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。
Why does a large, rapidly forming pericardial effusion lower the blood pressure?
A heavy smoker is having surgery tomorrow and asks whether stopping smoking now is pointless. Which reply is most accurate?
一名 AKI 患者的导尿管没有任何尿液引出。哪项快速床旁检查有助于排除肾后性原因?
A patient with Parkinson's disease becomes agitated and confused at night. Which newly prescribed drug should the nurse question?
Which advice helps a person with diabetes prevent foot ulcers?
为什么对术后阿片类药物引起呼吸抑制的患者,纳洛酮通常以小剂量重复给予?
A patient with DKA has an arterial blood gas showing a low pH and a low bicarbonate. Which disturbance is this?
一名使用阿片类 PCA 泵的患者呼吸频率为 7 次/分,且难以唤醒。首先应该做什么?
Why is a blood β-hydroxybutyrate level often preferred to a urine ketone dipstick in DKA?
一名患者 24 小时前大量过量服用对乙酰氨基酚(扑热息痛)。最预期出现哪些实验室改变?
某练习动脉血气显示 pH 7.64,PaCO₂ 39 mmHg (5.2 kPa),HCO₃⁻ 41 mmol/L。原发性紊乱是代谢性碱中毒。代偿到什么程度?点选你的答案。
某练习血气显示代谢性碱中毒,HCO₃⁻ 41 mmol/L。用预期 PaCO₂ = 0.7·HCO₃⁻ + 21 求预期PaCO₂。
测量这条 II 导联心电图上的QT 间期,以秒为单位。
依次按五个步骤解读这条 II 导联心电图:心率、节律、P 波、PR 间期、QRS 时限。你在哪一步发现第一个异常?点击它。
Which SBAR recommendation is the clearest?
A severely malnourished patient started nutrition two days ago and now has weakness and confusion. Which laboratory result should the nurse check first?
答案: C · It compresses the heart and stops the ventricles filling
The pericardial sac is fairly inelastic, so fluid that collects quickly raises the pressure around the heart. The ventricles cannot fill in diastole, stroke volume falls and the blood pressure drops. This is cardiac tamponade, treated by pericardiocentesis.
答案: D · Stopping even today lowers carbon monoxide levels before surgery
Carboxyhaemoglobin falls substantially within about 12–24 hours of stopping, improving oxygen delivery. Longer abstinence improves airway function, wound healing and reduces complications further. Any stop is beneficial, and support should be offered.
答案: B · 检查导尿管有无扭曲或堵塞,并做膀胱扫描
导尿管堵塞或扭曲,或膀胱膨胀,可以引起或模拟无尿。检查管路、在允许时冲洗或更换导尿管,以及做膀胱扫描,可迅速发现梗阻。肾脏超声用于寻找肾积水等更上方的梗阻。
答案: D · Haloperidol
Haloperidol is a dopamine antagonist and can severely worsen parkinsonian symptoms. Metoclopramide is avoided for the same reason. Causes of delirium should be looked for, and specialist advice is needed if a drug is required.
答案: D · Check the feet every day and never walk barefoot
Peripheral neuropathy and poor circulation mean injuries can go unnoticed. Daily inspection, well-fitting footwear, checking water temperature and regular podiatry help prevent ulcers.
答案: B · 恢复呼吸,同时不引起剧烈疼痛和戒断反应
大剂量推注可突然逆转镇痛,引起剧烈疼痛、躁动、高血压、肺水肿和心律失常。滴定小剂量可恢复足够的呼吸。因为纳洛酮的作用可能比阿片类药物短,可能需要监测并重复给药或持续输注。
答案: B · Metabolic acidosis
In DKA, ketoacids consume bicarbonate, causing a metabolic acidosis. The patient breathes deeply and fast (Kussmaul breathing) to lower PaCO2 as compensation.
答案: C · 停用 PCA,唤醒患者,给氧,并尽快给予纳洛酮
过度镇静和呼吸缓慢提示阿片类药物中毒。应停用阿片类药物,支持气道和呼吸,给氧,遵医嘱给予纳洛酮,并密切监测。
答案: D · It measures the main ketone in DKA, and the dipstick may miss it
In DKA, β-hydroxybutyrate is the main ketone, but most urine dipsticks detect acetoacetate, so they can underestimate ketosis. Blood β-hydroxybutyrate gives a current value that is also useful to monitor recovery.核对依据: Diabetic ketoacidosis - Medical Encyclopedia · MedlinePlus (NIH) (2025)
答案: C · ALT 和 AST 非常高,INR 上升
中毒剂量损害肝细胞,因此 ALT 和 AST 急剧升高,肝衰竭使 INR 升高。乙酰半胱氨酸是解毒剂,早期给予效果最好。核对依据: Acetaminophen Toxicity · StatPearls (NCBI Bookshelf) (2026)
答案: 未代偿
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:代谢性碱中毒时 PaCO₂ ≈ 0.7·HCO₃⁻ + 21 = 47.7–51.7 mmHg,所以实测 39 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: PaCO₂ = 49.7 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: QT = 0.38 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。
粗略的规则:在正常心率下,QT 应小于 R–R 间期的一半(此处 R–R = 0.72 s)。
答案: 折旧率
每条心电图的五个步骤:1. 心率(300 法或 1500 法;若不规则则用 6 秒法);2. 节律:R–R 间期是否相等;3. P 波:是否存在、在 II 导联直立、每个 QRS 之前各有一个且形态一致;4. PR 间期:0.12–0.20 s 且恒定;5. QRS 时限:低于 0.12 s。五个步骤做完之后才命名节律。正常窦性心律五项全部符合:60–100 次/分,规则,每个 QRS 之前有直立 P 波,PR 0.12–0.20 s,QRS 低于 0.12 s。
答案: C · “I would like you to see him within 15 minutes and consider a fluid bolus.”
A good recommendation is specific about the request and the time frame. Vague statements leave the provider unsure how urgent the problem is.
答案: D · Serum phosphate
In refeeding syndrome, a sudden change to carbohydrate metabolism moves phosphate, potassium and magnesium into cells. Low phosphate can cause weakness, confusion, heart failure and breathing problems.
ExamProblems · examproblems.com/courses/medical-surgical-nursing