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。
Virchow's triad describes three factors that promote venous thrombosis. Which patient factor represents venous stasis?
A patient with stable severe COPD has a blood gas showing pH 7.37, a raised PaCO₂ and a raised bicarbonate. How should this be interpreted?
一名高血压难以控制、血钾持续偏低的患者,未使用利尿剂。应考虑哪种疾病?
The nurse has four neurology patients. Which one needs to be seen first?
Which instruction is important during bowel preparation for colonoscopy?
A worker has a hydrofluoric acid burn on the hand and severe pain. After irrigation with water, which specific treatment is commonly applied?
A pressure ulcer shows full-thickness tissue loss with exposed bone. Which category (stage) is this?
A nurse teaches a patient with reflux disease. Which statement shows a need for further teaching?
A patient with diabetes is found unconscious with a blood glucose of 38 mg/dL (2.1 mmol/L). Which treatment is appropriate?
A patient who had pituitary surgery has fatigue and cold intolerance. The free T4 is low and the TSH is low. What does this pattern suggest?
某练习动脉血气显示 pH 7.43,PaCO₂ 52 mmHg (6.9 kPa),HCO₃⁻ 33 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 pH 7.27,PaCO₂ 29 mmHg (3.9 kPa),HCO₃⁻ 13 mmol/L,Na⁺ 144,Cl⁻ 105 mmol/L。利用阴离子间隙和 Δ 比值,点选最合适的解读。
这条 II 导联心电图条带显示窦性心律伴一次停顿。测量 停顿,即跨越停顿的 R–R 间期,单位为秒。
这条 II 导联心电图显示心房与心室之间存在传导问题。这是什么节律?点击你的答案。
Which patient with diabetes should the nurse see first?
An infant with pyloric stenosis has repeated projectile vomiting. Which acid-base imbalance is most likely?
答案: B · Immobility after major surgery
Virchow's triad is stasis of blood, vessel wall injury and hypercoagulability. Immobility, long journeys and heart failure cause stasis. Surgery and trauma injure vessel walls. Oestrogen, cancer, pregnancy and inherited thrombophilias increase coagulability.
答案: C · Chronic respiratory acidosis with metabolic compensation
In chronic CO₂ retention, the kidneys retain bicarbonate over days, bringing the pH back towards normal. A normal pH with high PaCO₂ and high bicarbonate is compensated chronic respiratory acidosis. These patients usually have target saturations of 88–92%.
答案: B · 原发性醛固酮增多症(Conn 综合征)
醛固酮过多导致钠水潴留(高血压)和钾丢失(低钾血症)。原发性醛固酮增多症是高血压常见的继发原因,通过醛固酮/肾素比值筛查。Addison 病的表现则相反。
答案: D · A patient with Guillain–Barré syndrome whose vital capacity is falling
A falling vital capacity and weak cough in Guillain–Barré syndrome warn of respiratory failure, which may need ventilation. The other patients have expected or less urgent problems.
答案: D · Drink plenty of clear fluids while taking the preparation
Bowel preparation causes profuse diarrhoea, which can lead to dehydration and electrolyte disturbance. Patients follow a low-residue diet, then clear fluids, and drink plenty of extra clear fluid.
答案: D · Calcium gluconate gel
Hydrofluoric acid penetrates deeply and binds calcium and magnesium, causing severe pain and possible life-threatening hypocalcaemia. Calcium gluconate gel binds fluoride; serum calcium and heart rhythm are monitored in larger exposures.
答案: B · 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 · "A big meal just before bed is fine if I take my tablet."
Large late meals increase reflux even when a PPI is taken. Raising the head of the bed, losing weight and reducing alcohol are correct measures.
答案: D · Glucagon by injection, or IV dextrose as prescribed
A patient who cannot swallow safely must not receive anything by mouth because of the risk of aspiration. Glucagon (injected or intranasal) or IV dextrose raises the glucose; once awake and able to swallow, the patient is given oral carbohydrate and a snack.
答案: A · Secondary (central) hypothyroidism from pituitary failure
In primary hypothyroidism, a low T4 causes a high TSH. A low T4 with a low or inappropriately normal TSH means the pituitary (or hypothalamus) is not producing enough TSH, so the TSH cannot be used alone to monitor treatment.
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:代谢性碱中毒时 PaCO₂ ≈ 0.7·HCO₃⁻ + 21 = 42.1–46.1 mmHg,所以实测 52 mmHg 提示合并呼吸性酸中毒(混合性紊乱)。上面的答案是按 ROME 法的考试分类。
答案: 单纯高间隙酸中毒
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: 停顿 = 2.16 s
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)。
停顿中没有出现 P 波,且停顿不是 P–P 周期的整数倍:窦性停搏。恰好两个或三个周期的停顿则提示窦房传导阻滞。
答案: 二度 I 型房室传导阻滞(文氏现象)
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。
答案: A · Glucose 48 mg/dL (2.7 mmol/L), sweating and confused
Severe hypoglycemia with confusion can quickly lead to seizures and loss of consciousness. The other patients have problems that matter but are not immediately dangerous.
答案: A · Metabolic alkalosis
Repeated vomiting of stomach contents loses hydrochloric acid, causing metabolic alkalosis, often with low chloride and potassium. Fluids and electrolytes are corrected before surgery.
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