http://dx.doi.org/10.4046/trd.2011.71.6.438 ISSN: 1738-3536(Print)/2005-6184(Online) Tuberc Respir Dis 2011;71:438-444 CopyrightC2011. The Korean Academy of Tuberculosis and Respiratory Diseases. All rights reserved. 치료된폐농양환자의폐실질병변의분석 Original Article 순천향대학교의과대학 1 내과학교실, 2 영상의학교실이지연 1, 구소미 1, 박경아 1, 서유리 1, 김세훈 1, 김양기 1, 김기업 1, 황정화 2, 어수택 1 Analysis of Lung Parenchymal Sequelae Following Treatment for Lung Abscess Ji-Yeon Lee, M.D. 1, So My Koo, M.D. 1, Kyong Ah Park, M.D. 1, Yu Ri Seo, M.D. 1, Se Hun Kim, M.D. 1, Yang-Ki Kim, M.D. 1, Ki-Up Kim, M.D. 1, Jung Hwa Hwang, M.D. 2, Soo-Taek Uh, M.D. 1 Departments of 1 Internal Medicine and 2 Radiology, Soonchunhyang University School of Medicine, Seoul, Korea Background: Lung abscess is necrosis of the pulmonary parenchyma caused by microbial infection. At present, clinical outcomes after treatment are good. However, the pulmonary parenchymal changes on the chest computed tomography (CT) after treatment are not well known. We studied the changes of pulmonary parenchyma on plane chest radiography and chest CT in patients with lung abscess following the administration of antibiotics. Methods: We retrospectively reviewed 39 patients who had lung abscess with or without combined pneumonia from January 2006 to July 2010. We studied the therapeutic response in plane chest radiography of them at 1, 2, or more than 3 months following treatment. If any chest CT of them during the study period, we reviewed. Results: Mean age of the patients was about 61.3±11.2. Mean duration of antibiotics administration was about 36.7±26.8 days. After 3 months of following plane chest radiography, 10 patients (36%) showed without residual sequelae among 28 patients. Findings from other patients showed decrease in densities (11 patients, 39%), fibrostreaky sequelae (4 patients, 14%) and bullae (3 patients, 10%). After more than 2 months, chest CT was checked only in 7 patients. Among the 7 patients, 4 patients showed no residual lesion, 3 patients showed decreased densities on plane chest radiography. Chest CT revealed fibrostreaky densities in 2 patients, ground glass opacities in 3 patients, bullous formation in 1 patient, and cystic bronchiectasis in 1 patient. Conclusion: After more than 2 months following treatment for lung abscess even though there were no lesions on plane chest radiography, chest CT showed fibrostreaky or ground glass opacity. Key Words: Lung Abscess; complications; Radiography, Thoracic; Tomography, X-Ray Computed; Cicatrix 서 폐농양은미생물감염으로인한폐실질내의괴사로정의하며괴사성농을함유한공동을형성한다. 폐농양은만성알콜중독자, 신경질환등의흡인이발생하기쉬운 Address for correspondence: Ki-Up Kim, M.D. Department of Internal Medicine, Soonchunhyang University Seoul Hospital, 22, Daesagwan-gil, Yongsan-gu, Seoul 140-743, Korea Phone: 82-2-709-9114, Fax: 82-2-792-5812 E-mail: kukim@schmc.ac.kr Received: Aug. 29, 2011 Accepted: Oct. 20, 2011 론 사람이나만성간질환, 만성폐질환, 악성종양, 당뇨등의면역억제자에서호발하고 1 항생제가폐조직을투과하기어렵기때문에치료가어려워사망률이 15% 에서 20% 에달한다 2. 최근전산화단층촬영및초음파등의영상학적진단방법들이발달하면서폐농양과폐경색, 농흉등의유사한질환들과의감별이수월해졌다 3,4. 또한항생제및중재학적시술이발달함에따라적절한배농이조기에이루어져폐농양과관련된사망률은감소하고있다. 일반적으로폐농양은치료후수개월이지나면단순흉부영상에서잔존병변이남지않는다고알려져있다. 1970년에발표된논문에서폐농양환자 79명중 36명이치 438
Tuberculosis and Respiratory Diseases Vol. 71. No. 6, Dec. 2011 료 8주이내, 79명중 50명이치료 6개월이내에단순흉부영상에서병변의소실을보였다 5. 그러나이는단순흉부영상에의한결과로써흉부전산화단층촬영을통한분석이이루어진다면단순흉부사진에서관찰되지않는잔존병변이존재할가능성이있다 6. 또한이탈리아에서 1,747명을대상으로한전향적연구 7 에서급성폐감염의병력이있는환자의폐기능추적검사에서 1초간노력성호기량의감소가관찰된결과를바탕으로하기도감염후후유증으로소기도의구조변화와기능변화가발생할가능성을예측해볼수있다. 아직까지국내에서는폐농양치료후흉부전산화단층촬영을통한폐실질합병증에대해서는연구된바가없다. 이에폐농양의진단과치료후퇴원한환자들에서폐실질의영상의학적후유증이남아있는지에대해알아보고자흉부영상소견및흉부전산화단층촬영소견의변화에대해후향적으로조사하였다. 대상및방법 2006년 1월부터 2010년 7월까지순천향대학교서울병원에입원한환자중에서병력청취및진찰소견에서발열을포함한전신증상과기침, 화농성객담등의호흡기증상이동반된환자와흉부단순영상에서공기-물음영등의이상을보여폐농양이의심되는환자에서흉부전산화단층촬영으로폐농양을확진한환자 39명을대상으로하였다. 폐농양의원인증명을위한세균학적검사로객담또는기관지내시경하객담채취후객담그람도말및배양검사, 객담항산균도말및배양검사를시행하였다. 최종배양검사및영상학적판단으로결핵에의한폐농양으로진단한환자 3명을제외하고 36명의자료를분석하였다. 폐농양의치료는미국감염학회의기준 8 에따라치료하였고, 추적기간은진단후 1개월째, 2개월째, 그리고 3개월째단순흉부사진을분석하였고, 흉부전산화단층촬영은치료완료후목적이나시기에관계없이얻어진영상을분석하였다. 폐농양진단후추적한단순흉부사진또는흉부전산화단층촬영에서농양의소실정도와잔존병변을확인하여기술하였다. 연구대상군의특징에대한분석으로성별및연령별발생빈도, 기저질환, 폐농양의위치, 배양균주및항생제사용일수를분석하였다. 결 1. 성별및연령별발생빈도 총 36명중남자가 28명 (78%), 여자가 8명 (22%) 이었다. 평균연령은 61.3±11.2 세 ( 평균 ± 표준편차 ) 로연령별로는 50대가 12명 (33%) 으로가장많았고, 70대가 11명 (31%), 60대 8명 (22%) 의순이었다. 2. 기저질환 기저질환으로는당뇨가 19명 (52%) 으로가장많았으며고혈압및관상동맥질환이 7명 (19%), 중추신경계질환 5명 (14%), 악성종양 5명 (14%) 의빈도를보였으며, 동반질환이없는경우가 7명 (19%) 이었다 (Table 1). 악성종양환자는위암 2명, 폐암 1명, 직장암 1명, 급성임파구성백혈병 1명이있었다. 3. 폐농양의위치 진단시폐농양의위치는우폐에 67%, 좌폐에 33% 였으며, 엽상분류로는우하엽에서 12명 (33%) 으로가장많았다 (Table 2). 폐렴이동반된폐농양은 12명 (33%) 이었으며다발성농양을가지는경우가 20명 (56%), 공기-액체층 (air-fluid level) 은 30명 (83%) 에서관찰되었다. Table 1. Underlying disease of the patients with lung abscess Underlying disease No. (%) Diabetes mellitus 19 (52) Hypertension and Coronary artery disease 7 (19) CNS disease 5 (14) Malignancy 5 (14) Liver disease 3 (8) COPD 2 (5) ESRD 1 (2) Relatively Healthy 7 (19) CNS: central nervous system; COPD: chronic obstructive pulmonary disease; ESRD: end stage renal disease. 과 4. 배양균주및항생제사용일수 36명의환자중총 8명 (22%) 의환자에서객담배양검사에서균이배양되었으며검출된균주는 Klebsiella pneumonia, Sternotrophomonas maltophilia, Entrococcus faecium, Pseudomonas aeruginosa, Citrobacter freundii, 439
JY Lee et al: Analysis of lung parenchymal sequelae of lung abscess Acinetobacter baumanii 가배양되었다. 세균검사와동시에시행한객담항산성도말및배양검사는모두음성이었으며항균제사용일수는평균 36.7±26.8 일 ( 평균 ± 표준편차 ) 이었다. Table 2. Location of the abscess cavity Location No. (%) Rt. lung 24 (67) Upper lobe 7 (19) Middle lobe 5 (14) Lower lobe 12 (33) Lt. lung 12 (33) Upper lobe 6 (17) Lower lobe 6 (17) 5. 추적관찰소견추적 3개월째단순흉부영상은 28명에서확인되었고나머지 8명에서는 1개월추적검사에서음영이감소되었음을확인하였으나 2개월이후에는추적검사가되지않았다. 28명중 10명 (36%) 에서진단시보였던음영의소실을보여정상흉부영상소견을보였다. 11명 (39%) 의환자에서음영이감소되었으나감소의정도는다양하였으며단순흉부촬영에서잔존병변 (sequelae) 의판단이어려웠다. 4명 (14%) 에서섬유선상의반흔형음영을보였다. 3명 (11%) 에서는기포 (bullae) 양반흔을보였다. 치료후추적흉부전산화단층촬영은 28명중 15명에서만시행되었다. 그중치료후 2개월이내에추적검사를시행한 8명에서공동의크기는줄었으나잔존병변이있었다. 28명중 2개월이상경과한시점에서추적흉부전 Figure 1. Chest radiography and chest CT during diagnosis and more than 2 months after treatments. (A, C) In a 67-year-old man patchy airspace consolidation in the superior segment of RLL was detected and confirmed lung abscess by chest CT. (B, D) Fifteen months later, the lesion is resolved except for the fibrosteaky density. CT: computed tomography. 440
Tuberculosis and Respiratory Diseases Vol. 71. No. 6, Dec. 2011 Figure 2. (A, C) In a 64- year-old man with underlying lung cancer in the LUL, segmental air space consoilidation with irregular cavitation is noted in the superior segment of the LLL which is associated with mild adjacent fissural bulging contour. (B, D) Two months later, previous lesion in LLL is improved with a mild residual scar and a pneumatocele. LUL: left upper lobe; LLL: left lower lobe. 산화단층촬영을시행한환자는 7명이었다. 7명의단순흉부영상은 4명에서는정상, 3명에서는음영의감소를보였다. 정상단순흉부영상을보인 4명의흉부전산화단층촬영은 2명에서섬유선상의잔존음영 (Figure 1) 을보였고, 2명에서간유리음영과폐경화가보였다. 단순흉부영상에서잔존음영이관찰되었던 3명에서는흉부전산화단층촬영에서 1명은기포양음영 (Figure 2) 이보였고, 치료전농양의크기가 13 cm였던 1명에서낭성기관지확장증 (Figure 3), 나머지 1명에서간유리음영이보였다 (Table 3). 폐농양으로진단한 36명에서중재적시술이나수술이필요한경우는없었다. 농흉으로의진행, 전이성뇌농양등합병증을동반하거나사망한환자는없었다. 고찰폐농양은흡인된물질이폐의존부 (dependent portion) 의작은기관지를막아서기관지주위조직으로폐렴이형성되고괴사및액화의결과로공동이형성된다. 흡인은앙와위 (supine position) 에서일어나기때문에폐농양의호발부위는상엽의후분절 (posterior segment), 하엽의상분절 (superior segment) 이다. 기존의보고에의하면폐농양의예후와관련된인자들은다수의기저질환동반, 병원내감염, 빈혈을포함한전신상태의불량등이있으며, 방사선영상의예후인자로는진단시폐농양의크기가크고, 우하엽에위치한폐농양의예후가나쁘다고알려져있다 2,9. 폐농양에대한연구는과거사망률이높았던시기에활발했으나진단기술의발달, 효과적인항생제도입및침습적시술로사망률이감소되면서관심이적어진질환이다. 441
JY Lee et al: Analysis of lung parenchymal sequelae of lung abscess Figure 3. (A) In a 52-yearold man Segmental air space consolidation with peripheral ground glass attenuation is noted in the superior segment of the LLL and lesser extent in the posterior segment of LLL with mild lung volume expansion. (B) Two months later, there is a decrease in the extent of segmental air space consolidation with peripheral ground glass attenuation in previous area. (C) Irregular shaped low density necrotic areas and multiple cavities were noted within the consolidations. (D) But irregular shaped multiple cavities are increased within the consolidations. Newly appeared cicatricial bronchiolectasis and bronchiectasis is seen. LLL: left lower lobe. Table 3. Chest radiography, CT finding after treatment Plane chest radiographic finding No remnant lesion Decreased densitiy Fibrostreaky density Bulla Cases (n=28) 10 11 4 3 (36) (39) (14) (11) Chest CT findings Cases (n=7) No remnant lesion Ground glass opacity/consolidation Fibrostreaky density Bulla Cystic bronchiectasis 0 3 2 1 1 (0) (43) (29) (14) (14) Data are presented as number (%). CT: computed tomography. 또한 흉부 전산화 단층촬영의 도입으로 진단뿐 아니라 유 사질환과의 감별이 쉬워졌다. 그러나 최근 원인 세균들의 추세가 변화되고 있으며10, 과거에 비해 치료경과와 예후 에 현저한 변화를 보이고 있어 이에 대한 연구가 필요하 다. 최근 폐농양으로 인한 사망률은 3%로 감소하였고, 치 442 11 료율은 85 90%까지 증가하였다. 폐농양치료율의 증가 는 영상의학적 진단기술을 통한 발병 초기의 적절한 항생 제 투여와 빠르고 정확한 중재학적 시술과 관련이 있다. 흉부 전산화 단층촬영이 발달하지 않았던 시기에는 비슷 한 질환인 농흉, 폐경색 등과의 감별이 힘들어 치료방법 및 치료기간의 설정이 어려웠으나 영상학적 진단기술의
Tuberculosis and Respiratory Diseases Vol. 71. No. 6, Dec. 2011 발달로폐농양의정확한위치와공동의수, 폐렴의동반유무및치료후추적관찰시폐병변변화의관찰이용이하다. 또한경피적배농법이결핵공동에처음도입된후현재까지폐농양의기본적인치료로이용되고있다. 폐농양의항생제치료로는이전 clindamycin 단독이던치료에서 penicillin 및 clindamycin 병합요법이초치료로추천되는데이는이전 1970년대까지는 Fusobacterium nucleatum, Peptostreptococcus spp., Bacteroides melanonogenicus 등의혐기성균이주로배양되었다가최근에는 Klebsiella pneumoniae 가주원인균으로배양되기때문이다 10. 농양원인균의확인은침습적인검사로경기관흡인 (transtracheal aspiration) 과경피적폐침생검 (transthoracic lung needle aspiration) 은거의사용하지않기때문에확인이어렵다 1,12. 본연구에서도원인균의동정비율이낮았던것은침습적생검을하지않은이유와혐기성세균감염이주로있었기때문으로판단된다. 본연구에서도폐농양이확인되면 penicillin계의항생제를주로사용하였으며혐기성세균이의심되었을때 clindamycin을추가하였다. 혐기성폐농양의경우치료기간은최소 4주이상이추천된다 13. 폐농양은감염초기에적절한항생제를선택하여충분히치료하면잔존병변없이회복될수있으나, 폐농양이 6 12 주이내에치료되지않으면기관지확장증이나섬유증등의비가역적인변화가나타난다는보고가있다 14,15. 1개월이상의항생제치료에도호전이확실하지않으면외과적치료를고려해야한다. 본연구는폐농양으로확인된 36명의환자에서치료후일정기간동안추적영상을분석한연구로병변의위치, 기저질환그리고균주의분포등에서는기존의연구와비슷한결과를얻었다. 그러나본연구에서는기존의연구에비하여다발성농양발견의비율이더많았으며, 이는폐침윤이나농양이의심되면즉시흉부전산화단층촬영을하였기때문으로추정된다. 이러한정밀검사를통한조기진단이환자의치료결과와예후에도영향을준것으로판단된다. 기존연구결과에따르면일반적으로폐농양치료후대부분의환자에서흉부단순촬영추적검사에서음영이소실된다고알려져있다 5. 그러나본연구에서는이와다른결과를보이고있는데, 치료후 3개월추적에서약 1/3에서만농양음영의소실을보였고, 약 2/5에서는다양한잔존음영을보였으며그외 1/4에서는섬유선상의반흔과기포영상을보였다. 또한우폐하엽에침범된큰농양 에서는치료후낭성기관지확장증의후유증을보였다. 단순흉부사진에서다양한잔존음영을보이는환자에서는향후음영의완전소실보다는흔적이남을수있는가능성이있을것으로추정된다. 흉부전산화단층촬영추적영상이있었던환자 7명에서모두잔존음영이남아있었다. 그러므로폐농양환자에서추적관찰한흉부영상이정상이더라도폐병변의잔존병변의유무를확인하기위해서는흉부전산화단층촬영이도움이될수있을것이다. 흉부전산화단층촬영을통한잔존병변의발견으로환자의잔존폐기능이나반흔성암 (scar carcinoma) 의발생 16-19 에대한위험도예측이가능하다면폐농양치료후흉부전산화단층촬영을통한환자의경과추적에유용할것이다. 본연구는연구기간동안의대상의수가적고, 후향적분석이었기때문에영상의학적추적간격이환자간차이가있으며흉부전산화단층촬영이이루어진환자의수가적다는제한점이있다. 향후폐농양치료후흉부전산화단층촬영을통한잔존병변평가의유용성을평가하기위해서는잔존병변과폐기능과의관련성, 잔존병변과반흔성암과의관련성에대한추가적인연구가필요할것이다. 참고문헌 1. Bartlett JG. Anaerobic bacterial infections of the lung. Chest 1987;91:901-9. 2. Hirshberg B, Sklair-Levi M, Nir-Paz R, Ben-Sira L, Krivoruk V, Kramer MR. Factors predicting mortality of patients with lung abscess. Chest 1999;115:746-50. 3. Stark DD, Federle MP, Goodman PC, Podrasky AE, Webb WR. Differentiating lung abscess and empyema: radiography and computed tomography. AJR Am J Roentgenol 1983;141:163-7. 4. Williford ME, Godwin JD. Computed tomography of lung abscess and empyema. Radiol Clin North Am 1983;21:575-83. 5. Wagley PF, Fisher AM, Block AJ. Primary pulmonary abscess. Trans Am Clin Climatol Assoc 1970;81:51-6. 6. Snow N, Bergin KT, Horrigan TP. Thoracic CT scanning in critically ill patients. Information obtained frequently alters management. Chest 1990;97:1467-70. 7. Jedrychowski W, Krzyzanowski M. The effect of acute broncho-pulmonary infections on the FEV1 change in 13-year follow-up. The Cracow Study. Eur J Epidemiol 1990;6:20-8. 443
JY Lee et al: Analysis of lung parenchymal sequelae of lung abscess 8. Tice AD, Rehm SJ, Dalovisio JR, Bradley JS, Martinelli LP, Graham DR, et al. Practice guidelines for outpatient parenteral antimicrobial therapy. IDSA guidelines. Clin Infect Dis 2004;38:1651-72. 9. Irwin RS, Garrity FL, Erickson AD, Corrao WM, Kaemmerlen JT. Sampling lower respiratory tract secretions in primary lung abscess: a comparison of the accuracy of four methods. Chest 1981;79:559-65. 10. Wang JL, Chen KY, Fang CT, Hsueh PR, Yang PC, Chang SC. Changing bacteriology of adult community-acquired lung abscess in Taiwan: Klebsiella pneumoniae versus anaerobes. Clin Infect Dis 2005;40:915-22. 11. Wali SO, Shugaeri A, Samman YS, Abdelaziz M. Percutaneous drainage of pyogenic lung abscess. Scand J Infect Dis 2002;34:673-9. 12. Bartlett JG. Anaerobic bacterial infections of the lung and pleural space. Clin Infect Dis 1993;16 Suppl 4: S248-55. 13. Levison ME. Anaerobic pleuropulmonary infection. Curr Opin Infect Dis 2001;14:187-91. 14. Fifer WR, Husebye K, Chedister C, Miller M. Primary lung abscess. Analysis of therapy and results in 55 cases. Arch Intern Med 1961;107:668-80. 15. Rumbaugh IF, Prior JA. Lung abscess: a review of forty-one cases. Ann Intern Med 1961;55:223-34. 16. Prasad US, Tiwary A. Scar cancer of the lung. Indian J Chest Dis Allied Sci 1989;31:125-8. 17. Auerbach O, Garfinkel L, Parks VR. Scar cancer of the lung: increase over a 21 year period. Cancer 1979;43: 636-42. 18. Bobba RK, Holly JS, Loy T, Perry MC. Scar carcinoma of the lung: a historical perspective. Clin Lung Cancer 2011;12:148-54. 19. Ardies CM. Inflammation as cause for scar cancers of the lung. Integr Cancer Ther 2003;2:238-46. 444