Jinkyeong Park

Acute exacerbation of idiopathic pulmonary fibrosis: frequency and clinical features

Although acute exacerbations of idiopathic pulmonary fibrosis are well recognised, there are no studies documenting their prevalence or identifying pre-existing risk factors. This study analysed the clinical, radiological and pathological data of 11 patients who satisfied the criteria for acute exacerbation among 147 patients with biopsy-proven idiopathic pulmonary fibrosis. There were five additional patients who had similar demographics, radiology and surgical lung biopsy pathology, but had clinically less severe disease, and so were not included. The 2-yr frequency of acute exacerbation was 9.6% after the diagnosis. Most exacerbations were idiopathic, although two cases presented after surgical lung biopsy and one after bronchoalveolar lavage. No significant risk factor was found by univariate proportional hazard analysis. Imaging revealed diffuse bilateral ground-glass opacification superimposed on subpleural reticular and honeycombing densities. The biopsies of four patients taken during acute exacerbation exhibited diffuse alveolar damage superimposed upon usual interstitial pneumonia. The findings of this study demonstrate that acute exacerbation of idiopathic pulmonary fibrosis is rather common and this exacerbation is likely to have a spectrum of severity.

Middle East Respiratory Syndrome Coronavirus Superspreading Event Involving 81 Persons, Korea 2015.

Since the first imported case of Middle East respiratory syndrome coronavirus (MERS-CoV) infection was reported on May 20, 2015 in Korea, there have been 186 laboratory-confirmed cases of MERS-CoV infection with 36 fatalities. Ninety-seven percent (181/186) of the cases had exposure to the health care facilities. We are reporting a superspreading event that transmitted MERS-CoV to 81 persons at a hospital emergency room (ER) during the Korean outbreak in 2015. The index case was a 35-yr-old man who had vigorous coughing while staying at the ER for 58 hr. As in severe acute respiratory syndrome outbreaks, superspreading events can cause a large outbreak of MERS in healthcare facilities with severe consequences. All healthcare facilities should establish and implement infection prevention and control measure as well as triage policies and procedures for early detection and isolation of suspected MERS-CoV cases.

Comorbidities of chronic obstructive pulmonary disease in Koreans: a population-based study.

Chronic obstructive pulmonary disease (COPD) includes pulmonary components with increased comorbidity rates, as well as being a systemic disease. Comorbidities may frequently occur in COPD patients over 40 yr old. We report the comorbidities of patients with COPD, diagnosed by spirometry, in a population-based epidemiologic survey in Korea. Data were derived from the fourth Korean Health and Nutrition Examination Survey in 2008, a stratified multistage clustered probability design survey of a sample representing the entire population of Korea. Results of spirometry and various health-related questionnaires were analyzed in 2,177 subjects aged ≥ 40 yr. The prevalence of COPD (FEV1/FVC < 0.7) in subjects ≥ 40 yr of age was 14.1%. Multivariate analysis showed that underweight (odds ratio [OR] 3.07, 95% confidence interval [CI] 1.05-8.98), coronary heart disease (OR, 0.43; 95% CI, 0.20-0.93) and dyslipidemia (OR, 0.61; 95% CI, 0.45-0.82) were significantly associated with COPD, whereas allergic rhinitis, anemia, arthritis, chronic renal failure, depression, diabetes mellitus, hypertension, gastrointestinal ulcer, and osteoporosis were not. Underweight might be more prevalent but coronary heart disease and dyslipidemia are less prevalent in Koreans with than without COPD in population setting.

Calorie intake of enteral nutrition and clinical outcomes in acutely critically ill patients: a meta-analysis of randomized controlled trials.

BACKGROUND The appropriate calorie intake to be provided to critically ill patients via enteral nutrition (EN) remains unclear. We performed a meta-analysis of randomized controlled trials to compare the effect of initial underfeeding and full feeding in acutely critically ill patients. MATERIALS AND METHODS We searched the Medline, EMBASE, and Cochrane Central Register of Controlled Trials databases to identify randomized controlled trials that compared underfeeding with full feeding in critically ill patients. The primary outcome was overall mortality. The secondary outcomes included length of hospital stay, length of intensive care unit (ICU) stay, duration of mechanical ventilation, incidence of pneumonia, Clostridium difficile colitis, other infectious complications, and gastrointestinal intolerance. RESULTS In total, 4 studies were included in this meta-analysis. There was no significant difference in overall mortality between the underfeeding and full-feeding groups (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.74-1.19; I (2) = 26.6%; P = .61). Subgroup analysis of the underfeeding subgroup that was fed ≥33.3% of the standard caloric requirement indicated that overall mortality was significantly lower in this underfeeding subgroup than in the full-feeding group (OR, 0.63; 95% CI, 0.40-1.00; I (2) = 0%; P = .05). In contrast, no difference in overall mortality was noted between the underfeeding subgroup that was fed <33.3% of the standard caloric requirement and the full-feeding group. The length of hospital stay and length of ICU stay did not differ between the 2 groups. Moreover, no differences in other secondary clinical outcomes were noted. CONCLUSIONS None of the analyzed clinical outcomes for the acutely critically ill patients were significantly influenced by the calorie intake of the initial EN.

Diseases Concomitant With Asthma in Middle-Aged and Elderly Subjects in Korea: A Population-Based Study

Purpose Asthma is prevalent in many countries. Few studies have investigated the association between asthma and concomitant diseases. We retrospectively analyzed the fourth Korean National Health and Nutrition Survey database, performed in 2008 using nationwide stratified random sampling to obtain a representative cohort of the Korean population. Methods We evaluated the association between both self-reported ever-asthmatics and wheezers and concomitant diseases such as arthritis, hypertension, gastrointestinal (GI) ulcers, dyslipidemia, diabetes mellitus, rhinitis, depression, stroke, and obesity in subjects aged ≥40 years. A multivariate analysis was performed to identify concomitant diseases independently associated with asthma, after adjustment for age, gender, income, cigarette smoking, and other chronic diseases. Results Of the total of 4,445 subjects, 2,596 (58.4%) were female and the mean age was 58.3 years. Of the 4,445 subjects, 195 (4.4%) had been diagnosed with asthma at some point, and 444 (10%) were wheezers. Multivariate analysis showed that arthritis (odds ratio [OR] 1.74, 95% confidence interval [CI] 1.26-2.42), rhinitis (OR 1.78, 95% CI 1.14-2.78), depression (OR 1.45, 95% CI 1.05-2.07), and obesity (OR 1.61, 95% CI 1.08-2.40) were significantly associated with self-reported ever-asthma, and arthritis (OR 1.50, 95% CI 1.19-1.909), hypertension (OR 1.34, 95% CI 1.07-1.67), GI ulcers (OR 1.48, 95% CI 1.05-2.08), rhinitis (OR 1.60, 95% CI 1.16-2.19), depression (OR 1.94, 95% CI 1.51-2.48), and obesity (OR 1.56, 95% CI 1.17-2.09) were significantly associated with wheezers. Conclusions These findings indicate that arthritis, rhinitis, depression, and obesity may be associated with both self-reported ever asthma and wheezers in the Korean population.

Endobronchial Ultrasound-guided Transbronchial Needle Biopsy for Diagnosis of Mediastinal Lymphadenopathy in Patients with Extrathoracic Malignancy

Mediastinal lymphadenopathy associated with extrathoracic malignancy or a metastasis of unknown origin (MUO) requires pathological verification. Surgical exploration or endoscopic ultrasound-guided fine needle aspiration is limited to application. We investigated the effectiveness of endobronchial ultrasound-guided transbronchial needle biopsy (EBUS-TBNA) for evaluating mediastinal lymphadenopathy in patients with an extrathoracic malignancy. We retrospectively analyzed data from 59 patients who underwent EBUS-TBNA with a core biopsy because of a suspected mediastinal metastasis between September 2008 and August 2010. All patients had previously been diagnosed with an extrathoracic malignancy (n = 39, 66.1%) or a suspected MUO without a thoracic lesion (n = 20, 33.9%). A total of 88 lymph nodes was analyzed. EBUS-TBNA findings indicated malignancies in 34 patients (57.6%). The EBUS-TBNA sensitivity and specificity for the detection of mediastinal malignancy in patients with a previous extrathoracic malignancy were 96.3% and 100%, respectively. For MUO patients without a thoracic lesion, the sensitivity and specificity were 61.5% and 100%, respectively. The overall sensitivity and specificity were 81.0% and 100%, respectively (P = 0.053). EBUS-TBNA is a safe and effective modality for evaluating mediastinal lymphadenopathy in patients with a previous extrathoracic malignancy or a MUO without a thoracic lesion. The application of this diagnostic tool is likely to have significant clinical implications.

Control of an Outbreak of Middle East Respiratory Syndrome in a Tertiary Hospital in Korea

BACKGROUND In 2015, a large outbreak of Middle East respiratory syndrome (MERS) occurred in the Republic of Korea. Half of the cases were associated with a tertiary care university hospital. OBJECTIVE To document the outbreak and successful control measures. DESIGN Descriptive study. SETTING A 1950-bed tertiary care university hospital. PATIENTS 92 patients with laboratory-confirmed MERS and 9793 exposed persons. MEASUREMENTS Description of the outbreak, including a timeline, and evaluation of the effectiveness of the control measures. RESULTS During the outbreak, 92 laboratory-confirmed MERS cases were associated with a large tertiary care hospital, 82 of which originated from unprotected exposure to 1 secondary patient. Contact tracing and monitoring exposed patients and assigned health care workers were at the core of the control measures in the outbreak. Nontargeted screening measures, including body temperature screening among employees and visitors at hospital gates, monitoring patients for MERS-related symptoms, chest radiographic screening, and employee symptom monitoring, did not detect additional patients with MERS without existing transmission links. All in-hospital transmissions originated from 3 patients with MERS who also had pneumonia and productive cough. LIMITATIONS This was a retrospective single-center study. Statistical analysis could not be done. Because this MERS outbreak originated from a superspreader, effective control measures could differ in endemic areas or in other settings. CONCLUSION Control strategies for MERS outbreaks should focus on tracing contacts of persons with epidemiologic links. Adjusting levels of quarantine and personal protective equipment according to the assumed infectivity of each patient with MERS may be appropriate. PRIMARY FUNDING SOURCE Samsung Biomedical Research Institute.

The efficacy and safety of prone positioning in adults patients with acute respiratory distress syndrome: a meta-analysis of randomized controlled trials

BACKGROUND Prone positioning for acute respiratory distress syndrome (ARDS) has no impact on mortality despite significant improvements in oxygenation. However, a recent trial demonstrated reduced mortality rates in the prone position for severe ARDS. We evaluated effects of prone position duration and protective lung strategies on mortality rates in ARDS. METHODS We extensively searched MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials to identify randomized controlled trials (RCTs) reporting on prone positioning during acute respiratory failure in adults for inclusion in our meta-analysis. RESULTS Eight trials met our inclusion criteria, Totals of 1,099 and 1,042 patients were randomized to the prone and supine ventilation positions. The mortality rates associated with the prone and supine positions were 41% and 47% [risk ratio (RR), 0.90; 95% confidence interval (CI), 0.82-0.98, P=0.02], but the heterogeneity was moderate (P=0.01, I(2)=61%). In a subgroup analysis, the mortality rates for lung protective ventilation (RR 0.73, 95% CI, 0.62-0.86, P=0.0002) and duration of prone positioning >12 h (RR 0.75, 95% CI, 0.65-0.87, P<0.0001) were reduced in the prone position. Prone positioning was not associated with an increased incidence of cardiac events (RR 1.01, 95% CI, 0.87-1.17) or ventilator associated pneumonia (RR 0.88, 95% CI, 0.71-1.09), but it was associated with an increased incidence of pressure sores (RR 1.23, 95% CI, 1.07-1.41) and endotracheal dislocation (RR 1.33, 95% CI, 1.02-1.74). CONCLUSIONS Prone positioning tends to reduce the mortality rates in ARDS patients, especially when used in conjunction with a lung protective strategy and longer prone position durations. Prone positioning for ARDS patients should be prioritized over other invasive procedures because related life-threatening complications are rare. However, further additional randomized controlled design to study are required for confirm benefit of prone position in ARDS.

The Influence of Asian Dust, Haze, Mist, and Fog on Hospital Visits for Airway Diseases

Background Asian dust is known to have harmful effects on the respiratory system. Respiratory conditions are also influenced by environmental conditions regardless of the presence of pollutants. The same pollutant can have different effects on the airway when the air is dry compared with when it is humid. We investigated hospital visits for chronic obstructive pulmonary disease (COPD) and asthma in relation to the environmental conditions. Methods We conducted a retrospective study using the Korean National Health Insurance Service claims database of patients who visited hospitals in Chuncheon between January 2006 and April 2012. Asian dust, haze, mist, and fog days were determined using reports from the Korea Meteorological Administration. Hospital visits for asthma or COPD on the index days were compared with the comparison days. We used two-way case-crossover techniques with one to two matching. Results The mean hospital visits for asthma and COPD were 59.37 ± 34.01 and 10.04 ± 6.18 per day, respectively. Hospital visits for asthma significantly increased at lag0 and lag1 for Asian dust (relative risk [RR], 1.10; 95% confidence interval [CI], 1.01-1.19; p<0.05) and haze (RR, 1.13; 95% CI, 1.06-1.22; p<0.05), but were significantly lower on misty (RR, 0.89; 95% CI, 0.80-0.99; p<0.05) and foggy (RR, 0.89; 95% CI, 0.84-0.93; p<0.05) days than on control days. The hospital visits for COPD also significantly increased on days with Asian dust (RR, 1.29; 95% CI, 1.05-1.59; p<0.05), and were significantly lower at lag4 for foggy days, compared with days without fog (RR, 0.85; 95% CI, 0.75-0.97; p<0.05). Conclusion Asian dust showed an association with airway diseases and had effects for several days after the exposure. In contrast to Asian dust, mist and fog, which occur in humid air conditions, showed the opposite effects on airway diseases, after adjusting to the pollutants. It would require more research to investigate the effects of various air conditions on airway diseases.

Vitamin D Inhibits Expression and Activity of Matrix Metalloproteinase in Human Lung Fibroblasts (HFL-1) Cells

Background Low levels of serum vitamin D is associated with several lung diseases. The production and activation of matrix metalloproteinases (MMPs) may play an important role in the pathogenesis of emphysema. The aim of the current study therefore is to investigate if vitamin D modulates the expression and activation of MMP-2 and MMP-9 in human lung fibroblasts (HFL-1) cells. Methods HFL-1 cells were cast into three-dimensional collagen gels and stimulated with or without interleukin-1β (IL-1β) in the presence or absence of 100 nM 25-hydroxyvitamin D (25(OH)D) or 1,25-dihydroxyvitamin D (1,25(OH)2D) for 48 hours. Trypsin was then added into the culture medium in order to activate MMPs. To investigate the activity of MMP-2 and MMP-9, gelatin zymography was performed. The expression of the tissue inhibitor of metalloproteinase (TIMP-1, TIMP-2) was measured by enzyme-linked immunosorbent assay. Expression of MMP-9 mRNA and TIMP-1, TIMP-2 mRNA was quantified by real time reverse transcription polymerase chain reaction. Results IL-1β significantly stimulated MMP-9 production and mRNA expression. Trypsin converted latent MMP-2 and MMP-9 into their active forms of MMP-2 (66 kDa) and MMP-9 (82 kDa) within 24 hours. This conversion was significantly inhibited by 25(OH)D (100 nM) and 1,25(OH)2D (100 nM). The expression of MMP-9 mRNA was also significantly inhibited by 25(OH)D and 1,25(OH)2D. Conclusion Vitamin D, 25(OH)D, and 1,25(OH)2D play a role in regulating human lung fibroblast functions in wound repair and tissue remodeling through not only inhibiting IL-1β stimulated MMP-9 production and conversion to its active form but also inhibiting IL-1β inhibition on TIMP-1 and TIMP-2 production.