肺炎

英文條目：https://en.wikipedia.org/wiki/Pneumonia 

中文條目：https://zh.wikipedia.org/wiki/%E8%82%BA%E7%82%8E 

預後

With treatment, most types of bacterial pneumonia will stabilize in 3–6 days.[86] It often takes a few weeks before most symptoms resolve.[86] X-ray finding typically clear within four weeks and mortality is low (less than 1%).[21][87] In the elderly or people with other lung problems, recovery may take more than 12 weeks. In persons requiring hospitalization, mortality may be as high as 10%, and in those requiring intensive care it may reach 30–50%.[21] Pneumonia is the most common hospital-acquired infection(院內感染) that causes death.[25] Before the advent of antibiotics, mortality was typically 30% in those that were hospitalized.[17]

大部分的細菌型肺炎，在治療後的3─6天內會趨於穩定[86]，但必須要花費數週時間，才能緩解大部分的症狀[86]。4週以內，可以從X光檢驗中測得肺部狀況已經乾淨，死亡率也會降低（低於1%）[21][87]。對於年長者和有其他肺部問題者，可能需要多於12周的時間復原。需要住院治療者，死亡率可能有10%那麼高，而需要加護者則可能達到30-50%[21]。肺炎是最常造成死亡的[[院內感染]][25]。在抗體的使用前，住院治療者死亡率一般為30%[17]。

Complications may occur in particular in the elderly and those with underlying health problems.[87] This may include, among others: empyema, lung abscess, bronchiolitis obliterans(闭塞性细支气管炎), acute respiratory distress syndrome(急性呼吸窘迫症候群), sepsis(敗血症), and worsening of underlying health problems.[87]

併發症可能容易發生在老人和有健康隱憂的人[87]。可能包含以下等等:[[胸膿]]、[[肺膿腫]]、[[閉塞性細支氣管炎]]、[[急性呼吸窘迫症候群]、[[敗血症]]，並導致健康隱憂加重[87]。

臨床預測準則

Clinical prediction rules have been developed to more objectively predict outcomes of pneumonia.[25] These rules are often used in deciding whether or not to hospitalize the person.[25]

針對肺炎，已經開發了臨床預測的準則，可以更客觀的預測肺炎的情形[25]，此準則常用來判斷病人是否需要住院[25]。

*{{le|肺炎嚴重指數|Pneumonia severity index}}（或PSI分數）[25]

*{{le|CURB-65|CURB-65}}分數，考慮到症狀的嚴重性、潛在的疾病以及年齡[88]。

胸腔積液，積膿及膿腫

In pneumonia, a collection of fluid may form in the space that surrounds the lung(胸膜腔).[89] Occasionally, microorganisms will infect this fluid, causing an empyema.[89] To distinguish an empyema from the more common simple parapneumonic effusion, the fluid may be collected with a needle (thoracentesis), and examined.[89] If this shows evidence of empyema, complete drainage of the fluid is necessary, often requiring a drainage catheter.[89] In severe cases of empyema, surgery may be needed.[89] If the infected fluid is not drained, the infection may persist, because antibiotics do not penetrate well into the pleural cavity. If the fluid is sterile, it must be drained only if it is causing symptoms or remains unresolved.[89]

在肺炎中[[胸膜腔]]會產生[[積液]][89]。有時候，胸膜積液會被微生物感染，造成[[胸膿]][89]。若要區分胸膿與[[類肺炎性胸腔積液]]，可以針頭採取胸膜積液([[胸腔穿刺]])，並進行檢驗[89]。如果檢驗結果顯示為胸膿，則必須進行積液的引流，通常會需要用到[[胸管]][89]。較嚴重的胸膿會需要[[手術]][89]。如果被感染的積液沒有被引流，感染會持續，因為抗生素無法有效穿透胸膜腔。如果積液沒被感染，那只有在造成症狀或持續未改善的情況下才需要進行引流[89]。

In rare circumstances, bacteria in the lung will form a pocket of infected fluid called a lung abscess.[89] Lung abscesses can usually be seen with a chest X-ray but frequently require a chest CT scan to confirm the diagnosis.[89] Abscesses typically occur in aspiration pneumonia, and often contain several types of bacteria. Long-term antibiotics are usually adequate to treat a lung abscess, but sometimes the abscess must be drained by a surgeon(外科学) or radiologist.[89]

在少數情況下，肺中的細菌會造成肺實質壞死，產生空腔積聚膿液，稱為[[肺膿瘍]][89]。肺膿瘍通常能透過胸部X光觀察到，但往往需要胸部電腦斷層掃描方能確診[89]。肺膿瘍通常發生於[[吸入性肺炎]]，而且通常包含數種細菌。長效抗生素通常能夠治療肺膿瘍，但有時候膿瘍會需要由[[外科醫師]]或[[放射科醫師]]進行引流。

呼吸及循環衰竭

Pneumonia can cause respiratory failure by triggering acute respiratory distress syndrome(急性呼吸窘迫症候群) (ARDS), which results from a combination of infection and inflammatory response. The lungs quickly fill with fluid and become stiff. This stiffness, combined with severe difficulties extracting oxygen due to the alveolar fluid, may require long periods of mechanical ventilation for survival.[32]

Sepsis(敗血症) is a potential complication of pneumonia but occurs usually in people with poor immunity or hyposplenism. The organisms most commonly involved areStreptococcus pneumoniae, Haemophilus influenzae, and Klebsiella pneumoniae. Other causes of the symptoms should be considered such as a myocardial infarction(心肌梗死)or a pulmonary embolism(肺栓塞).[90]

若肺炎導致了[[急性呼吸窘迫症候群]]（ARDS），可能會造成呼吸衰竭，是感染及發炎反應連帶的結果。肺部會快速充滿液體且變的僵硬，也因為有肺泡液難以提取空氣中的氧，和血紅素結合，為病患維生考量，可能需要{{le|機械通氣|mechanical ventilation}}一段較長的時間[32]。敗血症也是肺炎的可能併發症之一，但大部份會發生在免疫力不佳或{{le|脾机能亢进|hyposplenism}}的病患，病原體多半是肺炎鏈球菌，流感嗜血桿菌和肺炎克雷伯桿菌。不過需考慮是否有像[[心肌梗死]]及[[肺栓塞]]等可能造成類似症的原因[90]。

流行病學

Main article: Epidemiology of pneumonia

Age-standardized death rate: lower respiratory tract infections per 100,000 inhabitants in 2004[90]

no data >7000

Pneumonia is a common illness affecting approximately 450 million people a year and occurring in all parts of the world.[13] It is a major cause of death among all age groups resulting in 4 million deaths (7% of the world’s total death) yearly.[13][14] Rates are greatest in children less than five, and adults older than 75 years.[13] It occurs about five times more frequently in the developing world(发展中国家) than in the developed world(已開發國家).[13] Viral pneumonia accounts for about 200 million cases.[13] In the United States, as of 2009, pneumonia is the 8th leading cause of death.[21]

肺炎是十分常見的疾病，每年影響世界各地將近4.5億人[13]。 肺炎在各年齡層都是主要死亡原因之一，每年造成了將近4百萬人的死亡(將近7%的全球死亡人數[13][14]。小於五歲的小孩以及大於75歲的老年人肺炎的發病率較高[13]。於[[發展中國家]]的發生率約是[[已開發國家]]的五倍[13]。 病毒性肺炎有近2億個病例[13]。2009年，肺炎在美國名列第八大死因[21]。

In 2008, pneumonia occurred in approximately 156 million children (151 million in the developing world and 5 million in the developed world).[13] In 2010, it resulted in 1.3 million deaths, or 18% of all deaths in those under five years, of which 95% occurred in the developing world.[13][20][92] Countries with the greatest burden of disease include India (43 million), China (21 million) and Pakistan (10 million).[93] It is the leading cause of death among children in low income countries(发展中国家).[13][14] Many of these deaths occur in the newborn(嬰兒) period. The World Health Organization(世界卫生组织) estimates that one in three newborn infant deaths is due to pneumonia.[94] Approximately half of these deaths can be prevented, as they are caused by the bacteria for which an effective vaccine is available.[95] In 2011, pneumonia was the most common reason for admission to the hospital after an emergency department visit in the U.S. for infants and children.[96]

在2008年，肺炎發生在約略1億5千6百萬兒童身上(其中1億5千1百萬例發生在開發中國家而5百萬例發生在已開發國家)[13]。2010年，肺炎造成130萬例死亡，占五歲以下死亡案例的18%，在開發中國家中占95%的比例[13][20][92]。最受其擾的國家包括印度（4300萬）、中國（2100萬）和巴基斯坦（1000萬）[93]。肺炎是[[開發中國家]]兒童致死的主因[13][14]。其中許多案例發生在[[嬰兒]]時期。[[世界衛生組織]]估計有三分之一的嬰孩死因為肺炎[94]。在有效的疫苗可得的情況下，約略有一半的案例是可被預防的，因為這些案例皆是細菌導致的[95]。2011年，肺炎成為在急診引進美國後最常見的孩童住院原因[96]。