下呼吸道

第7講 下呼吸道感染 Lower Respiratory Tract Infections,DEFINITION,Lower respiratory tract infections include infectious processes of the lungs and bronchi, pneumonia, bronchitis, bronchiolitis, and lung abscess.下呼吸道感染是指肺炎、支氣管肺炎，支氣管炎，毛細(xì)支氣管炎，肺膿腫的感染過程。,BRONCHITIS,ACUTE BRONCHITIS支氣管炎是指氣管、支氣管樹的大范圍廣義呼吸道感染的一種炎癥狀態(tài)。不包括肺泡炎癥。常分為急性或慢性炎癥。急性支氣管炎可發(fā)生在所有年齡段，而慢性支氣管炎的主要影響成年人。Bronchitis refers to an inflammatory condition of the large elements of the tracheobronchial tree that is usually associated with a generalized respiratory infection. The inflammatory process does not extend to include the alveoli. The disease entity is frequently classified as either acute or chronic. Acute bronchitis occurs in all ages, whereas chronic bronchitis primarily affects adults.急性支氣管炎常發(fā)生于冬季，寒冷，潮濕的氣候和/或高濃度的刺激性的物質(zhì)，如空氣污染或香煙的煙霧中可能沉淀在氣管內(nèi)引起炎癥。Acute bronchitis most commonly occurs during the winter months. Cold, climates and/or the presence of high concentrations of irritating substances such as air pollution or cigarette smoke may precipitate attacks.,Pathophysiology,呼吸道病毒是迄今為止最常見的與急性支氣管炎有關(guān)的因素。普通感冒病毒，鼻病毒，冠狀病毒，下呼吸道病原體，包括流感病毒，腺病毒，呼吸道合胞病毒，占了大多數(shù)。肺炎支原體也是一個(gè)常見的急性支氣管炎病原。其他病原還包括肺炎衣原體、百日咳桿菌菌Respiratory viruses are by far the most common infectious agents associated with acute bronchitis. The common cold viruses, rhinovirus and coronavirus, and lower respiratory tract pathogens, including influenza virus, adenovirus, and respiratory syncytial virus, account for the majority of cases. Mycoplasma pneumoniae also appears to be a frequent cause of acute bronchitis. Other bacterial causes include Chlamydia pneumoniae and Bordetella pertussis.粘膜和支氣管分泌物增加，呼吸道上皮細(xì)胞從輕度到廣泛損傷，可能會(huì)影響支氣管纖毛功能。此外，增加的支氣管分泌物變得粘稠及厚實(shí)，進(jìn)一步削弱黏膜纖毛活動(dòng)。反復(fù)急性呼吸道感染可增加氣道高反應(yīng)性和慢性阻塞性肺疾病。Infection of the trachea and bronchi causes hyperemic and edematous mucous membranes and an increase in bronchial secretions. Destruction of respiratory epithelium can range from mild to extensive and may affect bronchial mucociliary function. In addition, the increase in bronchial secretions, which can become thick and tenacious, further impairs muco-ciliary activity. Recurrent acute respiratory infections may be associated with increased airway hyperreactivity and possibly the pathogenesis of chronic obstructive lung disease.,Clinical Presentation,支氣管炎是一種自限性疾病，很少致死。急性支氣管炎往往繼發(fā)于上呼吸道感染。急性支氣管炎患者通常沒有特異性主訴，主訴主要是如身體不適、頭痛、鼻炎，咽痛。Bronchitis is primarily a self-limiting illness and rarely a cause of death.Acute bronchitis usually begins as an upper respiratory infection. The patient typically has nonspecific complaints such as malaise and headache,coryza, and sore throat.咳嗽是急性支氣管炎的標(biāo)志。早期發(fā)生，并會(huì)持續(xù)，不管鼻腔或鼻咽部癥狀是否緩解。通常情況下，咳嗽最初是無痰的，但隨著進(jìn)展，會(huì)產(chǎn)生粘液膿性痰。 Cough is the hallmark of acute bronchitis. It occurs early and will persist despite the resolution of nasal or nasopharyngeal complaints. Frequently, the cough is initially nonproductive but progresses, yielding mucopurulent sputum.胸部檢查可能會(huì)顯示雙肺干啰音，呼吸音增粗、濕性羅音。胸部X線片通常是正常的。 Chest examination may reveal rhonchi and coarse, moist rales bilaterally.Chest radiographs, when performed, are usually normal.,一般來說痰細(xì)菌培養(yǎng)作用有限，因?yàn)椴蓸蛹夹g(shù)無法避免鼻咽正常菌群。當(dāng)需要某個(gè)特定診斷時(shí)，必須做病毒抗原檢測。 在長期或嚴(yán)重的情況下， 根據(jù)流行病學(xué)考慮，應(yīng)該進(jìn)行肺炎支原體的培養(yǎng)或血清學(xué)診斷及百日咳肺炎的培養(yǎng)或直接熒光抗體檢測。Bacterial cultures of expectorated sputum are generally of limited utility because of the inability to avoid normal nasopharyngeal flora by the sampling technique. Viral antigen detection tests can be used when a specific diagnosis is necessary. Cultures or serologic diagnosis of M.pneumoniae and culture or direct fluorescent antibody detection for B.pertussis should be obtained in prolonged or severe cases when epidemiologic considerations would suggest their involvement.,Treatment,急性支氣管炎的治療主要是對癥和支持療法。休息及單獨(dú)用退熱藥就足夠了。臥床休息和溫和的解熱鎮(zhèn)痛治療通常有助于減輕嗜睡，全身乏力，發(fā)熱等癥狀。應(yīng)鼓勵(lì)患者喝水，并可能降低的粘度呼吸道分泌物。The treatment of acute bronchitis is symptomatic and supportive in nature. Reassurance and antipyretics alone are often sufficient. Bedrest and mild analgesic-antipyretic therapy are often helpful in relieving the associated lethargy, malaise, and fever. Patients should be encouraged to drink fluids to prevent dehydration and possibly decrease the viscosity ofrespiratory secretions.阿司匹林或?qū)σ阴０被用?-6小時(shí)給藥一次（成人650毫克 或兒童10-15mg/kg，成人每日最大劑量為4g，兒童60毫mg/kg） Aspirin or acetaminophen (650 mg in adults or 10 to 15 mg/kg per dose in children with a maximum daily adult dose of 4 g and 60 mg/kg for children) or ibuprofen (200 to 800 mg in adults or 10 mg/kg per dose in children with a maximum daily dose of 3.2 g for adults and 40 mg/kg for children) is administered every 4 to 6 hours.在兒童，應(yīng)避免首選阿司匹林，因?yàn)榘⑺酒チ挚赡芤鹑鹨木C合癥。 In children, aspirin should be avoided and acetaminophen used as the preferred agent because of the possible association between aspirin use and the development of Reyes syndrome.,霧化吸入有助于稀釋支氣管分泌物。Mist therapy and/or the use of a vaporizer may further promote the thinning and loosening of respiratory secretions.持續(xù)的輕度咳嗽可以用右美沙芬治療，嚴(yán)重的咳嗽可以選用可待因或類似藥物。Persistent, mild cough, which may be bothersome, may be treated with dextromethorphan; more severe coughs may require intermittent codeine or other similar agents.不鼓勵(lì)對支氣管炎常規(guī)使用抗菌藥，然而別人持續(xù)發(fā)熱及呼吸道癥狀超過4-6天，應(yīng)該考慮使用抗菌藥。Routine use of antibiotics in the treatment of acute bronchitis is discouraged; however, in patients who exhibit persistent fever or respiratory symptomatology for more than 4 to 6 days, the possibility of a concurrent bacterial infection should be suspected.,如有必要使用抗菌藥，應(yīng)選擇直接作用于預(yù)期病原菌（如肺炎鏈球菌、流感嗜血桿菌）或者咽喉部優(yōu)勢菌。When possible, antibiotic therapy is directed toward anticipated respiratory pathogen(s) (i.e., Streptococcus pneumoniae, Haemophilus influenzae) and/or those demonstrating a predominant growth upon throat culture.如果因病史或感冒凝集素陽性（抗體滴度大于或等于1:32），應(yīng)懷疑感染 肺炎支原體，如果經(jīng)過培養(yǎng)或血清學(xué)檢查確認(rèn)，可用阿奇霉素治療。此外，對成人可選用喹諾酮類（如左氧氟沙星）。M. pneumoniae, if suspected by history or positive cold agglutinins (titers greater than or equal to 1:32) or if confirmed by culture or serology, may be treated with azithromycin. Also, a fluoroquinolone with activity against these pathogens (levofloxacin) may be used in adults.,在已知的流行病， 如果在病程的早期疑似感染A型流感病毒，金剛烷胺或金剛乙胺可有效地減少相關(guān)癥狀。During known epidemics involving the influenza A virus, amantadine or rimantadine may be effective in minimizing associated symptomatology if administered early in the course of the disease.,CHRONIC BRONCHITIS,Pathophysiology慢性支氣管炎是多種因素引起的：如吸煙、職業(yè)灰塵煙霧暴露、環(huán)境污染及細(xì)菌感染。Chronic bronchitis is a result of several contributing factors, including cigarette smoking; exposure to occupational dusts, fumes, and environmental pollution; and bacterial (and possibly viral) infection.在慢性支氣管炎，支氣管壁增厚和大支氣管及細(xì)支氣管表面分泌粘液的杯狀細(xì)胞數(shù)目顯著增加。粘液腺變得肥厚及黏液腺導(dǎo)管擴(kuò)張。作為這些損害的結(jié)果，慢性支氣管炎患者在其外圍呼吸道有更多的粘液，進(jìn)一步損害正常肺的防御，造成黏液堵塞較小的氣道。In chronic bronchitis, the bronchial wall is thickened and the number of mucus-secreting goblet cells in the surface epithelium of both larger and smaller bronchi is markedly increased. Hypertrophy of the mucus glands and dilatation of the mucus gland ducts are also observed. As a result of these changes, patients with chronic bronchitis have substantially more mucus in their peripheral airways, further impairing normal lung defenses and causing mucus plugging of the smaller airways.炎癥繼續(xù)進(jìn)展，可以導(dǎo)致殘留的小支氣管形成疤痕，氣道阻塞及支氣管壁的變薄Continued progression of this pathology can result in residual scarring of small bronchi, augmenting airway obstruction and the weakening of bronchial walls.,病 因,外因吸煙感染因素理化因素氣候過敏因素,內(nèi)因呼吸道局部防御及免疫功能減低植物神經(jīng)功能失調(diào),Clinical Presentation,慢支的典型癥狀是從輕度至“嗆煙樣”咳嗽，直至嚴(yán)重的持續(xù)性有大量濃痰的咳嗽。絕大部分患者晨早會(huì)咳出大量的痰液，也有患者整天都咳出大量痰液。痰液顏色呈白色至黃綠色。 The hallmark of chronic bronchitis is cough that may range from a mild “smokers” cough to severe incessant coughing productive of purulent sputum. Expectoration of the largest quantity of sputum usually occurs upon arising in the morning, although many patients expectorate sputum throughout the day. The expectorated sputum is usually tenacious and can vary in color from white to yellow-green.慢支的診斷主要依賴臨床表現(xiàn)及病史。只要咳嗽伴痰液每年至少持續(xù)3個(gè)月，連續(xù)2年以上即可確診為慢支。下表1列出慢支分類及治療方案。 The diagnosis of chronic bronchitis is based primarily on clinical assessment and history. By definition, any patient who reports coughing up sputum on most days for at least 3 consecutive months each year for 2 consecutive years suffers from chronic bronchitis. Table 43-1 presents a classification and treatment scheme for chronic bronchitis.排除其他肺病，輕中度慢支的體檢一般沒有明顯的表現(xiàn)（見表2）。 With the exception of pulmonary findings, the physical examination of patients with mild to moderate chronic bronchitis is usually unremarkable(Table 43-2).,痰液中中性粒細(xì)胞增加提示有持續(xù)性的支氣管刺激物存在，痰液中嗜酸性粒細(xì)胞增加提示有過敏原刺激，痰液細(xì)菌培養(yǎng)分離鑒定出的常見細(xì)菌：（常用總培養(yǎng)的百分?jǐn)?shù)表示）提示慢支的急性發(fā)作。An increased number of polymorphonuclear granulocytes in sputum often suggests continual bronchial irritation, whereas an increased number of eosinophils may suggest an allergic component. The most common bacterial isolates (expressed in percentages of total cultures) identified from sputum culture in patients experiencing an acute exacerbation of chronic bronchitis are as follows:流感嗜血桿菌 a 45% a:產(chǎn)beta-內(nèi)酰胺酶 卡他莫拉菌 a 30% b:對青霉素耐藥肺炎鏈球菌 b 20%E.coli，腸球菌屬、克雷伯桿菌、綠膿桿菌 5%,臨床表現(xiàn),癥狀咳嗽咳痰喘息或氣促,體征早期無異常體征；急性發(fā)作期可有散在的干、濕羅音；哮鳴音、肺氣腫體征。,經(jīng)常在胸部聽診聽到吸氣和呼氣羅音，哮鳴音，呼氣相輕度延長。敲擊心臟濁音區(qū)域有回聲,正常呼吸聲音減弱,杵狀指（晚期）,臨床分型、分期,分型單純型喘息型,分期急性發(fā)作期 1周慢性遷延期 1月臨床緩解期 2月,眼底至少有4耀斑，或者有嚴(yán)重的合并癥,Treatment,General Principles 一般原則首先必須評(píng)估病人是否有職業(yè)/環(huán)境毒物、刺激性氣體等暴露史、是否吸煙。如果有暴露史，必須減少暴露。 A complete occupational/environmental history for the determination of exposure to noxious, irritating gases, as well as cigarette smoking, must be assessed. Exposure to bronchial irritants should be reduced.減少或者禁止吸煙 Attempts should be made with the patient to reduce or eliminate cigarette smoking.加濕或者霧化吸入有助于稀釋濃痰，減少痰液分泌。使用的粘液裂解氣霧劑（例如，N-乙酰半胱氨酸;脫氧核糖核酸酶）對中度或重度的慢性阻塞性肺疾病又未接受糖皮質(zhì)激素吸入治療的患者有很大的治療價(jià)值。Humidification of inspired air may promote the hydration (liquefaction) of tenacious secretions, allowing for more effective sputum production. The use of mucolytic aerosols (e.g., N-acetylcysteine; deoxyribonuclease) is of questionable therapeutic value. Mucolytics may have the greatest benefit in patients with moderate or severe chronic obstructive pulmonary disease who are not receiving inhaled corticosteroids.體位引流可能有助于促進(jìn)肺部分泌物的清除。Postural drainage may assist in promoting clearance of pulmonary secretions.,Pharmacologic Therapy,急性發(fā)作期口服或者霧化吸入支氣管擴(kuò)張藥是有益的。如果有證據(jù)顯示病人有持續(xù)性的氣道阻塞，必須考慮改變擴(kuò)張支氣管。Oral or aerosolized bronchodilators (e.g., albuterol aerosol) may be of benefit to some patients during acute pulmonary exacerbations. For patients who consistently demonstrate limitations in airflow, a therapeutic change of bronchodilators should be considered.長期吸入異丙基阿托品可以降低咳嗽頻率、咳嗽嚴(yán)重程度及痰液分泌。Long-term inhalation of ipratropium decreases the frequency of cough,severity of cough, and the volume of expectorated sputum.抗菌藥是非常重要的治療藥物，但是對其使用存在爭議?？咕幈仨殞赡艿母腥静≡行В也缓推渌幬锇l(fā)生相互作用，增加病人的依從性。The use of antimicrobials has been controversial, although antibiotics are an important component of treatment. Agents should be selected that are effective against likely pathogens, have the lowest risk of drug interactions, and can be administered in a manner that promotes compliance,選擇抗菌藥前必須認(rèn)識(shí)到超過30-40%的流感嗜血桿菌，超過95%的肺炎支原體是產(chǎn)-內(nèi)酰胺酶的，30%的肺炎球菌對青霉素中度耐藥。Selection of antibiotics should consider that up to 30% to 40% of H.influenzae and 95% of M. pneumoniae are -lactamase producers, and up to 30% of S. pneumoniae are at least moderately penicillin resistant.抗菌藥使用總結(jié)見表43-3.在癥狀緩解期，使用抗菌藥治療劑量的上限為5-7天。Antibiotics commonly used in the treatment of these patients and their respective adult starting doses are outlined in Table 43-3. Duration of symptom-free periods may be enhanced by antibiotic regimens using the upper limit of the recommended daily dose for 5 to 7 days.某些病人的病史提示有些特定的因素會(huì)加重病情，如季節(jié)變化、冬季，應(yīng)該提前預(yù)防性使用抗菌藥。如果2-3年內(nèi)連續(xù)2-3月無明顯臨床效果，抗菌藥預(yù)防性治療無效。 In patients whose history suggests recurrent exacerbations of their disease that might be attributable to certain specific events (i.e., seasonal, winter months), a trial of prophylactic antibiotics might be beneficial. If no clinical improvement is noted over an appropriate period (e.g., 2 to 3 months per year for 2 to 3 years), prophylactic therapy could be discontinued.,BRONCHIOLITIS毛細(xì)支氣管炎,毛細(xì)支氣管炎是一種急性病毒性下呼吸道感染，50%患兒發(fā)作于1歲以內(nèi)的新生兒、100%發(fā)生于3歲以內(nèi)。 Bronchiolitis is an acute viral infection of the lower respiratory tract of infants that affects approximately 50% of children during the first year of life and 100% by 3 years.合胞病毒是引起毛細(xì)支氣管炎的主要病毒，大約占到70%。副流感病毒是第二位病原，細(xì)菌性感染作為繼發(fā)因素只占到很少的部分。Respiratory syncytial virus is the most common cause of bronchiolitis,accounting for up to 70% of all cases. Parainfluenza viruses are the second most common cause. Bacteria serve as secondary pathogens in only a small minority of cases.,Clinical Presentation,出現(xiàn)臨床癥狀之前，有2-8天前驅(qū)癥狀。The most common clinical signs of bronchiolitis are found in Table 43-4.A prodrome suggesting an upper respiratory tract infection, usually lasting from 2 to 8 days, precedes the onset of clinical symptoms.由于攝入量的限制，加上咳嗽、發(fā)熱、嘔吐、腹瀉，容易導(dǎo)致脫水。As a result of limited oral intake due to coughing combined with fever,vomiting, and diarrhea, infants are frequently dehydrated.毛細(xì)支氣管炎診斷主要根據(jù)臨床表現(xiàn)及病史。在喘息的患兒呼吸道分泌物中的分離病毒病原體確定毛細(xì)支氣管炎的診斷。The diagnosis of bronchiolitis is based primarily on history and clinical findings. The isolation of a viral pathogen in the respiratory secretions of a wheezing child establishes a presumptive diagnosis of infectious bronchiolitis.,Treatment,屬于自限性疾病，除了安撫及解熱外，毛細(xì)支氣管炎一般不需要處理，除非出現(xiàn)了缺氧及脫水。發(fā)熱的患兒可以給于口服補(bǔ)液、密切觀察。Bronchiolitis is a self-limiting illness and usually requires no therapy (other than reassurance and antipyretics) unless the infant is hypoxic or dehydrated. Otherwise healthy infants can be treated for fever, provided generous amounts of oral fluids, and observed closely.嚴(yán)重患者需要吸氧及IV補(bǔ)充液體。 In severely affected children, the mainstays of therapy for bronchiolitis are oxygen therapy and IV fluids.,除了判斷患兒發(fā)生了支氣管痙攣，霧化吸入beta-擬腎上腺素藥物是無益的。Aerosolized -adrenergic therapy appears to offer little benefit for the majority of patients but may be useful in the child with a predisposition toward bronchospasm.由于細(xì)菌不是主要的病原菌，不需要常規(guī)給與抗菌藥。但是醫(yī)生往往在等待培養(yǎng)結(jié)果時(shí)初始階段給藥空軍藥物治療。因?yàn)橛薪ㄗh認(rèn)為毛細(xì)管支氣管炎往往有可能引起細(xì)菌性肺炎。Because bacteria do not represent primary pathogens in the etiology of bronchiolitis, antibiotics should not be routinely administered. However, many clinicians frequently administer antibiotics initially while awaiting culture results because the clinical and radiographic findings in bronchiolitis are often suggestive of a possible bacterial pneumonia.大部分合胞病毒引起的可以考慮利巴韋林治療（無其他肺病、心血管病或這樣嚴(yán)重感染）。需要霧化吸入的設(shè)施及專門培訓(xùn)的人員。Ribavirin may be considered for bronchiolitis caused by respiratory syncytial virus in a subset of patients (those with underlying pulmonary or cardiac disease or with severe acute infection). Use of the drug requires special equipment (small-particle aerosol generator) and specifically trained personnel for administration via oxygen hood or mist tent.,PNEUMONIA,PATHOPHYSIOLOGY,病原微生物到達(dá)下呼吸道有以下3條路徑：和空氣顆粒物一起吸入；通過肺部以外感染進(jìn)入血液；鼻咽部病原菌吸入。Microorganisms gain access to the lower respiratory tract by three routes: they may be inhaled as aerosolized particles; they may enter the lung via the bloodstream from an extrapulmonary site of infection; or aspiration of oropharyngeal contents may occur.病毒感染能夠抑制肺部自潔功能，損害肺泡巨噬細(xì)胞功能及粘膜纖毛細(xì)胞的擺動(dòng)。導(dǎo)致繼發(fā)性細(xì)菌感染。Lung infections with viruses suppress the bacterial clearing activity of the lung by impairing alveolar macrophage function and mucociliary clearance, thus setting the stage for secondary bacterial pneumonia.大部分健康成人的肺炎由肺炎球菌引起的社區(qū)獲得性肺炎（75%以上急性肺炎患者），其他病原有肺炎支原體、軍團(tuán)菌、肺炎衣原體等“非典型”致病因子由金黃色葡萄球菌、G-細(xì)菌引起的獲得性肺炎主要見于老人、特別是養(yǎng)老院的老人，酗酒者及其他有傷害行為的人。The vast majority of pneumonia cases acquired in the community by otherwise healthy adults are due to S. pneumoniae (pneumococcus) (up to 75% of all acute bacterial pneumonias). Other common bacterial causes include M. pneumoniae, Legionella, and C. pneumoniae, which are referred to as “atypical” pathogens. Community-acquired pneumonias caused by Staphylococcus aureus and gram-negative rods are observed primarily in the elderly, especially those residing in nursing homes,and in association with alcoholism and other debilitating conditions.,革蘭陰性需氧桿菌和金黃色葡萄球菌是醫(yī)院獲得性肺炎的主要病原體Gram-negative aerobic bacilli and S. aureus are also the leading causativeagents in hospital-acquired pneumonia.口腔及鼻咽部病菌的吸入是引起厭氧菌肺炎的主要病菌Anaerobic bacteria are the most common etiologic agents in pneumonia that follows the gross aspiration of gastric or oropharyngeal contents.兒童階段的非要主要有病毒引起，特別是合胞病毒、副流感病毒及腺病毒。A組鏈球菌、金黃色葡萄球菌及肺炎球菌是常見的病原菌。In the pediatric age group, most pneumonias are due to viruses, especially respiratory syncytial virus, parainfluenza, and adenovirus. Pneumococcus is the most common bacterial cause, followed by Group A Streptococcus and S. aureus.,社區(qū)獲得性肺炎 Community Acquire Pneumonia CAP,一、社區(qū)獲得性肺炎(CAP)的定義：,社區(qū)獲得性肺炎是指在醫(yī)院外罹患的感染性肺實(shí)質(zhì)（含肺泡壁，即廣義上的肺間質(zhì)）炎癥，包括具有明確潛伏期的病原體感染而在入院后平均潛伏期內(nèi)發(fā)病的肺炎。,1.CAP的臨床診斷依據(jù)：,新近出現(xiàn)的咳嗽，咳痰，或原有呼吸道疾病加重,并出現(xiàn)膿性痰；伴或不伴胸痛發(fā)熱肺實(shí)變體征和(或)濕性羅音WBC1010/L或4109/L，伴或不伴核左移胸部X線檢查顯示片狀，斑片狀浸潤陰影或間質(zhì)性改變，伴或不伴胸腔積液,以上1-4項(xiàng)中任何一款加第5項(xiàng)，并除外肺結(jié)核，肺部腫瘤，非感染性肺間質(zhì)性疾病，肺水腫，肺不漲，肺栓塞，肺嗜酸性粒細(xì)胞潤浸癥，肺血管炎等，可建立臨床診斷。,2.CAP感染的細(xì)菌主要是：,肺炎鏈球菌、流感嗜血桿菌、副流感嗜血桿菌、卡他莫拉氏球菌、支原體、衣原體和其他病原菌,社區(qū)呼吸道感染(CARTI)常見致病菌1,其他,卡他10%,流感25%,肺鏈40%,社區(qū)獲得性感染常見病原菌,CAP 4重癥患者,3.成人CAP患者分類,CAP 3需住院(不需ICU)治療,CAP 2老年人有/無基礎(chǔ)疾病,CAP 1青壯年無基礎(chǔ)疾病,4.經(jīng)驗(yàn)治療CAP1的初始經(jīng)驗(yàn)性抗菌治療,抗菌藥物選擇大環(huán)內(nèi)酯類青霉素復(fù)方磺胺多西環(huán)素一代頭孢新喹諾酮類（如左氧氟沙星、司帕沙星、莫西沙星等）,常見病原體肺炎鏈球菌肺炎支原體肺炎衣原體流感嗜血桿菌等,抗菌藥物選擇二代頭孢-內(nèi)酰胺類/抑制劑或聯(lián)合大環(huán)內(nèi)酯類新喹諾酮類,常見病原體肺炎鏈球菌流感嗜血桿菌需氧革蘭陰性桿菌金黃色葡萄球菌卡他莫拉菌等,CAP2的初始經(jīng)驗(yàn)性抗菌治療,抗菌藥物選擇 二代頭孢單用，或聯(lián)合 大環(huán)內(nèi)酯類 頭孢噻肟或頭孢曲松單 用，或聯(lián)合大環(huán)內(nèi)酯類 新喹諾酮類或新大環(huán)內(nèi) 酯類 青霉素或一代頭孢聯(lián)合 喹諾酮類或氨基糖甙類,常見病原體肺炎鏈球菌流感嗜血桿菌復(fù)合菌(包括厭氧菌)需氧革蘭陰性桿菌金黃色葡萄球菌肺炎衣原體呼吸道病毒等,CAP3的初始經(jīng)驗(yàn)性抗菌治療