BackgroundConventional spirometric parameters have shown poor correlation with symptoms and health status of chronic obstructive pulmonary disease (COPD). While it is well-known that the pattern of the expiratory flow-volume curve (EFVC) represents ventilatory dysfunction, little attempts have been made to derive quantitative parameters by analyzing the curve. In this study, we aimed to derive useful parameters from EFVC via graphic analysis and tried to validate them in patients with COPD.MethodsUsing Graphical Analysis 3.4 Vernier Software, we derived from the EFVC such parameters as area of obstruction (Ao), area of triangle (AT), area of rectangle (AR) and ratio of volume at 75 and 25 % peak expiratory flow (PEF) (0.25/0.75 V). For validation, we reviewed clinical and spirometric data of 61 COPD patients from Seoul National University Airway Registry (SNUAR) and Korean obstructive Lung Disease (KOLD) cohorts.ResultsOf all parameters, only RV/TLC significantly correlated with scores from St. George’s Respiratory Questionnaire (SGRQ) (r = 0.447, p = 0.037). Six-minute walking distance (6MWD) highly correlated with Ao/AR (r = −0.618, p = 0.005) and Ao/PEF (r = −0.581, p = 0.009) whereas neither FEV1 nor FEV1/FVC had significant correlation with 6MWD.ConclusionsAo/AR and Ao/PEF are promising parameters which correlate well with the exercising capacity of COPD patients.Electronic supplementary materialThe online version of this article (doi:10.1186/s12890-016-0182-8) contains supplementary material, which is available to authorized users.

We investigated the causes of inpatient death after intensive care unit (ICU) discharge and determined predictors of in-hospital mortality in Korea. Using medical ICU registry data of Seoul National University Hospital, we performed a retrospective cohort study involving patients who were discharged alive from their first ICU admission with at least 24 hours of ICU length of stay (LOS). From January 2011 to August 2013, 723 patients were admitted to ICU and 383 patients were included. The estimated in-hospital mortality rate was 11.7% (45/383). The most common cause of death was respiratory failure (n = 25, 56%) followed by sepsis and cancer progression; the causes of hospital death and ICU admission were the same in 64% of all deaths; sudden unexpected deaths comprised about one-fifth of all deaths. In order to predict in-hospital mortality among ICU survivors, multivariate analysis identified presence of solid tumor (odds ratio [OR], 4.06; 95% confidence interval [CI], 2.01–8.2; P < 0.001), hematologic disease (OR, 4.75; 95% CI, 1.51–14.96; P = 0.013), Sequential Organ Failure Assessment (SOFA) score upon ICU admission (OR, 1.08; 95% CI, 0.99–1.17; P = 0.075), and hemoglobin (Hb) level (OR, 0.67; 95% CI, 0.52–0.86; P = 0.001) and platelet count (Plt) (OR, 0.99; 95% CI, 0.99–1.00; P = 0.033) upon ICU discharge as significant factors. In conclusion, a significant proportion of in-hospital mortality is predictable and those who die in hospital after ICU discharge tend to be severely-ill, with comorbidities of hematologic disease and solid tumor, and anemic and thrombocytopenic upon ICU discharge.

Treatment for latent tuberculosis was highly effective in preventing the development of tuberculosis among tumor necrosis factor antagonist users.