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。
A patient on home oxygen has dry, sore lips. Which product is safest to use?
在严重哮喘发作期间,一名患者的 PaCO₂ 从偏低升至正常,同时看起来精疲力竭。这意味着什么?
哪项护理措施有助于预防颅内压升高?
A patient with hypopituitarism needs both hydrocortisone and levothyroxine. Which is usually started first?
Which is a recognised cause of anaphylaxis during surgery?
上腹部手术后第 2 天,一名患者体温 37.8 °C,未吸氧时 SpO₂ 93%,双肺底呼吸音减弱。由于疼痛,他们没有使用激励式肺量计。最恰当的护理计划是什么?
Why are alternate sutures sometimes removed first when taking out stitches?
A patient with lung cancer develops swelling of the face and arms, distended neck veins and breathlessness that is worse lying down. What should be suspected?
一名患者钠为 124 mEq/L,头痛并新出现意识模糊。哪项护理措施最恰当?
Two days after bowel surgery, a patient with nasogastric suction has a distended abdomen, absent bowel sounds and muscle weakness. The potassium is 2.8 mEq/L. Which interpretation is best?
练习数值:Na⁺ 135 mmol/L,葡萄糖 29.9 mmol/L,尿素 23.2 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⁻ 36 mmol/L。用预期 PaCO₂ = 0.7·HCO₃⁻ + 21 求预期PaCO₂。
解读这条 II 导联心律条带。这是什么节律?点击你的答案。
这条 II 导联心电图显示房室传导阻滞,心室节律不规则。使用 6 秒法求出心室率(单位:次/分)。
A pregnant nurse is on the unit. Which patient should the charge nurse avoid assigning to her?
At the end of a shift, the nurse’s relief has not arrived and the patients are acutely ill. What should the nurse do?
答案: C · A water-based lubricant
Oil-based products such as petroleum jelly can ignite or burn intensely in high oxygen concentrations and have caused facial burns. Water-based products are recommended. Oxygen cylinders are kept upright and secured, away from heat and flames.
答案: D · 患者正在疲劳,随后可能发生呼吸衰竭
发作早期,过度通气会使 PaCO₂ 降低。呼吸困难且正在疲劳的患者 PaCO₂ 正常或升高,意味着通气功能衰竭,是危及生命的特征。需要紧急的高级医师和重症监护评估。
答案: A · 预防便秘,并分散安排护理操作
用力排便、咳嗽、长时间吸痰、髋部屈曲、疼痛和躁动都会使颅内压升高。使用大便软化剂、充分镇痛,以及分散安排护理使颅内压能在两次操作之间恢复,有助于使其保持较低水平。
答案: A · Hydrocortisone
Starting thyroid replacement first increases metabolism and cortisol clearance and can trigger an adrenal crisis in a patient with low cortisol. Glucocorticoid replacement is started before levothyroxine.
答案: A · Chlorhexidine skin preparation
Common causes of perioperative anaphylaxis include neuromuscular blockers, antibiotics, chlorhexidine and latex. Allergies are documented, and suspected reactions are investigated afterwards.
答案: B · 更好地控制疼痛、坐起、深呼吸、活动并上报
上腹部手术后,当疼痛限制深呼吸时,肺底部肺不张很常见。良好的镇痛、直立体位、深呼吸练习、激励式肺量计、支托下咳嗽和早期活动可使肺重新扩张。应报告这些发现,因为它们可能发展为肺炎;需要时给氧至目标值。
答案: A · To check the wound stays closed before removing the rest
Removing alternate sutures allows the nurse to see whether the wound edges stay together. If they begin to separate, the remaining sutures can be left and the team informed.
答案: C · Superior vena cava obstruction
Superior vena cava obstruction prevents venous drainage from the head and arms. It is an oncological emergency; patients are positioned upright and need urgent specialist treatment.
答案: C · 采取癫痫预防措施并监测神经系统状态
低钠血症可引起脑水肿和惊厥。护士应监测神经系统状态,采取癫痫预防措施并报告结果。额外的水和噻嗪类药物会使钠进一步降低。核对依据: Low blood sodium · MedlinePlus (NIH) (2025)
答案: C · Hypokalemia from gastric losses is contributing to paralytic ileus
Gastric suction removes potassium and causes metabolic alkalosis, which shifts more potassium into cells. Low potassium reduces smooth muscle contraction and contributes to ileus and weakness. The provider is informed and potassium is replaced as prescribed.核对依据: Hypokalemia · StatPearls (NCBI Bookshelf) (2025)
答案: Osm = 323 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 = 46.2 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: 室上性心动过速(SVT)
节律标准(II 导联):窦性心律每个 QRS 之前都有直立的 P 波,PR 恒定为 0.12–0.20 s,QRS 狭窄:60–100 次/分为正常窦性心律,低于 60 为窦性心动过缓,高于 100 为窦性心动过速。心房颤动:无 P 波,基线呈颤动,R–R 绝对不规则。心房扑动:约 250–350 次/分的锯齿状扑动波,伴固定的传导比例,如 2:1 或 4:1。一度房室传导阻滞:窦性心律,PR 恒定且大于 0.20 s。交界性心律:窄 QRS,40–60 次/分,P 波缺失或倒置(PR 低于 0.12 s,或 P 波在 QRS 之后)。室性早搏(PVC)是提前出现的宽大(0.12 s 或以上)、形态怪异的 QRS,没有 P 波,T 波方向相反,通常有完全性代偿间歇;二联律是指每隔一个搏动就有一个室性早搏。 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)。
答案: 心室率 = 40 bpm
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。
二度 I 型(文氏现象):每 2 个 QRS 波群对应 3 个 P 波。
答案: C · A patient with a sealed radioactive implant for cervical cancer
A sealed radioactive implant (brachytherapy) emits radiation, and pregnant staff should not care for these patients. The other patients pose no special risk to a pregnancy.
答案: B · Stay and tell the charge nurse, and hand over before leaving
The nurse must not leave patients without handing over to another qualified nurse. Telling the charge nurse allows staffing to be arranged safely.
ExamProblems · examproblems.com/courses/medical-surgical-nursing