흡입화상환자에서의폐기능검사소견 한림대학교의과대학내과학교실김종엽, 김철홍, 신현원, 채영제, 최철영. 신태림, 박용범, 이재영, 반준우, 박상면, 김동규, 이명구, 현인규, 정기석 The Findings of Pulmonary Function Test in Patients with Inhalation Injury Jong Yeop Kim, M.D., Cheol Hong Kim, M.D., Hyun Won Shin, M.D., Young Je Chae, M.D., Chul Young Choi, M.D., Tae Rim Shin, M.D., Yong Bum Park, M.D.,Jae Young Lee, M.D., Joon-Woo Bahn, M.D., Sang Myeon Park, M.D., Dong-Gyu Kim, M.D., Myung Goo Lee, M.D., In-Gyu Hyun, M.D., Ki-Suck Jung, M.D. Departments of Internal Medicine, Hallym University College of Medicine, Seoul, Korea Background: The changes in the pulmonary function observed in burn patients with an inhalation injury are probably the result of a combination of airway inflammation, chest wall and muscular abnormalities, and scar formation. In addition, it appears that prolonged ventilatory support and an episode of pneumonia contribute to the findings. This study investigated the changes in the pulmonary function in patients with inhalation injury at the early and late post-burn periods. Methods: From August, 2002, to August 30, 2005, surviving burn patients who had an inhalation injury were enrolled prospectively. An inhalation injury was identified by bronchoscopy within 48hours after admission. Spirometry was performed at the early phase during admission and the recovery phase after discharge, and the changes in the pulmonary function were compared. Results: 37 patients (M=28, F=9) with a total burn surface area (% TBSA), ranging from 0 to 8%, were included. The initial PaO 2/FiO 2ratio and COHb were 286.4±29.6 mmhg and 7.8±6.6 %. Nine cases (24.3%) underwent endotracheal intubation and 3 cases (8.%) underwent mechanical ventilation. The initial X-ray findings revealed abnormalities in, 8 cases (48.6%) with 5 (83.3%) of these being completely resolved. However, 3 (6.7%) of these had residual sequela. The initial pulmonary function test, showed an obstructive pattern in 9 (24.3%) with 4 (44.4%) of these showing a positive bronchodilator response, A restrictive pattern was also observed in 9 (24.3%) patients. A lower DLco was observed in only 4 (7.4%) patients of which 23 had undergone DLco. In the follow-up study, an obstructive and restrictive pattern was observed in only one (2.7%) case each. All the decreased DLco returned to mormal. Conclusions: Most surviving burn patients with an inhalation injury but with a small burn size showed initial derangements in the pulmonary function test that was restored to a normal lung function during the follow up period. (Tuberc Respir Dis 2006; 60: 653-662) Key words: Burn, Inhalation, Pulmonary function test 서 최근화상치료방법의발전으로화상으로인한사망률이감소하였지만, 여전히미국에서는연간 5,000 명이상의사망자가발생하고있으며, 우리나라에서 론 Address for correspondence : In-Gyu Hyun, M.D. Department of Internal Medicine, Hallym University Hangang Sacred Heart Hospital, 94-200 Yeoungdeungpo-dong, Yeoungdeungpo-gu, Seoul, 50-020, Korea Phone : 02-2639-500 Fax : 02-2677-9756 E-mail : ighyun@hallym.ac.kr Received : Feb. 4. 2006 Accepted : Jun. 5. 2006 도연간 500명이상의사망자와약 2,000명이상의화상환자가발생하고있다 2. 특히 2003년 92명의사망자를낸대구지하철참사는화재로인한인명피해가얼마나극심한가를보여주는단적인예로많은사회적파장을일으킨바있다. 화상관련급성사망은대부분일산화탄소중독, 저산소증, 질식및직 간접적인폐손상에기인한다 3,4. 화재현장에서의고열과연기흡입은정상적인호흡생리에영향을주게되는데상 하기도에광범위한기도손상을초래하게된다. 호흡상피가손상을입어괴사되는정도에따라일부기관지점막은탈락되고 casts를형성하여기도폐쇄를초래할수있다 5,6. 또한손상된기도는기관지수축을일으킬수있으며 653
JY Kim et al. : Pulmonary function in patients with inhalation injury 심한경우출혈성기관-기관지염을일으키기도한다 7. 하기도에올수있는변화로는폐포대식세포가손상을입음에따라세균이증식하기쉬운환경을제공하게되고 8, 폐안에존재하는표면활성제및제 2형폐세포의손상을초래하여급성호흡곤란증후군의병인을제공하기도한다 9. 결국, 흡입화상으로인한폐손상은호흡기계의일부에국한되지않고광범위하게이루어지기때문에결정적인예후인자로작용하게되는것이다,3,4,0,. 흡입화상에의한기도손상이실제적인폐기능의변화로이어지는지에대한연구로, Whitener 등은연기흡인에의한폐기능지표의저하가시간이지남에따라서서히회복됨을보고하였다 2. 하지만이연구는대상환자수가적고화상범위에따른폐기능의차이를본것으로환자의특성상기도손상에국한되었다고볼수없다. 저자들은피부화상범위가비교적경미한흡입화상환자들을대상으로초기및회복기의실제적인폐기능의변화를알아보고, 흡입화상에대한기관지내시경적중증도가 3 실제폐활량검사에어떻게영향을미치는지그리고어떠한호흡기적치료가도움이될수있을지를알아보고자하였다. 대상및방법. 대상 2002년 8월부터 2005년 8월까지한림의대한강성심병원호흡기내과에입원한흡입화상환자중기관지내시경에의해기도손상이확인된환자를대상으로하였다. 사망환자와후유증으로저산소성뇌손상을남긴환자는제외하였다. 또한, COPD, 기관지확장증및결핵파괴폐등의구조적만성폐질환이있는환자도제외하였다. 2. 방법 ) 기관지내시경검사흡입화상유무를확인하기위하여입원 48시간이내에기관지내시경검사를시행하였다. 전처치로 atropine 0.5 mg과 pethidine (25-30) mg을검사 30분전에근육주사하였으며, 국소마취는 4% lidocaine 5 ml(200 mg) 을분무기 (Pulmo aide ) 를통해 0-5분동안흡인시킨후구강혹은비강을통하여기관지경 A B Figure. Bronchoscopy performed day after inhalation injury showed some soots and hemorrhagec spots in trachea (A) and right upper lobes (B), in 54 years old female patient 654
Tuberculosis and Respiratory Diseases Vol. 60. No.6, Jun. 2006 < 부록 > Bronchoscopic grades for inhalation injury3. Edema 2. Blistering 3. Carbonaceous material 4. Soot 5. Hemorrhage 6. Inflammation 7. Ulceration 8. Necrosis of mucosa The patients are graded bronchoscopically. Mild -3 features present Moderate 4-6 features present Severe 7-8 features present 을삽입하여검사를시행하였다 (Figure ). 흡입폐손상에대한기관지내시경적중증도는항목수에따라경도 (mild), 중등도 (moderate) 및중증 (severe) 으로분류하였다 3 < 부록 >. 2) 폐기능검사흡입화상초기의폐기능검사는급성기의호흡기증상이호전된후안정상태에서실시하였으며, 회복기의검사는대부분흡입화상후 2-3 개월째에시행하였다. 폐활량측정법을이용하여 (Sensormedics, Vmax 22, Yorba Linda, California, USA) 노력성호기곡선에서강제폐활량 (FVC), 초시강제호기량 (FEV) 및최대중간호기유량 (FEF25-75%) 를구하였으며, 기류 -용량곡선에서최대날숨유량 (PEF) 을구하였다. 최대자발성호흡량 (MVV) 은환자로하여금 2-5 초간최대한빠르고깊게호흡을시켜호흡량을 분간의양으로환산하였다. FVC는제한성장애, FEV 은기류제한 (airflow limitation) 및폐쇄성장애중증도의지표로삼았으며, FEF25-75% 는말초소기도의유량에장애가있는지를확인하고자하였다. 그리고, 기류 -용량곡선과 PEF는기류제한및상기도폐쇄의지표로삼았다. MVV는안면부및흉곽의화상반흔혹은흡입화상으로야기되는호흡장애를극복하고자 하는환자의노력즉, 호흡근육의기능을접근하고자하였다. 폐확산능은 (diffusing capacity of the lung for carbon monoxide; DLco) 잔기량까지호기를한상태에서총폐용량까지혼합기체 (0.3% CO, 0.3% CH 4, 0.3% C 2 H 2, 2% O 2, balance N 2 ) 를빨리흡입시킨후약 0초간숨을멈춘후호기를하도록하여페포내기체가나오는호기시의 CO의농도를계속측정하여 Krogh 공식을이용하여확산능을계산하였다 4. 모든폐기능성적은실제측정치와추정정상치의백분율 (%) 을같이표시하였으며, FEV/FVC 가 70% 미만이고 FEV이추정정상치의 80% 미만인경우를폐쇄성장애로판정하였으며기류제한정도는 Global Initiative for Chronic Obstructive Lung Disease (GOLD) 5 에근거하여정상, 경증, 중등증및중증으로분류하였다. FEV/FVC 가 70% 이상이고 FVC가추정정상치의 80% 미만인경우를제한성장애로판정하였는데, FVC의추정정상치에따라정상 ( 80%), 경증 (60 79%), 중등증 (5 59%) 및중증 ( 50%) 으로분류하였다. 그리고 FEV/FVC 가 70% 미만이고 FVC가추정정상치의 80% 미만이면혼합성장애로판정하였다. DLco는추정정상치의 80 20% 의범위에있으면정상으로판독하였다. 기관지확장제반응을확인하기위해속효성베타항진제인살부타몰 (salbutamol) 을사용하였으며, 흡입 5-30 분뒤폐기능검사를시행하여 FVC 혹은 FEV이기저치보다 200 ml 및 2% 이상증가할때양성으로판단하였다 5. 3) 흉부방사선검사흡입화상으로내원한모든환자들에서흉부방사선검사를시행하였으며일부환자는폐실질의방사선학적변화를접근하기위하여고해상도흉부전산화단층촬영 (HRCT) 을시행하였다. 방사선학적소견상, 기관지주위의간유리음영, 경화, 기관지벽의비후, 무기폐, 제2 폐소엽중격의비후및기관지확장증등의소견이있으면흡입화상에의한변화로판단하였다. 655
JY Kim et al. : Pulmonary function in patients with inhalation injury 3. 통계처리 2. 초기, 회복기의폐기능검사및기관지내시경소견 통계적분석은 MS Window 용 SPSS-PC 0.0 (Statistical package for social science, SPSS Inc. Chicago, IL, USA) 을이용하였다. 측정치는평균 ± 표준편차로표시하였으며, 기관지내시경적중증도와폐기능측정치와의관계는 Spearman 상관분석을적용하였다. 급성기와회복기의폐기능검사지표비교는 paired t-test를시행하였으며 P 값이 0.05 미만일때통계적유의성을두었다.. 기초임상특성 Table. Demographic characteristics in burn patients with inhalation injury (n=37) Variables Values Age, yr 4.62±6.43 Sex 결 연구기간동안총 40명이등록되었으나, 3명은각각사망, 저산소성뇌손상및 COPD로제외되어, 최종적으로 37명 ( 남자 28, 여자 9) 을대상으로분석하였다. 화상체표면적은.86±4.24%(0-8%) 였으며화상의원인은전부화염화상에의해서였다. 내원당시의일산화탄소헤모글로빈 (COHb) 농도는 7.8±6.64%, PaO 2 /FiO 2 비는 286.4±29.6 mmhg, 신체질량지수 (kg/m 2 ) 는 22.66±3.05 였다 (Table ). Male, n(%) 28(75.5) Female, n(%) 9(24.3) %TBSA burn(range).86±4.24(0-8) Flame burn, n(%) 37(00) COHb, % 7.8±6.64 PaO2/FiO2 at admission, (mmhg) 286.4±29.6 CRP (mg/l) 50.56±77.47 Body-mass index (kg/m2) 22.66±3.05 Values are means±standard deviation. TBSA, total body surface area; COHb, carboxyhemoglobin 과 흡입화상초기의폐기능검사는급성호흡기증상이안정되고환자와의협조가가능한상태에서화상후제 6병일 (range; 2-56 days) 에시행되었다. FVC, FEV, FEF25-75%, PEF, MVV 및 DLco(n=23) 의추정정상치는각각 82%, 84%, 75%, 73%, 75% 및 97% 였다 (Table 2). 흡입화상에대한기관지내시경적중증도는정상 예, 경도 2예, 중등도 예및중증이 4예였다. 이들소견과초기폐기능검사와의관련성을살펴보았을때, FVC, FEV, FEF25-75% 및 PEF 의정상추정치모두통계적으로유의한상관성을보여주지는않았다. 한편, FEV의정상추정치와내시경적중증도사이에는유의하지는않으나음의상관성 (R=-0.32, P=0.053) 을보여주는경향을보여주었다 (Figure 2). 퇴원후회복기의폐기능검사는화상후제 59병일 (range; 3-264 days) 에시행하였는데대부분외래 Table 2. Initial findings* of pulmonary function test after inhalation injury Variables Values FVC, liter 3.56±.3 % predicted 82.43±8.62 FEV, liter 2.82±0.98 % predicted 83.9±9.05 FEF25-75, liter/sec 2.77±.42 % predicted 75.29±30.00 PEF, L/sec 5.88±2.38 % predicted 73.48±25.26 MVV, liter/min 05.54±39.89 % predicted 74.80±2.83 DLco, ml/mmhg/min 23.53±8.98 % predicted 96.84±28.68 Values are means±standard deviation. *:post-burn 6 day(2-56), : 23 patients FVC, forced vital capacity; FEV, forced expiratory volume in second; FEF25-75%, forced expiratory flow rate between 25% and 75%; PEF, peak expiratory flow; MVV, maximum voluntary ventilation; DLco, diffusing capacity of the lung for carbon monoxide, 656
Tuberculosis and Respiratory Diseases Vol. 60. No.6, Jun. 2006 에서이루어졌다. FVC, FEV, FEF25-75%, PEF, MVV 및 DLco(n=6) 의추정정상치는각각 89%, 92%, 87%, 84%, 80% 및 2% 였다 (Table 3). 초기폐기능검사에서이상을보인 2명을대상으로추적폐기능지표들의변화를 paired t-test를통해살펴본결과 FVC, FEV, FEF25-75%, PEF 및 MVV 값의유의한증가를보여주었다 (P<0.05). 한편, DLco는초기폐기능검사에서 23명에서시행되었는데이중 4명이정상추정치보다감소되어있었으며추적폐기능검사에서는모두정상추정치에도달하였다. 3. 폐쇄성혹은제한성장애및기관지확장제에대한반응초기폐기능검사소견상 9예 (5.4%) 가정상이었으며, 나머지 8예 (48.6%) 는각각 9예씩폐쇄성및제 한성장애를보여주었다. 폐쇄성장애를보인 9예중 4예 (44.4%) 가기관지확장제에대한반응이양성이었다. 회복기폐기능검사소견을살펴본결과 35예 (94.6%) 에서정상이었으며, 나머지 2예 (5.4%) 는각각 예씩폐쇄성및제한성장애를보여주었다 (Figure 3). 4. 임상경과및방사선학적소견입원경과중 9예 (24.3%) 에서기도유지를위해기관내삽관이필요하였으며이중 3예는호흡부전으로기계호흡치료가필요하였다. 기관절개는 2예 (5.4%) 에서시행되었으며이중 예는회복되어기관절개부위를봉합할수있었으나나머지 예는기관협착증으로진행하였다. 폐렴이 7예 (8.7%) 에서발생하였으며 bronchial toilet을요할정도의무기폐가 9예 (24.3%) 에서있었다. 한편흡입화상초기에 HRCT 40 20 R= - 0.2 P= 0.209 20 00 R= - 0.32 P= 0.053 % predicted FVC 00 80 60 40 % predicted FEV 80 60 40 % predicted FEF25-75 20-40 20 00 80 60 40 20-0 0 2 3 Bronchoscopic R= Gr - 0.228 P= 0.75 2 3 4 4 % predicted PEF 20-40 20 00 80 60 40 20 0-0 0 2 3 Bronchoscopic Gr R= - 0.39 P= 0.43 2 3 4 4 Bronchoscopic Gr Bronchoscopic Gr Figure 2. Correlation between bronchoscopic grades for inhalation injury and initial pulmonaty function tests; % predicted values of FVC, FEV, FEF25-75% and PEF, FVC, forced vital capacity; FEV, forced expiratory volume in second; FEF25-75, forced expiratory flow rate between 25% and 75%; REF, peak expiratory flow, Gr, grade. 657
JY Kim et al. : Pulmonary function in patients with inhalation injury Table 3. Follow-up Findings* of Pulmonary Function Test after Inhalation Injury Table 4. Clinical outcomes and Chest X-ray findings in patients with inhalation injury Variables Values Number(%) FVC, liter 4.6±.2 % predicted 88.74±4.02 FEV, liter 3.39±.3 % predicted 9.75±5.62 FEF25-75, liter/sec 3.56±.47 % predicted 88.67±27.36 PEF, L/sec 7.24±3.0 % predicted 84.40±27. MVV, liter/min 24.75±49.56 % predicted 80.7±23.09 DLco, ml/mmhg/min 27.78±8.56 % predicted.64±29.62 Values are means±standard deviation. *:post-burn 59 day (3-264), :6 patients FVC, forced vital capacity; FEV, forced expiratory volume in second; FEF25-75%, forced expiratory flow rate between 25% and 75%; PEF, peak expiratory flow; MVV, maximum voluntary ventilation; DLco, diffusing capacity of the lung for carbon monoxide. Intubation 9(24.3) Mechanical Ventilation 3(8.) Tracheostomy * 2(5.4) Pneumonia 7(8.7) Atelectasis 9(24.3) Initial CXR findings Normal 9(5.4) Any abnormalities 8(48.6) Follow-up CXR findings Normal 34(9.9) Any abnormalities 3(8.) * : closure after resolved and tracheal stenosis, : including ground glass appearance, bronchial attenuation, bronchial thickening, consolidation, atelectasis, edema, bronchiectasis. 고 찰 Follow-up Initial normal mild obstructive mod obstructive severe obstructive mild restrictive mod restrictive 9(5.4%) 35(94.6%) 2 5 BDR (+); 4/9(44.4%) BDR (-) 2 7 2 0 5 0 5 20 25 30 35 40 Figure 3. The changes of obstructive and restrictive patterns according to initial and follow-up spirometric values. Mod, moderate; BDR, bronchodilator response. 혹은흉부방사선사진에서이상소견을보인경우가 8예 (48.6%) 에서있었으며, 이중 3예는기관지비후, 공동및기관지확장증등의반흔을남기고치유되었다 (Table 4). 고열과연기의흡인혹은흡입에의한폐손상은화상환자의사망률을결정하는주요인자로화상관련사망률을 20-60% 까지증가시키는것으로알려져있다 3,4. 임상적으로는일산화탄소및시안화물의중독, 상기도폐쇄, 폐부종및폐렴등의형태로이어지게된다. 상기도의점막이손상받아궤양, 기도부종으로인해호흡곤란, 천명및청색증을유발할수있으며심한경우기관내삽관을요하는기도폐쇄가일어날수있다. 또한성문아래하기도로의고열의연기흡입은기관-기관지염을초래하고, 기도상피세포의손상및섬유소의융합으로 casts를형성하여기도폐쇄및무기폐를일으킬수있다. 폐실질에도변화를초래하여폐포및폐혈관의투과성의증가로인해폐부종및급성호흡곤란증후군의병인을제공하기도한다 4,6,0. 현재흡입폐손상에대한급성기의치료는보존적인치료에의존하고있다. 즉, 기도유지, 적절한산소농도및환기, 적극적인기도분비물제거및혈액학적안정등이치료에있어서중요한요소이 658
Tuberculosis and Respiratory Diseases Vol. 60. No.6, Jun. 2006 다 6. 이는환자를소생시키는것이무엇보다도중요하기때문이다. 하지만급성호흡기증상에서회복된일부환자들에서기침, 호흡곤란혹은운동시호흡곤란등의폐쇄성및제한성장애를시사하는호흡기증상을경험하게된다. 본연구는흡입화상후의폐기능의변화를폐활량검사를통해알아보고자하였다. 즉, 흡입폐손상으로인한급성호흡기증상으로부터회복된상태에서초기및회복기에폐기능검사를시행하여실제적인폐기능지표들의변화를알아보았다. 흡입화상초기의폐기능검사소견에서전체적으로는각지표들의실제측정치혹은정상추정치가정상범위에있었으나각각을분석해보면약절반에서는정상폐기능소견을보여주었으며나머지는여러폐기능지표들의감소와함께폐쇄성혹은제한성장애를보여주고있었다. 하지만추적검사에서는초기폐기능검사에서이상소견을보였던지표들이대부분정상범위로회복되는것을확인할수있었다. 실제초기폐기능검사에서이상을보인환자들만갖고서초기및추적폐기능검사를 paired t-test 해본결과 FVC, FEV, FEF25-75%, PEF 및 MVV의측정치및추정정상치모두의미있게증가하여정상범위에도달하는것을확인할수있었다. 화재현장에서의연기흡입이후의폐기능에대한연구에대해서는많은이론의여지가있을것으로사료된다. Kinsella 등은 7 연기흡입 3일이내에 3개월이후의폐기능및기도과민성을살펴보았는데, FEV과기도저항은큰변화가없었으며, 일부환자에서초기에기도과민성을확인할수있었는데이역시시간이지남에따라서서히회복함을관찰하였다. Whitener 등도 2 흡입화상환자들에서초기에폐기능검사에서심한폐쇄성장애가관찰되었고시간이지남에따라서서히회복됨을보고하여본연구결과비슷한결과를보여주었다. 하지만 Mlcak 등은소아중증화상환자에서초기의폐기능저하가비가역적임을보고하였고 7, Tasaka 등은흡입화상환자에서장기적인합병증으로기관지확장증및폐쇄성세기관지염 (bronchiolitis obliterans) 등이올수있음을보고한바있다 8. 상기연구모두소규모연구로진행되었기때문에흡입폐손상으로인한폐기능에대한경과를정확히예측하기위해서는향후더많은연구가뒤따라야할것으로사료된다. 하지만흡입화상초기의환자를접근함에있어서기도손상으로인한기도폐쇄및폐합병증을인지하는것은매우중요하다. 고열은포함한연기의흡입은처음에기관및기관지에국한되어점막충혈, 혈관투과성의증가, 상피세포의탈락, 점액분비및염증세포의유입을초래하여결과적으로호흡부전의병인을제공하기때문이다. 흡입화상환자에서자주관찰되는기도 casts는기관및기관지에국한할것으로생각되었으나 6,9, Hubbard 등은 20 동물실험을통해이보다더작은세기관지에까지관여함을보고하였다. 따라서흡입화상환자에서기도의 casts를제거하는전략이향후예상되는기관지폐렴및폐포성저산소증을예방하는데도움을될것으로사료된다. Cox 등은 2 연기흡입초기의기도 casts는점액성분이주를이루며, 세기관지의폐쇄는주로호중구에기인함을확인하였다. 따라서초기의상기도폐쇄를제거하는전략이하기도의호중구침윤을감소시키며결과적으로는호흡기기능을증진시킬수있다고보았다 2-23. 저자들역시흡입화상초기에기관지내시경을적극적으로시행하여하기도의 soots 혹은염증성분비물을제거하는데주력하고있다. 기도폐쇄를초래하는 casts는잠재적으로생명을위협하는상황을초래할수있기때문이다 4,23. 이들소기도의 casts는폐기능지표들에게도영향을미칠것으로사료된다. 본연구에서도초기폐기능검사에서제한성장애를보인경우가 9예있었는데이는세기관지의 casts가기류제한을보이는만성기도질환의경우처럼공기포획현상 (air trapping) 혹은기도저항증가로작용했을것으로생각된다. 한편, 흡입화상에대한기관지내시경적중증도가폐기능과의연관성에대해서는아직이루어진바없는데저자들은내시경적중증도와폐기능지표간에유의한연관성을확인하지는못하였다. 다만 FEV의정상추정치와내시경적중증도사이에비록통계적으로는유의하지않지만내시경적중증도가증가함에따라 FEV이감소하는경향을확인할수있었다. 659
JY Kim et al. : Pulmonary function in patients with inhalation injury Bingham 등은초기의내시경적지표가기관내삽관의기간혹은기계호흡유무를판단하는지표로사용하기에는무리가있을것으로보고한바있다 24. 따라서초기의기관지내시경적중증도와향후폐기능지표에미치는영향에대해서는더많은연구가필요할것으로생각된다. 저자들은초기에진단적목적으로기관지내시경을시행하였지만결과적으로는기도내의 soots 혹은기도폐쇄의요소가있는기도분비물들을적극적으로제거하였다. 실제로이러한적극적인상 하기도세정 (toilet) 를통해서불필요한기관내삽관및기계호흡기간을줄일수있었다. 결과적으로흡입화상으로치료받아생존한성인환자들에서급성호흡기증상이안정된상태에서시행한폐기능검사상이상소견을보인환자들에서처음에는폐쇄성장애가많을것으로생각되었으나실제로는처음예상과달리폐쇄성및제한성장애양상이비슷한분율로나타났다. 폐쇄성장애를보이는 9명중 4명 (44.4%) 이기관지확장제에대한반응이양성이었다. 따라서기류제한을시사하는임상적소견및중환자실치료를요하는흡입화상환자들에게는적극적인기관지확장제사용이도움이될것으로판단하였다. 제한성장애를보이는일부환자는초기에적극적으로기관지내시경적기도세정 (toilet) 이이루어졌다하더라도일부는자그마한 casts들이세기도폐쇄의빌미를제공했을것으로추정된다. 또한연기흡입으로폐섬유화로인한제한성장애의가능성을생각할때 25, 흡입화상으로인한폐손상이기도에국한되지않고폐실질까지이어질수있음을염두에두어야할것으로사료된다. 본연구에서도폐쇄성및제한성장애가각각 명씩남아있었는데추적결과, 제한성장애환자는흡입화상후 6 개월째에정상으로회복되었으나폐쇄성장애환자는 2 개월이지났는데도완전하게회복되지않고있다. 이환자는 62세남자환자로이미선행폐쇄성폐질환을갖고있었을수도있지만, 흡입화상초기에치료를위해기관절개가불가피했던경우로아마도이로인한후유장애가지속되는것으로사료되나중등도에서경도로회복되고있는것을고려할때, 향후정상으로회복될지여부는장기간의추적관찰을통해알아보아야할것 이다. 본연구는몇가지제한점을갖고있는데첫째, 대상환자수가많지않다는것이며, 둘째, 흡입화상이전의기초폐기능검사결과가없다는것이다. 비록병력청취를통해만성호흡기질환을배제하였지만일부환자는흡입화상이외의기저호흡기상태가폐기능에반영되었을것으로사료된다. 셋째로는제한성환기장애를접근함에있어체적변동기록기에의한폐용적을제시하지않고강제폐활량 (FVC) 에의존했다는것이다. 이는극히일부환자를제외하고는거의대부분의환자가정상소견을보여주었기때문이기도한데, 향후폐기능검사에서이상소견을보이는경우선별적으로적용하는것에대해서는더많은고찰이필요할것으로사료된다. 넷째로는흡입폐손상에대한기도및폐실질에대한정량적접근에의해이루어지지않았다는것이다. 현재, 흡입화상으로기도및폐실질에오는손상정도를정확하게정량화해서진단하는것이쉽지않고, 호흡기계손상에대한방어능력및회복능력이개인차에따라매우다양하다는것을고려할때, 어느한가지기법으로접근하기는어려울것으로사료된다. 향후정량화된흡입화상진단기법이개발된다면이를이용하여많은환자들을대상으로흡입폐손상이폐기능에미치는영향에대한장기적인전향적연구가필요할것으로사료된다. 요약연구배경 : 흡입화상은폐렴, 호흡부전등의폐합병증으로인해이환율및사망률증가에기인하는것으로알려져있다. 화기흡입에의한기도손상이폐기능에영향을줄것으로예상되나이에대한연구는빈약한실정이다. 흡입화상으로인한폐기능검사소견의변화를알아보고자하였다. 방법 : 2002년 8월부터 2005년 8월까지기관지내시경검사에의해흡입폐손상이확인된환자들을대상으로급성기및회복기에폐기능검사를시행하여비교및 660
Tuberculosis and Respiratory Diseases Vol. 60. No.6, Jun. 2006 분석하였다. 초기폐기능검사에서 FVC, FEV, FEV25-75% 및 PEF의정상추정치는흡입화상에대한내시경적중증도와의상관성을알아보았다. 사망환자, 연기흡입으로뇌손상을입은환자및선행만성호흡기질환자는제외하였다. 결과 : 화상체표면적이 0-8% 의범위에있는총 37명 ( 남 28, 여 9) 의환자를대상으로하였다. 내원당시의 PaO 2 /FiO 2 비는 286.4±29.6 mmhg, COHb은 7.8± 6.6% 였으며, 기관내삽관은 9예 (24.3%), 기계호흡은 3예 (8.%) 에서이루어졌다. 초기방사선소견에서이상소견을보인 8예 (48.6%) 중 5예 (83.3%) 는정상화되었으나 3예 (6.7%) 는잔흔을남기고치유되었다. 초기폐기능검사에서 9예 (5.4%) 가정상소견이었다. 폐쇄성장애가 9예 (24.3%) 있었으며이중 4예 (44.4%) 는기관지확장제에양성반응을보였다. 제한성장애도 9예 (24.3%) 관찰되었다. DLco를시행한 23 예중 4예 (7.4%) 만이감소된소견을보여주었다. 추적폐기능검사에서초기에이상폐기능소견을보인대부분이정상으로회복되었으며, 폐쇄성및제한성장애가각각 예 (2.7%) 씩관찰되었다. DLco는전부정상화되었다. 결론 : 흡입화상이후생존한환자를대상으로급성호흡기증상이안정된상태에서시행한초기폐기능검사상정상, 폐쇄성및제한성장애로나타나특이적인환기장애양상은관찰되지않았다. 또한초기에이상소견을보여주었다하더라도추적검사에서대부분정상으로회복되는것을관찰할수있었다. 그리고, 기관지확장제양성을보이는일부환자는기관지확장제치료를적극적으로시도해볼수있을것으로사료된다. 참고문헌. Ryan CM, Schoenfeld DA, Thorpe WP, Sheridan RL, Cassem EH, Tompkins RG. Objective estimates of the probability of death from burn injuries. N Engl J Med 998;338:362-6. 2. http://www.kfsa.or.kr/. 3. Thompson PB, Herndon DN, Traber DL, Abston S. Effect on mortality of inhalation injury. J Trauma 986;26:63-5. 4. Shirani KZ, Pruitt BA Jr, Mason AD Jr. The influence of inhalation injury and pneumonia on burn mortality. Ann Surg 987;205:82-7. 5. Trunkey DD. Inhalation injury. Surg Clin North Am 978;58:33-40. 6. Herndon DN, Traber DL, Niehaus GD, Linares HA, Traber LD. The pathophysiology of smoke inhalation injury in a sheep model. J Trauma 984;24:044-5. 7. Kinsella J, Carter R, Reid WH, Campbell D, Clark CJ. Increased airways reactivity after smoke inhalation. Lancet 99;337:595-7. 8.Demarest GB, Hudson LD, Altman LC. Impaired alveolar macrophage chemotaxis in patients with acute smoke inhalation. Am Rev Respir Dis 979; 9:279-86. 9. Hallman M, Spragg R, Harrell JH, Moser KM, Gluck L. Evidence of lung surfactant abnormality in respiratory failure: study of bronchoalveolar lavage phospholipids, surface activity, phospholipase activity, and plasma myoinositol. J Clin Invest 982;70:673-83. 0. Large AA, Owens GR, Hoffman LA. The short-term effects of smoke exposure on the pulmonary function of firefighters. Chest 990;97:806-9.. Darling GE, Keresteci MA, Ibanez D, Pugash RA, Peters WJ, Neligan PC. Pulmonary complications in inhalation injuries with associated cutaneous burn. J Trauma 996;40:83-9. 2. Whitener DR, Whitener LM, Robertson KJ, Baxter CR, Pierce AK. Pulmonary function measurements in patients with thermal injury and smoke inhalation. Am Rev Respir Dis 980;22:73-9. 3. Khoo AK, Lee ST, Poh WT. Tracheobronchial cytology in inhalation injury. J Trauma 997;42:8-5. 4. American Thoracic Society. Single-breath carbon monoxide diffusing capacity (transfer factor): recommendations for a standard technique--995 update. Am J Respir Crit Care Med 995;52:285-98. 5. Pauwels RA, Buist AS, Calverley PM, Jenkins CR, Hurd SS. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: NHLBI/WHO Global Initiative for Chronic Obstructive Lung Disease (GOLD) Workshop summary. Am J Respir Crit Care Med 200;63 :256-76. 6. Heimbach DM, Waeckerle JF. Inhalation injuries. Ann Emerg Med 988;7:36-20. 7. Mlcak R, Desai MH, Robinson E, Nichols R, Herndon DN. Lung function following thermal injury in children: an 8-year follow up. Burns 998;24:23-6. 66
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