答案及解析：D.
Asthma is a type of reactive airway disease characterized by hyperresponsive airways, reversible expiratory airflow obstruction, and chronic inflammation. Sudden bronchospasm in response to external/internal stimuli and response to bronchodilators like β2-agonists are important distinguishing features of asthma. Elastase deficiency in the airways is a feature of emphysema.哮喘是一種反應性氣道疾病，其特徵是氣道反應性增高、可逆性的呼氣氣流阻塞和慢性炎症。由於外界或內在的刺激而突發支氣管痙攣，並且使用支氣管擴張劑（如β2-受體激動劑）有效是哮喘的重要特點。彈性蛋白酶缺乏是肺氣腫的一個特徵。圖1描述了哮喘發作的機制
（Yao and Artusio's Anesthesiology P5）
2. A 55-year-old male presented to you with a pulmonary function test report, which shows an increase of FEV1 percent predicted of more than 12%, and an increase in FEV1 of greater than 0.2 L in response to bronchodilators. Which characteristic of his respiratory illness is depicted here?一位55歲的男性患者像你提供了肺功能檢查報告，報告顯示：使用支氣管擴張劑，FEV1百分比預計值增加12%，FEV1實際增加0.2L。這裡描述了患者呼吸系統疾病哪一特徵？A. Bronchial asthma—acute bronchodilator responsivenessB. Chronic obstructive pulmonary disease(COPD)—variability in airflow obstructionC. COPD—acute bronchodilator responsivenessD. All the above are correct
Response to a bronchodilator drug resulting in relief of airway obstruction is highly suggestive of bronchial asthma. A more than 12% increase in predicted FEV1 and an absolute increase in FEV1 of more than 0.2L suggest acute bronchodilator responsiveness and variability in airflow obstruction. The reversibility of this magnitude is almost always indicative of bronchial asthma. COPD patients do respond to bronchodilators but not to the same extent. Early stages of asthma are diagnosed by decreased mid expiratory flow rates (effort independent) and decreased FEV1 and by its reversibility.
使用支氣管擴張劑使氣管阻塞緩解高度提示支氣管哮喘。預測FEV1增加12%以上，且FEV1實際增加0.2L以上，提示支氣管擴張劑的反應性和氣道阻塞的可逆性。這種程度的可逆性是支氣管哮喘的指標。COPD患者對支氣管擴張劑確實有反應，但程度不同。早期哮喘的診斷依據是呼氣中期流速的減少（和用力呼吸無關）和FEV1的減少及其可逆性。
3. Which of the following techniques is associated with a lower complication rate related to bronchospasm in the asthmatic population?B. General anesthesia — laryngeal maskairway (LMA)C. General anesthesia — endotracheal tube (ETT) D. Combined general and neuraxialanesthesiaIn a severely asthmatic patient, regional anesthesia is superior to general anesthesia with an LMA, which is better than general anesthesia with ETT. The choice of anesthetic technique is often influenced by the severity of asthma, history of previous intubations for asthma, dependence on inhaled bronchodilators, and patient preference. The goal in any such circumstance is to decrease airway manipulation and stimulation. If a general anesthetic technique is pursued, inhaled bronchodilator therapy immediately prior to induction, use of non–histamine-releasing drugs, airway manipulation only after deep anesthetic plane, and use of intravenous lidocaine prior to intubation have all been proven to be useful.
在嚴重哮喘患者麻醉中，局部麻醉優於喉罩全麻，而喉罩優於氣管插管麻醉。麻醉技術的選擇往往受哮喘嚴重程度、既往插管史、對支氣管擴張劑的依賴以及患者的偏好等因素的影響。這種情況下的目標是減少氣道操作和刺激，如果採用全麻技術，在誘導前應立即吸入支氣管擴張劑、非組胺釋放藥物治療，且僅在深麻醉情況下進行氣道操作，插管前靜脈使用利多卡因已被證實有效。
圖2描述支氣管痙攣的誘發因素（Yao and Artusio's Anesthesiology P26）4. A 22-year-old patient with a history of moderate persistent asthma on medium-dose inhaled corticosteroids and long-acting inhaled β-agonist presents for an emergency appendectomy. On clinical examination, he is actively wheezing, but maintaining an oxygen saturation of 99% on room air. Which of the following statements about this clinical scenario is most appropriate?
一名22歲有中度持續性哮喘病史的患者，吸入中等劑量的糖皮質激素和長效的β受體激動劑，緊急行闌尾切除術。臨床檢查時，他有明顯的哮喘，但是吸入空氣時，脈氧飽和度保持在99%。以下哪一說法最正確？
A. Presence of wheezing on physical examination indicates that he is having a severe attack of asthmaB. Volatile anesthetics cause bronchodilation（支氣管擴張）through catecholamine（兒茶酚胺）-independent mechanismsC. Increased airway resistance that occurs intraoperatively is usually due to acute exacerbation of asthmaD. A laryngeal mask airway (LMA) is more stimulating to the airway than an endotracheal tube, and should be avoided in asthmaticsHistory and physical examination can suggest presence of severe asthma if the patient has had repeated intubations for asthma. Even though high pitched, musical wheezes are characteristic of asthma, they are not specific and they have no correlation with the severity of obstruction. Spirometry is the only objective method to quantify the severity of obstruction. Sudden severe bronchospasm can present as high airway pressures with absence of breath sounds and very high resistance to mechanical ventilation. Mechanical causes of obstruction such as a kinked endotracheal tube or a mucous plug can also present a similar clinical picture and are more common. If bronchospasm is suspected, anesthesia should be augmented with an intravenous anesthetic such as propofol. General anesthesia through a LMA is less stimulating to the airway than through an endotracheal tube. Volatile anesthetics are potent bronchodilators, and they act through catecholamine-independent mechanisms. They are rarely used as second-line agents in cases of bronchospasm refractory to medical therapy.如果患者多次通過插管治療哮喘，病史和體格檢查可提示重症哮喘。儘管哮喘的特徵是哮鳴音，但它不是特異性的，也與阻塞的程度無關。呼吸量測定法是唯一客觀量化阻塞嚴重程度的方法。突發性嚴重支氣管痙攣可表現為氣道壓力高、無呼吸音、機械通氣阻力大。機械性阻塞如氣管導管打折或粘液栓塞，也可以呈現類似的臨床表現，且更常見。如果懷疑支氣管痙攣，應靜脈注射異丙酚等麻醉藥物以增加麻醉深度。經LMA的全身麻醉對氣道的刺激比經氣管內插管的少。揮發性麻醉藥是強效的支氣管擴張劑，它們通過與兒茶酚胺無關的機制起作用。在藥物治療難以控制的支氣管痙攣病例中，它們很少被用作二線藥物。5. During the above case, the end-tidal sevoflurane concentration reads 3.5, but the anesthesia ventilator is alarming because of high peak airway pressures. Which of the following is the most likely cause?在上述病例中，患者呼氣末七氟醚濃度為3.5，但麻醉呼吸機因氣道峰值壓力過高報警。下列哪項是最可能的原因：A. Acute bronchospasm（支氣管痙攣）B. Anaphylactic（過敏的） reaction to intravenous muscle relaxant that you just administeredC. Mechanical causes of obstructionD. Inadequate depth of anesthesia
答案及解析; C.
Acute bronchospasm causes expiratory wheezing, increased peak inspiratory pressure or decreased tidal volume (depending on the mode of ventilation), and a characteristic upslope of the capnogram. Any airway stimulation can cause severe reflex bronchoconstriction and bronchospasm inseverely asthmatic patients with hyperactive airways. Mechanical causes of obstruction such as a kinked endotracheal tube or a mucous plug can also present a similar clinical picture and are more common. When troubleshooting such a scenario, an intravenous anesthetic agent is very helpful to deepen the plane of anesthesia as the delivery of inhaled anesthetic agents may not be effective.
急性支氣管痙攣引起呼氣相哮鳴音、吸氣峰壓值增高或潮氣量減少（取決於通氣方式）以及典型的二氧化碳波形呈特徵性的上升形態。任何的氣道刺激都可能引起嚴重的反射性支氣管收縮和支氣管痙攣。機械原因的阻塞，如氣管導管打折或粘液栓，也可能呈現類似的波形，且更常見。在處理這種情況時，靜脈麻醉藥有利於加深麻醉深度，而吸入麻醉藥可能無效。
本題中提及「capnogram」，中文翻譯為「二氧化碳描記圖」。下面為大家簡單介紹一下二氧化碳描記圖。雖然術語二氧化碳描記圖和二氧化碳檢測儀常被誤認為同義詞，但後者僅對二氧化碳進行測量（即只能分析），沒有連續的記錄和波形功能。二氧化碳描記圖的波形可以基於時間和容量進行圖形描記。2. 二氧化碳描記圖採集技術有兩種為主流式和側流式（圖3）。臨床上多採用側流式。側流(A)和主流(C)採樣方法的示意圖，以及在二氧化碳濃度增加曲線圖(B和D中的紅色曲線)。上升時間(T70)對應於傳感器從其最終值的10%更改到70%所需的時間。側流採樣法延遲時間較長。3. 側流式二氧化碳描記圖時間波形以及各種典型圖的意義，在第四章 第9次曾重點介紹，不妨複習一下吧。堅持分享不容易，歡迎大家多多轉發推薦，直接點擊右下方的「在看」鼓勵。謝謝大家了！