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。
Which investigation is usually used to confirm a deep vein thrombosis in the leg?
髋关节手术后,一名患者突然出现呼吸困难和焦虑,心率 124 次/分,未吸氧时 SpO₂ 86%,呼吸时有尖锐疼痛。听诊胸部清晰。护士首先应做什么?
During continuous bladder irrigation, 3200 mL drains out in a shift. 2500 mL of irrigation fluid was put in. What is the true urine output?
The day after a lumbar puncture, a patient has a headache that is severe when standing and almost gone when lying flat. Temperature and neck movement are normal. What is the most likely cause?
哪项饮食建议可降低新回肠造口堵塞的风险?
A patient with long-standing chronic pancreatitis now has weight loss, thirst and passing large volumes of urine. What should the nurse check first?
一名患者的液体平衡记录显示 24 小时入量 1,200 mL,出量 2,300 mL。这表示什么?
Which drug group is first-line for a prolonged convulsive seizure?
Which blood collection practice helps prevent hemolysis of the sample?
Four drug levels are reported. Which patient should the nurse assess first?
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⁻。
某练习血气显示呼吸性酸中毒:pH 7.23,PaCO₂ 66 mmHg (8.8 kPa),HCO₃⁻ 27 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。
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。
识别这条 II 导联心电图上的节律。点击你的答案。
After a hip replacement, a patient has sudden severe hip pain, and the operated leg looks shorter and turned. What should the nurse suspect?
Four patients arrive at the emergency department at the same time. Who should be seen first?
答案: C · Compression duplex ultrasound
Compression ultrasound shows whether a deep vein is compressible and whether flow is normal; a vein containing clot does not compress. A low clinical probability with a negative D-dimer can rule out DVT without imaging.
答案: C · 给氧、协助坐起、呼叫紧急评估并留在床边
骨科手术后突发呼吸困难、心动过速、胸膜性疼痛和低氧血症提示肺栓塞。立即措施是支持性的:给氧至目标饱和度、血压允许时取直立位、紧急上报并持续监测,随后按医嘱进行检查和抗凝。镇静可能掩盖病情恶化并抑制呼吸。
答案: A · 700 mL
True urine output equals total drainage minus irrigation volume: 3200 − 2500 = 700 mL. If drainage is less than the irrigant volume, the catheter may be blocked and fluid is being retained.
答案: D · Post-dural puncture headache
A positional headache after a lumbar puncture, without fever or neck stiffness, fits a CSF leak. It is managed with rest, fluids, analgesia and caffeine, and an epidural blood patch if it persists. Fever or neck stiffness would suggest infection instead.
答案: A · 充分咀嚼,并缓慢引入含纤维的食物
坚果、甜玉米、干果和水果皮等含纤维的食物可形成团块,堵塞狭窄的造口。彻底咀嚼、缓慢引入这些食物和饮用足够的水可降低风险。堵塞的症状包括绞痛、造口肿胀和无排出物。
答案: D · Capillary blood glucose
Destruction of islet cells in chronic pancreatitis can cause diabetes (type 3c). Thirst, polyuria and weight loss suggest hyperglycaemia, which is checked straight away.
答案: A · 液体负平衡 1,100 mL
1,200 − 2,300 = −1,100 mL。负平衡意味着丢失的液体多于获得的液体,可能导致脱水。
答案: D · Benzodiazepines, such as buccal midazolam or IV lorazepam
Benzodiazepines enhance GABA and are first-line for seizures lasting over five minutes. If seizures continue, second-line antiepileptic drugs are given and senior help is needed.
答案: A · Gently inverting the tubes instead of shaking them
Hemolysis falsely raises potassium and affects other results. It is reduced by gentle inversion of tubes, avoiding very small needles, avoiding strong suction or forcing blood through a needle, and keeping tourniquet time short.
答案: A · Lithium 1.8 mEq/L with a new coarse tremor
A lithium level of 1.8 mEq/L with a coarse tremor suggests toxicity, which can progress to confusion and seizures. The digoxin, phenytoin and valproate levels are within commonly cited ranges and the patients are stable.
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: 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: QTc = 0.52 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。
高于 0.50 s:明显延长。(520 ms)
答案: 心脏停搏
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。
平直线必须核实:查看患者、导联和增益,并换看第二个导联,因为电极脱落或细颤型室颤都可能看起来像心脏停搏。
答案: C · Dislocation of the new hip
Sudden pain with shortening and rotation of the leg suggests prosthetic hip dislocation. The nurse keeps the leg still, checks circulation and informs the surgeon.
答案: B · An older adult with weakness on one side that began 40 minutes ago
Sudden one-sided weakness suggests a stroke, and treatment depends on how quickly it starts. Severe kidney stone pain needs prompt pain relief, but the patient is stable.
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