SMN SURGICAL METABOLISM AND NUTRITION Vol. 7, No. 2, December, 2016 pissn 2233-5765, eissn 2465-8383 https://doi.org/10.18858/smn.2016.7.2.32 ORIGINAL ARTICLE 수술후외과중환자실재원환자의영양공급현황및유효위험인자의분석 김병철ㆍ이인규ㆍ김은영 가톨릭대학교의과대학서울성모병원외과학교실 Analysis of Current Status and Predisposing Factors for Nutritional Support of Patients in Surgical Intensive Care Unit Byung Chul Kim, M.D., In Kyu Lee, M.D., Ph.D., Eun Young Kim, M.D. Department of Surgery, Seoul St. Mary s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea Purpose: Enteral feeding is strongly recommended for critically ill patients since it can enhance the immunologic function, which serves as a host defense mechanism against inflammation or metabolic response to stress. Herein, we investigated nutritional status and estimated the adequacy of the nutritional supply for acutely ill patients admitted to the surgical intensive care unit (SICU) after a major operation. Materials and Methods: From February to October 2016, patients admitted and stayed over 48 hours after major surgical procedures at SICU in Seoul St. Mary s Hospital were reviewed. The nutritional parameters and surgical outcomes were compared according to the status of nutritional support. Results: A total of 220 patients composed of 130 males (59.1%) and 90 females (40.9%) were enrolled, and mean age was 61.4±13.6 years. All patients were classified into two groups according to nutritional status, which was assessed by the ratio of total delivered calories to total required calories (D/R); group A (54 cases, 24.5%, D/R 0.7) versus group B (166 cases, 75.5%, D/R<0.7). In multivariate analysis, incision in the lower abdomen (Odds Ratio 2.277, P=0.078), absence of NST consultation (Odds Ratio 2.728, P=0.011), and not receive minimal invasive surgery (Odds Ratio 3.518, P=0.001) were independent risk factors associated with poor nutritional status. Conclusion: Clinicians should pay more attention to patients who had an incision in the lower abdomen or did not receive minimal invasive surgery or NST consultation, which would be predisposing factors for nutritional insufficiency resulting in postoperative morbidities. (Surg Metab Nutr 2016;7:32-38) Key Words: Nutritional status, Nutritional support, Postoperative period, Risk factors, Intensive care unit 서론 적절한영양공급은입원환자에있어면역력의증가, 세포항산화시스템의향상, 장관점막장벽유지, 창상회복촉진등과같은효과를기대할수있어, 특히복강내장관수술이나창상을동반한대다수의수술후환자에게서그중요성이강조되고있다.[1] 하지만, 영양공급의임상적중요성에비하여실 제수술후입원환자에서의불량한영양상태는비교적흔하게관찰되는문제이다. 일례로 Barr 등 [1] 의연구에서는성인입원환자의약 40% 에서불량한영양공급을경험한다고보고하고있는데, 특히대수술을마친중증환자에게있어부적절한영양공급은면역기능의저하, 감염발생빈도증가, 상처회복지연, 기계환기기간증가등을통해중환자실재원기간의증가및각종합병증발생빈도의증가를 2배에서 20배까지유발할수 Received December 22, 2016. Accepted December 23, 2016. Correspondence to: Eun Young Kim, Division of Trauma and Surgical Critical Care, Department of Surgery, Seoul St. Mary s Hospital, College of Medicine, The Catholic University of Korea, 222 Banpodae-ro, Seocho-gu, Seoul 06591, Korea Tel: +82-2-2258-2876, Fax: +82-2-595-2822, E-mail: freesshs@naver.com CC This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyrights c The Korean Society of Surgical Metabolism and Nutrition
Byung Chul Kim, et al: Analysis of Current Status and Predisposing Factors for Nutritional Support 33 있어더욱주의를요한다.[1-4] 실제로부적절한영양공급은국내중환자실재실환자의치료과정에서드물지않게관찰되는데, 국내한대학병원보고에따르면중환자실재원환자의칼로리요구량보다실제처방및공급되는칼로리의비율이부족한경우가 94.7% 에달하는것으로나타났다.[4] 이러한중환자실재원환자에대한부적절한영양공급의원인으로는검사및수술에의한금식기간, 수술직후경정맥영양사용의제한및의료진의인식부족등이있다고보여진다. 이에대한보완책으로서최근다각적팀접근방식으로서의영양지원팀 (Nutritional Support Teams, NST) 의임상적중요성및효용성이강조되고있으나, 현재까지수술후중환자실재원환자에대한적절한영양공급의현황이나 NST 협진에따른치료성적에대해서는자세한연구가이루어진것이거의없는실정이다.[3,4] 따라서이번연구에서저자들은본원외과중환자실재원환자를대상으로영양공급실태및 NST 협진의현황을분석하고, 영양공급적절성에따른치료성적을비교해보았다. 또한수술후중환자실입실환자들에대한부적절한영양공급의위험인자에대해서도분석해보았다. 대상및방법 2016년 2월부터 2016년 10월까지본원에서전신마취하복부수술을시행한뒤외과중환자실에입실한환자들중중환자실재원시간이 48시간이상으로 18세이상 80세이하인환자를대상으로하였다. 이들중환자가심폐소생술거부, 뇌사, 혹은임신상태인경우, 외과중환자실퇴실이전에경구식이를진행한경우, 기존에가지고있던신장질환등으로인해수술전부터신대체요법을시행받았던경우는연구대상에서제외하였다. 또한신경외과혹은신경과혹은소아과환자역시분석에서제외하였으며, 최종적으로총 220명의환자를선정, 분석하였다. 본연구는본원기관생명윤리위원회의허가를받았으며, 의무기록열람을통하여환자의성별, 나이, 체중, APACHE score, 중환자실재원일수, 영양지원의경로, 실제일일공급량등에대한자료를전향적으로수집하여후향적으로분석하였다. 모든자료수집및분석은환자혹은보호자에게동의받은후진행하였다. 연구에포함된모든환자는 칼로리총공급량 (total delivered calorie)/ 칼로리총필요량 (total required calorie) (D/R ratio) 를이용한영양상태평가에따라두그룹으로구분하였다. De Jonghe 등 [3] 의연구에서서술한바와같이 D/R 0.7은영양공급이적절하게이루어진것으로간주한반면, D/R<0.7은불량한영양공급이이루어진것으로판 단하였다. 이와같이그룹을나눈뒤, 환자별연령및성별, 수술시행과, 수술의방식및부위, 질환의종류, 혈액검사결과, 중환자실재원기간등에관해두그룹간기록을분석및비교하였다. 최소침습수술은복강경혹은로봇수술로정의하였고, 수술후합병증중폐렴은수술후 38.5도이상의발열, 화농성객담, 객담배양검사상양성소견, 그리고임상과영상의학적으로폐경화소견이새롭게진단된경우로진단하였다. 심혈관항목은수술후새롭게발생한협심증, 심부전으로한정하였다. 출혈항목은수술후발생한출혈로인해재수술을필요로하거나수혈을시행한경우로한정하였다. 본연구의통계분석은 SPSS software 버전 21.0 (SPSS, Chicago, IL, USA) 프로그램으로처리하였으며, P값은 0.05 미만을통계학적으로유의한것으로정의하였다. 다변량분석의경우 P값을 0.1 미만을통계학적으로유의한것으로정의하였다. 범주형변수의분석에는 Chi-square test를사용해도수분포와백분율로표기하였고, 연속형변수의분석에는 Student s t-test를사용하여평균값 ± 표준편차로표기하였다. 불량한영양공급과관련있는위험인자는다변량로지스틱회귀분석법을사용해서구했으며 95% 의신뢰구간을갖고위험도 (Odds ratio) 를제시하였다. 결과 전체 220명의환자가분석되었고이들의평균연령은 61.4±13.6세였으며성별은각각남자 130명 (59.1%), 여자 90 명 (40.9%) 이었다 (Table 1). 평균체질량지수는 23.8±4.0이었으며평균 APACHE II score는 14.0±4.8 로나타났다. 원인질환으로는악성종양이 128명 (58.2%), 양성종양이 70명 (31.8%) 로나타났으며, 이중악성종양에서는상부위장관및간담도질환이 76명 (34.5%) 로가장많았고양성종양에서는하부장관및신장질환이 41명 (18.6%) 으로가장많았다. 피부절개위치로는상복부가 123명 (55.9%) 로하복부 (74명, 33.6%) 에비하여상대적으로더많은비중을차지하였다. 외과중환자실입실후새롭게기계환기를시작한경우는 23명 (10.5%), 신대체요법을시작한경우는 21명 (9.5%) 으로조사되었다. 수술후발생한합병증으로는호흡기, 심혈관, 재수술이필요한출혈, 그리고급성신부전이각각 27명 (12.3%), 9명 (4.1%), 10명 (4.5%), 그리고 34명 (15.5%) 으로조사되었다. 외과중환자실에서의퇴실형태를살펴보면, 성공적으로회복하여일반병실로이실한경우는 196명 (89.1%) 으로가장큰비중을차지하였고, 이외여러이유로다른센터로전원된경우는 9명 (4.1%), 사망한경우가
34 Surgical Metabolism and Nutrition Vol. 7, No. 2, 2016 Table 1. Demographic characteristics of the study population (n=220) Characteristics Value (mean±sd) or number of patients (%) Age (yr) 61.4±13.6 Sex (Male/Female) 130/90 BMI 23.8±4.0 APACHE II score 14.0±4.8 Primary diagnosis (%) Malignant disease Upper GI tract and hepatobiliary 76 (34.5) Lower GI tract and kidney 21 (9.5) Gynecological disease 11 (5) Others 20 (9.1) Benign disease Upper GI tract and hepatobiliary 23 (10.5) Lower GI tract and kidney 41 (18.6) Others 6 (2.7) Others* 22 (10) Incisional site (%) Upper abdomen 123 (55.9) Lower abdomen 74 (33.6) Others 23 (10.5) Performed procedures in SICU (%) Mechanical ventilation 23 (10.5) Extrarenal replacement 21 (9.5) Postsurgical morbidities (%) Pneumonia or Respiratory 27 (12.3) Cardiovascular 9 (4.1) Bleeding needed laparotomy 10 (4.5) Acute kidney injury 34 (15.5) Type of discharge from SICU (%) Successfully recovered 196 (89.1) Transfer to other center 9 (4.1) Expire 15 (6.8) BMI = body mass index; GI = gastrointestinal; SICU = surgical intensive care unit. *A 7 cases of trauma and a 4 cases of miscellaneous disease were included. 15명 (6.8%) 이었다. 영양공급의적절성에따른임상결과의차이를평가하기위하여, D/R 0.7인그룹을그룹 A로, D/R<0.7인그룹을그룹 B로나누어임상적특징및수술시행과, 수술방식및부위, 질환의종류, 혈액검사결과, 중환자실재원기간등의결과를비교, Table 2에나타냈다. 두그룹은 group A와 group B가각각 54명 (24.5%), 166명 (75.5%) 으로불량한영양공급을받은 group B에속한환자가더많았다. 평균연령, 성별, BMI 및 APACHE II score에서는두그룹간유의한차이가보이지않았으며, 가장흔한임상과는외과로 (42 cases, 77.8% in group A vs. 150 cases, 90.4% in group B) 환자별입원임상과의분포역시유의한차이를보이지않았다. 원인질환별로는, 하부장관의양성종양의경우 group B에속한비율이유의하게높아불량한영양공급이이루지는경우가많음을알수 있었다 (5 cases, 9.3% in group A vs. 36 cases, 21.7% in group B, P=0.045). 반면, 비종양질환의경우 group A에속한비율이 group B에비해유의하게높아 (11 cases, 20.4% in group A vs. 11 cases, 6.6% in group B, P=0.006) 우수한영양공급이이루지는경우가상대적으로많음을알수있었다. 피부절개부위에서는하복부절개인경우 group B에속한비율이유의하게높았으며 (12 cases, 22.2% in group A vs. 82 cases, 49.4% in group B, P<0.001), 반면상복부나하복부절개에한정되지않는절개인경우 group A에속한비율이 group B에비해유의하게높았다 (16 cases, 29.6% in group A vs. 14 cases, 8.4% in group B, P<0.001). 최소침습수술의경우 group A에속한비율이유의하게더높았던반면 (32 cases, 59.3% in group A vs. 39 cases, 23.5% in group B, P<0.001), 수술후기계환기, 신대체요법을시행한비율, 그리고외과중환자실재실기간과병원재원기간은두군간유의한차이를보이지않았다. 환자별영양공급현황을살펴보면, 평균하루칼로리필요량에있어서는두군간유의한차이를보이지않았으나, 평균하루칼로리공급량에서는 group A가유의하게높았고 (1052.6±1252.4 kcal in group A vs. 356.2±333.2 kcal in group B, P<0.001), 외과중환자실재실기간중 NST 자문을얻은비율역시 group A에서유의하게높은것으로나타났다 (36 cases, 66.7% in group A vs. 52 cases, 31.3% in group B, P<0.001). 외과중환자실입실시시행했던혈액검사에서, creatinine 수치만이두군간유의한차이를보였고 (1.3±1.5 in group A vs. 1.9±2.4 in group B, P=0.022), 외과중환자실에서의퇴실형태에있어서는두군간유의한차이를보이지않았다. 저자들은수술후외과중환자실입실한환자들의불량한영양공급과관련되는위험인자를파악하고자, Table 2에서두군간통계학적으로유의한차이를보였던항목인하부장관의양성종양, 외상등종양이외의질환, 하복부절개, 최소침습수술, 외과중환자실재실기간중 NST 협진여부, 혈중 creatinine 수치를대상으로다변량분석을시행하였고, 그결과를 Table 3에제시하였다. 다변량분석결과, 하복부절개 (Odds ratio 2.277, 95% CI 0.911 5.695, P=0.078), 최소침습수술을하지않은경우 (Odds ratio 3.518, 95% CI 1.665 7.435, P=0.001), 그리고외과중환자실재실기간중 NST 협진을시행하지않은경우 (Odds ratio 2.728, 95% CI 1.264 5.888, P=0.011) 는불량한영양공급과관련해유의한위험인자로나타났다. 추가적으로본연구에서는임상과에따른상기위험인자들의분포를조사하였는데, NST 협진시행의경우외과중에
Byung Chul Kim, et al: Analysis of Current Status and Predisposing Factors for Nutritional Support 35 Table 2. The comparison of demographics and perioperative outcomes between the group A (D/R*<0.7) and the group B (D/R 0.7) Parameters Total (n=220) Group A (D/R 0.7, n=54) Group B (D/R<0.7, n=166) P-value Age (yr) 64.4±13.4 65.3±11.5 64.1±14 0.590 Sex (Male/Female) 130/90 29/25 101/65 0.426 BMI 23.8±4.0 23.5±3.9 23.9±4.1 0.483 APACHE II score 13.1±5.0 13.5±4.7 14.2±4.9 0.384 Clinical department (%) 0.092 surgery 192 (87.3) 42 (77.8) 150 (90.4) OS 4 (1.8) 1 (1.9) 3 (1.8) CS 9 (4.1) 5 (9.3) 4 (2.4) ENT 6 (2.7) 3 (5.6) 3 (1.8) OBGY 9 (4.1) 3 (5.6) 6 (3.6) Primary diagnosis (%) 0.028 Malignant disease Upper GI tract 76 (34.5) 16 (29.6) 60 (36.1) 0.414 Lower GI tract 21 (9.5) 6 (11.1) 15 (9) 0.790 Gynecological disease 11 (5) 5 (9.3) 6 (3.6) 0.143 Others 20 (9.1) 6 (11.1) 14 (8.4) 0.588 Benign disease Upper GI tract 23 (10.5) 4 (7.4) 19 (11.4) 0.457 Lower GI tract 41 (18.6) 5 (9.3) 36 (21.7) 0.045 Others 6 (2.7) 1 (1.9) 5 (3) 1.000 Others 22 (10) 11 (20.4) 11 (6.6) 0.006 Incisional site (%) <0.001 Upper abdomen 103 (46.8) 26 (48.1) 70 (42.2) 0.528 Lower abdomen 94 (42.7) 12 (22.2) 82 (49.4) <0.001 Others 30 (13.6) 16 (29.6) 14 (8.4) <0.001 Minimal invasive surgery (%) 71 (32.3) 32 (59.3) 39 (23.5) <0.001 Performed procedures in SICU (%) Mechanical ventilation 23 (10.5) 8 (14.8) 15 (9) 0.304 Extrarenal replacement 21 (9.5) 4 (7.4) 17 (10.2) 0.838 Postsurgical morbidities (%) 76 (34.5) 17 (31.5) 59 (35.5) 0.017 Pneumonia or Respiratory 27 (12.3) 8 (14.8) 19 (11.4) 0.633 Cardiovascular 9 (4.1) 1 (1.9) 8 (4.8) 0.459 Bleeding 10 (4.5) 3 (5.6) 7 (4.2) 0.710 Acute kidney injury 34 (15.5) 9 (16.7) 25 (15.1) 0.829 Mean length of SICU stay (day) 3.8±4.6 4.3±4.3 3.6±4.7 0.384 Mean length of hospital stay (day) 15.6±8.1 12.4±5.9 16.7±8.5 0.066 NST consultation during SICU stay (%) 88 (40) 36 (66.7) 52 (31.3) <0.001 Mean daily calculated caloric requirement (kcal/day) 1614.6±222.4 1566.4±238.5 1630.3±215.4 0.066 Mean daily delivered caloric amount (kcal/day) 522.1±735.6 1052.6±1252.4 356.2±333.2 <0.001 Laboratory results at the time of SICU admission Total protein 5.3±0.9 5.1±0.9 5.3±0.9 0.093 Transferrin 43.6±71.3 57.3±67.8 38.5±72.5 0.343 White blood cells 4038±7124 4145±8328 4,002±6,703 0.903 Hemoglobin 11.3±2.1 10.9±2.0 11.4±2.1 0.093 Hematocrit 33.6±6 32.5±5.9 34±6 0.109 BUN 26±22.5 24.1±21.3 26.6±22.9 0.490 Creatinine 1.8±2.2 1.3±1.5 1.9±2.4 0.022 Sodium 140±3.8 140±3.4 140±4 0.966 Potassium 4.0±0.7 4.0±0.5 4.0±0.7 0.900 Type of discharge from SICU (%) 0.275 Successfully recovered 196 (89.1) 51 (94.4) 145 (87.3) Transfer to other center 9 (4.1) 2 (3.7) 7 (4.2) Expire 15 (6.8) 1 (1.9) 14 (8.4) BMI = body mass index; OS = orthopedic CS = chest ENT = ear-nose-throat; OBGY = obstetrics and gynecology; GI = gastrointestinal; SICU = surgical intensive care unit; NST = nutritional support team. *The ratio of the total delivered calorie to total required calorie. P-value<0.05.
36 Surgical Metabolism and Nutrition Vol. 7, No. 2, 2016 Table 3. Risk factors associated with the poor nutritional status (D/R*<0.7) Variable OR 95% CI P-value No minimal invasive surgery 3.518 1.665 7.435 0.001 No NST* consultation during SICU stay 2.728 1.264 5.888 0.011 Lower abdomen incision 2.277 0.911 5.695 0.078 Serum creatinine** 1.095 0.832 1.442 0.517 Benign disease of lower GI tract 0.423 0.096 1.860 0.255 Trauma or miscellaneous disease 0.448 0.158 1.269 0.131 NST = nutritional support team; SICU = surgical intensive unit; GI = gastrointestinal; CI = confidence interval. P-value<0.1 was regarded as having the statistical significance in multivariate analysis. *The ratio of the total delivered calorie to total required calorie. **The laboratory result at the time of SICU admission. Table 4. Presentation of risk factors associated with poor nutritional support according to the type of clinical departments Parameters Upper GI Lower GI Hepatobiliary Vascular OS CS ENT OBGY Minimal invasive surgery 19 (46.3) 11 (44.0) 27 (36.0) 12 (23.5) 0 2 (22.2) 0 0 NST consultation during SICU stay 21 (51.2) 14 (56.0) 25 (33.3) 13 (25.5) 1 (33.3) 8 (88.9) 2 (33.3) 3 (33.3) Lower abdominal incision 1 (2.4) 23 (92.0) 2 (2.6) 39 (76.5) 0 0 0 8 (88.9) NST = nutritional support team; SICU = surgical intensive unit; GI = gastrointestinal; OS = orthopedic CS = chest ENT = ear-nose-throat; OBGY = obstetrics and gynecology. 서는혈관외과분과에서가장적게이루어졌으며 (12명, 23.5%; 13명, 25.5%; respectively), 하복부절개는외과대장항문분과에서 (23명, 92.0%) 가장많이이루어짐을확인할수있었고이들임상과별위험인자분포를 Table 4에기술하였다. 고찰 수술후환자는수술에의한생리적스트레스에대한대사적반응으로영양요구량이매우증가되어체지방이나골격근분해를통해근육소모를초래한다. 특히장관수술을포함해복부수술을받은환자의경우이로인한경구섭취가제한되는예가많으며, 수술전부터질환에의해장기간영양불량상태인경우가많아적절한영양공급의중요성이더욱강조된다.[5] 수술후중증환자치료에있어적절한영양공급은영양결핍, 그리고그와관련된면역력저하, 감염률증가, 기계환기시행등의합병증예방에도움을주기에그중요성이대두되고있으며 [6-10], 중환자실입실후 72시간내의경장영양시작은감염등의합병증예방과중증환자의임상적호전에도움을준다는보고가있어그중요성이더욱크다고할수있다.[1,3,11,12] 특히일부연구에서는문합술이포함된위장관수술후에도조기경장영양의시작은기존의우려와달리문합부누출의위험 을오히려감소시키며, 장마비상태에서도영양소흡수가가능하다는결과를보고한바있다.[1] 그러나, 적절한영양공급의다양한장점들에도불구하고실제로중환자실입실환자에서적절한영양공급이이루어지는경우는드문것으로보고되고있는데, Barr 등 [1] 의연구에서는중등도이상의불량한영양공급이이루어지는경우가약 81 88% 에달하였고, 국내한기관을대상으로시행한 Moon 등 [4] 의연구에서는영양공급률이필요량의절반에미치지못하는경우가 57.4% 로보고되었으며, 실제우리연구에서도총연구대상자 220명중 166명이 D/R ratio 0.7 미만의불량한영양공급을받는것으로나타났다. 이러한문제점의근본적인원인중하나로의료진의처방율부족과처방의실제시행율이낮다는점을들수가있으며, 이외에도영양공급방식에대한의료진들의이해부족및관리소홀로인해발생하는누출및소실등을들수있다.[3,4,13,14] 따라서, 이의개선을위해서는처방을내리는의사및처방을수행하는보조인력들에대한적극적이고체계적인교육및다각적팀접근방식으로서의영양지원 (NST) 이필요할것으로생각되며 [3,4,12,15] 실제우리결과에서도 NST 협진을시행한경우가다변량분석에서적절한영양공급의유의미한인자로밝혀졌다. 이러한결과는 NST와같은팀접근방식을통한다각도의체계화된영양공급의긍정적인영향및임상적효과를반
Byung Chul Kim, et al: Analysis of Current Status and Predisposing Factors for Nutritional Support 37 영한다고볼수있을것이다. 본연구에서 NST 협진시행이외불량한영양공급에관여하는것으로나타난인자들중최소침습수술의시행여부는 Table 3에서보이듯시행되지않은경우불량한영양공급의위험인자로나타났다. 이러한결과의원인으로추정되는바로는최소침습수술이이루어지지않은경우개복창상으로인한통증등으로인해조기보행의어려움이유발되고이로인해위장관마비상태의지속및운동성회복의지연이발생할수있으며이에대한의료진들의우려등을들수있다. 따라서최소침습수술을시행할경우에이같은위험성을줄일수있어결과적으로적절한영양공급에도움이될수있었을것이라생각된다. 이외에도, 본연구에서는절개부위가하복부에위치한경우역시불량한영양공급의유의한위험인자로본연구에서나타났으며, 수술절개부위의위치에따라환자의영양공급현황이다르게나타남을관찰할수있었는데이는복부통증의유발혹은보행시통증의유발등으로인한조기보행의지연, 위장관기능회복의지연등에있어복부절개위치에따른차이가발생했기때문이라생각된다. 추가적으로저자들은다양한임상과가입실하는중환자실의특성을고려, 각임상과별영양공급의상태를간접적으로확인하고자위험인자의분포를조사하였는데각위험인자들은임상과별로매우다양한분포형태를보였다. 이같은결과는적절한영양공급을위해서임상과별로차별화된개별적맞춤형접근법이필요함을시사한다고보여진다. 본연구의이러한결과들에대해서는추후대규모의임상자료를바탕으로한전향적연구를통해확인되어야할것이라생각된다. 본연구는위에서제시한여러흥미로운결과에도불구하고몇가지한계점을가지고있다. 우선, 본논문은후향적조사를시행하였기에의무기록의부실, 누락등의이유로환자의수술전영양상태, 중증도등의평가에한계가있었다. 하지만본연구는수술후중환자를선택적으로대상으로하여자료를전향적으로수집하여후향적으로분석함으로써선택편향을최소화시키고자노력하였다. 둘째로, 무작위연구를시행하지못하였기에자료및결과수집의편향이존재할수있다. 셋째로, 환자개개인간이질적인개체별특성을가지고있기에이것이교란변인으로작용했을가능성이있다. 따라서본연구에서나타난결과를뒷받침하기위해서는추후대규모의전향적인무작위대조연구를통해이러한한계를극복하고, 아울러각임상과별영양공급상태에영향을줄수있는개별인자들에대한객관적인연구및분석이필요할것으로생각된다. 그러나이러한한계에도불구하고본연구는수술후중환자실에입실 한환자를대상으로자료를전향적으로수집함으로써적절한영양공급의현황과관련된위험인자들을밝힌연구로, 현재까지수술후중환자실재원환자에대한적절한영양공급의현황이나 NST 협진에따른치료성적에대해서자세한연구가이루어진것이거의없는실정을고려할때그의의가있다고할수있다. 또한임상분과에따라위험인자분포율이다름을보임으로서, 각임상분과에따라개별적맞춤형접근이필요함을밝힐수있었다. 결론적으로, 임상의사들은최소침습수술의미시행, 하복부절개, NST 협진의미시행, 대장항문양성종양, 중환자실입실시높은 creatinine 수치와같은부적절한영양공급과관련된선행요인이있을경우더욱주의를기울여야할것이다. 특히 NST 협진의시행은특별한노력이나부담없이시행할수있으면서도불량한영양공급을지양할수있는요인으로, 체계화된 NST의적극적운영을통해영양지원에대한지속적관리가이루질수있도록노력해야할것이다. REFERENCES 1. Barr J, Hecht M, Flavin KE, Khorana A, Gould MK. Outcomes in critically ill patients before and after the implementation of an evidence-based nutritional management protocol. Chest 2004;125:1446-57. 2. Blackburn GL, Wollner S, Bistrian BR. Nutrition support in the intensive care unit: an evolving science. Arch Surg 2010; 145:533-8. 3. De Jonghe B, Appere-De-Vechi C, Fournier M, Tran B, Merrer J, Melchior JC, et al. A prospective survey of nutritional support practices in intensive care unit patients: what is prescribed? what is delivered? Crit Care Med 2001;29:8-12. 4.Moon SS, Lim HS, Choi JW, Kim DK, Lee JW, Ko SH, et al. Analysis of nutritional support status in the intensive care unit. Korean J Crit Care Med 2009;24:129-33. 5.Desborough JP. The stress response to trauma and surgery. Br J Anaesth 2000;85:109-17. 6. Arora NS, Rochester DF. Respiratory muscle strength and maximal voluntary ventilation in undernourished patients. Am Rev Respir Dis 1982;126:5-8. 7. Chandra RK. Nutrition, immunity, and infection: present knowledge and future directions. Lancet 1983;1:688-91. 8. Dempsey DT, Mullen JL, Buzby GP. The link between nutritional status and clinical outcome: can nutritional intervention modify it? Am J Clin Nutr 1988;47(2 Suppl):352-6. 9. Robinson G, Goldstein M, Levine GM. Impact of nutritional status on DRG length of stay. JPEN J Parenter Enteral Nutr 1987;11:49-51. 10.Shukla VK, Roy SK, Kumar J, Vaidya MP. Correlation of immune and nutritional status with wound complications in patients undergoing abdominal surgery. Am Surg 1985;51:442-5. 11. Klein S, Kinney J, Jeejeebhoy K, Alpers D, Hellerstein M, Murray M, et al. Nutrition support in clinical practice: review of published data and recommendations for future research directions. Clin Nutr 1997;16:193-218. 12. Mackenzie SL, Zygun DA, Whitmore BL, Doig CJ, Hameed SM. Implementation of a nutrition support protocol increases the proportion of mechanically ventilated patients reaching enteral
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