Seong Hoon Yoon

Impact of Implementation of an Automated Liquid Culture System on Diagnosis of Tuberculous Pleurisy.

This study was conducted to evaluate the impact of implementation of an automated liquid culture system on the diagnosis of tuberculous pleurisy in an HIV-uninfected patient population. We retrospectively compared the culture yield, time to positivity, and contamination rate of pleural effusion samples in the BACTEC Mycobacteria Growth Indicator Tube 960 (MGIT) and Ogawa media among patients with tuberculous pleurisy. Out of 104 effusion samples, 43 (41.3%) were culture positive on either the MGIT or the Ogawa media. The culture yield of MGIT was higher (40.4%, 42/104) than that of Ogawa media (18.3%, 19/104) (P<0.001). One of the samples was positive only on the Ogawa medium. The median time to positivity was faster in the MGIT (18 days, range 8-32 days) than in the Ogawa media (37 days, range 20-59 days) (P<0.001). No contamination or growth of nontuberculous mycobacterium was observed on either of the culture media. In conclusion, the automated liquid culture system could provide approximately twice as high yields and fast results in effusion culture, compared to solid media. Supplemental solid media may have a limited impact on maximizing sensitivity in effusion culture; however, further studies are required. Graphical Abstract

Validity of Outcome Prediction Scoring Systems in Korean Patients with Severe Adult Respiratory Distress Syndrome Receiving Extracorporeal Membrane Oxygenation Therapy

Recently, several prognostic scoring systems for patients with severe acute respiratory distress syndrome (ARDS) requiring extracorporeal membrane oxygenation (ECMO) have been published. The aim of this study was to validate the established scoring systems for outcome prediction in Korean patients. We retrospectively reviewed the data of 50 patients on ECMO therapy in our center from 2012 to 2014. A calculation of outcome prediction scoring tools was performed and the comparison across various models was conducted. In our study, the overall hospital survival was 46% and successful weaning rate was 58%. The Predicting Death for Severe ARDS on V-V ECMO (PRESERVE) score showed good discrimination of mortality prediction for patients on ECMO with AUC of 0.80 (95% CI 0.66-0.90). The respiratory extracorporeal membrane oxygenation survival prediction (RESP) score and simplified acute physiology score (SAPS) II score also showed fair prediction ability with AUC of 0.79 (95% CI 0.65-0.89) and AUC of 0.78 (95% CI 0.64-0.88), respectively. However, the ECMOnet score failed to predict mortality with AUC of 0.51 (95% CI 0.37-0.66). When evaluating the predictive accuracy according to optimal cut-off point of each scoring system, RESP score had a best specificity of 91.3% and 66.7% of sensitivity, respectively. This study supports the clinical usefulness of the prognostic scoring tools for severe ARDS with ECMO therapy when applying to the Korean patients receiving ECMO.

Current Status and Future of Lung Donation in Korea

Lung transplantation is the only effective treatment option for patients with end-stage lung disease. However, donor organ shortage makes timely transplant not possible for all patients, especially in Korea. We investigated the number and utilization of donor lungs by retrospectively reviewing all donor organs registered in the Korea Network for Organ Sharing database from March 2012 to March 2016. The donors were stratified into 4 groups by donor acceptability criteria. A total of 1,304 donors were included. Of those, 295 brain-dead donors (22.6%) consented to lung donation. Among these consented donors, 168 donors (12.9%) were retrieved for lung transplant. Retrieval rate was very low compared with that of the kidney (93.9%), liver (86.3%), and heart (27.3%). The characteristics of utilized donor lungs were: mean age, 40.5 years (range: 18 to 63 years); mean partial pressure of oxygen, 356.5 mmHg; mean smoking history, 5.9 pack-years; and mean body mass index, 22.6 kg/m2. The proportion of donors with acceptable condition of the transplanted lungs was only 39.3% (ideal 19, standard 47, marginal 70, unusable 32). Among brain-dead patients who denied to donate lungs (n = 1,009), 82 were potentially acceptable donors (ideal 19, standard 63), which was equal to half of actually transplanted lung donations. Many potential donor lungs, which are currently excluded, may be successfully used in lung transplantation in Korea. The available lung donors must be actively selected and managed to maximize the utilization of this precious resource.

Upregulation of P21-Activated Kinase 1 (PAK1)/CREB Axis in Squamous Non-Small Cell Lung Carcinoma

Background/Aims: p21-activated Ser/Thr kinase 1 (PAK1) is essential for the genesis and development of many cancers. The purpose of this study was to investigate the role of the PAK1–cyclic AMP response element-binding (CREB) axis in non-small cell lung cancer (NSCLC) tumorigenesis and its related mechanisms. Methods: Western blot assay and immunohistochemical staining were employed to investigate the PAK1 and CREB expression in the tissue microarray of human squamous NSCLC. Co-immunoprecipitation and immunofluorescence confocal assays were performed to determine the link between PAK1 and CREB. NSCLC xenograft models were used to study oncogenic function of PAK1 in vivo. Results: We observed that PAK1 and CREB expression levels were significantly elevated in human squamous NSCLC-tissue specimens, compared with those in adjacent normal bronchial or bronchiolar epithelial-tissue specimens, as well as their phosphorylated forms, based on western blotting. We showed in vitro that PAK1 knockdown by small-interfering RNA (siRNA) blocked CREB phosphorylation, whereas plasmid-based PAK1 overexpression resulted in CREB phosphorylation at Ser133, based on western blotting. In addition, PAK1 interacted with CREB in co-immunoprecipitation assays. Additionally, our in vitro findings detected by flow cytometry revealed that PAK1 silencing attenuated cell cycle progression, inducing apoptosis. Inhibition of PAK1 expression reduced tumor sizes and masses by modulating CREB expression and activation in xenograft models. Conclusion: These results suggest a novel mechanism whereby the PAK1–CREB axis drives carcinogenesis of squamous-cell carcinomas, and have important implications in the development of targeted therapeutics for squamous-cell lung cancer.

Safety of Surgical Tracheostomy during Extracorporeal Membrane Oxygenation

Background The risk of bleeding during extracorporeal membrane oxygenation (ECMO) is a potential deterrent in performing tracheostomy at many centers. To evaluate the safety of surgical tracheostomy (ST) in critically ill patients supported by ECMO, we reviewed the clinical correlation between preoperative coagulation status and bleeding complication-related ST during ECMO. Methods From April 1, 2012 to March 31, 2016, ST was performed on 38 patients supported by ECMO. We retrospectively reviewed and analyzed the medical records including complications related to ST. Results Heparin was administered to 23 patients (60.5%) for anticoagulation during ECMO, but 15 patients (39.5%) underwent ECMO without anticoagulation. Of the 23 patients administered anticoagulation therapy, heparin infusion was briefly paused in 13 prior to ST. The median platelet count, international normalized ratio, and activated partial thromboplastin time before ST were 126 × 109/L (range, 46 to 434 × 109/L), 1.2 (range, 1 to 2.3) and 62 seconds (27 to 114.2 seconds), respectively. No peri-procedural clotting complications related to ECMO were observed. Two patients (5.3%) suffering from ST-related major bleeding required surgical hemostasis. Minor bleeding after ST occurred in two cases (5.3%). No significant difference was found according to anticoagulation management (P = 0.723). No fatality was attributable to ST. Conclusions The complication rates of ST in the patients supported by ECMO were low. Therefore, ST performed by an experienced operator, and with careful optimization of coagulation status, is a relatively safe procedure; the use of ST with ECMO should thus not be dismissed on account of the potential for bleeding caused by the administration of anticoagulants.

87P: Qualitative and quantitative interpretation of F-18 FDG PET/CT to differentiate metastatic mediastinal lymph node in non-small cell lung carcinoma patients with benign mediastinal lymph node hyperplasia.

Y.S. Kim1, S.H. Yoon1, B.S. Son2, D.H. Kim2, K. Kim3, I.-J. Kim4. 1 Pulmonology, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea, 2 Thoracic surgery, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea, 3 Nuclear Medicine, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea, 4 Internal Medicine, Pusan National University Hospital, Busan, Republic of Korea