Prevalence and impact of airway diseases on clinical outcomes in idiopathic pulmonary fibrosis

BACKGROUND/AIMS

The prevalence and effects of airway diseases, including asthma, eosinophilic bronchitis (EB), chronic obstructive pulmonary disease (COPD), and asthma-COPD overlap (ACO) have not been thoroughly studied in patients with idiopathic pulmonary fibrosis (IPF). This study aimed to evaluate the prevalence of airway diseases in patients with IPF and to identify the differences in symptoms based on the presence of airway diseases.

METHODS

This single-institution prospective cohort study was conducted from June 2017 to September 2018, at the Seoul National University Hospital. Spirometry with bronchodilator, methacholine bronchial provocation test, induced sputum with eosinophil stain, and exhaled nitric oxide were performed to confirm the presence of airway disease. The modified Medical Research Council (mMRC) dyspnea scale, COPD assessment test (CAT), St. George's Respiratory Questionnaire (SGRQ), EuroQol-5 dimension (EQ-5D) index, and cough-specific quality of life questionnaire (CQLQ) data were collected to assess symptom severity.

RESULTS

Total 147 patients with IPF were screened, and 70 patients were analyzed. The prevalence of airway diseases in the participants was as follows: 5.0% had COPD, 1.7% had asthma, 3.3% had ACO, and 1.7% had EB. The mMRC, CAT, SGRQ, EQ-5D, and CQLQ scores did not differ regardless of combined airway disease. After 3 months, the SGRQ (p = 0.028) and CQLQ (p = 0.030) scores were significantly higher in patients with airway disease than in those without.

CONCLUSION

The prevalence of airway diseases in patients with IPF is low, but when airway diseases are accompanied by IPF, symptom severity and quality of life may worsen rapidly.

Solar background noise mitigation using the orbital angular momentum mode in vertical FSO downlink transmissions

Free-space optical communication (FSO) is used to provide network configuration flexibility. A network-flying platform-based vertical FSO connection can be employed to enhance mobile network coverage and capacity. Solar background noise can be a potential risk that disrupts the seamless connection in the vertical FSO downlink channel. In this paper, we propose signal transmission using an orbital angular momentum (OAM) beam. The OAM demodulation process can filter sunlight out of the optical receiver except for the signal corresponding to the azimuthal state. We experimentally verified that most of the solar background noise could be reduced. To verify the feasibility of the proposed scheme in a vertical FSO channel, we modeled a FSO vertical downlink with an OAM modulation/demodulation process.

Validation of age, PaO2/FlO2 and plateau pressure score in Korean patients with acute respiratory distress syndrome: a retrospective cohort study

Background

A predictive scoring system for acute respiratory distress syndrome (ARDS) patients, which incorporates age, PaO₂/FlO₂, and plateau pressure, APPS, was developed recently. It was validated externally in a Caucasian population but has not been studied in Asian populations. The aim of this study was to validate APPS in Korean ARDS patients.

Methods

We retrospectively reviewed the medical records of patients who were diagnosed with ARDS using the Berlin criteria and admitted to the medical ICU at Seoul National University Hospital from January 2015 to December 2016. The validation of the APPS was performed by evaluating its calibration and predictive accuracy. Its calibration was plotted and quantified using the Hosmer–Lemeshow test. Its predictive accuracy was assessed by calculating the area under the receiver operating characteristics (AUC–ROC) curve.

Results

A total of 116 patients were analyzed, 32 of whom survived. Of the 116 patients, 11 (9.5%) were classified as APPS grade 1 (score 3–4), 88 (75.9%) as grade 2 (score 5–7) and 17 (14.6%) as grade 3 (score 8–9). In-hospital mortality was 27.3% for grade 1, 73.9% for grade 2 and 94.1% for grade 3 (P for trend < 0.001). The APPS was well calibrated (Hosmer–Lemeshow test, P = 0.578) and its predictive accuracy was acceptable (AUC–ROC 0.704, 95% confidence interval 0.599–0.809).

Conclusions

The APPS predicted in-hospital mortality in Korean patients with ARDS with similar power to its application in a Western population and with acceptable predictive accuracy.

Trial registration

Retrospectively registered.

Multidrug-resistant tuberculosis over 20 years at a referral hospital in South Korea: trends and outcomes

SETTING

A referral centre in South Korea.

OBJECTIVE

To investigate trends in drug resistance, treatment modalities and outcomes, and adverse events of multidrug-resistant tuberculosis (MDR-TB) over two decades.

DESIGN

MDR-TB patients treated at Seoul National Hospital University between 1996 and 2015 were divided into four 5-year cohorts according to the date of initial diagnosis. Changes in demographic characteristics, drug resistance, drugs used, treatment outcomes and adverse events over time were elucidated.

RESULTS

Between 1996 and 2015, 418 patients were treated for MDR-TB: 86 patients between 1996 and 2000, 125 between 2001 and 2005, 123 between 2006 and 2010, and 84 between 2011 and 2015. The proportion of patients with positive acid-fast bacilli sputum (60.5-29.7%, P < 0.001) or cavities on chest radiographs (86.0-40.5%, P < 0.001) decreased over time. Resistance to pyrazinamide, fluoroquinolones, cycloserine and p-aminosalicylic acid decreased. Later-generation fluoroquinolones (77.9-90.5%) and linezolid (0-26.2%) became more frequently prescribed. The treatment success rate increased (45.3-88.1%, P < 0.001); neurological adverse events, including peripheral neuropathy also increased (4.7-13.1%, P = 0.027).

CONCLUSION

MDR-TB patients presented with less severe disease and better resistance profiles over time in South Korea, with treatment outcomes improving continuously.

Mortality risk and causes of death in patients with non-cystic fibrosis bronchiectasis

BACKGROUND

All-cause mortality risk and causes of death in bronchiectasis patients have not been fully investigated. The aim of this study was to compare the mortality risk and causes of death between individuals with bronchiectasis and those without bronchiectasis.

METHODS

Patients with or without bronchiectasis determined based on chest computed tomography (CT) at one centre between 2005 and 2016 were enrolled. Among the patients without bronchiectasis, a control group was selected after applying additional exclusion criteria. We compared the mortality risk and causes of death between the bronchiectasis and control groups without lung disease. Subgroup analyses were also performed according to identification of Pseudomonas or non-tuberculous mycobacteria, airflow limitation, and smoking status.

RESULTS

Of the total 217,702 patients who underwent chest CT, 18,134 bronchiectasis patients and 90,313 non-bronchiectasis patients were included. The all-cause mortality rate in the bronchiectasis group was 1608.8 per 100,000 person-years (95% confidence interval (CI), 1531.5-1690.0), which was higher than that in the control group (133.5 per 100,000 person-years; 95% CI, 124.1-143.8; P < 0.001). The bronchiectasis group had higher all-cause (adjusted hazard ratio (aHR), 1.26; 95% CI, 1.09-1.47), respiratory (aHR, 3.49; 95% CI, 2.21-5.51), and lung cancer-related (aHR, 3.48; 95% CI, 2.33-5.22) mortality risks than the control group. In subgroup analysis, patients with airflow limitation and ever smokers showed higher all-cause mortality risk among bronchiectasis patients. Therefore, we observed significant interrelation between bronchiectasis and smoking, concerning the risks of all-cause mortality (P for multiplicative interaction, 0.030, RERI, 0.432; 95% CI, 0.097-0.769) and lung cancer-related mortality (RERI, 8.68; 95% CI, 1.631-15.736).

CONCLUSION

Individuals with bronchiectasis had a higher risk of all-cause, respiratory, and lung cancer-related mortality compared to control group. The risk of all-cause mortality was more prominent in those with airflow limitation and in ever smokers.

Sleep duration and health-related quality of life in Korean adults: 2007-2015 Korea National Health and Nutrition Examination Survey

PURPOSE

To evaluate the association of sleep duration with health-related quality of life (HRQOL) and examine the influence of age, sex, and common comorbidities on this association.

METHODS

Using appropriate survey design, we analyzed 50,181 adults who participated in the 2007-2015 Korea National Health and Nutrition Examination Survey. Participants were categorized into five groups according to self-reported sleep duration ≤ 5 (short sleeper), 6, 7, 8, and ≥ 9 h (long sleeper). HRQOL was measured with the European Quality of Life-5 Dimensions (EQ-5D) index and visual analogue scale (VAS).

RESULTS

In multiple linear regression, short sleep duration was associated with lower EQ-5D index (β = - 0.024; 95% confidence interval [CI], - 0.027 to - 0.021) and lower EQ-VAS (β = - 3.0; 95% CI, - 3.7 to - 2.3), and long sleep duration was associated with lower EQ-5D index (β = - 0.016; 95% CI, - 0.021 to - 0.011) and lower EQ-VAS (β = - 2.2; 95% CI, - 3.1 to - 1.3) compared with 7-h sleepers. Old-age (≥ 65 years old) short and long sleepers had significantly lower EQ-5D index than those of < 65 years old. When separated according to sex, men with long sleep and women with short sleep showed the lowest EQ-5D index. Short and long sleepers with hypertension, diabetes, hypercholesterolemia, cardiovascular disease, or depression showed significantly lower EQ-5D index than those without comorbidities.

CONCLUSIONS

Extreme sleep duration was associated with poor HRQOL. Short and long sleepers with old age and comorbidities had significantly lower HRQOL than those without such conditions.

Role of ethambutol and rifampicin in the treatment of Mycobacterium avium complex pulmonary disease

Background

A three-drug regimen (macrolide, ethambutol, and rifampicin) is recommended for the treatment of Mycobacterium avium complex pulmonary disease (MAC-PD). Although macrolide has proven efficacy, the role of ethambutol and rifampicin in patients without acquired immune deficiency syndrome is not proven with clinical studies. We aimed to clarify the roles of ethambutol and rifampicin in the treatment of MAC-PD.

Methods

Patients treated for MAC-PD between March 1st, 2009 and October 31st, 2018 were reviewed retrospectively. Rates of culture conversion, microbiological cure, treatment failure, and recurrence were compared according to the maintenance (≥6 months) of ethambutol or rifampicin with macrolide.

Results

Among the 237 patients, 122 (51.5%) maintained ethambutol and rifampicin with macrolide, 58 (24.5%) maintained ethambutol and macrolide, 32 (13.5%) maintained rifampicin and macrolide, and 25 (10.6%) maintained macrolide only. Culture conversion was reached for 190/237 (80.2%) patients and microbiological cure was achieved for 129/177 (72.9%) who completed the treatment. Treatment failure despite ≥12 months of treatment was observed in 66/204 (32.4%), and recurrence was identified in 16/129 (12.4%) who achieved microbiological cure. Compared with maintenance of macrolide only, maintenance of ethambutol, rifampicin or both with macrolide were associated with higher odds of culture conversion [odds ratio (OR), 95% confidence interval (CI): 18.06, 3.67–88.92; 15.82, 2.38–105.33; and 17.12, 3.93–74.60, respectively]. Higher odds of microbiological cure were associated with maintenance of both ethambutol and rifampicin with macrolide (OR, 95% CI: 5.74, 1.54–21.42) and macrolide and ethambutol (OR, 95% CI: 5.12, 1.72–15.24) but not macrolide and rifampicin. Maintenance of both ethambutol and rifampicin with macrolide was associated with lower odds of treatment failure (OR, 95% CI: 0.09, 0.01–0.53) compared with macrolide only, while maintenance of one of these with macrolide was not. Maintenance of both ethambutol and rifampicin or one of these with macrolide did not decrease the probability of recurrence when compared with macrolide only.

Conclusions

Maintenance (≥6 months) of ethambutol and rifampicin with macrolide was associated with the most favorable treatment outcomes among patients with MAC-PD. Given the association between ongoing ethambutol use and microbiological cure, clinicians should maintain ethambutol unless definite adverse events develop.

Reduction of PaCO2 by high-flow nasal cannula in acute hypercapnic respiratory failure patients receiving conventional oxygen therapy

Background:

It has been suggested that a high-flow nasal cannula (HFNC) could help to remove carbon dioxide (CO₂) from anatomical dead spaces, but evidence to support that is lacking. The objective of this study was to elucidate whether use of an HFNC could reduce the arterial partial pressure of CO₂ (PaCO₂) in patients with acute hypercapnic respiratory failure who are receiving conventional oxygen (O₂) therapy.

Methods:

A propensity score-matched observational study was conducted to evaluate patients treated with an HFNC for acute hypercapnic respiratory failure from 2015 to 2016. The hypercapnia group was defined as patients with a PaCO₂ >50 mm Hg and arterial pH <7.35.

Results:

Eighteen patients in the hypercapnia group and 177 patients in the nonhypercapnia group were eligible for the present study. Eighteen patients in each group were matched by propensity score. Decreased PaCO₂ and consequent pH normalization over time occurred in the hypercapnia group (P=0.002 and P=0.005, respectively). The initial PaCO₂ level correlated linearly with PaCO₂ removal after the use of an HFNC (R²=0.378, P=0.010). The fraction of inspired O₂ used in the intensive care unit was consistently higher for 48 hours in the nonhypercapnia group. Physiological parameters such as respiratory rate and arterial partial pressure of O₂ improved over time in both groups.

Conclusions:

Physiological parameters can improve after the use of an HFNC in patients with acute hypercapnic respiratory failure given low-flow O₂ therapy via a facial mask. Further studies are needed to identify which hypercapnic patients might benefit from an HFNC.

Treatment Outcomes of Mycobacterium avium Complex Lung Disease: A Systematic Review and Meta-analysis

Background

The advent of macrolides has led to therapeutic advances in the treatment of Mycobacterium avium complex lung disease (MAC-LD). The aim of this study was to elucidate the treatment outcomes of macrolide-containing regimens.

Methods

We performed a systematic review and meta-analysis of published studies reporting treatment outcomes of macrolide-containing regimens for MAC-LD using the Medline, Embase, and Cochrane Library databases through 31 July 2016. The rates of treatment success, default from treatment, and adverse events of macrolide-containing regimens were assessed. Treatment success was defined as either 12 months of sustained culture negativity while on therapy or achievement of culture conversion and completion of the planned treatment without relapse.

Results

In total, 16 studies involving 1462 patients were included. The rate of treatment success was 60.0% (95% confidence interval [CI], 55.1%-64.8%). The proportion of patients who defaulted from the treatment was 16.0% (95% CI, 12.3%-19.7%). When a thrice-weekly dosing schedule was available, the default rate was 12.0% (95% CI, 8.9%-15.0%). Adverse events necessitating treatment discontinuation or dosage modification of macrolides were observed in 6.4% of patients (95% CI, 3.2%-9.5%), and decreased auditory acuity was the most common adverse event.

Conclusions

Treatment outcomes of macrolide-containing regimens are relatively poor in terms of both the treatment success and default rates. The default rate could be reduced if a thrice-weekly dosing schedule is available. Clinicians should be aware of decreased auditory function as the most common adverse event associated with macrolide-containing regimens.

Diagnostic and prognostic values of serum activin-a levels in patients with acute respiratory distress syndrome

Background

We aimed to evaluate whether serum activin-A levels are elevated and have any value in predicting severity and prognosis in acute respiratory distress syndrome (ARDS).

Methods

Retrospective cohort study was performed with patients who were admitted to MICU with diagnosis of ARDS and have serum samples stored within 48 h of Intensive care unit (ICU) admission between March 2013 and December 2016 at a single tertiary referral hospital. Serum activin-A levels were measured with ELISA kit, and were compared with those of normal healthy control and non-ARDS sepsis patients.

Results

Total 97 ARDS patients were included for the study. Levels of Activin-A were elevated in ARDS patients compared to those of healthy controls (Log-transformed activin-A levels 2.89 ± 0.36 vs. 2.34 ± 0.11, p < 0.001, absolute activin-A levels 1525.6 ± 1060.98 vs. 225.9 ± 30.1, p = 0.016) and non-ARDS sepsis patients (Log-transformed activin-A levels 2.89 ± 0.36 vs. 2.73 ± 0.34, p = 0.002, Absolute activin-A levels 1525.6 ± 1060.98 vs. 754.8 ± 123.5 pg/mL, p = 0.036). When excluding five outliers with extremely high activin-A levels, activin-A showed statistically significant correlation with in-hospital mortalities (In-hospital survivors 676.2 ± 407 vs. non-survivors 897.9 ± 561.9 pg/mL, p = 0.047). In predicting in-hospital mortality, serum activin-A concentrations showed superior area under curve compared to that of Acute physiologic and chronic health evaluation II scores (0.653; 95% CI [0541, 0.765] vs. 0.591, 95% CI [0.471, 0.710]). With cut-off level of 708 pg/mL, those with high serum activin-A levels had more than twofold increased risk of in-hospital mortalities. However, those relations were missing when outliers were in.

Conclusions

Serum activin-A levels in ARDS patients are elevated. However, its levels are weakly associated with ARDS outcomes.

Electronic supplementary material

The online version of this article (10.1186/s12890-019-0879-6) contains supplementary material, which is available to authorized users.

Nontuberculous mycobacterial pulmonary disease diagnosed by two methods: a prospective cohort study

Background

Microbiological criteria for diagnosing nontuberculous mycobacterial pulmonary disease (NTM-PD) include positive culture results from at least two separately expectorated sputum specimens or one bronchial washing or lavage. However, the clinical similarities and differences between patients diagnosed by these two methods remain unclear. We compared clinical features and prognoses of patients with NTM-PD diagnosed from both specimen types.

Methods

We analysed data from patients who participated in the Seoul National University Hospital NTM-PD cohort (ClinicalTrials.gov identifier: NCT01616745). Baseline demographics, symptoms, radiographic findings, disease progression, and treatment responses were summarized and compared between patients diagnosed from sputum specimens and patients diagnosed from bronchoscopic specimens.

Results

Three hundred forty-seven patients were included in the analyses. Of these, 279 (80.4%) were diagnosed from two separately expectorated sputum specimens, and 68 (19.6%) were diagnosed from bronchoscopic specimens. Patients diagnosed from sputum specimens had more frequent and severe cough, sputum, postnasal drip, and high St. George’s Respiratory Questionnaire scores. However, the extent and severity of the radiographic lesions, disease progression, and treatment responses were similar for both groups. Further analysis based on the following three groups (sputum culture positive, sputum culture negative/bronchoscopy, and scanty sputum/bronchoscopy groups) suggested that the scanty sputum/bronchoscopy group appeared to have the worst prognosis in terms of both time to progression and time to culture conversion.

Conclusions

Although some symptoms and quality of life were worse in patients with NTM-PD diagnosed from sputum specimens, their prognoses were similar to those of patients diagnosed by bronchoscopic specimen. We recommend bronchoscopic sampling for patients in whom NTM-PD is suspected clinically or radiographically, especially those who have no or scanty sputum.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4078-0) contains supplementary material, which is available to authorized users.

Improved oxygenation 48 hours after high-flow nasal cannula oxygen therapy is associated with good outcome in immunocompromised patients with acute respiratory failure

Background

Respiratory failure requiring intubation is a risk factor for mortality in immunocompromised patients, therefore, noninvasive methods to avoid intubation are preferred in such patients. A high-flow nasal cannula (HFNC) is an alternative noninvasive technique for oxygen delivery but can be potentially harmful in cases of delayed intubation. We sought to identify the physiological predictors of outcome to assess the responsiveness to HFNC of immunocompromised patients with acute respiratory failure.

Methods

We retrospectively analyzed the medical records of immunocompromised patients treated with HFNC in 2015 and 2016 in a tertiary hospital. Oxygenation was assessed by calculating the SpO₂/FiO₂ (SF) ratio. Subjects were defined as "SF-improved" when HFNC resulted in an increase in the SF ratio compared with baseline. The values were collected at baseline, 12, 24, and 48 h.

Results

Ninety-one patients with a median age of 64 years were analyzed; 68.1% were men. There was no significant difference between the SF₄₈-improved and the SF₄₈-nonimproved groups in clinical baseline characteristics or severity of illness as evaluated at the time of initiation of HFNC by APACHE II, SAPS II, and SOFA. The 28-day mortality was significantly lower in the SF₄₈-improved compared with the SF₄₈-nonimproved group. In univariate analysis, mortality was significantly associated with body mass index (BMI), poor functional status, do-not-intubate (DNI) status, the "SF₄₈-improved" group, the reason for immunocompromise, and the severity of illness at the time of initiation of HFNC. In multivariate analysis, "SF₄₈-improved" group was not significantly associated with increased mortality [odds ratio (OR) 0.462; 95% confidence interval (CI), 0.107-1.988; P=0.299].

Conclusions

In immunocompromised patients with acute respiratory failure, an improved SF ratio 48 h after HFNC treatment was associated with improved 28-day mortality.

The effect of metformin on culture conversion in tuberculosis patients with diabetes mellitus

BACKGROUND/AIMS

Patients with diabetes mellitus (DM) and tuberculosis (TB) have increased morbidity and a high risk of treatment failure or recurrence. It is important to manage both diseases simultaneously. Among anti-diabetic drugs, metformin inhibits intracellular growth of mycobacteria. Therefore, we examined the effects of metformin on TB treatment, especially in patients with DM.

METHODS

This retrospective cohort study included patients with culture-positive pulmonary TB diagnosed between 2011 and 2012. The primary study outcome was sputum culture conversion after 2 months of treatment.

RESULTS

Of 499 patients diagnosed with culture-positive pulmonary TB, 105 (21%) had DM at diagnosis. Among them, 62 (59.5%) were treated with metformin. Baseline characteristics, except for the presence of chronic renal disease, were not significantly different between the metformin and non-metformin groups. Metformin treatment had no significant effect on sputum culture conversion (p = 0.60) and recurrence within 1 year after TB treatment completion (p = 0.39). However, metformin improved the sputum culture conversion rate in patients with cavitary pulmonary TB, who have higher bacterial loads (odds ratio, 10.8; 95% confidence interval, 1.22 to 95.63).

CONCLUSION

Among cavitary pulmonary TB patients with DM, metformin can be an effective adjunctive anti-TB agent to improve sputum culture conversion after 2 months of treatment.

Respiratory virus of severe pneumonia in South Korea: Prevalence and clinical implications

Background

Severe viral pneumonia is associated with a high mortality rate. However, due to the vulnerability of critically ill patients, invasive diagnostic methods should be performed with caution in the intensive care unit (ICU). It would be helpful if the prevalence, risk factors, and clinical impact of virus detection are elucidated.

Methods

We evaluated patients with severe pneumonia between January 1^st 2008 and December 31^st 2015. Reverse transcription-polymerase chain reaction (RT-PCR) analysis was performed for 8 respiratory viruses when viral pathogen could not be excluded as the origin of severe pneumonia. The baseline characteristics, laboratory results, microbiological findings, and clinical outcomes of the patients were analyzed.

Results

Of the 2,347 patients admitted to the medical ICU, 515 underwent RT-PCR for respiratory viruses, 69 of whom had positive results. The detection rate was higher during the winter, with a community onset, in patients with history of recent chemotherapy, and low platelet count. Additional bronchoscopic sampling along with upper respiratory specimen increased the yield of viral detection. Respiratory syncytial virus was the most common pathogen detected, while influenza A was the most common virus with bacterial coinfection. Respiratory virus detection led to changes in clinical management in one-third of the patients.

Conclusions

The detection of viral pathogens in patients with severe pneumonia is not rare, and can be more common in certain group of patients. Invasive sampling for RT-PCR can be helpful, and such detection can lead to positive changes in clinical management.

Rapid Muscle Loss Negatively Impacts Survival in Critically Ill Patients With Cirrhosis

PURPOSE

To assess the impact of rapid muscle loss before admission to intensive care unit (ICU) in critically ill patients with cirrhosis.

MATERIALS AND METHODS

Patients with cirrhosis who had undergone 2 or more recent computed tomography scans before admission to the medical ICU were included. Muscle cross-sectional area at the level of the third lumbar vertebra was quantified using OsiriX software. The rate of muscle mass change and skeletal muscle index (SMI) were also calculated. Multivariable Cox proportional hazards regression was used to evaluate the association between muscle loss and mortality.

RESULTS

Among 125 patients, 113 (90.4%) patients were classified as having sarcopenia. The mean body mass index was 22.6 (3.9) kg/m². Thirty-nine (31.2%) patients were within the normal range for muscle mass change, while 86 (68.8%) patients demonstrated rapid decline in muscle mass before admission to the ICU. Patients with rapid muscle loss showed high ICU mortality (59.3%) and in-hospital mortality (77.9%). Multivariate Cox analysis showed that ICU mortality and in-hospital mortality were independently associated with malignancy, Acute Physiology and Chronic Health Evaluation (APACHE) II score, SMI, and rapid muscle loss.

CONCLUSION

Rapid muscle decline is correlated with increased ICU mortality and in-hospital mortality in critically ill patients with cirrhosis.

Histopathologic heterogeneity of acute respiratory distress syndrome revealed by surgical lung biopsy and its clinical implications

BACKGROUND/AIMS

Diffuse alveolar damage (DAD) is the histopathologic hallmark of acute respiratory distress syndrome (ARDS). However, there are several non-DAD conditions mimicking ARDS. The purpose of this study was to investigate the histopathologic heterogeneity of ARDS revealed by surgical lung biopsy and its clinical relevance.

METHODS

We retrospectively analyzed 84 patients with ARDS who met the criteria of the Berlin definition and underwent surgical lung biopsy between January 2004 and December 2013 in three academic hospitals in Korea. We evaluated their histopathologic findings and compared the clinical outcomes. Additionally, the impact of surgical lung biopsy on therapeutic alterations was examined.

RESULTS

The histopathologic findings were highly heterogeneous. Of 84 patients undergoing surgical lung biopsy, DAD was observed in 31 patients (36.9%), while 53 patients (63.1%) did not have DAD. Among the non-DAD patients, diffuse interstitial lung diseases and infections were the most frequent histopathologic findings in 19 and 17 patients, respectively. Although the mortality rate was slightly higher in DAD (71.0%) than in non-DAD (62.3%), the difference was not significant. Overall, the biopsy results led to treatment alterations in 40 patients (47.6%). Patients with non-DAD were more likely to change the treatment than those with DAD (58.5% vs. 29.0%), but there were no significant improvements regarding the mortality rate.

CONCLUSIONS

The histopathologic findings of ARDS were highly heterogeneous and classic DAD was observed in one third of the patients who underwent surgical lung biopsy. Although therapeutic alterations were more common in patients with non-DAD-ARDS, there were no significant improvements in the mortality rate.

Clinical Outcome of Eosinophilic Airway Inflammation in Chronic Airway Diseases Including Nonasthmatic Eosinophilic Bronchitis

We enrolled patients with confirmed sputum eosinophilia who had visited our tertiary referral hospital between 2012 and 2015. We evaluated the incidence and predictors of exacerbations in patients with nonasthmatic eosinophilic bronchitis (NAEB), and investigated predictors of improvement in eosinophilic inflammation in chronic airway diseases with or without persistent airflow limitation. In total, 398 patients with sputum eosinophilia were enrolled. Of these, 152 (38.2%) had NAEB. The incidence rate of exacerbations requiring treatment with antibiotics, systemic corticosteroids, or hospital admission was 0.13 per patient-year (95% CI, 0.06-0.19) in NAEB. Inhaled corticosteroid (ICS) did not affect the risk of exacerbations, even in an analysis of propensity score. One hundred seventy-six patients had chronic airway diseases; in 37 of these (21.0%), sputum eosinophilia had improved at the 1-year follow-up. Patients who had persistent airflow limitation were less likely to show an improvement in eosinophilic inflammation (aOR, 0.26; 95% CI, 0.09-0.77) when they were treated with ICSs for less than 75% of the follow-up days. Exacerbations requiring systemic corticosteroids, antibiotics, or hospitalization did occur, although infrequently, in NAEB patients. Among patients with chronic airway diseases, those with persistent airflow limitation were less likely to show an improvement in eosinophilic airway inflammation.

Implication of species change of Nontuberculous Mycobacteria during or after treatment

Background

Co-existence or subsequent isolation of multiple nontuberculous mycobacteria (NTM) species in same patient has been reported. However, clinical significance of these observations is unclear. The aim of this study was to determine clinical implications of changes of NTM species during or after treatment in patients with NTM lung disease.

Methods

Patients with NTM lung disease, who experienced changes of NTM species during treatment or within 2 years of treatment completion between January 1, 2009 and December 31, 2015, were included in the analysis. Demographic, clinical, microbiological, and radiographic data were reviewed and analyzed.

Results

During the study period, 473 patients were newly diagnosed with NTM lung disease. Treatment was started in 164 patients (34.6%). Among these 164 patients, 16 experienced changes of NTM species during or within 2 years of treatment completion. Seven showed changes from M. avium complex (MAC) to M. abscessus subspecies abscessus (MAA) and five patients displayed changes from M. abscessus subspecies massiliense (MAM) to MAC. With isolation of new NTM species, 6 out of 7 patients with change from MAC to MAA reported worsening of symptoms, whereas none of the five patients with change from MAM to MAC reported worsening of symptoms. All MAA isolated during or after treatment for MAC lung diseases showed inducible resistance to clarithromycin.

Conclusions

Change of NTM species may occur during or after treatment for NTM lung disease. Especially, changes from MAC to MAA is accompanied by symptomatic and radiographic worsening as well as inducible resistance to clarithromycin.

Rapidly Progressive Lactic Acidosis in Patients with Flufenoxuron Poisoning

Flufenoxuron is an insect growth regulator which inhibits chitin (exoskeleton) biosynthesis in insect's body. Not much is known about its toxicity to human. This report describes three patients who developed worsening lactic acidosis and hypotension after ingestion of flufenoxuron-containing materials. Two of the three patients received continuous renal replacement therapy and survived. (Hong Kong j.emerg.med. 2014;21:181-184)

Utility of the National Lung Screening Trial Criteria for Estimation of Lung Cancer in the Korean Population

Purpose

Screening forlung cancerin high-risk patients using theNational Lung Screening Trial (NLST) criteria resulted in a decreased lung cancer-related mortality rate. However, whether these criteria are applicable to the Korean has not been investigated thus far. Therefore, we estimated the utility of the NLST criteria as a screening tool for lung cancer in the Korean population.

Materials and Methods

The total number of newly diagnosed lung cancer cases in 2013 was obtained from the Korea National Statistical Office. The proportion of newly diagnosed lung cancer cases that met the NLST criteria was calculated via a retrospective cohort of a tertiary referral hospital. We estimated the nationwide proportion of patients who met the NLST criteria using the 5th Korea National Health and Nutrition Examination Survey conducted during 2010-2012 (KNHANES V).

Results

Using KNHANES V data, we found that approximately 6.92% of the general population of Korea would meet the NLST criteria. In the tertiary referral hospital, 29.6% of the 2,689 newly diagnosed lung cancer patients met the NLST criteria. In 2013, the total number of newly diagnosed lung cancer cases in Korea was 23,177. The estimated nationwide proportions of lung cancer patients who met and did not meet the NLST criteria were 0.37% and 0.06%, respectively, yielding a ratio of 5.78.

Conclusion

The NLST criteria demonstrated sound clinical utility for lung cancer screening of high-risk patients in Korea.

Effect of Preadmission Metformin Use on Clinical Outcome of Acute Respiratory Distress Syndrome among Critically Ill Patients with Diabetes

Background

Acute respiratory distress syndrome (ARDS) is related to high mortality and morbidity. There are no proven therapeutic measures however, to improve the clinical course of ARDS, except using low tidal volume ventilation. Metformin is known to have pleiotropic effects including anti-inflammatory activity. We hypothesized that pre-admission metformin might alter the progress of ARDS among intensive care unit (ICU) patients with diabetes mellitus (DM).

Methods

We performed a retrospective cohort study from January 1, 2005, to April 30, 2005 of patients who were admitted to the medical ICU at Seoul National University Hospital because of ARDS, and reviewed ARDS patients with DM. Metformin use was defined as prescribed within 3-month pre-admission.

Results

Of 558 patients diagnosed with ARDS, 128 (23.3%) patients had diabetes and 33 patients were treated with metformin monotherapy or in combination with other antidiabetic medications. Demographic characteristics, cause of ARDS, and comorbid conditions (except chronic kidney disease) were not different between metformin users and nonusers. Several severity indexes of ARDS were similar in both groups. The 30-day mortality was 42.42% in metformin users and 55.32% in metformin nonusers. On multivariable regression analysis, use of metformin was not significantly related to a reduced 30-day mortality (adjusted β-coefficient, −0.19; 95% confidence interval, −1.76 to 1.39; p=0.816). Propensity score-matched analyses showed similar results.

Conclusion

Pre-admission metformin use was not associated with reduced 30-day mortality among ARDS patients with DM in our medical ICU.

Effect of Renin-Angiotensin System Blockage in Patients with Acute Respiratory Distress Syndrome: A Retrospective Case Control Study

Background

Acute respiratory distress syndrome (ARDS) remains a life-threatening disease. Many patients with ARDS do not recover fully, and progress to terminal lung fibrosis. Angiotensin-converting enzyme (ACE) inhibitor is known to modulate the neurohormonal system to reduce inflammation and to prevent tissue fibrosis. However, the role of ACE inhibitor in the lungs is not well understood. We therefore conducted this study to elucidate the effect of renin-angiotensin system (RAS) blockage on the prognosis of patients with ARDS.

Methods

We analyzed medical records of patients who were admitted to the medical intensive care unit (ICU) at a tertiary care hospital from January 2005 to December 2010. ARDS was determined using the Berlin definition. The primary outcome was the mortality rate of ICU. Survival analysis was performed after adjustment using propensity score matching.

Results

A total of 182 patients were included in the study. Thirty-seven patients (20.3%) took ACE inhibitor or angiotensin receptor blocker (ARB) during ICU admission, and 145 (79.7%) did not; both groups showed similar severity scores. In the ICU, mortality was 45.9% in the RAS inhibitor group and 58.6% in the non-RAS inhibitor group (P = 0.166). The RAS inhibitor group required a longer duration of mechanical ventilation (29.5 vs. 19.5, P = 0.013) and longer ICU stay (32.1 vs. 20.2 days, P < 0.001). In survival analysis, the RAS inhibitor group showed better survival rates than the non-RAS group (P < 0.001).

Conclusions

ACE inhibitor or ARB may have beneficial effect on ARDS patients.

Medical Thoracoscopy in Pleural Disease: Experience from a One-Center Study

Background

Medical thoracoscopy (MT) is a minimally invasive, endoscopic procedure for exploration of the pleural cavity under conscious sedation and local anesthesia. MT has been performed at the Seoul National University Hospital since February 2014. This paper summarizes the findings and outcomes of MT cases at this hospital.

Methods

Patients who had undergone MT were enrolled in the study. MT was performed by pulmonologists, using both rigid and semi-rigid thoracoscopes. During the procedure, patients were under conscious sedation with fentanyl and midazolam. Medical records were reviewed for clinical data.

Results

From February 2014 to January 2016, 50 procedures (47 cases) were performed (diagnostic MT, 26 cases; therapeutic MT, 24 cases). The median age of patients was 66 years (59–73 years), and 38 patients (80.9%) were male. The median procedure duration from initial incision to insertion of the chest tube was 37 minutes. The median doses of fentanyl and midazolam were 50 µg and 5 mg, respectively. All procedures were performed without unexpected events. Of the 26 cases of pleural disease with an unknown cause, 19 were successfully diagnosed using MT. Additionally, diagnostic MT provided clinically useful information in the other six patients. Therapeutic MT was very effective for treatment of malignant pleural effusion or empyema. The median number of days with chest tube drainage was 6 (3 days for diagnostic MT and 8 days for therapeutic MT).

Conclusion

MT is a useful and necessary procedure for both diagnosis and treatment of pleural diseases.

The additional role of Xpert MTB/RIF in the diagnosis of intrathoracic tuberculous lymphadenitis

BACKGROUND

Diagnosis of intrathoracic tuberculosis (TB) lymphadenitis remains a challenge because of difficulties in obtaining adequate tissue and the lack of a sensitive test. Recently, Xpert MTB/RIF assay is being used for rapid diagnosis of pulmonary TB, but it has not yet been widely validated in intrathoracic TB lymphadenitis. The aim of this study was to assess the additional role of Xpert MTB/RIF in diagnosing intrathoracic TB lymphadenitis using endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) specimen.

METHODS

Consecutive patients who underwent Xpert MTB/RIF assay using EBUS-TBNA specimen from January 2012 and November 2013 at a tertiary referral hospital were recruited. Among them, the cases with malignant lymph nodes were excluded.

RESULTS

Among 73 patients, 13 (17.8%) cases were diagnosed with intrathoracic TB lymphadenitis. In detail, 10 patients were diagnosed using conventional methods only (histology or AFB culture) and 3 patients were additionally diagnosed when adding Xpert MTB/RIF assay. The median time to diagnosis using Xpert MTB/RIF (1 day) was shorter than conventional methods (3 days for histology, 14 days for AFB culture). Rifampin resistance was not detected in any patients.

CONCLUSION

In patients with enlarged intrathoracic lymph nodes and low suspicion of malignancy, combination of conventional diagnostic methods with Xpert MTB/RIF could lead to additional and rapid diagnosis of intrathoracic TB lymphadenitis.

Serum Uric Acid Level as a Prognostic Marker in Patients With Acute Respiratory Distress Syndrome

PURPOSE:

Uric acid acts as both a pathogenic inflammatory mediator and an antioxidative agent. Several studies have shown that uric acid level correlates with the incidence, severity, and prognosis of pulmonary diseases. However, the association between uric acid level and acute respiratory distress syndrome (ARDS) has not been studied. This study was conducted to elucidate how serum uric acid level is related with clinical prognosis of ARDS.

METHODS:

A retrospective cohort study with propensity score matching was conducted at a medical intensive care unit of a tertiary teaching hospital. The medical records of patients diagnosed with ARDS admitted from 2005 through 2011 were reviewed.

RESULTS:

Two hundred thirty-seven patients with ARDS met the inclusion criteria. Patients with a serum uric acid level <3.0 mg/dL were classified into the low uric acid group, and those with a level ≥3 mg/dL were classified into the normal to high uric acid group. We selected 40 patients in each group using propensity score matching. A higher percentage of patients in the low uric acid group experienced clinical improvement in ARDS. More patients died from sepsis in the normal to high uric acid group. Kaplan-Meier analysis showed that a low serum uric acid level was significantly associated with better survival rate.

CONCLUSION:

In patients with ARDS, a low serum uric acid level may be a prognostic marker of a low risk of in-hospital mortality.

Analysis of Fifty Hotspot Mutations of Lung Squamous Cell Carcinoma in Never-smokers

Smoking is the major risk factor for lung squamous cell carcinoma (SCC), although a small number of lung SCCs occurs in never-smokers. The purpose of this study was to compare 50 hotspot mutations of lung SCCs between never-smokers and smokers. We retrospectively reviewed the medical records of patients newly diagnosed with lung SCC between January 1, 2011 and December 31, 2013 in the Seoul National University Hospital. Formalin-fixed, paraffin-embedded tumor samples were used for analysis of hotspot mutations. Fifty cancer-related genes in never-smokers were compared to those in ever-smokers. Of 379 lung SCC patients, 19 (5.0%) were never-smokers. The median age of these 19 patients was 67 years (interquartile range 57-73 years), and 10 of these patients were women (52.5%). The incidence rates of stage I, II, III, and IV disease in this group were 26.4%, 5.3%, 31.6%, and 36.8%, respectively, and sequencing was performed successfully in 14 cases. In the 26 lung SCC tumor samples (12 from never-smokers and 14 from ever-smokers) sequenced using personal genome machine, the most common mutations were in TP53 (75.0%), RAS (66.7%), and STK11 (33.3%), but mutations were also found in EGFR, KIT, and PTEN. The distribution of hotspot mutations in never-smokers was similar to that in ever-smokers. There was no significant difference in overall survival between the 2 groups. The 50 hotspot mutations of lung SCC in never-smokers were similar to those of ever-smokers.

Proportion and clinical features of never-smokers with non-small cell lung cancer

BACKGROUND

The proportion of never-smokers with non-small cell lung cancer (NSCLC) is increasing, but that in Korea has not been well addressed in a large population. We aimed to evaluate the proportion and clinical features of never-smokers with NSCLC in a large single institution.

METHODS

We analyzed clinical data of 1860 consecutive patients who were newly diagnosed with NSCLC between June 2011 and December 2014.

RESULTS

Of the 1860 NSCLC patients, 707 (38.0%) were never-smokers. The proportions of women (83.7% vs. 5.6%) and adenocarcinoma (89.8% vs. 44.9%) were higher among never-smokers than among ever-smokers. Significantly more never-smokers were diagnosed at a younger median age (65 vs. 68 years, P < 0.001) and earlier stage (stage I-II, 44.5% vs. 38.9%, P = 0.015) compared with ever-smokers. Epidermal growth factor receptor mutations (57.8% vs. 24.4%, P < 0.001) and anaplastic lymphoma kinase rearrangements (7.8% vs. 2.8%, P < 0.001) were more common in never-smokers, whereas Kirsten rat sarcoma viral oncogene homolog mutations (5.8% vs. 9.6%, P = 0.021) were less frequently encountered in never-smokers than in ever-smokers. Never-smokers showed longer survival after adjusting for the favorable effects of younger age, female sex, adenocarcinoma histology, better performance status, early stage disease, being asymptomatic at diagnosis, received antitumor treatment, and the presence of driver mutations (hazard ratio, 0.624; 95% confidence interval, 0.460-0.848; P = 0.003).

CONCLUSIONS

More than one-third of the Korean patients with NSCLC were never-smokers. NSCLC in never-smokers had different clinical characteristics and major driver mutations and resulted in longer overall survival compared with NSCLC in ever-smokers.

Characteristics associated with progression in patients with of nontuberculous mycobacterial lung disease : a prospective cohort study

Background

Patients with distinctive morphotype were more susceptible to nontuberculous mycobacterial lung disease (NTM-LD). However, little is known about the association between body morphotype and progression of NTM-LD. The aim of this study was to elucidate predictors of NTM-LD progression, focusing on body morphotype and composition.

Methods

Data from patients with NTM-LD who participated in NTM cohort which started in 1 July 2011 were analyzed. Patients with more than 6 months of follow up were included for analysis. NTM-LD progression was defined as clinician-initiated anti-NTM treatment, based on symptomatic and radiologic aggravation. Body morphotype and composition was measured at entry to the cohort using bioelectrical impedance analysis.

Results

NTM-LD progressed in 47 out of 150 patients with more than 6 months of follow up. Patients with middle (adjusted hazard ratio [aHR], 2.758; 95% confidence interval [CI], 1.112–6.843) or lowest tertile (aHR, 3.084; 95% CI, 1.241–7.668) of abdominal fat ratio had a higher risk of disease progression compared with the highest tertile. Other predictors for disease progression were presence of cavity on chest computed tomography (aHR, 4.577; 95% CI, 2.364–8.861), and serum albumin level <3.5 g/dL (aHR, 12.943; 95% CI, 2.588–64.718).

Conclusions

Progression of NTM-LD is associated with body composition. Lower abdominal fat ratio is an independent predictor of NTM-LD progression.

Trial registration

ClinicalTrials.gov, NCT01616745 Registered 25 March 2012

Incidence of Fever Following Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration

BACKGROUND

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive diagnostic method for mediastinal and hilar lymphadenopathy. This study aimed to investigate the incidence of fever following EBUS-TBNA.

METHODS

A total of 684 patients who underwent EBUS-TBNA from May 2010 to July 2012 at Seoul National University Hospital were retrospectively reviewed. The patients were evaluated for fever by a physician every 6-8 hours during the first 24 hours following EBUS-TBNA. Fever was defined as an increase in axillary body temperature over 37.8℃.

RESULTS

Fever after EBUS-TBNA developed in 110 of 552 patients (20%). The median onset time and duration of fever was 7 hours (range, 0.5-32 hours) after EBUS-TBNA and 7 hours (range, 1-52 hours), respectively, and the median peak body temperature was 38.3℃ (range, 37.8-39.9℃). In most patients, fever subsided within 24 hours; however, six cases (1.1%) developed fever lasting longer than 24 hours. Infectious complications developed in three cases (0.54%) (pneumonia, 2; mediastinal abscess, 1), and all three patients had diabetes mellitus. The number or location of sampled lymph nodes and necrosis of lymph node were not associated with fever after EBUS-TBNA. Multiple logistic regression analysis did not reveal any risk factors for developing fever after EBUS-TBNA.

CONCLUSION

Fever is relatively common after EBUS-TBNA, but is transient in most patients. However, clinicians should be aware of the possibility of infectious complications among patients with diabetes mellitus.

The Association of EGFR Mutations with Stage at Diagnosis in Lung Adenocarcinomas

Background

The prognostic role of epidermal growth factor receptor (EGFR) mutations in patients with lung adenocarcinomas remains controversial and the association between EGFR mutations and stage at the time of the initial diagnosis is debatable. In this study, we evaluated the association of EGFR mutations with stage at diagnosis in lung adenocarcinomas.

Materials and Methods

We retrospectively analyzed 1004 consecutive patients who were diagnosed with lung adenocarcinomas and tested for EGFR mutations between June 2011 and December 2014.

Results

EGFR mutations were detected in 49.2% of 1004 patients with lung adenocarcinomas. In multivariable analysis, EGFR mutations were significantly associated with early stage disease (stage I to II) at diagnosis (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.49–0.87; P = 0.003). When adjusted for age, sex, smoking status, and screening, the adjusted proportion of EGFR mutations significantly decreased according to stage. The adjusted proportions of EGFR mutations were 57.6% (95% CI, 51.7%–63.3%) for stage I, 47.9% (95% CI, 36.9%–59.0%) for stage II, 47.5% (95% CI, 39.6%–55.5%) for stage III, and 43.4% (95% CI, 38.3%–48.6%) for stage IV (P = 0.0082).

Conclusions

The presence of EGFR mutations is significantly associated with early stage disease at initial diagnosis in lung adenocarcinomas after adjusting for age, sex, smoking status, and screening. This finding implies that EGFR mutations may play a role as a positive prognostic marker.

Progression and Treatment Outcomes of Lung Disease Caused by Mycobacterium abscessus and Mycobacterium massiliense

BACKGROUND

Mycobacterium abscessus and Mycobacterium massiliense are grouped as the Mycobacterium abscessus complex. The aim of this study was to elucidate the differences between M. abscessus and M. massiliense lung diseases in terms of progression rate, treatment outcome, and the predictors thereof.

METHODS

Between 1 January 2006 and 30 June 2015, 56 patients and 54 patients were diagnosed with M. abscessus and M. massiliense lung diseases, respectively. The time to progression requiring treatment and treatment outcomes were compared between the 2 groups of patients, and predictors of progression and sustained culture conversion with treatment were analyzed. In addition, mediation analysis was performed to evaluate the effect of susceptibility to clarithromycin on treatment outcomes.

RESULTS

During follow-up, 21 of 56 patients with M. abscessus lung diseases and 21 of 54 patients with M. massiliense lung diseases progressed, requiring treatment. No difference was detected in the time to progression between the 2 patient groups. Lower body mass index, bilateral lung involvement, and fibrocavitary-type disease were identified as predictors of disease progression. Among the patients who began treatment, infection with M. massiliense rather than M. abscessus and the use of azithromycin rather than clarithromycin were associated with sustained culture conversion. The difference in treatment outcomes was partly mediated by the organism's susceptibility to clarithromycin.

CONCLUSIONS

Progression rates were similar but treatment outcomes differed significantly between patients with lung disease caused by M. abscessus and M. massiliense. This difference in treatment outcomes was partly explained by the susceptibility of these organisms to clarithromycin.

Factors influencing the initiation of intensive care in elderly patients and their families: A retrospective cohort study

BACKGROUND

The number of elderly patients admitted to the intensive care unit is constantly growing. However, a decision regarding intensive care in these populations remains a challenge.

AIM

To identify factors that influences the decision of elderly patients and their families about whether to initiate intensive care in case of an acute event.

DESIGN/PARTICIPANTS

Medical records of patients (>80 years), who were admitted to general wards and referred for intensive care, were retrospectively reviewed. Patients who received intensive care were compared with those not agreeing to the initiation of intensive care.

RESULTS

Among the 125 patients, 45 agreed to receiving intensive care. Baseline characteristics at the time of intensive care unit referral were similar between the intensive care and non-intensive care groups. Only one patient had advance directives before the intensive care unit referral. Lower economic status (odds ratio = 0.27, 95% confidence interval = 0.08-0.94) and cognitive impairment (odds ratio = 0.20, 95% confidence interval = 0.07-0.56) were found associated with a lower likelihood of agreeing to intensive care, while a large number of participants involved in the decision-making process were associated with a higher likelihood of intensive care unit use (odds ratio = 1.82, 95% confidence interval = 1.08-3.09). Mean duration of hospital stay was longer for the intensive care group as compared with the non-intensive care group (28.8 days and 19.8 days, respectively, p = 0.03). However, there was no significant difference in the survival rate.

CONCLUSION

The initiation of intensive care in elderly patients was influenced not only by medical conditions but also by the patient's economic status and the number of family members involved in the decision-making process.

Evaluation of Xpert(®) MTB/RIF assay: diagnosis and treatment outcomes in rifampicin-resistant tuberculosis

SETTING

The Xpert(®) MTB/RIF assay is endorsed by the World Health Organization for the detection of rifampicin (RMP) resistant tuberculosis (TB).

OBJECTIVE

To evaluate Xpert for its diagnostic accuracy in detecting RMP-resistant TB and its impact on treatment outcomes.

DESIGN

Patients with available phenotypic drug susceptibility testing (DST) results and those in whom RMP-resistant pulmonary TB was diagnosed using Xpert were evaluated. The accuracy and turnaround time (TAT) of Xpert for determining RMP-resistant TB was calculated. The TATs for treatment between patients diagnosed with RMP-resistant TB using Xpert and those diagnosed without the assay (phenotypic DST group) were compared.

RESULTS

In 321 patients, when phenotypic DST was used as the gold standard, Xpert sensitivity and specificity for RMP resistance diagnosis was respectively 100% and 98.7%; the positive and negative predictive values were respectively 86.2% and 100%. The Xpert group had a much shorter interval from initial evaluation to commencing second-line anti-tuberculosis treatment (64 vs. 2 days, P < 0.001), and negative conversion of mycobacterial cultures (197 vs. 62.5 days, P < 0.001) than the phenotypic DST group.

CONCLUSION

Xpert was accurate at diagnosing RMP resistance in this setting with an intermediate TB burden and a low level of RMP resistance. Xpert might reduce disease transmission by reducing the sputum culture conversion times for patients with RMP-resistant TB.

Long-term survival of patients with multidrug-resistant tuberculosis according to treatment outcomes

Survival times of 219 patients diagnosed with multidrug-resistant tuberculosis were calculated and treatment outcomes compared. Mean survival of 20 patients who failed to be cured was 109.8 months (95% confidence interval [CI], 87.4-132.1), shorter than that of 150 patients who were cured (140.4 months; 95% CI, 136.1-144.7; P < .01) and that of 28 patients classified as treatment completed (138.5 months; 95% CI, 131.0-146.1; P = .02). The results demonstrate that patients with multidrug-resistant tuberculosis with poor treatment outcomes live 9 years, on average.

Prevalence of and risk factors for postoperative pulmonary complications after lung cancer surgery in patients with early-stage COPD

PURPOSE

This study aimed to investigate whether the prevalence of postoperative pulmonary complications (PPCs) in patients with non-small-cell lung cancer (NSCLC) is even higher in the early stages of COPD than in such patients with normal lung function and to verify the usefulness of symptom- or quality of life (QoL)-based scores in predicting risk for PPCs.

PATIENTS AND METHODS

Patients undergoing pulmonary resection for NSCLC between July 2012 and October 2014 were prospectively enrolled. Preoperative measurements of lung function, dyspnea, and QoL, operative characteristics, PPCs, duration of postoperative hospitalization, and in-hospital mortality were assessed.

RESULTS

Among 351 consecutive patients with NSCLC, 343 patients with forced expiratory volume in 1 second (FEV1) ≥70% of predicted value were enrolled. At least one PPC occurred in 57 (16.6%) patients. Prevalence of PPC was higher in patients with COPD (30.1%) than in those with normal spirometry (10.0%; P<0.001). However, in patients with COPD, the prevalence of PPC was not different in patients with FEV1 ≥70% compared to those with FEV1 <70% and between group A (low risk and less symptoms) and group B (low risk and more symptoms) patients with COPD, based on the new Global initiative for chronic Obstructive Lung Disease 2011 guidelines. In patients with COPD, body mass index (odds ratio [OR]: 0.80, P=0.007), carbon monoxide diffusing capacity of the lung (DLCO), % predicted value (OR: 0.97, P=0.024), and operation time (OR: 1.01, P=0.003), but not COPD assessment test or St George Respiratory Questionnaire scores, were significantly associated with PPCs.

CONCLUSION

Even in patients with early-stage COPD, the prevalence of PPCs is higher than in patients with NSCLC with normal spirometry. However, this rate is not different between group A and group B patients with COPD. In accordance with this, scores based on symptoms or QoL are not predictors of risk of PPCs in patients with early-stage COPD.

Serum activin-A as a predictive and prognostic marker in critically ill patients with sepsis

BACKGROUND AND OBJECTIVE

There are limited data regarding serum activin-A as a biomarker for sepsis. We examined whether serum activin-A concentration could predict sepsis severity and prognosis in the management of critically ill patients with sepsis.

METHODS

The subjects were adult patients suspected of having sepsis and admitted to intensive care unit (ICU) from January 2013 to March 2014. Serum activin-A concentration was measured in blood sampled within 48 h after ICU admission. The primary and secondary outcomes were the diagnostic value of serum activin-A concentration as a biomarker of sepsis and the prognostic value for predicting the clinical outcomes of sepsis, respectively.

RESULTS

One hundred and thirty patients who had clinically suspected sepsis were included. Most (66.2%) were male; their median age was 65 years, and their Acute Physiology and Chronic Health Evaluation II score was 22.3. Serum activin-A concentration tended to increase with sepsis severity and differed significantly between those with non-sepsis and severe sepsis and between those with severe sepsis and septic shock. The risks of sepsis, severe sepsis and septic shock were significantly higher in patients with a serum activin-A concentration of 251, 319 and 432 pg/mL or greater, respectively. Serum activin-A concentration was significantly associated with the Acute Physiology and Chronic Health Evaluation II score, Sequential Organ Failure Assessment score, Charlson comorbidity index and ICU mortality.

CONCLUSION

Serum activin-A was a predictor of sepsis severity and a prognostic marker in critically ill patients with sepsis. Serum activin-A concentration in the early phase of sepsis was associated with prognostic indexes on ICU admission and with ICU mortality.

Non-tuberculous mycobacterial lung disease: diagnosis based on computed tomography of the chest

OBJECTIVES

To elucidate the accuracy and inter-observer agreement of non-tuberculous mycobacterial lung disease (NTM-LD) diagnosis based on chest CT findings.

METHODS

Two chest radiologists and two pulmonologists interpreted chest CTs of 66 patients with NTM-LD, 33 with pulmonary tuberculosis and 33 with non-cystic fibrosis bronchiectasis. These observers selected one of these diagnoses for each case without knowing any clinical information except age and sex. Sensitivity and specificity were calculated according to degree of observer confidence. Inter-observer agreement was assessed using Fleiss' κ values. Multiple logistic regression was performed to elucidate which radiological features led to the correct diagnosis.

RESULTS

The sensitivity of NTM-LD diagnosis was 56.4 % (95 % CI 47.9-64.7) and specificity 80.3 % (73.1-86.0). The specificity of NTM-LD diagnosis increased with confidence: 44.4 % (20.5-71.3) for possible, 77.4 % (67.4-85.0) for probable, 95.2 % (87.2-98.2) for definite (P < 0.001) diagnoses. Inter-observer agreement for NTM-LD diagnosis was moderate (κ = 0.453). Tree-in-bud pattern (adjusted odds ratio [aOR] 6.24, P < 0.001), consolidation (aOR 1.92, P = 0.036) and atelectasis (aOR 3.73, P < 0.001) were associated with correct NTM-LD diagnoses, whereas presence of pleural effusion (aOR 0.05, P < 0.001) led to false diagnoses.

CONCLUSIONS

NTM-LD diagnosis based on chest CT findings is specific but not sensitive.

KEY POINTS

• Diagnosis of NTM-LD based on radiological findings showed high specificity. • Sensitivity of NTM-LD diagnosis was around 50 %. • Inter- observer agreement was moderate. • Identification of tree-in-bud pattern, consolidation and atelectasis led to correct diagnoses.

Bleeding complications in critically ill patients with liver cirrhosis

BACKGROUND/AIMS

Patients with liver cirrhosis (LC) are at risk for critical events leading to Intensive Care Unit (ICU) admission. Coagulopathy in cirrhotic patients is complex and can lead to bleeding as well as thrombosis. The aim of this study was to investigate bleeding complications in critically ill patients with LC admitted to a medical ICU (MICU).

METHODS

All adult patients admitted to our MICU with a diagnosis of LC from January 2006 to December 2012 were retrospectively assessed. Patients with major bleeding at the time of MICU admission were excluded from the analysis.

RESULTS

A total of 205 patients were included in the analysis. The median patient age was 62 years, and 69.3% of the patients were male. The most common reason for MICU admission was acute respiratory failure (45.4%), followed by sepsis (27.3%). Major bleeding occurred in 25 patients (12.2%). The gastrointestinal tract was the most common site of bleeding (64%), followed by the respiratory tract (20%). In a multivariate analysis, a low platelet count at MICU admission (odds ratio [OR], 0.98; 95% confidence interval [CI], 0.97 to 0.99) and sepsis (OR, 8.35; 95% CI, 1.04 to 67.05) were independent risk factors for major bleeding. The ICU fatality rate was significantly greater among patients with major bleeding (84.0% vs. 58.9%, respectively; p = 0.015).

CONCLUSIONS

Major bleeding occurred in 12.2% of critically ill cirrhotic patients admitted to the MICU. A low platelet count at MICU admission and sepsis were associated with an increased risk of major bleeding during the MICU stay. Further study is needed to better understand hemostasis in critically ill patients with LC.

Impact of GOLD groups of chronic pulmonary obstructive disease on surgical complications

Purpose

Chronic obstructive pulmonary disease (COPD) is associated with increased postoperative complications. Recently, the Global Initiative for Chronic Obstructive Lung Disease (GOLD) classified COPD patients into four groups based on spirometry results and the severity of symptoms. The objective of this study was to evaluate the impact of GOLD groups on postoperative complications.

Patients and methods

We reviewed the medical records of COPD patients who underwent preoperative spirometry between April and August 2013 at a tertiary hospital in Korea. We divided the patients into GOLD groups according to the results of spirometry and self-administered questionnaires that assessed the symptom severity and exacerbation history. GOLD groups, demographic characteristics, and operative conditions were analyzed.

Results

Among a total of 405 COPD patients, 70 (17.3%) patients experienced various postoperative complications, including infection, wound, or pulmonary complications. Thoracic surgery, upper abdominal surgery, general anesthesia, large estimated blood loss during surgery, and longer anesthesia time were significant risk factors for postoperative complications. Patients in high-risk group (GOLD groups C or D) had an increased risk of postoperative complications compared to those in low-risk group (GOLD groups A or B).

Conclusion

COPD patients in GOLD groups representing a high exacerbation risk have an increased risk of postoperative complications compared to those with low risk.

Changes in treatment outcomes of multidrug-resistant tuberculosis

SETTING

After several changes in treatment modalities, it is time to re-evaluate treatment outcomes of multidrug-resistant tuberculosis (MDR-TB).

OBJECTIVE

To evaluate treatment outcomes, elucidate changes in outcomes over time and identify predictors of treatment success for MDR-TB.

DESIGN

Patients diagnosed with MDR-TB at a tertiary referral centre in South Korea between January 2006 and December 2010 were included. Treatment modalities and outcomes were assessed. Predictors of treatment success were analysed using multiple logistic regression. The treatment modalities and outcomes of these patients were compared with those of MDR-TB patients between January 1996 and December 2005.

RESULTS

Of the 123 MDR-TB patients diagnosed during the later study period, treatment was successful in 103 (83.7%). Extensive drug resistance (OR 0.31, P = 0.044) and additional resistance to fluoroquinolones (OR 0.23, P = 0.039) were inversely associated with treatment success. The treatment success rate improved from 53.5% in 1996-2000 to 68.8% in 2001-2005 and 83.7% in 2006-2010 (P < 0.001). Improved outcomes were accompanied with more frequent use of later-generation fluoroquinolones and linezolid and less frequent surgical resection.

CONCLUSION

Treatment outcomes for MDR-TB improved at a tertiary referral centre in South Korea. The improvement was associated with more frequent use of later-generation fluoroquinolones and linezolid.

Age-related annual decline of lung function in patients with COPD

Background

According to the Fletcher–Peto curve, rate of decline in forced expiratory volume in 1-second (FEV₁) accelerates as age increases. However, recent studies have not demonstrated that the rate of FEV₁ decline accelerates with age among COPD patients. The objective of the study is to evaluate annual rate of FEV₁ decline as age increases among COPD patients.

Methods

In this retrospective cohort study, we enrolled COPD patients who were followed up at two tertiary care university hospitals from January 2000 to August 2013. COPD was defined as post-bronchodilator (BD) FEV₁/forced vital capacity (FVC) of <0.7. All participants had more than two spirometries, including BD response. Age groups were categorized as follows: below versus above median age or four quartiles.

Results

A total of 518 participants (94.2% male; median age, 67 years; range, 42–90 years) were included. Mean absolute and predictive values of post-BD FEV₁ were 1.57±0.62 L and 52.53%±18.29%, respectively. Distribution of Global initiative for Chronic Obstructive Lung Disease groups did not show statistical differences between age groups categorized by two different criteria. After grouping the population by age quartiles, the rate of FEV₁ decline was faster among older patients than younger ones whether expressed as absolute value (−10.60±5.57 mL/year, −15.84±6.01 mL/year, −18.63±5.53 mL/year, 32.94±6.01 mL/year, respectively; P=0.048) or predicted value (−0.34%±0.19%/year, −0.53%±0.21%/year, −0.62%±0.19%/year, −1.26%±0.21%/year, respectively, P=0.010).

Conclusion

As suggested conceptually by the Fletcher−Peto curve, annual FEV₁ decline among COPD patients is accelerated among older patients than younger ones.

Effect of drug resistance on negative conversion of sputum culture in patients with pulmonary tuberculosis

OBJECTIVE

Negative conversion of sputum culture is a useful marker for predicting treatment outcome and relapse of pulmonary tuberculosis (TB). The effect of drug resistance on negative conversion of sputum culture with treatment was evaluated in this study.

METHODS

A total of 535 patients with culture-proven pulmonary TB were classified into three groups: drug-susceptible (DS), other drug-resistant (ODR), and multidrug-resistant/extensively drug-resistant (MDR/XDR). Rates of conversion of sputum culture at 4, 8, and 12 weeks were compared.

RESULTS

At 4 weeks of treatment, the conversion rate in the DS group (52.7%) was higher than that in the ODR group (30.8%, p=0.003), but was not different compared with the MDR group (45.7%, p=0.427). At 8 weeks, the conversion rate in the DS group (76.3%) was higher than that in the ODR (63.5%, p=0.042) and MDR groups (60.0%, p=0.031). At 12 weeks, the conversion rate in the DS group (85.9%) tended to be higher than that in the MDR group (74.3%, p=0.062), but was not different from that in the ODR group (84.6%, p=0.796).

CONCLUSION

The pattern of resistance to anti-TB drugs affects culture conversion rates in the early phase of treatment and also prolongs the time to culture conversion.

Effect of inhalers on the development of haemoptysis in patients with non-cystic fibrosis bronchiectasis

BACKGROUND

The association of inhaler use with haemoptysis has rarely been reported in patients with non-cystic fibrosis (CF) bronchiectasis.

OBJECTIVE

To elucidate the effect of inhaler use on the development of haemoptysis in patients with non-CF bronchiectasis.

METHODS

In a case-crossover study of 192 non-CF bronchiectasis patients with a history of haemoptysis and inhaler use, the risk of haemoptysis associated with the use of inhalers was elucidated. Two inhaled corticosteroids/long-acting β₂-agonists (ICS/LABA), one long-acting muscarinic antagonist and one short-acting β₂-agonist (SABA) were evaluated. The case and control periods were defined respectively as 030 and 180210 days before haemoptysis.

RESULTS

The risk of haemoptysis during the case period was 3.51 times higher than during the control period with any use of inhalers (95%CI 1.966.28). The results of clinically significant haemoptysis showed good agreement with those of total events. These associations were consistent with the sensitivity analyses. In the sub-analysis according to inhaler type, ICS/LABA and SABA were significantly associated with an increased risk of haemoptysis (aOR 2.62, 95%CI 1.255.45; aOR 2.51, 95%CI 2.235.15).

CONCLUSIONS

In patients with non-CF bronchiectasis, the use of inhalers, especially including 2-agonist, was associated with an increased risk of haemoptysis.

Clinical manifestations of pneumonia according to the causative organism in patients in the intensive care unit

BACKGROUND/AIMS

Whether the causative organism influences the clinical course of pneumonia in the intensive care unit (ICU) is controversial. We assessed the clinical manifestations and prognosis of pneumonia according to the causative pathogens in patients in a medical ICU.

METHODS

A retrospective observational study was performed in a medical ICU. Among 242 patients who were admitted to the ICU, 103 who were treated for pneumonia were analyzed.

RESULTS

The causative pathogen was identified in 50 patients (49.0%); 22 patients (21.6%) had multidrug-resistant (MDR) pathogens. The distribution of causative micro-organisms was Staphylococcus aureus (20%), Pseudomonas species (16%), Klebsiella pneumoniae (14%), and Acinetobacter baumannii (12%). No significant difference in ICU mortality rate, duration of ICU stay, duration of mechanical ventilation, or frequencies of re-intubation and tracheostomy were detected based on the identification of any pathogen. In sub-analyses according to the pneumonia classification, the number of pathogens identified did not differ between pneumonia types, and a higher incidence of identified MDR pathogens was detected in the hospital-acquired pneumonia group than in the community-acquired or healthcare- acquired pneumonia groups. However, the clinical outcomes of pneumonia according to identification status and type of pathogen did not differ significantly between the groups.

CONCLUSIONS

Neither the causative micro-organism nor the existence of MDR pathogens in critically ill patients with pneumonia was associated with the clinical outcome of pneumonia, including ICU mortality. This result was consistent regardless of the pneumonia classification.

Effect of tiotropium on lung function decline in early-stage of chronic obstructive pulmonary disease patients: propensity score-matched analysis of real-world data

Background

Tiotropium failed to slow the annual rate of forced expiratory volume in 1 second (FEV₁) decline in chronic obstructive pulmonary disease (COPD) patients with <70% predicted FEV₁. However, the rate of FEV₁ decline is known to be faster at early stages, which suggests that the effects of tiotropium may be more prominent in early-stage of COPD patients. The aim of this study was to test the hypothesis that tiotropium modifies the rate of FEV₁ decline in COPD patients with an FEV₁≥70%.

Methods

We retrospectively reviewed the records of COPD patients diagnosed between January 1, 2004, and July 31, 2012, at Seoul National University Hospital, Seoul National University Bundang Hospital, and Seoul Metropolitan Government-Seoul National University Boramae Medical Center. The inclusion criteria were as follows: age ≥40 years, postbron-chodilator (BD) FEV₁≥70% of predicted and FEV₁/FVC (forced vital capacity) <0.70, and spirometry more than two times at certain times of the year. Conversely, the exclusion criteria were as follows: asthma, lung cancer, pulmonary tuberculosis, pulmonary resection, or long-term use of a short-acting muscarinic antagonist. The annual lung function decline in patients using tiotropium was compared with that in patients not using the drug.

Results

Of the 587 patients enrolled in the study, 257 took tiotropium. Following propensity score matching, 404 patients were included in the analysis. The mean annual rate of post-BD FEV₁ decline was 23.9 (tiotropium) and 22.5 (control) mL/yr (P=0.86); corresponding pre-BD values were 30.4 and 21.9 mL/yr (P=0.31), respectively. Mean annual rate of post-BD FVC decline was 55.1 (tiotropium) and 43.5 (control) mL/yr (P=0.33); corresponding pre-BD values were 37.1 and 33.3 mL/yr (P=0.13).

Conclusion

Therefore, tiotropium does not reduce the rate of lung function decline in COPD patients with FEV₁≥70%.

Accuracy of the Xpert® MTB/RIF assay for the diagnosis of extra-pulmonary tuberculosis in South Korea

SETTING

The Xpert(®) MTB/RIF assay has been endorsed by the World Health Organization for the detection of pulmonary and extra-pulmonary tuberculosis (EPTB).

OBJECTIVE

To determine the accuracy of the Xpert assay in diagnosing EPTB in South Korea, a country with an intermediate TB burden.

DESIGN

We retrospectively reviewed the medical records of 1429 patients in whom the Xpert assay using EPTB specimens was requested between 1 January 2011 and 31 October 2013 in a tertiary referral hospital in South Korea. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the diagnosis of EPTB and detection of rifampicin (RMP) resistance were calculated.

RESULTS

Using culture as gold standard, the sensitivity, specificity, PPV and NPV of the assay were respectively 67.7%, 98.1%, 60% and 98.6%. Using a composite reference standard, the sensitivity, specificity, PPV and NPV were respectively 49.3%, 100%, 100% and 95.1%. The sensitivity, specificity, PPV and NPV for the detection of RMP resistance among specimens with positive results for Mycobacterium tuberculosis were respectively 80%, 100%, 100% and 97.7%.

CONCLUSION

The Xpert assay showed acceptable sensitivity in certain groups and excellent specificity in diagnosing EPTB and detecting RMP resistance in an intermediate TB burden country.

Chronic obstructive pulmonary disease (COPD) assessment test scores corresponding to modified Medical Research Council grades among COPD patients

BACKGROUND/AIMS

In assigning patients with chronic obstructive pulmonary disease (COPD) to subgroups according to the updated guidelines of the Global Initiative for Chronic Obstructive Lung Disease, discrepancies have been noted between the COPD assessment test (CAT) criteria and modified Medical Research Council (mMRC) criteria. We investigated the determinants of symptom and risk groups and sought to identify a better CAT criterion.

METHODS

This retrospective study included COPD patients seen between June 20, 2012, and December 5, 2012. The CAT score that can accurately predict an mMRC grade ≥ 2 versus < 2 was evaluated by comparing the area under the receiver operating curve (AUROC) and by classification and regression tree (CART) analysis.

RESULTS

Among 428 COPD patients, the percentages of patients classified into subgroups A, B, C, and D were 24.5%, 47.2%, 4.2%, and 24.1% based on CAT criteria and 49.3%, 22.4%, 8.9%, and 19.4% based on mMRC criteria, respectively. More than 90% of the patients who met the mMRC criteria for the 'more symptoms group' also met the CAT criteria. AUROC and CART analyses suggested that a CAT score ≥ 15 predicted an mMRC grade ≥ 2 more accurately than the current CAT score criterion. During follow-up, patients with CAT scores of 10 to 14 did not have a different risk of exacerbation versus those with CAT scores < 10, but they did have a lower exacerbation risk compared to those with CAT scores of 15 to 19.

CONCLUSIONS

A CAT score ≥ 15 is a better indicator for the 'more symptoms group' in the management of COPD patients.

Changes in Diagnostic Methods for Pulmonary Tuberculosis between 2005 and 2013

Background

Diagnostic methods for pulmonary tuberculosis (TB) have recently advanced. The aim of this study was to evaluate the changes in TB diagnostic tests that prompted the initiation of anti-TB treatment over time in South Korea, an industrialized country with an intermediate TB burden.

Methods

Patients diagnosed with pulmonary TB in the first halves of 2005 and 2013 at a tertiary referral hospital were included. Diagnostic methods that prompted the initiation of anti-TB treatment were compared between the 2 groups of patients.

Results

A greater proportion of patients were diagnosed with pulmonary TB using bronchoscopy in 2013 than in 2005 (26.7% vs. 6.6%, respectively; p<0.001), while the proportion of patients clinically diagnosed with pulmonary TB was lower in 2013 than in 2005 (24.7% vs. 49.0%, respectively; p<0.001). Additionally, more patients started anti-TB treatment based on positive polymerase chain reaction (PCR) results for Mycobacterium tuberculosis DNA in 2013 than in 2005 (47.3% vs. 7.9%, respectively; p<0.001).

Conclusion

The initiation of treatment for pulmonary TB in South Korea has become more frequently based on PCR and the use of bronchoscopic specimens.