（節(jié)選）醫(yī)學外文翻譯--社區(qū)獲得性肺炎的住院與門診研究進展（英文）

1、Recent Advances in Community- Acquired Pneumonia*Inpatient and OutpatientMichael S. Niederman, MD, FCCPCommunity-acquired pneumonia (CAP) is a common illness, with the majority of patients treated out of the hospital, ye

2、t the greatest burden of the cost of care comes from inpatient management. In the past several years, the management of these patients has advanced, with new information about the natural history and prognosis of illness

3、, the utility of serum markers to guide management, the use of appropriate clinical tools to guide the site-of-care decision, and the finding that guidelines can be developed in a way that improves patient outcome. The c

4、hallenges to patient management include the emergence of new pathogens and the progression of antibiotic resistance in some of the common pathogens such as Streptococcus pneumoniae. Few new antimicrobial treatment option

5、s are available, and the utility of some new therapies has been limited by drug-related toxicity. Ancillary care for severe pneumonia with activated protein C and corticosteroids is being studied, but recently, inpatient

6、 care has been most affected by the development of evidence-based “core measures” for management that have been promoted by the Centers for Medicare and Medicaid Services, which form the basis for the public reporting of

7、 hospital performance in CAP care. (CHEST 2007; 131:1205–1215)Key words: community-acquired pneumonia; drug resistance; methicilllin-resistant pneumonia; severe pneumonia; severity index; Staphylococcus aureus; Streptoco

8、ccus pneumoniaeAbbreviations: APACHE ? acute physiology and chronic health evaluation; CAP ? community-acquired pneumonia; CMS ? Centers for Medicare and Medicaid Services; CRP ? C-reactive protein; CURB-65 ? confusion,

9、elevated BUN level, elevated respiratory rate, low systolic or diastolic BP, and age ? 65 years of age; DRSP ? drug-resistant Streptococcus pneumoniae; HCAP ? health-care-associated pneumonia; MRSA ? methicillin-resistan

10、t Staphylococcus aureus; OR ? odds ratio; PCT ? procalcitonin; PSI ? pneumonia severity index; SARS ? severe acute respiratory syndromeI n the past several years, clinical advances in community-acquired pneumonia (CAP) h

11、ave emerged in a number of areas that can aid in the care of both inpatients and outpatients. Major clinical issues for all CAP patients have been the changingspectrum of etiology, including drug-resistant Strep- tococcu

12、s pneumoniae (DRSP), methicillin-resistant Staphylococcus aureus (MRSA), and emerging viral pathogens (eg, severe acute respiratory syndrome [SARS] and avian influenza). In addition, there has been an interest in better

13、understanding the natural history and prognosis of CAP by trying to define the role of prognostic scoring systems in guiding the decision about site of care (ie, inpatient, outpatient, or ICU) and by applying a number of

14、 serum markers (ie, C-reactive protein [CRP] and procalcitonin [PCT]) to prognosticate outcome. New antimicrobial agents have become available for both outpatients and inpatients, in several antibiotic classes, but the u

15、tility of some of these agents has been limited by new findings of toxicities that were not evident in registration trials of these medications (ie, gatifloxa-*From the Department of Medicine, State University of New Yor

16、k at Stony Brook, Stony Brook, NY. Dr. Niederman has been a speaker, consultant, or researcher for Schering, Johnson and Johnson, Aventis, Pfizer, Bayer, Merck, Elan, and Wyeth. Manuscript received August 10, 2006; revis

17、ion accepted October 5, 2005. Reproduction of this article is prohibited without written permission from the American College of Chest Physicians (www.chestjournal. org/misc/reprints.shtml). Correspondence to: Michael Ni

18、ederman, MD, FCCP, Department of Medicine, Winthrop-University Hospital, 222 Station Plaza N, Suite 509, Mineola, NY 11501; e-mail: mniederman@winthrop.org DOI: 10.1378/chest.06-1994CHEST Recent Advances in Chest Medicin

19、ewww.chestjournal.org CHEST / 131 / 4 / APRIL, 2007 1205by whether or not a patient is admitted to the hospital.3 In the United States, ? 20% of all CAP patients are admitted to the hospital, but the dollars spent on the

20、se patients account for ? 90% of the total cost of care for this disease, emphasizing the impact of the hospital admission decision.3 For a number of years, prognostic scoring systems have been used to define not only th

21、e predicted mortality rate of CAP, but also, by inference, the site of care, reserving hospital admission for those with a high predicted mortality rate. The two commonly used tools for the purpose of predicting outcome

22、in CAP patients have been the pneumonia severity index (PSI), which was devel- oped in the United States, and the British Thoracic Society rule, which has recently been modified to the CURB-65 (referring to its assessmen

23、t of the follow- ing five factors: confusion; elevated BUN level; elevated respiratory rate; low systolic or diastolic BP; and age ? 65 years of age) rule.4 Each of these approaches has limitations, and it may be best to

24、 view them as complementary, ideally identifying patients at opposite ends of the disease spectrum.5The PSI has been best validated as a way to identify patients with a low risk of mortality, but the scoring system can o

25、ccasionally underestimate severity of illness, especially in young patients without comor- bid illness because it heavily weights age and comor- bidity, and does not measure CAP-specific disease severity.5 On the other h

26、and, the CURB-65 ap- proach may be ideal for identifying patients with a high risk of mortality with severe illness due to CAP, who might otherwise be overlooked without the formal assessment of subtle aberrations in key

27、 vital signs.5 However, one deficiency of the CURB-65 approach is that it does not generally account for comorbid illness and thus may not be easily applied in older patients who may still have a substantial mortality ri

28、sk if even a mild form of CAP destabilizes a chronic, but compensated, disease process. In one recent study4 that compared the PSI to the CURB-65 in 3,181 patients seen in an emergency department, both were determined to

29、 be good for predicting mortality and for identifying patients with a low risk of mortality. However, the PSI appeared to be more discriminating in identifying patients with a low risk of mortality, with 68% being define

30、d by PSI to have a low risk (classes I to III), with a mortality rate of 1.4%, while 61% were defined by the CURB-65 to have a low risk (score of 0 to 1) with a mortality rate of 1.7%. However, the CURB-65 may have been

31、more valuable at the severe disease end of the spectrum because it defined high-risk patients as those with a score of 2, 3, 4, or 5, each with a progressively increasing risk of death, while the PSIwas less discriminati

32、ng, defining only two groups as being severely ill. In another analysis,6 the CURB-65 score also appeared to identify, most accurately, those patients with CAP who were likely to benefit from treatment with drotrecogin a

33、lfa in the recom- binant Human Activated Protein C Worldwide Eval- uation in Severe Sepsis (or PROWESS) study. A reexamination of the data from that study demon- strated that a threshold CURB-65 score of ? 3 was associat

34、ed with a decrease in the 28-day mortality rate in drotrecogin alfa-treated patients of 10.8% when compared to control subjects (p ? 0.018) vs a decrease in mortality rate in treated patients in PSI classes IV and V of 9

35、.7% compared to control subjects (p ? 0.013).6Capelastegui and colleagues7 used both the PSI and the CURB-65 approach to evaluate a large number of both inpatients and outpatients with CAP in Spain. They observed that th

36、e CURB-65 (and its simpler CRB-65 version, which excludes the mea- surement of BUN, and therefore can be used in outpatients) could accurately predict the 30-day mortality rate, the need for mechanical ventilation, and,

37、to some extent, the need for hospitalization. In addition, the CURB-65 criteria correlated with the time to clinical stability, and thus a higher score was predictive of a longer duration of IV therapy and a longer lengt

38、h of hospital stay. The PSI also worked well to predict mortality in that study. While both the PSI and CURB-65 are good for predicting mortality, neither can be used to define the site of care, without considering other

39、 clinical and social variables. A study at a public hospital in the United States, with many indigent patients, showed that the PSI could not define the need for hospital admission if patients were homeless or acutely in

40、toxicated, or if they did not have a stable home environment that allowed them to be dis- charged from the hospital while receiving oral anti- biotic therapy.8 In one recent commentary,5 the suggestion was made to combin

41、e both of these prognostic scoring tools, recognizing that neither approach can stand alone. Low-risk patients (ie, PSI classes I to III or CURB-65 score of 0 to 1) can be managed at home if serious vital sign abnormalit

42、ies (in the case of PSI) or comorbidities (in the case of CURB-65) are absent, and if patients do not have social factors or other illnesses that are unstable and that necessitate hospitalization. Moderate-risk pa- tient

43、s (ie, CURB-65 score of ? 2 or PSI classes IV and V) probably should be admitted to the hospital, and clinical assessment should be used to separate those who need ICU care from those who are likely to become clinically