Yon Ju Ryu

Triple-Combination Antiviral Drug for Pandemic H1N1 Influenza Virus Infection in Critically Ill Patients on Mechanical Ventilation

ABSTRACT A recent in vitro study showed that the three compounds of antiviral drugs with different mechanisms of action (amantadine, ribavirin, and oseltamivir) could result in synergistic antiviral activity against influenza virus. However, no clinical studies have evaluated the efficacy and safety of combination antiviral therapy in patients with severe influenza illness. A total of 245 adult patients who were critically ill with confirmed pandemic influenza A/H1N1 2009 (pH1N1) virus infection and were admitted to one of the intensive care units of 28 hospitals in Korea were reviewed. Patients who required ventilator support and received either triple-combination antiviral drug (TCAD) therapy or oseltamivir monotherapy were analyzed. A total of 127 patients were included in our analysis. Among them, 24 patients received TCAD therapy, and 103 patients received oseltamivir monotherapy. The 14-day mortality was 17% in the TCAD group and 35% in the oseltamivir group (P = 0.08), and the 90-day mortality was 46% in the TCAD group and 59% in the oseltamivir group (P = 0.23). None of the toxicities attributable to antiviral drugs occurred in either group of our study, including hemolytic anemia and hepatic toxicities related to the use of ribavirin. Logistic regression analysis indicated that the odds ratio for the association of TCAD with 90-day mortality was 0.58 (95% confidence interval, 0.24 to 1.42; P = 0.24). Although this study was retrospective and did not provide virologic outcomes, our results suggest that the treatment outcome of the triple combination of amantadine, ribavirin, and oseltamivir was comparable to that of oseltamivir monotherapy.

Prevalence of Depression and Anxiety in Outpatients with Chronic Airway Lung Disease

Background/Aims Patients with chronic airway lung diseases often experience depression and anxiety, but little information is available regarding Koreans with these conditions. We thus assessed depression and anxiety in Korean patients with chronic airway lung diseases. Methods The degree of depression and anxiety in 84 outpatients with chronic obstructive pulmonary disease (COPD), 37 with asthma, 33 with bronchiectasis, and 73 healthy controls were evaluated by the Beck Depression Inventory (BDI) and the State-Trait Anxiety Inventory (STAI). Results The patients with COPD and bronchiectasis had higher BDI scores and were more likely than controls to experience depression ([COPD, 17; range, 0 to 42; prevalence, 55%], [bronchiectasis, 16; range, 3 to 51; prevalence, 55%], [controls, 13; range, 0 to 31; prevalence, 30%], p < 0.05). The state-anxiety scores of the patients were higher than those of the controls, but only the bronchiectasis group demonstrated a higher frequency of state-anxiety compared with the controls (39 vs. 16%, patients vs. controls, p = 0.015). Among all patients, 22% presented with concomitant depression and state-anxiety, and 25% demonstrated depression and trait-anxiety. Depression was positively correlated with both state-anxiety (r = 0.644) and trait-anxiety (r = 0.597, p < 0.0001). Irrespective of individual diagnosis, post-bronchodilator FEV1 (odds ratio [OR], 0.972; p = 0.027) and smoking history (OR, 3.894; p = 0.018) were independent risk factors for depression in patients with chronic airway lung diseases. Conclusions Chronic airway lung diseases are associated with depression and/or anxiety, particularly in those with a higher airflow limitation and/or history of smoking.

Ultra-Low-Dose CT of the Thorax Using Iterative Reconstruction: Evaluation of Image Quality and Radiation Dose Reduction

OBJECTIVE The purpose of this study is to assess the image quality and radiation dose reduction of ultra-low-dose CT using sinogram-affirmed iterative reconstruction (SAFIRE). SUBJECTS AND METHODS This prospective study enrolled 25 patients who underwent three consecutive unenhanced CT scans including low-dose CT (120 kVp and 30 mAs) and two ultra-low-dose CT protocols (protocol A, 100 kVp and 20 mAs; protocol B, 80 kVp and 30 mAs) with image reconstruction using SAFIRE. The image quality and radiation dose reduction were assessed. RESULTS The mean (± SD) effective radiation dose was 1.06 ± 0.11, 0.44 ± 0.05, and 0.31 ± 0.03 mSv for low-dose CT, ultra-low-dose CT protocol A, and ultra-low-dose CT protocol B, respectively. Overall image quality was determined as diagnostic in 100% of low-dose CT scans, 96% of ultra-low-dose CT protocol A scans, and 88% of ultra-low-dose CT protocol B scans. All patients with nondiagnostic quality images had a body mass index (weight in kilograms divided by the square of height in meters) greater than 25. There was no statistically significant difference in detection frequencies of 14 lesion types among the three CT protocols, but pulmonary emphysema was detected in fewer patients (3/25) in ultra-low-dose CT protocol B scans compared with ultra-low-dose CT protocol A scans (5/25) or low-dose CT scans (6/25). We measured the longest dimensions of 33 small solid nodules (3.8-12.4 mm in long diameter) and found no statistically significant difference in the values afforded by the three CT protocols (p = 0.135). CONCLUSION Iterative reconstruction allows ultra-low-dose CT and affords acceptable image quality, allowing size measurements of solid pulmonary nodules to be made.

Diagnosis and Treatment of Nontuberculous Mycobacterial Lung Disease: Clinicians' Perspectives

Nontuberculous mycobacteria (NTM) are emerging pathogens that affect both immunocompromised and immunocompetent patients. The incidence and prevalence of NTM lung disease are increasing worldwide and rapidly becoming a major public health problem. For the diagnosis of NTM lung disease, patients suspected to have NTM lung disease are required to meet all clinical and microbiologic criteria. The development of molecular methods allows the characterization of new species and NTM identification at a subspecies level. Even after the identification of NTM species from respiratory specimens, clinicians should consider the clinical significance of such findings. Besides the limited options, treatment is lengthy and varies by species, and therefore a challenge. Treatment may be complicated by potential toxicity with discouraging outcomes. The decision to start treatment for NTM lung disease is not easy and requires careful individualized analysis of risks and benefits. Clinicians should be alert to those unique aspects of NTM lung disease concerning diagnosis with advanced molecular methods and treatment with limited options. Current recommendations and recent advances for diagnosis and treatment of NTM lung disease are summarized in this article.

Diagnosis of Pulmonary Tuberculosis: Recent Advances and Diagnostic Algorithms

Pulmonary tuberculosis (TB) persists as a great public health problem in Korea. Increases in the overall age of the population and the rise of drug-resistant TB have reinforced the need for rapid diagnostic improvements and new modalities to detect TB and drug-resistant TB, as well as to improve TB control. Standard guidelines and recent advances for diagnosing pulmonary TB are summarized in this article. An early and accurate diagnosis of pulmonary TB should be established using chest X-ray, sputum microscopy, culture in both liquid and solid media, and nucleic acid amplification. Chest computed tomography, histopathological examination of biopsy samples, and new molecular diagnostic tests can be used for earlier and improved diagnoses, especially in patients with smear-negative pulmonary TB or clinically-diagnosed TB and drug-resistant TB.

Characteristics and self-rated health of overlap syndrome.

Background and objective Overlap syndrome shares features of both asthma and chronic obstructive pulmonary disease (COPD). The aim of this study was to investigate characteristics of overlap syndrome and their effect on self-rated health (SRH). Methods We analyzed data from the Fourth Korea National Health and Nutrition Examination Survey of 2007–2009. Subjects with acceptable spirometry and available wheezing history were included. Subjects were classified into four groups based on forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) results and the presence or absence of self-reported wheezing for the previous 12 months: 1) COPD group, defined as having FEV1/FVC <0.7 without self-reported wheezing history; 2) asthma group, defined as having self-reported wheezing history without FEV1/FVC <0.7; 3) overlap syndrome group, having both FEV1/FVC <0.7 and wheezing history; and 4) non-obstructive disease (NOD) group, having neither FEV1/FVC <0.7 nor self-reported wheezing. SRH was categorized as better or lower based on responses to a questionnaire. Results From a total 9,104 subjects, 700 were assigned to the COPD group, 560 to the asthma group, 210 to the overlap syndrome group, and 7,634 to the NOD group. Compared to the other groups, subjects in the overlap syndrome group were more likely to have low lung function, a high proportion of smokers, low socioeconomic status, short education duration, lower SRH, and past diagnosis of pulmonary tuberculosis or bronchiectasis. Multiple logistic regression analysis revealed that both overlap syndrome and asthma groups were independently associated with lower SRH after adjustment for age, sex, socioeconomic status, education level, smoking status, comorbidities, and lung function. Female, old age, low education level, low economic status, smoker and other comorbidities were also associated with lower SRH. Conclusion Overlap syndrome was accompanied by high morbidity and was associated with lower SRH, which needs more appropriate care.

Comparison of natural and Dumon airway stents for the management of benign tracheobronchial stenoses.

Objective and background:  To investigate the utility and safety of the ‘Natural stent’, a newly designed silicone airway stent, the authors compared clinical outcomes and complications in patients who underwent silicone airway stenting for the management of benign airway stenosis.

Risk factors for chronic obstructive pulmonary disease among never-smokers in Korea

Background Chronic obstructive pulmonary disease (COPD) patients include those who have never smoked. However, risk factors other than smoking in never-smokers have not been elucidated sufficiently. This study investigated the risk factors for COPD among never-smokers in Korea using population-based data. Methods The data were retrieved from the Korean National Health and Nutrition Survey IV conducted from 2007 to 2009. Among subjects aged 40 years or older who underwent appropriate pulmonary function tests, never-smokers not diagnosed with asthma and not showing a restrictive pattern on pulmonary function tests were enrolled. Risk factors of COPD in never-smokers were analyzed using logistic regression models. Results Among 24,871 participants in the representative Korean cohort, 3,473 never-smokers were enrolled. COPD patients accounted for 7.6% of the never-smokers. In the logistic regression analysis, low education status (odds ratio [OR]: 2.0; 95% confidence interval [CI]: 1.2–3.2), occupational exposure (OR: 2.6; 95% CI: 1.3–5.3), a history of tuberculosis (OR: 4.5; 95% CI: 2.3–8.7), bronchiectasis (OR: 6.0; 95% CI: 1.4–25.4), male sex (OR: 4.2; 95% CI: 2.6–6.7), advanced age (60–69 years vs 40–49 years; OR: 3.8; 95% CI: 2.0–7.0), and being underweight (body mass index <18.5 vs 18.0–24.9 kg/m2; OR: 3.1; 95% CI: 1.0–9.4) were associated with the development of COPD. Conclusion Low education status, manual labor, a history of tuberculosis and bronchiectasis, as well as male sex, advanced age and being underweight were risk factors for COPD in Korean never-smokers.

Outcomes and Prognostic Factors for Severe Community-Acquired Pneumonia that Requires Mechanical Ventilation

Background Community-acquired pneumonia (CAP) remains a common and serious condition worldwide. The mortality from severe CAP remains high, and this has reached 50% in some series. This study was conducted to determine the mortality and predictors that contribute to in-hospital mortality for patients who exhibit CAP and acute respiratory failure that requires mechanical ventilation. Methods We retrospectively reviewed the medical records of 85 patients with severe CAP as a primary cause of acute respiratory failure, and this required mechanical ventilation in a setting of the medical intensive care unit (ICU) of a tertiary university hospital between 2000 and 2003. Results The overall in-hospital mortality was 56% (48/85). A Cox-proportional hazard model revealed that the independent predictive factors of in-hospital mortality included a PaCO2 of less than 45 mmHg (p<0.001, relative risk [RR]: 4.73; 95% confidence interval [CI]: 2.16-10.33), a first 24-hour urine output of less than 1.5 L (p=0.006, RR: 2.46, 95% CI: 1.29-4.66) and a high APACHE II score (p=0.004, RR: 1.09, 95% CI: 1.03-1.16). Conclusions Acute respiratory failure caused by severe CAP and that necessitates mechanical ventilation is associated with a high mortality rate. Initial hypercapnia and a large urine output favored survival, whereas a high APACHE II score predicted mortality.

The body mass index as a prognostic factor of critical care.

Background/Aims Obesity is a worldwide concern, but its influence on critical care outcomes is not well understood. We tested the hypothesis that abnormal body mass index (BMI) would be an independent predictor of higher mortality rates in intensive care unit (ICU). Methods We retrospectively reviewed patients who had admitted to the ICU from January 2007 to December 2007. Admission BMI was analyzed as both a three categorical (underweight, < 18.5 kg/m2; normal weight, 18.5 to 24.9 kg/m2; overweight and obese, ≥ 25 kg/m2) and continuous variables among all patients with an ICU lenth of stay ≥ 4 days. The primary outcome was ICU mortality. Results The multivariate analysis on ICU mortality selected Mortality Prediction Model-Admission (MPM at time zero) (hazard ratio [HR], 1.024; p = 0.001; 95% confidence interval [CI], 1.010 to 1.037), failed extubation (HR, 5.092; p = 0.0001; 95% CI, 2.742 to 9.456) as significant risk factors. When controlling these variables, none of the BMI group and BMI as a continuous variable had an independent association with ICU mortality. Conclusions BMI did not have a significant influence on ICU mortality. The ICU mortality was influenced more strongly by severity of illness and failed extubation rather than BMI.