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 patient taking ramipril and indapamide for hypertension starts regular ibuprofen for back pain. A week later, creatinine has risen sharply. What is the most likely cause?
Which signs suggest rejection of a kidney transplant?
A patient with a head injury now has a blood pressure of 190/70 mmHg, a pulse of 48/min and irregular breathing. How should the nurse interpret this?
哪项饮食建议可降低新回肠造口堵塞的风险?
A nurse teaches a patient to self-inject low molecular weight heparin at home. Which statement shows a need for further teaching?
世卫组织三阶梯镇痛原则建议:
A patient due a blood transfusion is not wearing an identity band. What should the nurse do?
A patient with diabetes also takes propranolol. Why is regular glucose monitoring especially important?
A patient with acute kidney injury has a potassium of 6.8 mEq/L despite medical treatment, a pH of 7.12 and pulmonary edema not responding to diuretics. Which treatment is most likely needed?
某练习动脉血气显示 pH 7.36,PaCO₂ 22 mmHg (2.9 kPa),HCO₃⁻ 12 mmol/L。原发性紊乱是代谢性酸中毒。代偿到什么程度?点选你的答案。
练习数值:Na⁺ 142,Cl⁻ 103,HCO₃⁻ 17 mmol/L。使用 AG = Na⁺ − (Cl⁻ + HCO₃⁻) 计算 Δ 比值 (AG − 12)/(24 − HCO₃⁻)。保留两位小数。
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。
A patient on a nasal cannula at 6 L/min still has a low SpO₂. What should the nurse do?
一名患者正通过中心静脉导管接受肠外营养。哪项发现需要立即处理?
答案: C · 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 · An ACE inhibitor, diuretic and NSAID together reducing kidney perfusion
NSAIDs constrict the afferent arteriole, ACE inhibitors dilate the efferent arteriole and diuretics reduce volume. Together (sometimes called the "triple whammy") they can cause acute kidney injury. The NSAID is stopped, and the prescriber reviews the other drugs.
答案: C · Less urine, a rising creatinine and a tender graft
Acute rejection may cause falling urine output, rising creatinine, weight gain, fever, and pain or tenderness over the graft. Many episodes are found on blood tests before symptoms appear, so regular monitoring is essential.
答案: A · Cushing's triad, a late sign of raised intracranial pressure
Cushing's triad is hypertension with a widening pulse pressure, bradycardia and irregular respiration. It shows that the brainstem is being compressed and herniation may be imminent, so it is an emergency.
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: B · "I'll rub the area afterwards to spread the medicine."
Rubbing the site after LMWH increases bruising and is avoided. Rotating sites, reporting bleeding and safe sharps disposal are correct.
答案: D · 随着疼痛加重,从非阿片类药物逐步升级到弱阿片类,再到强阿片类
阶梯从非阿片类药物(如对乙酰氨基酚)到弱阿片类,再到强阿片类,每一阶梯都可加用辅助药物。对于持续性疼痛,首选按时给药。
答案: B · Not start until a correct identity band is in place and identity is confirmed
Positive patient identification, using an identity band checked against the blood unit and prescription, is essential before every transfusion. Wrong blood incidents can cause fatal ABO incompatibility reactions.
答案: D · The drug can mask warning signs of hypoglycemia
Beta-blockers, especially nonselective ones, blunt adrenergic warning signs of hypoglycemia such as tremor and tachycardia, and they can delay recovery. Sweating usually remains. Glucose checks help detect lows that the patient may not feel.核对依据: Low blood sugar · MedlinePlus (NIH) (2026)
答案: D · Urgent dialysis
Indications for urgent dialysis in AKI include refractory hyperkalemia, severe metabolic acidosis, fluid overload not responding to diuretics, uremic complications and some poisonings. This patient has three of them.核对依据: Acute tubular necrosis · MedlinePlus (NIH) (2025)
答案: 完全代偿
解读血气(ROME):先看 pH:低于 7.35 为酸血症,高于 7.45 为碱血症。然后找出能解释它的指标。PaCO₂(正常 35–45 mmHg,4.7–6.0 kPa)是呼吸方面的指标,在呼吸性紊乱中与 pH 反向(Opposite)变化;HCO₃⁻(正常 22–26 mmol/L)是代谢方面的指标,与 pH 同向变化(Respiratory Opposite, Metabolic Equal,即呼吸性相反,代谢性相同)。另一个指标显示代偿情况:正常表示未代偿;沿着使 pH 回升的方向异常、而 pH 仍然异常,表示部分代偿;pH 正常而两个指标都异常,表示完全代偿。各实验室的范围略有差异;这些是练习用数值。
临床上还应检查预期代偿:按温特公式,预期 PaCO₂ 为 24–28 mmHg,所以实测 22 mmHg 提示合并呼吸性碱中毒(混合性紊乱)。上面的答案是按 ROME 法的考试分类。
答案: Δ 比值 = 1.429
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。
介于 1 和 2 之间:单纯高阴离子间隙酸中毒。
答案: QTc = 0.397 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)。(397 ms)
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: B · Report it, because a different oxygen device is likely to be needed
Standard nasal cannulas are usually run at up to about 6 L/min; higher flows dry the nose without much benefit. If the patient still needs more oxygen, the nurse assesses and escalates for a different device.
答案: B · 输注意外中断后出现出汗、颤抖,血糖 62 mg/dL(3.4 mmol/L)
肠外营养含有大量葡萄糖,身体会以高胰岛素水平作出反应。如果输注突然中断,可能随后出现反跳性低血糖。护士应按规程处理低血糖,通知医疗人员,并遵循输注中断的政策。血糖轻度升高、敷料完整和体重小幅变化是预期的或轻微的。
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