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。
一名患者心房颤动已超过 48 小时,并已安排择期电复律。为什么事先需要抗凝?
During drainage of a large pleural effusion, a patient starts coughing and feels tight in the chest. What should the nurse do?
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?
A patient has had a high sodium of 160 mmol/L for several days. Why must it be corrected slowly?
How should a patient with facial burns usually be positioned?
Which preoperative task can a registered nurse usually delegate to a healthcare assistant (nursing assistant)?
A pressure ulcer shows full-thickness tissue loss with exposed bone. Which category (stage) is this?
A nurse is teaching a patient who is starting warfarin. Which statement shows a need for further teaching?
A patient taking phenazopyridine for bladder pain has bright orange urine. What should the nurse know about urine tests?
A patient with severe sepsis is oozing blood from IV sites. Platelets 40 × 10³/µL, fibrinogen low, D-dimer very high, PT and aPTT both prolonged. Which condition fits best?
某练习动脉血气显示 pH 7.44,PaCO₂ 29 mmHg (3.9 kPa),HCO₃⁻ 19 mmol/L。原发性紊乱是呼吸性碱中毒。代偿到什么程度?点选你的答案。
在海平面,某练习血气取自吸入 24% 氧气时,显示 PaO₂ 64 mmHg (8.5 kPa),PaCO₂ 49 mmHg (6.5 kPa)。用 PAO₂ = FiO₂·(760 − 47) − PaCO₂/0.8 求A–a 梯度。
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 Fridericia 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)。从一组的第一个搏动到第二个搏动,PR 间期增加了多少(ΔPR),以秒为单位?
A parent of a child with influenza talks with the nurse. Which statement shows a need for further teaching?
一名上消化道出血的患者心率 128 次/分,血压 84/50 mmHg。以下都有医嘱。护士首先开始哪一项?
答案: A · 恢复窦性心律时,心房内的血栓可能脱落
心房颤动超过 48 小时后,心房内可能存在血栓。恢复有序收缩可将其排出而引起卒中。患者通常在复律前至少抗凝三周(或经食管超声排除血栓),复律后至少抗凝四周。
答案: D · Stop or clamp the drainage and inform the doctor
Rapid removal of a large effusion can cause re-expansion pulmonary oedema. Coughing, chest tightness or pain are warning signs. Drainage is stopped and the doctor is informed, and the volume is usually drained in a controlled way.
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: C · Rapid correction can cause brain swelling
In chronic hypernatraemia, brain cells adapt by holding extra solutes. If the sodium falls too quickly, water rushes into the cells and causes cerebral oedema and seizures. Correction is gradual, with regular sodium checks.
答案: A · With the head of the bed raised to reduce swelling
Raising the head reduces facial and airway swelling. The airway is monitored closely because swelling can increase over the first 24–48 hours.
答案: B · Recording baseline vital signs
Trained assistants can record routine observations and report them. Assessment, teaching and interpreting results need registered nurse knowledge and judgement.
答案: A · Category 4
Category 4 involves full-thickness tissue loss with exposed bone, tendon or muscle. Category 3 is full-thickness skin loss without exposed bone or tendon. US (NPIAP) terminology calls these stages rather than categories.
答案: D · "I can take aspirin if I get a headache."
Aspirin and other NSAIDs increase the bleeding risk with warfarin, so patients should ask before taking any new medicine. Paracetamol (acetaminophen) is usually the safer choice for simple pain.
答案: C · The dye can interfere with dipstick color readings
Phenazopyridine is a urinary analgesic dye that turns urine orange-red. It can interfere with color-based dipstick tests, so the laboratory should be told. The color is harmless, but it can stain contact lenses and clothing.核对依据: Urine - abnormal color · MedlinePlus (NIH) (2025)
答案: B · Disseminated intravascular coagulation (DIC)
In DIC, widespread clotting consumes platelets and clotting factors, so PT and aPTT are prolonged and fibrinogen falls, while clot breakdown raises the D-dimer. ITP lowers platelets only, and hemophilia A prolongs only the aPTT.核对依据: Fibrinogen blood test · MedlinePlus (NIH) (2025); Prothrombin time (PT) · MedlinePlus (NIH) (2025); D-Dimer Test · MedlinePlus (NIH) (2024)
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。
答案: A–a 梯度 = 45.87 mmHg
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: QTc = 0.482 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。
超过男性(约 0.45 s)和女性(约 0.46 s)的通常上限:延长。(482 ms)
答案: ΔPR = 0.14 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: C · “I will give my child aspirin to bring the fever down.”
Aspirin in children with viral illnesses such as influenza or chickenpox is linked to Reye syndrome. Fluids, rest at home and reporting breathing trouble are correct.
答案: C · 通过大口径套管静脉输液或输血
心动过速和低血压显示低血容量性休克,因此首先恢复循环血容量,按医嘱使用液体或血制品并密切监测。抑酸和内镜检查在复苏进行之后,口服铁剂属于后期恢复。
ExamProblems · examproblems.com/courses/medical-surgical-nursing