Inhalation lung injury associated with humidifier disinfectants in adults

Younsuck Koh(고윤석) 대한직업환경의학회 2016 대한직업환경의학회 학술대회 논문집 Vol.2016 No.11

The Inhaled Nitric Oxide in Acute Respiratory Distress Syndrome: from a Bedside to a Bench

Younsuck Koh Korean Society of Critical Care Medicine 2001 Acute and Critical Care Vol.16 No.2

Because inhaled nitric oxide (NO) induces selective vasodilation of well-ventilated lung regions diverting pulmonary artery blood flow towards these well-ventilated alveoli, it has been applied to some of ARDS patients, who show severe hypoxemia despite of positive pressure ventilation with moderate to high positive end-expiratory pressure. The beneficial effect of inhaled NO on oxygenation was lower than 5 ppm of inhaled NO and the maximum effect was about 10 ppm in patients with ARDS according to the studies. Combinations of inhaled NO with various therapies, such as the use of intravenous almitrine or phenylephrine, and prone positioning may produce additive effects on oxygenation. Approximately 65% of patients had response to inhaled NO in studies of critically ill patients with ARDS who were ventilated with less than 40 ppm of inhaled NO. However, there was no survival benefit by inhaled NO in a multicenter phase 2 trial with 177 patients of non-septic ARDS. It is unclear whether inhaled NO exerts detrimental or beneficial effects in the pathogenesis of ARDS. Laboratory studies suggest that inhaled NO has important effects in reducing some forms of lung and tissue injury. If these effects are clinically significant, early and continued therapy with inhaled NO could potentially reduce the severity of some forms of lung injury. In contrast, NO and nitrite interacted with neutrophil myeloperoxidase to stimulate oxidative reactions during inflammation. In summary, NO inhalation would be acceptable as a rescue therapy in severe ARDS without serious complications related to the application. In addition, the effect of inhaled NO on the pathophysiology of ARDS should be elucidated.

Medical Ethics on Medical Resource Allocation in COVID-19 Pandemic

( Younsuck Koh ) 대한결핵 및 호흡기학회 2020 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.128 No.-

Clinical Significance of Hypercapnia during Mechanical Ventilation

Younsuck Koh Korean Society of Critical Care Medicine 2005 Acute and Critical Care Vol.20 No.2

No abstract available.

감염증 치료에 항생제는 만능인가?

고윤석 한양대학교 의과대학 1998 한양의대 학술지 Vol.18 No.2

The issues related to the antimicrobial resistance and the immunologic meaning of fever are briefly reviewed. Antimicrobial resistance is an ongoing challenge for the clinicial. The resistance is associated with inappropriate use of antimicrobial drugs. The emergence of penicillin-resistant Streptococcus pneumoniae, methicillin-resistant staphylococcus, expanded spectrum β-lactam antibiotics, and vancomycin-resistant enterococci have the great impact on the practice of medicine. The problem of multi-drug resistant tuberculosis is also serious problem in our country. We might be faced with post-antibiotic era if current practice prevails; high usage and misuse of antimicrobials. Despite increasing awareness, health care providers have paid little attention to the problem. To reduce antimicrobial resistance, physicians should throughly stick to appropriate principles of antimicrobial chemotherapy. Fever has been recognized as a common sign of clinical disease but its biological purpose is unclear. To investigate the effect of heat shock response on acute lung injury (ALI) of the rats induced by intratracheally administered tumor necrosis factor-α (TNF) which is an important mediator of sepsis, we instilled either saline or TNF intratracheally with and without heat pretreatment in Sprague-Dawley rats weighing 325-375 g. The heated rats were raised their rectal temperature to 41℃ and was maintained thereafter for 13 mins at 18 h before intratracheal administration of saline or TNF. We found that there is no difference in lung leak index and myeloperoxidase (MPO) activity after 5 h of teratment among the rats given saline intratracheally with and without heat pretreatment. Rats administered TNF with heat-pretreatment had decreased lung leak index (0.137±0.012) and lung MPO activity (5.51 ± 1.04 U/gm) compared to those of TNF administered rats without heat-pretreatment (0.186±0.016, 14.34±1.22 U/gm) (P〈0.05 in each). There were no significant difference in lung leak index and MPO activity between TNF-treated rats with heatpretreatment and saline-treated rats. These findings indicate that the heat shock response attenuated neutrophil recruitment and acute lung leak induced by intratracheal instillation of TNF in rats. Although fever has not been determined a definite beneficial effect in ALI, it would be cautious before determintion of fever suppression in the patients with ALI based on evaluation of relative risks and benefits of fever individually.

Effect of Timing of Do-Not-Resuscitate Orders on the Clinical Outcome of Critically Ill Patients

백문성,Younsuck Koh,Sang-Bum Hong,Chae-Man Lim,Jin Won Huh 대한중환자의학회 2016 Acute and Critical Care Vol.31 No.3

Background: Many physicians hesitate to discuss do-not-resuscitate (DNR) orders with patients or family members in critical situations. In the intensive care unit (ICU), delayed DNR decisions could cause unintentional cardiopulmonary resuscitation, patient distress, and substantial cost. We investigated whether the timing of DNR designation affects patient outcome in the medical ICU. Methods: We enrolled retrospective patients with written DNR orders in a medical ICU (13 bed) from June 1, 2014 to May 31, 2015. The patients were divided into two groups: early DNR patients for whom DNR orders were implemented within 48 h of ICU admission, and late DNR patients for whom DNR orders were implemented more than 48 h after ICU admission. Results: Herein, 354 patients were admitted to the medical ICU and among them, 80 (22.6%) patients had requested DNR orders. Of these patients, 37 (46.3%) had designated DNR orders within 48 hours of ICU admission and 43 (53.7%) patients had designated DNR orders more than 48 hours after ICU admission. Compared with early DNR patients, late DNR patients tended to withhold or withdraw life-sustaining management (18.9% vs. 37.2%, p = 0.072). DNR consent forms were signed by family members instead of the patients. Septic shock was the most common cause of medical ICU admission in both the early and late DNR patients (54.1% vs. 37.2%, p = 0.131). There was no difference in in-hospital mortality (83.8% vs. 81.4%, p = 0.779). Late DNR patients had longer ICU stays than early DNR patients (7.4 ± 8.1 vs. 19.7 ± 19.2, p < 0.001). Conclusions: Clinical outcomes are not influenced by the time of DNR designation in the medical ICU. The late DNR group is associated with a longer length of ICU stay and a tendency of withholding or withdrawing life-sustaining treatment. However, further studies are needed to clarify the guideline for end-of-life care in critically ill patients.

암성흉수의 진단에 있어서 Flow cytometry를 이용한 DNA Ploidy 측정의 역할

김우성,고윤석,최정은,김동순,김원동,이상도,임채만,지현숙 울산대학교 의과대학 1995 울산의대학술지 Vol.4 No.1

연구배경 : 암성 흉수는 한국에서 흔한 결핵성 흉수와 마찬가지로 흉수내에 림프구를 주로 보이나, 일반 생화학 검사나 흉수 세포 진단법 및 흉막 조직 검사상에도 특이적 소견이 나타나지 않는 경우가 흔하여 감병진단에 어려움이 있다. 최근 악성 종양에서 염색체이상에 따르는 DNA 양적이상이 보고되었으며 Flow cytometry는 세포들의 주기 분석 및 DNA양의 분석이 가능하며 조작이 간편하고 신속히 수행할 수 있는 객관적인 검사방법으로 인정되고 있다. 이에 저자들은 림프구를 주로 보이는 흉수에서 Flow cytometry를 이용한 DNA 양적 이상의 측정이 암성 흉수의 감별 진단에 도움을 줄 수 있는지 여부를 조사하기 위하여 다음과 같은 연구를 시행하였다. 방법 : 흉수 세포 진단법 및 흉박 조직 검사상 확진된 결핵성 흉막염 환자 14명과 암성 흉막염환자 21명의 흉수를 99% 에탄올로 고정시키고 popidiumiodide로 DNA를 염색한후 Flow cytometry를 이용하여 이수배수체의 여부와 합성기의 세포 분포율을 조사하였다. 결과 : 결핵성 흉막염군의 흉수 분석 결과 14예 모두 두배수체를 보였다. 암성 흉막염군의 경우 총 21예중 10예에서 이수배수체를 보였고 11예는 두배수체를 보였다. 합성기(S기)의 분포를 비교한 결과 결핵성 흉박염군의 평균 합성기 분포는 3.72±1.06%, 암성 흉막염군의 평균 합성기 분포는 6.69±1.79%로 두군간에 통계적으로 유익한 차이가 없었다.(p=0.1152). DNA 이수배수체제에 의한 암성흉수진단의 민감도는 47.6%, 특이도는 100%이었다. 결론 : 삼출액이면서 림프구를 주로 보이는 흉수 환자에서 flow cytometry를 이용한 DNA 분석상 이수배수체를 보일 때 암성 흉수의 가능성이 높으므로 세포 진단법이나 흉막 생검상 비특이적 소견이 보이더라도 확진을 위한 적극적인 노력이 필요한 것으로 사료된다. Backround There are some difficulties in the differential diagnosis of lymphocyte-dominant exudative pleural effusion because of nonspecific chemocal findings and poor positive yield of cytopathologic findings. It has been known that most malignant tumor cells possess an abnormal number of chromosome and consequently an abnormal DNA content. Flow cytomery allows rapid and accurate analysis of DNA contents. Therefore the detection of aneuploidy in pleural fluid using flow cytometry could be used for the differential diagnosis between malignant and benign effusion. Methods Flow cytometric DNA analysis were perfomed in 14 tuberculous pleural effusions and 21 malignant effusions, which were confirmed by cytopathological method. Samples were fixed in absolute ethanol and stained with propidium iodide, a DNA intercalating fluorescent stain. Results All of the 14 tuberculous effusions showed diploidy. Among the 21 malignant effusions, 10 samples had aneuploidy. The comparison of S-phase fraction, the indicator of cellular proliferative activity, showed no significant difference between tuberculous and malignant effusions. Flow cytometric analysis, compared to cytopathology, yields 46.7% sensitivity, 100% specificity. Conclusion The finding of aneuploidy in pleural fluid highly suggest malignancy in etiology. Therefore if flow cytometric DNA analysis show aneploidy, further diagnostic work up would be required.

Analysis of Cases Requested to the Ethics Committee of an University Hospital for the Discontinuation of Therapy

Jeong Min Kang,Younsuck Koh Korean Society of Critical Care Medicine 2005 Acute and Critical Care Vol.20 No.1

BACKGROUND: A hospital ethics committee (HEC) handles ethics problems in a hospital and mediates conflicts between patients and caregivers. The role of HEC on treatment withdrawal has increased after Boramae-hospital's case on 1997 in Korea. This study is an analysis of cases referred to the HEC of Asan Medical Center for the discontinuation of patient therapy. METHODS: The conference records of the HEC from January 1998 to December 2003 and the relevant patient charts were reviewed retrospectively. RESULTS: Twenty-seven cases related to treatment withdrawal were referred to the HEC during the study period. Based on the number of admitted ICU patients during the study period, the case request rate was 0.05%. The bimodal distribution of the cases in terms of age was neonate, 13 (48%); infant, 6 (22%); adult, 8 (30%). The major causes of treatment withdrawal were futile management, financial difficulty and patient suffering. The HEC recommended the continuation of treatment in 7 cases (25.9%); treatment withdrawal in 11 (40.7%); treatment withholding in 8 (29.6%); transfer to another hospital in one case (3.8%). Of the seven recommendations for treatment continuation, only three were accepted by their families. These three patients were eventually discharged alive. Treatment was withdrawn within one week in all eleven cases recommended for that by the HEC. Treatment was withheld in seven of those eight such recommended cases. CONCLUSIONS: The case referral rate was low in the studied hospital. In all cases, the patients' families requested the case to the HEC. Although the committee's recommendations to withhold or withdraw the treatment were followed by the families, the recommendation to continue therapy was often refused.

Thematic Poster : TP-27 ; The Failure of High Flow Nasal Cannula Therapy May Cause Delayed Intubation and Mortality

( Byung Ju Kang ),( Younsuck Koh ),( Chae Man Lim ),( Jin Won Huh ),( Myong Ja Han ),( Hyun Suk Seo ),( Sang Bum Hong ) 대한결핵 및 호흡기학회 2014 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.118 No.0

Background: High flow nasal cannula (HFNC) provides a high flow of humidified and heated oxygen. The use of HFNC allows respiratory failure patients required mechanical ventilation a chance to delay intubation. We compared the hospital outcomes of critical ill patients with HFNC therapy, early failure or late failure. Methods: We performed a retrospective observational study of patients receiving HFNC therapy in a tertiary hospital between January 2013 and March 2014. We selected intubated patients for the failure of HFNC therapy and classified the patients into two groups depending on the timing of intubation, intubation before and after 48 hours. Results: A total of 615 patients receiving HFNC therapy were enrolled in our study. Among them, 175 patients clinically deteriorated despite HFNC therapy and finally received endotracheal intubation. Before 48 hours, 130 patients (74.3%) were intubated and after 48 hours, 45 patients (25.7%) were intubated. There were no significant differences in baseline characteristics between two groups except higher diabetes mellitus (33.85% vs. 15.56%, p=0.02) and Sequential Organ Failure Assessment (SOFA) score day 1 (9.81±3.82 vs. 8.07±3.85, p=0.009) in the patients with intubation before 48 hours. The patients with intubation before 48 hours had higher extubation (37.69% vs. 15.56%, p=0.006) and ventilator weaning rate (55.38% vs. 28.89%, p=0.002), lower ICU mortality (39.23% vs. 66.67%, p=0.001), and longer ventilator free days (8.58±10.06 vs. 3.62±7.48, p=0.011). Conclusions: In a patient with clinically deterioration during HFNC therapy, delayed failure may cause bad outcome and harmful.

The effect of an improvement of experience and training in extracorporeal membrane oxygenation management on clinical outcomes

Go-Woon Kim,Younsuck Koh,Chae-Man Lim,Jin Won Huh,Sung-Ho Jung,Joon Bum Kim,Sang-Bum Hong 대한내과학회 2018 The Korean Journal of Internal Medicine Vol.33 No.1

Background/Aims: The use of extracorporeal membrane oxygenation (ECMO) is spreading rapidly, with successful procedures reported in the ECMO for Severe Adult Respiratory failure (CESAR) trial and treatment of the H1N1 pandemic. However, ECMO is associated with a high mortality rate. This study aimed to show that increased experience and improved teamwork through education may reduce the mortality rate associated with ECMO. Methods: A retrospective study was performed. Data were collected from January 1, 2009, to December 31, 2011. The data were divided into two periods: 2009/2010 (period 1) and 2011 (period 2). The protocol and training program were applied during period 2. Results: Seventy-six patients were included. The most common disease requiring ECMO support was pneumonia (43.4%). ECMO was applied within 7 days in 76.3% of patients. The primary outcomes, such as Intensive Care Unit (ICU) and hospital mortality rates, were higher during period 1 (91.3%) than period 2 (66.7%, p = 0.013). A multivariate analysis revealed that ECMO weaning failure was the only factor associated with ICU and hospital mortality (ICU mortality: hazard ratio [HR], 11.349; 95% confidence interval [CI], 1.281 to 100.505; p = 0.029; hospital mortality: HR, 17.976; 95% CI, 2.263 to 142.777; p = 0.006). Conclusions: The mortality rate associated with the ECMO procedure decreased following the ECMO training program. However, applying the training program to ECMO management is not an independent factor for the mortality rate. Further studies should be performed to help reduce the mortality rate associated with ECMO.