A patient is receiving IV fluids for several days. Which monitoring is essential?
Which finding suggests hypocalcaemia?
A patient with a low clinical probability of deep vein thrombosis has a normal (negative) D-dimer. What is the best interpretation?
In the first 24 hours after a major burn, which laboratory pattern is most expected?
某练习血气显示 PaCO₂ 48 mmHg (6.4 kPa)。利用规则:在慢性呼吸性酸中毒中,PaCO₂ 每比 40 高出 10 mmHg,HCO₃⁻ 升高 3.5 mmol/L,以HCO₃⁻ 24 mmol/L 为起点,求预期HCO₃⁻。
某练习血气显示代谢性碱中毒,HCO₃⁻ 40 mmol/L。用预期 PaCO₂ = 0.7·HCO₃⁻ + 21 求预期PaCO₂。
这条 II 导联心电图条带显示窦性心律伴一次停顿。测量 停顿,即跨越停顿的 R–R 间期,单位为秒。
这条 II 导联心电图显示二度房室传导阻滞 I 型(文氏现象)。测量未下传 P 波之前最后一个下传搏动的 PR 间期(即最长的 PR),以秒为单位。
A nurse sees a nursing assistant leave a confused patient’s bed in the highest position after care. What should the nurse do?
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: A · 尽快进行心肺复苏和除颤
心室颤动是心脏骤停的心律。高质量的心肺复苏和早期非同步除颤才是提高生存率的干预措施。同步电复律用于有脉搏的快速性心律失常;阿托品和起搏用于心动过缓。
答案: D · "Tell me straight away if his SpO₂ is under 88% or he is more breathless."
Delegated tasks should come with specific parameters for reporting. Changing oxygen therapy, chest assessment and patient teaching need a registered nurse's knowledge and judgement. Clear reporting instructions keep the patient safe.
答案: D · 增加糖皮质激素剂量,常为加倍
患病期间,接受类固醇替代治疗的人需要更多的糖皮质激素。病日规则通常建议发热期间剂量加倍,如果呕吐而无法服药,则使用应急注射用氢化可的松或紧急就医,以预防肾上腺危象。
答案: B · Hypoactive delirium
Hypoactive delirium presents with drowsiness, withdrawal and slowness rather than agitation, so it is often missed. It has a worse prognosis than the hyperactive form. A family report of a sudden change is important, and a screening tool such as the 4AT or the CAM (Confusion Assessment Method) can be used.
答案: D · An urgent review by a clinician skilled in acute illness
NEWS2 scores respiratory rate, SpO₂, oxygen use, BP, pulse, consciousness or new confusion, and temperature. A score of 5–6 needs an urgent response, and 7 or more an emergency response.
答案: D · Line infection; escalate and take blood cultures
Fever and rigors after flushing a central line suggest a catheter-related bloodstream infection. The nurse escalates urgently, takes cultures from the line and peripherally per policy, and starts sepsis care.
答案: B · Fluid balance, regular weights and urea, creatinine and electrolytes
IV fluids can cause overload or electrolyte imbalance. Fluid balance charts, weight, clinical assessment and blood tests guide the prescription.
答案: A · Spasm of the hand when a blood pressure cuff is inflated on the arm
Trousseau's sign, carpal spasm during cuff inflation, and Chvostek's sign, facial twitching on tapping the facial nerve, indicate neuromuscular irritability from low calcium.
答案: C · A DVT is unlikely and can usually be ruled out
D-dimer is very sensitive, so a negative result in a patient with low clinical probability makes DVT or PE unlikely. A positive result is not specific, because surgery, infection, pregnancy and cancer also raise D-dimer; imaging is then needed.核对依据: D-Dimer Test · MedlinePlus (NIH) (2024)
答案: C · High potassium and high hematocrit
Early after a burn, damaged cells release potassium, and plasma shifts into the tissues, which concentrates the blood and raises the hematocrit. Later, as fluid returns and the kidneys excrete potassium, hypokalemia can develop.核对依据: High potassium level · MedlinePlus (NIH) (2025)
答案: HCO₃⁻ = 26.8 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: PaCO₂ = 49 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: 停顿 = 1.68 s
窄 QRS 心动过速与停顿:室上性心动过速(SVT)是规则的心动过速,约 150–250 次/分钟,QRS 波群较窄;P 波通常看不到,因为它们隐藏在 QRS 波群或 T 波中。成人静息时的窦性心动过速通常低于约 150 次/分钟,且每个 QRS 前都有可见的 P 波;伴 2:1 传导的心房扑动常在约 150 次/分钟,并显示锯齿波。窦性停搏是指窦房结暂时停止发放冲动:出现既无 P 波也无 QRS 的停顿,其长度不是 P–P 周期的整数倍(恰好两个或三个周期的停顿则提示窦房传导阻滞)。
停顿中没有出现 P 波,且停顿不是 P–P 周期的整数倍:窦性停搏。恰好两个或三个周期的停顿则提示窦房传导阻滞。
答案: 最长的 PR = 0.38 s
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。
PR 最大的增幅出现在一组的第一个和第二个搏动之间;之后的增幅较小,这就是暂停之前 R–R 间期缩短的原因。
答案: A · Lower the bed now and remind the assistant why it matters
A high bed increases the risk of a serious fall, so the nurse corrects it at once and gives brief, clear feedback. Leaving it or delaying feedback leaves the patient at risk.
答案: C · 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.
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