pissn: 2288-0402 eissn: 2288-0410 2(4):266-271, September 2014 http://dx.doi.org/10.4168/aard.2014.2.4.266 ORIGINAL ARTICLE 소아에서급성호흡곤란증후군의임상결과및예후 : 단일기관연구 강성실, 배라미, 이의경, 방경원, 김환수, 전윤홍, 윤종서, 김현희, 김진택, 이준성 가톨릭대학교의과대학소아과학교실 Outcome of acute respiratory distress syndrome in children: a single center study Sung Shil Kang, Ra Mee Pae, Eu Kyoung Lee, Kyung Won Bang, Hwan Soo Kim, Yoon Hong Chun, Jong-Seo Yoon, Hyun Hee Kim, Jin Tack Kim, Joon Sung Lee Department of Pediatrics, The Catholic University of Korea College of Medicine, Seoul, Korea Purpose: This study aimed to determine the incidence, etiology, prognostic factors, and outcome of acute respiratory distress syndrome (ARDS) in children and to provide epidemiological data of children with ARDS treated at the pediatric intensive care unit (PICU) of a single center in Korea. Methods: We conducted a retrospective medical chart review of 19 children diagnosed with ARDS at the PICU of The Catholic University of Korea, Seoul St. Mary's Hospital, between March 2009 and February 2012. Results: Of the 334 PICU patients, 19 (5.6%) satisfied the American-European Consensus Conference definition of ARDS. Thirteen patients with ARDS died (mortality rate, 68.4%). Pneumonia was the most common cause of ARDS and observed in 10 patients (52.6%). There were significant differences between survivors and nonsurvivors in the PaO2/FiO2 ratio and the number of organ failure. The mortality rate was significantly higher in patients with a baseline PaO2/FiO2 ratio 100 mmhg than in those with a baseline PaO2/ FiO2 ratio > 100 mmhg (84.6% vs. 33.3%, P= 0.046). We observed that a higher number of organ failure during the PICU stay, resulted in a higher mortality rate (P= 0.037). Multiple logistic regression analysis showed that the PaO2/FiO2 ratio (adjusted odds ratio, 0.958) was independently associated with the increased risk of death after controlling for the number of organ failure. Conclusion: The mortality rate of ARDS in children was 68.4% in this study, a higher rate than those reported in other national and international studies. The PaO2/FiO2 ratio at the time of ARDS onset was a helpful prognostic factor for predicting the mortality rate of children with ARDS. ( 2014;2:266-271) Keywords: Outcome, Acute respiratory distress syndrome, Children 서론급성호흡곤란증후군 (acute respiratory distress syndrome, ARDS) 은심한생리적손상뒤에오는폐포-모세혈관의투과성증가의결과로양측폐의급성미만성부종과폐포의염증반응을보이며이로인한폐단락의증가, 심한저산소혈증, 폐탄성의감소를특징으로하는질환이다. 1,2) 1967년 Ashbaugh 등 3) 에의해보고된이후 ARDS의발병기전의 이해와더불어치료에대한많은연구 4,5) 가이루어져왔다. 그러나, 기계호흡치료등의집중적치료에도불구하고 ARDS는중환자실사망의중요한원인중하나로여전히사망률이높은편이다. 성인의경우문헌에보고된사망률은 40% 60% 6-9) 정도로알려져있다. 소아에서도 1994년 American-European Consensus Conference (AECC) 에서 ARDS의진단기준 10) 이제안된이후발생률및사망률등역학에대한연구가이루어지기시작하였다. 2012년스페인의 21개소아중환자실에서보고한자료에따르면 ARDS의유병률 Correspondence to: Eu Kyoung Lee Department of Pediatrics, Bucheon St. Mary's Hospital, The Catholic University of Korea College of Medicine, 327 Sosa-ro 327beon-gil, Wonmi-gu, Bucheon 420-717, Korea Tel: +82-32-340-7046, Fax: +82-32-340-2673, E- mail: euneun99@gmail.com Received: December 17, 2013 Revised: April 7, 2014 Accepted: April 7, 2014 2014 The Korean Academy of Pediatric Allergy and Respiratory Disease The Korean Academy of Asthma, Allergy and Clinical Immunology This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/). 266 http://www.aard.or.kr
강성실외 급성호흡곤란증후군의임상결과 은 1.4%, 사망률은 26% 로성인에서보다낮았으며 ARDS 진단당시와 24시간후의 PaO 2/FiO 2 비가사망률을예측하는중요한인자라는결론을내렸다. 1) 우리나라에서는 2005년단일기관연구에서소아중환자실에입원한환아중 ARDS의유병률은 3.7%, 사망률은 37.5% 로보고하였다. 2) 또한 ARDS 진단 2일째의 PaO 2/ FiO 2 비와폐포-동맥간산소분압차, 산소화지수의호전정도가환자의예후를예측할수있는지표로유용하다는결론을내렸다. 2) 그런데, ARDS의발생빈도, 원인질환, 사망률등은의료의질과의료수준, 의료시스템등의차이가있기때문에지역에따라다를수있다. 또한의학기술의발전및사회환경의변화에의해시대에따라서도발생률및사망률이달라질수있다. 이에저자들은소아중환자실입원환자중 ARDS의발생빈도, 원인질환, 사망률등을조사, 분석하여현재우리나라단일의료기관에서의 ARDS의역학에대해알아보고자하였다. 아울러, 이연구결과를이전의연구결과및다른나라의결과와비교하여차이가있는지분석하고자하였다. 대상및방법 1. 연구대상 2009년 3월 1일부터 2012년 2월 28일까지 36개월동안가톨릭대학교서울성모병원소아중환자실에입원하여침습적기계호흡치료를받은환자중 ARDS로진단된 19명의환자를대상으로하였다. ARDS의진단은 AECC의진단기준에따라좌심방고혈압의임상적증거가없는상태 ( 좌심방압력 18 mmhg 이하 ) 에서호흡부전의발생이급성이며방사선소견에서양측폐야에음영이증가한폐부종소견을보이면서 PaO 2/FiO 2 가 200 이하인경우로하였다. 10) 2. 연구방법대상환자들의의무기록을후향적으로검토하여 ARDS의발생률, 원인질환, 사망률을조사하였으며 ARDS의진단은환자가 AECC criteria 10) 를처음으로만족하는시기를기준으로하였다. 임상기록을통하여 ARDS 진단당시의평균연령, 성별, 기저질환유무, pediatric risk of mortality (PRISM) III score 11), 중환자실재원기간, 호기말양압, 최고흡기압, 일회환기량등의기계환기설정및기계호흡일수등을조사하여기본임상양상과중증도를평가하였다. 기저질환의유무는소아중환자실입실전환자가호흡기질환외다른질환 ( 백혈병및소아암, 선천성심질환, 신경질환등 ) 을가지고있었는지여부를조사하여판단하였다. PRISM III score는소아환자의생리현상과검사소견을점수화하여, 그수치에따라소아중환자사망률을예측할수있는지표로생리학적항목으로는혈압, 맥박, 체온, 동공반사, 의식이있으며, 검사실항목에는혈액, 생화학, 혈중가스소견이포함된다. 12) ARDS 환자의초기예후를예측할수있는인자들을알아보기위하여생 존군과사망군으로나누어진단당시의성별, 연령, PRISM III score, PaO 2/FiO 2 비, 호기말양압, 기저질환, 동맥혈이산화탄소분 압, 폐외장기부전수를비교하였다. AECC 에서제시한기준에따르면 PaO 2/FiO 2 값이 300 이하인 경우를급성폐손상 (acute lung injury, ALI) 으로정의하며 ARDS 는 ALI 보다더심한상태로 PaO 2/FiO 2 값이 200 이하인경우로정 의한다. 10) 본연구에서는저산소혈증 (hypoxemia) 정도에따라 PaO 2/FiO 2 비 100 을기준으로하여 ARDS 를두그룹으로나누었 다. ARDS 진단당시 PO 2/FiO 2 >100 mmhg 인군을중등도의 ARDS 로 PO 2/FiO 2 100 mmhg 인군을중증의 ARDS 군으로나 누어사망률을비교하여진단당시의저산소혈증정도와사망률의 관계를알아보았다. 또한 Goldstein 등 13) 의연구에서제안한소아에서의장기부전 정의 (standard definition for pediatric sepsis and organ failure) 13) 를 이용하여심혈관, 호흡기, 신경, 혈액학, 신장, 간의장기부전을평 가하였다. 그러나사망전 6 시간이내의장기부전에대해서는임종 과정의한부분으로간주하여제외하였다. 이를바탕으로각각의 장기부전이사망률에미치는영향을알아보았고소아중환자실재 원중의폐외장기부전의수와사망률사이의관계를알아보았다. Table 1. Demographics and general clinical data at study entry from 19 children with the acute respiratory distress syndrome Variable Value Age (yr) 9 (1.23 13) Gender Male/female 11/8 PRISM III 14.3± 9.3 Days in the hospital 44 (16 69) Days in PICU 18 (6 33) Days on mechanical ventilation 12 (5 33) PaO2/FiO2 at ARDS onset (mmhg) 84± 36 Tidal volume at ARDS onset (ml/kg) 7.5± 2.1 PEEP at ARDS onset (cmh2o) 8.6± 3.8 PIP at ARDS onset (cmh2o) 37± 11 No. of failing organs 2.9± 0.9 Underlying diseases 17 (89.4) Pneumothorax after initiation of mechanical ventilation 3 (15.7) PICU mortality 13 (68.4) Causes of ARDS, no. of cases (no. of deaths) Pneumonia Sepsis Near-drowning Others 10 (7) 3 (2) 2 (1) 4 (3) Values are presented as median (P25 P75), mean± standard deviation, or number (%) unless otherwise indicated. P25 P75, 25th and 75th interquartile range; PRISM, pediatric risk of mortality; PICU, pediatric intensive care unit; ARDS, acute respiratory syndrome; PEEP, positive end expiratory pressure; PIP, peak inspiratory pressure. http://dx.doi.org/10.4168/aard.2014.2.4.266 267
Kang SS, et al. Outcome of acute respiratory distress syndrome 3. 통계분석통계값은빈도 (%), 평균 ± 표준편차, 또는중앙값 (medians) 과사분범위 (interquartile range) 로나타내었다. 두군간의비연속변수에대한비교분석은 chi-square test 또는 Fisher exact test를이용하였고연속변수에대한비교분석은 Mann-Whitney U-test를이용하였다. 단변수분석에서사망여부에통계적으로유의하게차이가있는변수인 PaO 2/FiO 2 비와폐외장기부전수에대해서는다중회귀분석을시행하여상대위험도를측정하였다. 폐외장기부전수와사망률과의연관성분석은 linear by linear association 으로경향분석법을이용하였다. 사망률에대한 95% 신뢰구간은 Wilson interval을이용하였다. 통계분석은 IBM SPSS Statistics ver. 21.0 (IBM Co., Armonk, NY, USA) 를이용하였으며, P 값은 0.05 미만일때의미있는것으로간주하였다. 결과 3년간총 334명의환자가소아중환자실에입원하여 106명의환자가기계호흡치료를받았으며이중 ARDS 환자는 19명으로입원환자의 5.6% 에해당하였다. ARDS로진단받은환자 19명중 13명이 사망하여 68.4% 의사망률을보였으며 ARDS의원인질환으로는폐렴이 10명으로가장많았으며패혈증 3명, 익수 2명이었으며그외에폐결핵 2명, 쯔쯔가무시병 1명, 급성신부전 1명이었다 (Table 1). 대상환자의연령은중앙값 9 (1.23 13) 세였으며 57.8% 가남자였다. 입원일수는중앙값 44 (16 69) 일, 중환자실재원일수는중앙값 18 (6 33) 일, 기계호흡치료일수는중앙값 12 (5 33) 일이었으며소아중환자실입실 24시간이내의 PRISM III score 11) 는 14.3 ±9.3이었다. 기계호흡치료를받은환자의 ARDS 진단시의인공호흡기평균일회환기량은 7.5±2.1 ml/kg, 평균호기말양압은 8.6 ±3.8 cmh 2O, 평균최고흡기압은 37±11 cmh 2O, PaO 2/FiO 2 비는 84±36 mmhg이었다 (Table 1). 기계호흡치료의합병증으로기흉이발생한경우는 3예 (15.7%) 였으며 ARDS 진단당시의일회환기량과압력손상에의한기흉발생률사이에는유의한상관관계가없었다 (P = 0.146). ARDS의발생률 (5.6%) 과사망률 (68.4%) 은 AECC에서제안한 ARDS 진단기준 10) 을따라서연구한국내외의연구와비교했을때상대적으로높은편이었다. ARDS의발생률은 Lopez-Fernandez 등 1) 의연구에서 1.4% 로가장낮았으며그외연구에서도 1.9% 3.7% 2,14-18) 로본연구와비교했을때낮았다. 또한 ARDS 의사망률 Table 2. Characteristics of main studies reporting pediatric ARDS incidence and outcome using the AECC definition Variable Current study Lopez-Fernandez et al. 1) Ko et al. 2) Dahlem et al. 14) Zimmerman et al. 15) Erickson et al. 16) Kneyber et al. 17) Hu et al. 18) Country South Korea Spain South Korea The Netherlands United States Australia, New Zealand The Netherlands Study period 3 yr (2009 2012) 1 yr (2010 2011) 20 mo (2002 2004) 2 yr (1998 1999) 1 yr (1999 2000) 1 yr (2004 2005) 2 yr (2004 2006) 1 yr (2005 2006) Study design Retrospective Prospective Retrospective Prospective Prospective Prospective Retrospective Prospective Criteria AECC+MV AECC+MV AECC+MV AECC+MV AECC+MV AECC+MV AECC+MV AECC Age 2 mo 17 yr 1 mo 15 yr 1 mo 15 yr 0 18 yr 0.5 15 yr < 16 yr 0 16 yr 1 mo 15 yr Single/multicenter Single center Multicenter Single center Single center Multicenter Multicenter Single center Multicenter PICU beds 5 217 Not reported 12 Not reported Not reported 9 Not reported PICU admission 334 10,521 647 1,100 Not reported 5,252 1,174 11,521 Patient on MV 106 1,748 Not reported 443 141 1,887 533 Not reported ARDS cases 19 146 24 35 29 103 41 306 ARDS cases/picu admission (%) 5.6 1.4 3.7 Not reported Not reported 1.9 3.4 2.6 Age 9 yr (1.23 13)* 2 yr (0.34 5)* Not reported 27 mo (5 58)* 1.8 yr (1.3 4.7)* Not reported 31.6± 7 mo 11 mo (3 40) Tidal volume (ml/kg) 7.5± 2.1 7.6± 1.8 Not reported Not reported 9.3± 1.5 9.3 (7.8 11.6)* Not reported 8.8 (6.7 10)* PEEP (cmh2o) 8.6± 3.8 8.9± 2.9 Not reported Not reported Not reported 8.5 (7 11)* Not reported 5 (3 7)* PIP (cmh2o) 37± 11 27± 6 Not reported Not reported Not reported Not reported Not reported Not reported PaO2/FiO2 (mmhg) 84± 36 99± 41 96.2± 36 Not reported Not reported Not reported Not reported 115 (76 168)* Pneumothorax after initiating mechanical ventilation, n (%) 3 (15.7) 18 (12.3) Not reported 8 (22.8) Not reported Not reported Not reported Not reported PICU mortality (%) 68.4 26 37.5 31.4 Not reported Not reported 24.4 Not reported ARDS, acute respiratory distress syndrome; AECC, American-European Consensus Conference; MV, mechanical ventilation; PICU, pediatric intensive care unit; PEEP, positive end expiratory pressure; PIP, peak inspiratory pressure. *Median (range). Mean± standard deviation. China 268 http://dx.doi.org/10.4168/aard.2014.2.4.266
강성실외 급성호흡곤란증후군의임상결과 도다기관후향적연구를시행한 Kneyber 등 17) 의연구에서 24.4% 로가장낮았으며국내외다른연구에서는 26.0% 37.5% 1,2,14-16,18) 로보고하였다. 인공호흡기평균일회환기량 (7.5±2.1 ml/kg) 은다기관전향적연구를시행한 Lopez-Fernandez 등 1) 의평균일회환기량 (7.6±1.8 ml/kg) 과유사했으며평균호기말양압 (8.6±3.8 cmh 2O) 은 Lopez-Fernandez 등 1) 의평균호기말양압 (8.6±3.8 cmh 2O) 과호주에서다기관전향적연구를시행한 Erickson 등 16) 의평균호기말양압 (8.5 [7 11]) 과유사했다. ARDS진단당시평균 PaO 2/FiO 2 비는 84±36 mmhg으로국내연구인 Ko 등 2) 의 96.2 ±36 mmhg, 스페인의 Lopez-Fernandez 등 1) 의 99±41 mmhg 와비교하여낮았다 (Table 2). 사망에따른두군간의비교에서성별, 연령, 기저질환은차이가없었으며 PRISM III score, 호기말양압, 동맥혈이산화탄소분압도두군간에차이가없었다. 하지만 PaO 2/FiO 2 비 (110±27 vs. 71 ±34, P<0.05) 는사망한군에서유의하게낮았고폐외장기부전수 (2.0±0.6 vs. 2.9±0.8, P < 0.05) 는사망한군에서유의하게더높았다 (Table 3). PaO 2/FiO 2 비를기준으로 ARDS의중증도 를분류한두군간의비교에서진단당시 PaO 2/FiO 2 100 mmhg 인군의사망률은 84.6% 로 PaO 2/FiO 2 >100 mmhg인군의사망률 인 33.3% 와비교하여두배이상높았다 [84.6% {95% confidence interval (CI), 57.8 95.7} vs. 33.3% {95% CI, 9.7 70}, P = 0.046] (Fig. 1). 소아중환자실입원기간중평균폐외장기기능부전의수는 2.9 ±0.9개였으며장기부전의수가증가할수록 ARDS 환자에서사 망률도유의하게증가하였다 (P = 0.037) (Fig. 2). 그러나, 특정장기 의부전과사망률과의연관성은없었다 (Table 4). 단변수분석에서사망여부에따라통계적으로유의한차이가 Table 4. Comparison of organ dysfunction of survivors and nonsurvivors Organ dysfunction Survivors (n= 6) Nonsurvivors (n= 13) P-value Renal 0 (0) 3 (23.1) 0.200 Cardiovascular 1 (16.7) 8 (61.5) 0.069 Hematologic 5 (83.3) 13 (100) 0.130 Hepatic 1 (16.7) 5 (38.5) 0.342 Neurologic 5 (83.3) 8 (61.5) 0.342 Values are presented as number (%). Table 3. Comparison of characteristics of survivors and nonsurvivors Variable Survivors (n= 6) Non-survivors (n= 13) P-value Adjusted OR (95% CI) Age (yr), median (P25 P75) 5.5 (0 12.25) 9 (2 15) 0.375 Male sex, n (%) 4 (66.6) 7 (53.8) 0.599 PRISM III 14.8± 12.6 14± 7.9 0.866 Underlying disease, n (%) 5 (83.3) 12 (92..3) 0.554 No. of failing organs 2± 0.6 2.9± 0.8 0.032 0.205 (0.003 12.719) PEEP at ARDS onset (cmh2o) 6.8± 1.5 7.8± 2.3 0.313 PaO2/FiO2 at ARDS onest (mmhg) 110± 27 71± 34 0.024 0.958 (0.918 0.999) PaCO2 at ARDS onest (mmhg) 50± 14 56± 20 0.554 Values are presented as mean± standard deviation unless otherwise indicated. OR, odds ratio; CI, confidence interval; P25 P75, 25th and 75th interquartile range; PRISM, pediatric risk of mortality; PEEP, positive end expiratory pressure; ARDS, acute respiratory syndrome. Mortality (%) 100 90 80 70 60 50 40 30 20 10 0 84.6% (95% CI, 57.8 95.7) P= 0.046 N=13 33.3% (95% CI, 9.7 70) N=6 100 > 100 Mortality (%) 110 100 90 80 70 60 50 40 30 20 10 0 100% P= 0.037 80% 55.6% N=4 N=4 N=5 N=0 1 2 3 > 3 Baseline PaO2/Fio2 (mmhg) Number of extrapulmonary organ failure Fig. 1. Distribution of pediatric acute respira tory syndrome (ARDS) patients and mortality rate by the degree of hypoxemia (measured as PaO2/FiO2 ratio) at ARDS onset. Thirteen patients (68.4%) had a PaO2/FiO2 100 mmhg. N, number of patients who died in each category; CI, confidence interval. Fig. 2. Mortality of 19 pediatric acute respira tory syndrome patients in relation to the number of organ failure during pediatric intensive care unit stay, as represented by the number of patients who died in each category (N) and mortality for each category. http://dx.doi.org/10.4168/aard.2014.2.4.266 269
Kang SS, et al. Outcome of acute respiratory distress syndrome 있던변수인 PaO 2/FiO 2 비와폐외장기부전수에대한상대위험도분석에서는 PaO 2/FiO 2 비 (adjusted odd ratio, 0.958; 95% CI, 0.918 0.999) 만이폐외장기부전수의영향을보정한상태에서도독립적으로유의한사망의위험인자였다. 고찰본연구에서 3년간가톨릭대학교서울성모병원소아중환자실입원환자 334명중 ARDS 환자는 19명으로 5.6% 에해당하였다. ARDS로진단받은환자 19명중 13명이사망하여 68.4% 의사망률을보였으며 ARDS의원인질환으로는폐렴이 10명으로가장많았으며이외에도패혈증, 익수, 폐결핵, 쯔쯔가무시감염, 신부전등이있었다. 폐렴의원인은호흡기세포융합바이러스 (respiratory syncitial virus) 2명, 인플루엔자바이러스 2명, Candida albicans 2명, Staphylococcus aureus 1명, 흡인 1명이었으며나머지는원인을알수없었다. 생존군과사망군의임상적특성비교에서두군간의연령및성별, 기저질환유무, PRISM III 점수, 호기말양압, 동맥혈이산화탄소분압에서는유의한차이가없었다. 그러나, 사망군에서진단당시의 PaO 2/FiO 2 비가유의하게낮았으며폐외장기부전수는유의하게높았다. 특히, PaO 2/FiO 2 비는다른위험인자의영향을보정한상태에서도독립적으로사망의위험인자였다. AECC criteria에따르면급성폐손상 (ALI) 과 ARDS는같은병태생리기전을가지고있지만질환의중증도에따라 PaO 2/FiO 2 비 200을기준으로구분되는질환이며 10) ALI (PaO 2/FiO 2, 200 300 mmhg) 보다 ARDS가사망률이높다고알려져있다. 1) 본연구에서는 ARDS 진단당시의 PaO 2/ FiO 2 비가중요한사망의위험인자였으므로 ARDS의중증도를 PaO 2/FiO 2 비 100을기준으로중등도 ARDS와중증 ARDS로나누어사망률을비교해보았다. ARDS 진단당시 PaO 2/FiO 2 100 mmhg인군의사망률은 84.6% 로 PaO 2/FiO 2 >100 mmhg인군의사망률인 33.3% 와비교하여유의하게높았다. 따라서, ARDS의조기예후판정에진단당시의 PaO 2/FiO 2 비가유용한예측인자임을알수있었다. 또한소아중환자실입원기간중폐외장기기능부전의수가증가할수록 ARDS 환자에서사망률도증가하는것으로나타났다. 그러나, 생존군과사망군의비교에서각장기부전에따른사망유무의유의한차이는보이지않아특정장기의부전이사망률의증가에영향을미치지는않은것으로생각되었다. 소아 ARDS의발생률은가톨릭대학교서울성모병원소아중환자실입원환자의 5.6% 였다. 이는 AECC 진단기준을이용하여 ARDS의발생률을연구한국내외의다른기관의발생률과비교했을때다소높은편이었다 (Table 2). 국내단일기관연구인 Ko 등 2) 의연구에서는 20개월동안소아중환자실입원환자 647명중 24명 이 ARDS로진단받아 3.7% 의발생률을보였다. 또한, 국외의단일기관 / 다기관연구에서는 1.4% 3.4% 1,14-18) 로 ARDS의발생률을보고하였다. 본연구에서의소아사망률은 68.4% 로 26.0% 31.4% 1,14-18) 의사망률을보고한외국의연구및 37.5% 2) 의사망률을보인국내의다른기관연구보다높았다 (Table 2). 이처럼발생빈도와사망률에서차이를보이는것은국내외연구기관들마다의료의질과수준, 의료시스템및사회환경이서로다르기때문에발생할수있는진단과치료과정의차이에의한것으로여겨진다. 또한 ARDS 의예후와관련이있는진단시의평균 PaO 2/FiO 2 는 84±36로국내연구인 Ko 등 2) 의 96.2±36, 스페인의 Lopez-Fernandez 등 1) 의 99 ±41보다낮았다. 이것은본연구에서 ARDS 진단시의환자의중증도가다른기관의연구보다상대적으로높았고이러한차이가사망률에영향을끼친것으로생각된다. 저자들의연구는후향적연구로가장최근의국내대학병원소아중환자실에서의 ARDS의발생률및사망률에대한연구이다. 또한임상기록을토대로 ARDS 진단당시의평균연령, 성별, 기저질환유무, PRISM III score, 중환자실재원기간, 기계환기설정및기계호흡일수등의기본임상양상과중증도를평가하여 ARDS에대한자료를제공할수있었다. 아울러 ARDS 진단당시 PaO 2/FiO 2 비와폐외장기기능부전의수가사망률에영향을미치는예후인자라는것도알수있었다. 특히, ARDS 진단당시의 PaO 2/FiO 2 비가다른변수에독립적인중요한예후예측인자였으며 PaO 2/FiO 2 100 mmhg인중증 ARDS군의사망률이중증도 ARDS (PaO 2/FiO 2 >100 mmhg) 군보다유의하게높았으므로진단당시 PaO 2/FiO 2 100 mmhg인중증 ARDS환자에서보다적극적인처치를시행하여향후예후를향상시킬수있는가능성을제시하였다. 그러나, 전향적연구와달리 ARDS로진단된환자에대한치료에있어서폐보호기계호흡전략 5,19-24) 등과같은보다체계적이고표준화된치료를하지못하였기때문에주요변수들이불완전할수있다는한계를지니고있다. 또한연구기관의소아중환자실의병상수가 5개로 3년간총입원환자수및 ARDS로진단된환자수가상대적으로적어보다다양한인자를분석하는데제한이있었다. 게다가연구대상의배경이도심중앙에위치한 3차의료기관의소아중환자실에국한되어있어상대적으로일반인구의역학적특성을완전히반영하지는못할수있다는단점이있었다. 본연구는최근 3년간의국내소아중환자실에서발생한소아 ARDS의역학적자료를제공했다는점에서의의가있다. 이를통하여향후소아중환자실입원환자중 ARDS의발생을예측하고조기에적절한치료를하는데도움을줄수있을것이라생각한다. 또한진단당시 PaO 2/FiO 2 비와폐외장기기능부전의수등사망률에영향을미치는인자를조기에파악하여보다적극적인치료를시행함으로써치료성적을향상시키는데기여할수있다는점에서도의미가있다. 270 http://dx.doi.org/10.4168/aard.2014.2.4.266
강성실외 급성호흡곤란증후군의임상결과 본연구에서는소아 ARDS 의발생빈도, 사망률, 진단당시의중 증도와예후인자등에대한조사를하였지만 ARDS 의치료법및 치료효과에대한연구는이루어지지않았다. 소아 ARDS 는여전히 사망률이높은질환이므로환자의생존율향상을위해서는효과적 인치료법에대한연구가필요하다. 또한대상환자군이 19 명으로 비교적적었기때문에환자를기저질환에따라분류하고이에따 른사망률이나예후인자를분석하지는못했다. 따라서향후의연 구에서는더많은기관과환자를대상으로 ARDS 진단당시의중증 도와환자특성에따른체계적인치료전략을도입하고치료효과 를평가할수있는전향적인연구가이루어져야할것이다. 결론적으로, 최근 3 년간가톨릭대학교서울성모병원소아중환 자실에서소아 ARDS 의발생빈도는 5.6% 이고 ARDS 환자의사망 률은 68.4% 로국내외의다른연구보다는발생률과사망률이높은 편이었다. 또한 ARDS 진단시의 PaO 2/FiO 2 비가환자의사망률에 영향을끼치는중요한인자이므로이를조기에파악하여더욱적극 적이고신속한치료를하는것이예후결정에중요하리라생각한다. REFERENCES 1. Lopez-Fernandez Y, Azagra AM, de la Oliva P, Modesto V, Sanchez JI, Parrilla J, et al. Pediatric Acute Lung Injury Epidemiology and Natural History study: incidence and outcome of the acute respiratory distress syndrome in children. Crit Care Med 2012;40:3238-45. 2. Ko JM, Ha EJ, Lee EH, Lee SY, Kim HB, Hong SJ, et al. Clinical outcome and prognostic factors of acute respiratory distress syndrome in children. Korean J Pediatr 2005;48:599-605. 3. 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