Prognosis of mechanically ventilated patients with COVID-19 after failure of high-flow nasal cannula: a retrospective cohort study.

BACKGROUND: There is an argument whether the delayed intubation aggravate the respiratory failure in Acute respiratory distress syndrome (ARDS) patients with coronavirus disease 2019 (COVID-19). We aimed to investigate the effect of high-flow nasal cannula (HFNC) failure before mechanical ventilation on clinical outcomes in mechanically ventilated patients with COVID-19. METHODS: This retrospective cohort study included mechanically ventilated patients who were diagnosed with COVID-19 and admitted to the intensive care unit (ICU) between February 2020 and December 2021 at Asan Medical Center. The patients were divided into HFNC failure (HFNC-F) and mechanical ventilation (MV) groups according to the use of HFNC before MV. The primary outcome of this study was to compare the worst values of ventilator parameters from day 1 to day 3 after mechanical ventilation between the two groups. RESULTS: Overall, 158 mechanically ventilated patients with COVID-19 were included in this study: 107 patients (67.7%) in the HFNC-F group and 51 (32.3%) in the MV group. The two groups had similar profiles of ventilator parameter from day 1 to day 3 after mechanical ventilation, except of dynamic compliance on day 3 (28.38 mL/cmH2O in MV vs. 30.67 mL/H2O in HFNC-F, p = 0.032). In addition, the HFNC-F group (5.6%) had a lower rate of ECMO at 28 days than the MV group (17.6%), even after adjustment (adjusted hazard ratio, 0.30; 95% confidence interval, 0.11-0.83; p = 0.045). CONCLUSIONS: Among mechanically ventilated COVID-19 patients, HFNC failure before mechanical ventilation was not associated with deterioration of respiratory failure.

Particulate matter-induced metabolic recoding of epigenetics in macrophages drives pathogenesis of chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is a group of illnesses associated with unresolved inflammation in response to toxic environmental stimuli. Persistent exposure to PM is a major risk factor for COPD, but the underlying mechanism remains unclear. Using our established mouse model of PM-induced COPD, we find that repeated PM exposure provokes macrophage-centered chronic inflammation and COPD development. Mechanistically, chronic PM exposure induces transcriptional downregulation of HAAO, KMO, KYNU, and QPRT in macrophages, which are the enzymes of de novo NAD+ synthesis pathway (kynurenine pathway; KP), via elevated chromatin binding of the CCCTC-binding factor (CTCF) near the transcriptional regulatory regions of the enzymes. Subsequent reduction of NAD+ and SIRT1 function increases histone acetylation, resulting in elevated expression of pro-inflammatory genes in PM-exposed macrophages. Activation of SIRT1 by nutraceutical resveratrol mitigated PM-induced chronic inflammation and COPD development. In agreement, increased levels of histone acetylation and decreased expression of KP enzymes were observed in pulmonary macrophages of COPD patients. We newly provide an evidence that dysregulated NAD+ metabolism and consecutive SIRT1 deficiency significantly contribute to the pathological activation of macrophages during PM-mediated COPD pathogenesis. Additionally, targeting PM-induced intertwined metabolic and epigenetic reprogramming in macrophages is an effective strategy for COPD treatment.

Clinical impact of pre-existing acute exacerbation in patients with interstitial lung disease who underwent lung transplantation.

BACKGROUND: Acute exacerbation of interstitial lung disease (AE-ILD) significantly impacts prognosis, leading to high mortality rates. Although lung transplantation is a life-saving treatment for selected patients with ILD, its outcomes in those presenting with AE-ILD have yielded conflicting results compared with those with stable ILD. This study aims to investigate the impact of pre-existing AE on the prognosis of ILD patients who underwent lung transplantation. METHOD: We conducted a single-center retrospective study by reviewing the medical records of 108 patients who underwent lung transplantation for predisposing ILD at Asan Medical Center, Seoul, South Korea, between 2008 and 2022. The primary objective was to compare the survival of patients with AE-ILD at the time of transplantation with those without AE-ILD. RESULTS: Among the 108 patients, 52 (48.1%) experienced AE-ILD at the time of lung transplantation, and 81 (75.0%) required pre-transplant mechanical ventilation. Although the type of ILD (IPF vs. non-IPF ILD) did not affect clinical outcomes after transplantation, AE-ILD was associated with worse survival outcomes. The survival probabilities at 90 days, 1 year, and 3 years post-transplant for patients with AE-ILD were 86.5%, 73.1%, and 60.1%, respectively, while those for patients without AE-ILD were higher, at 92.9%, 83.9%, and 79.6% (p = 0.032). In the multivariable analysis, pre-existing AE was an independent prognostic factor for mortality in ILD patients who underwent lung transplantation. CONCLUSIONS: Although lung transplantation remains an effective treatment option for ILD patients with pre-existing AE, careful consideration is needed, especially in patients requiring pre-transplant mechanical respiratory support.

Extended Versus Intermittent Meropenem Infusion in the Treatment of Nosocomial Pneumonia: A Retrospective Single-Center Study.

The efficacy of extended meropenem infusions in patients with nosocomial pneumonia is not well defined. Therefore, we compared the clinical outcomes of extended versus intermittent meropenem infusions in the treatment of nosocomial pneumonia. We performed a retrospective analysis of extended versus intermittent meropenem infusions in adult patients who had been treated for nosocomial pneumonia at a medical ICU between 1 May 2018 and 30 April 2020. The primary outcome was mortality at 14 days. Overall, 64 patients who underwent an extended infusion and 97 with an intermittent infusion were included in this study. At 14 days, 10 (15.6%) patients in the extended group and 22 (22.7%) in the intermittent group had died (adjusted hazard ratio (HR), 0.55; 95% confidence interval (CI): 0.23-1.31; p = 0.174). In the subgroup analysis, significant differences in mortality at day 14 were observed in patients following empirical treatment with meropenem (adjusted HR, 0.17; 95% CI: 0.03-0.96; p = 0.045) and in Gram-negative pathogens identified by blood or sputum cultures (adjusted HR, 0.01; 95% CI: 0.01-0.83; p = 0.033). Extended infusion of meropenem compared with intermittent infusion as a treatment option for nosocomial pneumonia may have a potential advantage in specific populations.

Impact of a cumulative positive fluid balance during the first three ICU days in patients with sepsis: a propensity score-matched cohort study.

BACKGROUND: The optimal strategy for fluid management during the first few days of ICU in sepsis patients remains controversial. We aimed to investigate the impact of cumulative fluid balance during the first three days of ICU on the mortality of patients with sepsis. METHODS: This study analyzed prospectively collected data from the Korean Sepsis Alliance Database, which registered 11,981 sepsis patients from 20 hospitals. We selected three propensity score-matched cohorts consisting of patients with a negative or positive cumulative fluid balance during the first three ICU days: from ICU admission to the first midnight as the D1 cohort, until the second midnight as the D2 cohort, and until the third midnight as the D3 cohort. The propensity score for fluid balance was calculated using covariates including the amount of fluid output during the first three ICU days. The primary outcome was mortality at day 28 in the ICU. RESULTS: From a total of 11,981 patients, 2516 patients were included for propensity score matching. After matching in a 1:1 ratio, there were 483, 373, and 392 matched pairs of patients assigned to the D1, D2, and D3 cohorts, respectively. In the D1 cohort, there were no significant differences in mortality at day 28 (hazard ratio [HR], 1.17; 95% confidence interval [CI] 0.85-1.60; P = 0.354) between the two groups. The positive fluid groups in both the D2 (HR, 2.13; 95% CI 1.48-3.06; P < 0.001) and D3 (HR, 1.56; 95% CI 1.10-2.22; P = 0.012) cohorts had significantly higher mortality rates than the negative fluid groups. CONCLUSIONS: In patients with sepsis, a positive fluid balance on the first ICU day was not associated with mortality at day 28. In contrast, cumulative positive fluid balances on the second and third ICU days were associated with higher mortality at day 28.

Longitudinal trajectories of sedation level and clinical outcomes in patients who are mechanically ventilated based on a group-based trajectory model: a prospective, multicentre, longitudinal and observational study in Korea.

OBJECTIVES: Changes in sedation levels over a long time in patients who are mechanically ventilated are unknown. Therefore, we investigated the long-term sedation levels of these patients by classifying them into different longitudinal patterns. DESIGN: This was a multicentre, prospective, longitudinal, and observational study. SETTING: Twenty intensive care units (ICUs) spanning several medical institutions in Korea. PARTICIPANTS: Patients who received mechanical ventilation and sedatives in ICU within 48 hours of admission between April 2020 and July 2021. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary objective of this study was to identify the pattern of sedation practice. Additionally, we analysed the associations of trajectory groups with clinical outcomes as the secondary outcome. RESULTS: Sedation depth was monitored using Richmond Agitation-Sedation Scale (RASS). A group-based trajectory model was used to classify 631 patients into four trajectories based on sedation depth: persistent suboptimal (13.2%, RASS ≤ -3 throughout the first 30 days), delayed lightening (13.9%, RASS ≥ -2 after the first 15 days), early lightening (38.4%, RASS ≥ -2 after the first 7 days) and persistent optimal (34.6%, RASS ≥ -2 during the first 30 days). 'Persistent suboptimal' trajectory was associated with delayed extubation (HR: 0.23, 95% CI: 0.16 to 0.32, p<0.001), longer ICU stay (HR: 0.36, 95% CI: 0.26 to 0.51, p<0.001) and hospital mortality (HR: 13.62, 95% CI: 5.99 to 30.95, p<0.001) compared with 'persistent optimal'. The 'delayed lightening' and 'early lightening' trajectories showed lower extubation probability (HR: 0.30, 95% CI: 0.23 to 0.41, p<0.001; HR: 0.72, 95% CI: 0.59 to 0.87, p<0.001, respectively) and ICU discharge (HR: 0.44, 95% CI: 0.33 to 0.59, p<0.001 and HR: 0.80, 95% CI: 0.65 to 0.97, p=0.024) compared with 'persistently optimal'. CONCLUSIONS: Among the four trajectories, 'persistent suboptimal' trajectory was associated with higher mortality.

The Profile of Early Sedation Depth and Clinical Outcomes of Mechanically Ventilated Patients in Korea.

BACKGROUND: Current international guidelines recommend against deep sedation as it is associated with worse outcomes in the intensive care unit (ICU). However, in Korea the prevalence of deep sedation and its impact on patients in the ICU are not well known. METHODS: From April 2020 to July 2021, a multicenter, prospective, longitudinal, noninterventional cohort study was performed in 20 Korean ICUs. Sedation depth extent was divided into light and deep using a mean Richmond Agitation-Sedation Scale value within the first 48 hours. Propensity score matching was used to balance covariables; the outcomes were compared between the two groups. RESULTS: Overall, 631 patients (418 [66.2%] and 213 [33.8%] in the deep and light sedation groups, respectively) were included. Mortality rates were 14.1% and 8.4% in the deep and light sedation groups (P = 0.039), respectively. Kaplan-Meier estimates showed that time to extubation (P < 0.001), ICU length of stay (P = 0.005), and death (P = 0.041) differed between the groups. After adjusting for confounders, early deep sedation was only associated with delayed time to extubation (hazard ratio [HR], 0.66; 95% confidence interval [CI], 0.55-0.80; P < 0.001). In the matched cohort, deep sedation remained significantly associated with delayed time to extubation (HR, 0.68; 95% CI, 0.56-0.83; P < 0.001) but was not associated with ICU length of stay (HR, 0.94; 95% CI, 0.79-1.13; P = 0.500) and in-hospital mortality (HR, 1.19; 95% CI, 0.65-2.17; P = 0.582). CONCLUSION: In many Korean ICUs, early deep sedation was highly prevalent in mechanically ventilated patients and was associated with delayed extubation, but not prolonged ICU stay or in-hospital death.

Incidence, risk factors, and clinical characteristics of airway complications after lung transplantation.

Airway complications may occur after lung transplantation and are associated with considerable morbidity and mortality. We investigated the incidence, risk factors, and clinical characteristics of these complications. We retrospectively reviewed the medical records of 137 patients who underwent lung transplantation between 2008 and 2021. The median follow-up period was 20 months. Of the 137 patients, 30 (21.9%) had postoperative airway complications, of which 2 had two different types of airway complications. The most common airway complication was bronchial stenosis, affecting 23 patients (16.8%). Multivariable Cox analysis revealed that a recipient's body mass index ≥ 25 kg/m2 (hazard ratio [HR], 2.663; p = 0.013) was a significant independent risk factor for airway complications, as was postoperative treatment with extracorporeal membrane oxygenation (ECMO; HR, 3.340; p = 0.034). Of the 30 patients who had airway complications, 21 (70.0%) were treated with bronchoscopic intervention. Survival rates did not differ significantly between patients with and without airway complications. Thus, our study revealed that one fifth of patients who underwent lung transplantation experienced airway complications during the follow-up period. Obesity and receiving postoperative ECMO are risk factors for airway complications, and close monitoring is warranted in such cases.

Continuous Piperacillin-Tazobactam Infusion Improves Clinical Outcomes in Critically Ill Patients with Sepsis: A Retrospective, Single-Centre Study.

Continuous infusion of beta-lactam antibiotics has emerged as an alternative for the treatment of sepsis because of the favourable pharmacokinetics of continuous infusion. This study aimed to evaluate the survival benefits of continuous vs. intermittent infusion of piperacillin-tazobactam in critically ill patients with sepsis. We retrospectively conducted a single-centre study of continuous infusion vs. intermittent infusion of piperacillin-tazobactam for adult patients who met the Sepsis-3 criteria and were treated at a medical ICU within 48 h after hospitalisation between 1 May 2018 and 30 April 2020. The primary outcome was mortality at 28 days. A total of 157 patients (47 in the continuous group and 110 in the intermittent group) met the inclusion criteria for evaluation. The 28-day mortality rates were 12.8% in the continuous group and 27.3% in the intermittent group (p = 0.07). However, after adjustment for potential covariables, patients in the continuous group (12.8%) showed significantly lower mortality at 28 days than those in the intermittent group (27.3%; adjusted hazard ratio (HR), 0.31; 95% confidence interval (CI), 0.13-0.79; p = 0.013). In sepsis patients, continuous infusion of piperacillin-tazobactam may confer a benefit regarding the avoidance of mortality at 28 days compared with intermittent infusion.

Mortality of patients with hospital-onset sepsis in hospitals with all-day and non-all-day rapid response teams: a prospective nationwide multicenter cohort study.

BACKGROUND: Hospital-onset sepsis is associated with a higher in-hospital mortality rate than community-onset sepsis. Many hospitals have implemented rapid response teams (RRTs) for early detection and timely management of at-risk hospitalized patients. However, the effectiveness of an all-day RRT over a non-all-day RRT in reducing the risk of in-hospital mortality in patient with hospital-onset sepsis is unclear. We aimed to determine the effect of the RRT's operating hours on in-hospital mortality in inpatient patients with sepsis. METHODS: We conducted a nationwide cohort study of adult patients with hospital-onset sepsis prospectively collected from the Korean Sepsis Alliance (KSA) Database from 16 tertiary referral or university-affiliated hospitals in South Korea between September of 2019 and February of 2020. RRT was implemented in 11 hospitals, of which 5 (45.5%) operated 24-h RRT (all-day RRT) and the remaining 6 (54.5%) had part-day RRT (non-all-day RRT). The primary outcome was in-hospital mortality between the two groups. RESULTS: Of the 405 patients with hospital-onset sepsis, 206 (50.9%) were admitted to hospitals operating all-day RRT, whereas 199 (49.1%) were hospitalized in hospitals with non-all-day RRT. A total of 73 of the 206 patients in the all-day group (35.4%) and 85 of the 199 patients in the non-all-day group (42.7%) died in the hospital (P = 0.133). After adjustments for co-variables, the implementation of all-day RRT was associated with a significant reduction in in-hospital mortality (adjusted odds ratio 0.57; 95% confidence interval 0.35-0.93; P = 0.024). CONCLUSIONS: In comparison with non-all-day RRTs, the availability of all-day RRTs was associated with reduced in-hospital mortality among patients with hospital-onset sepsis.

Reliability of Central Venous Blood Gas Values Compared With Arterial Blood Gas Values in Critically Ill Patients.

BACKGROUND: Central venous blood gas (cVBG) values are correlated with arterial blood gas (ABG) values. However, the substitution of cVBG values for ABG values in critically ill patients remains uninvestigated. Thus, we investigated the reliability between cVBG and ABG values and sought to define the conditions that could improve the reliability of cVBG values as a substitute. METHODS: We conducted a prospective comparison of 292 sets of cVBG values and ABG values from 82 subjects admitted to the medical ICU between October 2017-July 2018. Paired cVBG and ABG samples were collected daily during the first 5 d of ICU treatment and on days 8, 15, 22, and 29. Intraclass correlation coefficient (ICC) and Bland-Altman limits of agreement (LOA) were obtained. RESULTS: The ICC between ABG and cVBG was 0.626 for pH, 0.696 for PCO2 , 0.869 for bicarbonate, 0.866 for base excess, and 0.989 for lactic acid. Bland-Altman plots showed clinically unacceptable LOA between all parameters. Subgroup analysis indicated a significant increase in the ICCs of PCO2 in samples with mechanical ventilation (0.0574-0.735, P = .02) and central venous oxygen saturation (ScvO2) ≥ 70% (0.611-0.763, P = .008). After adjustment, the 95% LOA between ABG and cVBG was -0.06 to 0.07 for pH and -7.09 to 7.05 for PCO2 in mechanically ventilated subjects with ScvO2 ≥ 70%. CONCLUSIONS: ABG and cVBG values showed clinically acceptable agreements and improved reliability in mechanically ventilated subjects with ScvO2 ≥ 70%. cVBG analysis may be a substitute for ABG analysis in mechanically ventilated patients once tissue perfusion is restored.

Constitutive activation of the PI3K-Akt-mTORC1 pathway sustains the m.3243 A > G mtDNA mutation.

Mutations of the mitochondrial genome (mtDNA) cause a range of profoundly debilitating clinical conditions for which treatment options are very limited. Most mtDNA diseases show heteroplasmy - tissues express both wild-type and mutant mtDNA. While the level of heteroplasmy broadly correlates with disease severity, the relationships between specific mtDNA mutations, heteroplasmy, disease phenotype and severity are poorly understood. We have carried out extensive bioenergetic, metabolomic and RNAseq studies on heteroplasmic patient-derived cells carrying the most prevalent disease related mtDNA mutation, the m.3243 A > G. These studies reveal that the mutation promotes changes in metabolites which are associated with the upregulation of the PI3K-Akt-mTORC1 axis in patient-derived cells and tissues. Remarkably, pharmacological inhibition of PI3K, Akt, or mTORC1 reduced mtDNA mutant load and partially rescued cellular bioenergetic function. The PI3K-Akt-mTORC1 axis thus represents a potential therapeutic target that may benefit people suffering from the consequences of the m.3243 A > G mutation.

A physician-led medical emergency team increases the rate of medical interventions: A multicenter study in Korea.

BACKGROUND: According to the rapid response system's team composition, responding teams were named as rapid response team (RRT), medical emergency team (MET), and critical care outreach. A RRT is often a nurse-led team, whereas a MET is a physician-led team that mainly plays the role of an efferent limb. As few multicenter studies have focused on physician-led METs, we comprehensively analyzed cases for which physician-led METs were activated. METHODS: We retrospectively analyzed cases for which METs were activated. The study population consisted of subjects over 18 years of age who were admitted in the general ward from January 2016 to December 2017 in 9 tertiary teaching hospitals in Korea. The data on subjects' characteristics, activation causes, activation methods, performed interventions, in-hospital mortality, and intensive care unit (ICU) transfer after MET activation were collected and analyzed. RESULTS: In this study, 12,767 cases were analyzed, excluding those without in-hospital mortality data. The subjects' median age was 67 years, and 70.4% of them were admitted to the medical department. The most common cause of MET activation was respiratory distress (35.1%), followed by shock (11.8%), and the most common underlying disease was solid cancer (39%). In 7,561 subjects (59.2%), the MET was activated using the screening system. The commonly performed procedures were arterial line insertion (17.9%), intubation (13.3%), and portable ultrasonography (13.0%). Subsequently, 29.4% of the subjects were transferred to the ICU, and 27.2% died during hospitalization. CONCLUSIONS: This physician-led MET cohort showed relatively high rates of intervention, including arterial line insertion and portable ultrasonography, and low ICU transfer rates. We presume that MET detects deteriorating patients earlier using a screening system and begins ICU-level management at the patient's bedside without delay, eventually preventing the patient's condition from worsening and transfer to the ICU.

Predictive powers of the Modified Early Warning Score and the National Early Warning Score in general ward patients who activated the medical emergency team.

BACKGROUND: The current early warning scores may be insufficient for medical emergency teams (METs) to use in assessing the severity and the prognosis of activated patients. We evaluated the predictive powers of the Modified Early Warning Score (MEWS) and the National Early Warning Score (NEWS) for 28-day mortality and to analyze predictors of 28-day mortality in general ward patients who activate the MET. METHODS: Adult general ward inpatients who activated the MET in a tertiary referral teaching hospital between March 2009 and December 2016 were included. The demographic and clinical characteristics and physiologic parameters at the time of MET activation were collected, and MEWS and NEWS were calculated. RESULTS: A total of 6,729 MET activation events were analyzed. Patients who died within 28 days were younger (mean age 60 vs 62 years), were more likely to have malignancy (72% vs 53%), were more likely to be admitted to the medical department rather than the surgical department (93% vs 80%), had longer intervals from admission to MET activation (median, 7 vs 5 days), and were less likely to activate the MET during nighttime hours (5 PM to 8 AM) (61% vs 66%) compared with those who did not die within 28 days (P < 0.001 for all comparisons). The areas under the receiver operating characteristic curves of MEWS and NEWS for 28-day mortality were 0.58 (95% CI, 0.56-0.59) and 0.60 (95% CI, 0.59-0.62), which were inferior to that of the logistics regression model (0.73; 95% CI, 0.72-0.74; P < 0.001 for both comparisons). CONCLUSIONS: Both the MEWS and NEWS had poor predictive powers for 28-day mortality in patients who activated the MET. A new scoring system is needed to stratify the severity and prognosis of patients who activated the MET.

Vitamin C alone does not improve treatment outcomes in mechanically ventilated patients with severe sepsis or septic shock: a retrospective cohort study.

BACKGROUND: Vitamin C has shown several beneficial effects on sepsis in preclinical studies. However, clinical data supporting these reports are scarce. This study aimed to evaluate whether adjunctive intravenous vitamin C therapy could reduce hospital mortality in patients with severe sepsis or septic shock requiring mechanical ventilation. METHODS: For this retrospective cohort study, consecutive medical ICU patients with severe sepsis or septic shock requiring mechanical ventilation were included. The study patients were classified into the vitamin C or control groups depending on the administration of intravenous vitamin C (2 g every 8 hours). The primary outcome was hospital mortality. RESULTS: Thirty-five patients in the vitamin C group and 40 patients in the control group were included. The two groups were comparable in regards to the baseline characteristics at ICU admission. The hospital mortality was 46% (16 of 35 patients) in the vitamin C group and 40% (16 of 40 patients) in the control group, showing a statistically nonsignificant difference (P=0.62). The mortality at 90 days after ICU admission (60% vs. 48%) did not significantly differ between groups. The median time to shock reversal was 3 days [interquartile range (IQR), 2 to 5 days] in both groups. The changes in the Sepsis-related Organ Failure Assessment (SOFA) scores during the first 4 ICU days were -1.4±3.3 and -1.4±3.0 in the vitamin C and control groups, respectively. CONCLUSIONS: Adjunctive intravenous vitamin C therapy alone did not reduce hospital mortality in mechanically ventilated patients with severe sepsis or septic shock.

Prognostic role of FEV1 for survival in bronchiolitis obliterans syndrome after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: Bronchiolitis obliterans syndrome (BOS) can occur after hematopoietic stem cell transplantation (HSCT) and is associated with significant mortality. We investigated the role of forced expiratory volume in one s (FEV1 ) as a prognostic marker in BOS after HSCT. METHODS: Among all patients who underwent HSCT between December 1993 and November 2013 at a tertiary center in South Korea, 1187 patients were enrolled. Patient medical records were retrospectively analyzed to evaluate the prognostic factors associated with survival in these cases. RESULTS: During a median follow-up period of 30.7 months after HSCT, 82 patients (6.9%) were diagnosed with BOS. The mean FEV1 of the BOS patients was 34.7% of predicted, and the mean FEV1 of 31 of these patients (37.8%) was <30% of predicted. The estimated overall survival rate for BOS patients excluding three patients who received lung transplantation was 74% at three yr from BOS diagnosis. Multivariate analysis showed that diagnosis of BOS within six months and FEV1 < 30% of predicted at the time of BOS diagnosis were associated with shorter survival. CONCLUSIONS: An FEV1 < 30% of predicted at the time of diagnosis is significantly associated with an increased risk of death in patients with BOS after HSCT.

Clinical characteristics and survival of Korean idiopathic pulmonary arterial hypertension patients based on vasoreactivity.

We aimed to identify a vasoreactive subset of patients with idiopathic pulmonary arterial hypertension (IPAH) in Korea and to show their clinical characteristics and prognosis. Data on patients who were diagnosed with IPAH at Asan Medical Center between January 1994 and March 2013 were retrospectively collected. Acute vasodilator testing was performed with inhaled nitric oxide during diagnostic right heart catheterization. A positive acute response was defined as a reduction in mean pulmonary arterial pressure (PAP) ≥10 mmHg to an absolute level of mean PAP <40 mmHg without a decrease in cardiac output. Among a total of 60 IPAH patients included for analysis, 9 (15%) showed a positive acute response to acute vasodilator testing. Acute responders showed significantly lower peak velocity of a tricuspid regurgitation jet on echocardiography (4.1±0.3 m/s vs. 4.6±0.6 m/s; P=0.01) and significantly lower mean PAP hemodynamically (47±10 mmHg vs. 63±17 mmHg; P=0.003) than non-responders at baseline. The survival rate of acute responders was 88% at 1, 3, 5, and 10 yr, respectively, which was significantly higher than that of non-responders (85%, 71%, 55%, and 40%, respectively; P=0.029). In conclusion, Korean IPAH patients with vasoreactivity showed better baseline hemodynamic features and survival than those without vasoreactivity.

A Case of IgG4-Related Lung Disease Presenting as Interstitial Lung Disease.

Intrathoracic involvement of immunoglobulin G4 (IgG4)-related disease has recently been reported. However, a subset of the disease presenting as interstitial lung disease is rare. Here, we report a case of a 35-year-old man with IgG4-related lung disease with manifestations similar to those of interstitial lung disease. Chest computed tomography showed diffuse ground glass opacities and rapidly progressive pleural and subpleural fibrosis in both upper lobes. Histological findings showed diffuse interstitial lymphoplasmacytic infiltration with an increased number of IgG4-positive plasma cells. Serum levels of IgG and IgG4 were also increased. The patient was diagnosed with IgG4-related lung disease, treated with anti-inflammatory agents, and showed improvement. Lung involvement of IgG4-related disease can present as interstitial lung disease and, therefore, should be differentiated when evaluating interstitial lung disease.