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

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

Safety and Utility of Rush Immunotherapy with Aqueous Allergen Extracts for Treatment of Respiratory Allergies.

BACKGROUND: Generally, allergen immunotherapy must be administered for three to five years. Meanwhile, rush immunotherapy (RIT) shortens the required duration for the build-up phase, thereby improving the therapy's convenience compared with conventional immunotherapy (CIT). However, RIT is often performed with modified allergens. Therefore, this study aimed to investigate the safety and utility of RIT with aqueous allergens. METHODS: Medical records of 98 patients sensitized with at least one inhalant allergen who had received subcutaneous immunotherapy for allergic rhinitis with or without asthma were retrospectively reviewed. All patients were classified into three groups: depot-RIT (n = 25), receiving RIT with depot allergen; aqueous-RIT (n = 48), receiving RIT with aqueous allergen; and aqueous-CIT (n = 25), receiving CIT with aqueous allergen. Patients who had received immunotherapy targeting only house dust mites were excluded. RESULTS: The proportions of patients presenting with a systemic reaction to depot-RIT, aqueous-RIT, or aqueous-CIT were 80.0%, 85.4%, and 48.0%, respectively (P = 0.002). The proportions of patients experiencing severe systemic reaction were 4.0%, 16.7%, and 8.0% in depot-RIT, aqueous-RIT and aqueous-CIT, respectively (P = 0.223). The proportions of depot-RIT and aqueous-RIT patients presenting with systemic reaction or severe systemic reaction did not differ significantly (P = 0.553 and P = 0.118, respectively). Significantly fewer depot-RIT (1.0 ± 0.2) and aqueous-RIT patients (2.0 ± 1.3) required outpatient clinical visits during the build-up phase, compared to those administered aqueous-CIT (13.6 ± 1.9; P < 0.001). Moreover, the build-up phase decreased to 17.4 ± 1.8 days in depot-RIT and 23.7 ± 10.9 days in aqueous-RIT, compared to 92.0 ± 12.5 days in aqueous-CIT (P < 0.001). CONCLUSION: RIT with aqueous allergen reduced the build-up phase duration and frequency of hospital visits, with acceptable safety levels. RIT with aqueous allergen may, therefore, be suitable for broad application to patients with respiratory allergies.

Effects of Adjunctive Therapeutic Hypothermia Combined With Hyperbaric Oxygen Therapy in Acute Severe Carbon Monoxide Poisoning.

OBJECTIVE: To determine the effects of adjunctive therapeutic hypothermia, by comparing hyperbaric oxygen therapy versus hyperbaric oxygen therapy combined with therapeutic hypothermia in acute severe carbon monoxide poisoning. DESIGN: Retrospective analysis of data from our prospectively collected carbon monoxide poisoning registry. SETTING: A single academic medical center in Wonju, Republic of Korea. PATIENTS: Patients with acute severe carbon monoxide poisoning older than 18 years. Acute severe carbon monoxide poisoning was defined as mental status showing response to painful stimulus or unresponsive at the emergency department, and a continuation of this depressed mental status even after the first hyperbaric oxygen therapy. Patients were classified into the no-therapeutic hypothermia and therapeutic hypothermia groups. Hyperbaric oxygen therapy was performed up to twice within 24 hours after emergency department arrival, whereas therapeutic hypothermia was performed at a body temperature goal of 33°C for 24 hours using an endovascular cooling device after the first hyperbaric oxygen therapy. INTERVENTIONS: Hyperbaric oxygen therapy versus hyperbaric oxygen therapy combined with therapeutic hypothermia. MEASUREMENTS AND MAIN RESULTS: We investigated the difference in the Global Deterioration Scale score at 1 and 6 months after carbon monoxide exposure, between the no-therapeutic hypothermia and therapeutic hypothermia groups. Global Deterioration Scale scores were classified as follows: 1-3 points (favorable neurocognitive outcome) and 4-7 points (poor neurocognitive outcome). During the study period, 37 patients were treated for acute severe carbon monoxide poisoning, with 16 and 21 patients in the no-therapeutic hypothermia and therapeutic hypothermia groups, respectively. The therapeutic hypothermia group demonstrated significantly higher number of patients with favorable outcomes (p = 0.008) at 6 months after carbon monoxide exposure and better improvement of the 6-month Global Deterioration Scale score than the 1-month score (p = 0.006). CONCLUSIONS: Our data suggest that in acute severe carbon monoxide poisoning, patients who were treated using therapeutic hypothermia combined with hyperbaric oxygen therapy had significantly more favorable neurocognitive outcomes at 6 months after carbon monoxide exposure than those treated with hyperbaric oxygen therapy alone.

The association of delta neutrophil index with the prognosis of acute exacerbation of chronic obstructive pulmonary disease.

BACKGROUND: Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) is associated with infective triggers including bacterial or viral in many cases, and pneumonia is a major contributor to hospitalization for AECOPD and has a close relationship with poor outcomes. Increased delta neutrophil index (DNI) can be useful in the detection of COPD patients with pneumonia. METHODS: A retrospective cohort study was performed to investigate the mortality rate of the patients who were re-admitted within 6 months after discharge from the hospital due to AECOPD with or without CAP. We analyzed the difference of cumulative survival rate according to serum DNI level and readmission duration. RESULTS: Finally, 140 AECOPD patients with community-acquired pneumonia (CAP) and 174 AECOPD patients without CAP were enrolled during 6 months, respectively. The mean age was 72.2 ± 9.4 year-old, and 240 patients (76.4%) were male. When comparing the cumulative survival rate according to readmission duration (≤ 30 vs >  30 days) and DNI level (< 3.5 vs ≥ 3.5%), AECOPD patients with readmission ≤30 days and DNI ≥ 3.5% showed the lowest cumulative survival rate compared to other groups (P <  0.001). Multivariate analysis revealed readmission duration ≤30 days (HR 7.879, 95% CI 4.554-13.632, P <  0.001); and serum DNI level (HR 1.086, 95% CI 1.043-1.131, P <  0.001) were significantly associated with the mortality of AECOPD patients during 6 months. The area under the curve for readmission (≤ 30 days) + DNI level (≥ 3.5%) was 0.753 (95% CI 0.676-0.830, P <  0.001) with a sensitivity of 73.7% and a specificity of 67.3%. CONCLUSION: AECOPD patients who were readmitted ≤30 days and DNI ≥ 3.5% showed higher mortality. DNI level can be used as a predictor of prognosis in AECOPD patients who were readmitted after discharge.

Pleural fluid ADA activity in tuberculous pleurisy can be low in elderly, critically ill patients with multi-organ failure.

BACKGROUND: Adenosine deaminase (ADA) activity is typically elevated in patients with tuberculous pleural effusion (TPE), but low ADA has occasionally been reported in patients with TPE. The characteristics of these patients are not well-known, and erroneous exclusion of the possibility of TPE can result in a delayed diagnosis. This study investigated the characteristics of patients with TPE who had low ADA activity. METHODS: We retrospectively reviewed patients with microbiologically or pathologically confirmed TPE between 2012 to 2018 in a tertiary hospital in South Korea. Patients were categorised into two groups: high ADA (≥40 IU/L) and low ADA (< 40 IU/L). Clinical characteristics and Sequential Organ Failure Assessment (SOFA) scores were compared between groups. RESULTS: A total of 192 patients with TPE were included; 36 (18.8%) had ADA < 40 IU/L with a mean ADA activity level of 20.9 (±9.2) IU/L. Patients with low ADA were older (75.3 vs. 62.0 years, p < 0.001) and had a lower mean lymphocyte percentage (47.6% vs. 69.9%, p < 0.001) than patients with high ADA. Patients in the low ADA group had a significantly higher mean SOFA score (2.31 vs. 0.68, p < 0.001), and patients with organ dysfunction were significantly more common in the low ADA group (p < 0.001). Patients with 2 or ≥ 3 organ dysfunctions constituted 19.4 and 13.9% of the patients in the low ADA group, whereas they constituted 7.1 and 1.3% of the patients in the high ADA group (p < 0.001). Multivariate logistic regression analyses showed that older age (odds ratio = 1.030, 95% confidence interval 1.002-1.060, p = 0.038) and a higher SOFA score (odds ratio = 1.598, 95% confidence interval 1.239-2.060, p < 0.001) were significantly associated with low ADA activity in patients with TPE. CONCLUSIONS: ADA activity can be low in patients with TPE who are elderly, critically ill, and exhibit multiorgan failure. Low ADA activity cannot completely exclude the diagnosis of TPE, and physicians should exercise caution when interpreting pleural fluid exams.

Predictive Value of the Neutrophil-to-Lymphocyte Ratio for the Diagnosis of Pneumonia in Normothermic Dyspneic Patients with Chronic Heart Failure in the Emergency Department.

BACKGROUND: Differentiating pneumonia from chronic heart failure (HF) in normothermic subjects in the emergency department (ED) is significantly difficult. OBJECTIVE: This study aimed to evaluate the predictive value of the neutrophil-to-lymphocyte ratio (NLR) in establishing the diagnosis of pneumonia in normothermic subjects with chronic HF in the ED. METHODS: This study included 523 adult dyspneic patients with chronic HF presenting in the ED. We categorized the selected patients into the nonpneumonia group (NPG) and the pneumonia group (PG), and the patients' serum white blood cell (WBC), neutrophil, and lymphocyte counts, NLR, and C-reactive protein (CRP) levels were measured upon arrival in the ED. Subsequently, we compared their predictive powers after performing a propensity score-matching (PSM) analysis. RESULTS: The PG included 120 (22.9%) patients. After performing PSM, the mean NLR was significantly higher in the PG than in the NPG group (p < 0.001). According to the receiver operating characteristic area under the curve (AUC) analysis of inflammatory markers, the AUC of the NLR was significantly higher than that of WBCs, neutrophils, lymphocytes, and CRP. CONCLUSION: The predictive value of the NLR was significantly higher than that of WBCs, neutrophils, lymphocytes, and CRP. Therefore, NLR may be a useful adjunctive marker to establish the early diagnosis of pneumonia in normothermic patients with chronic HF in the ED.

Early readmission and mortality in acute exacerbation of chronic obstructive pulmonary disease with community-acquired pneumonia.

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are important causes of hospital admission and mortality. Pneumonia is a major contributor to hospitalization for AECOPD and has a close relationship with poor outcomes. We performed a prospective cohort study to evaluate the prognosis of AECOPD patients with or without community-acquired pneumonia (CAP) who hospitalized from January 2012 to December 2015. We investigated mortality and readmission rates within 6 months after the first admission between two groups and analyzed the difference of survival rate according to readmission duration (≤30 vs. >30 days) or intensive care unit (ICU) treatment. Total 308 AECOPD patients (134 with CAP and 174 without CAP) were enrolled. The mean age was 72.3 ± 9.5 years old, and 235 patients (76.3%) were male. The 180-day mortality was higher in AECOPD with CAP than without CAP (24.6% vs. 13.2%; hazard ratio (HR): 1.982; 95% CI: 1.164-3.375; p = 0.012). However, readmission rate showed no significant difference between two groups (51.5% vs. 46.6%; HR: 1.172; 95% CI: 0.850-1.616; p = 0.333). It showed a significantly lower survival rate in AECOPD with CAP rather than without CAP when were readmitted within 30 days (HR: 1.738; 95% CI:1.063-3.017; p = 0.031). According to ICU treatment, survival rate was not significantly different between two groups. Multivariate analysis revealed the readmission within 30 days ( p < 0.001), serum hemoglobin concentration ( p = 0.010), and albumin level ( p = 0.049) were significantly associated with 180-day mortality of AECOPD with CAP. AECOPD with CAP showed lower survival rate than AECOPD without CAP during 6 months. Early readmission within 30 days was significantly associated with an increased risk of mortality.

Clinical characteristics of patients with newly developed acute cholecystitis after admission to the intensive care unit.

INTRODUCTION: Critical care patients have many risk factors for acute cholecystitis (AC). However, less data are available regarding newly developed AC in critically ill patients. OBJECTIVES: To investigate the clinical features of AC occurring in critically ill patients after admission to an intensive care unit (ICU). METHODS: We performed a retrospective cohort study from January 2006 to August 2016 at a tertiary care university hospital. We included patients diagnosed with AC with or without gallstones after ICU admission. All cases of AC were confirmed by gastroenterologists or general surgeons. We excluded patients with AC diagnosed before or at the time of ICU admission. RESULTS: A total of 38 patients were diagnosed with AC after ICU admission between January 2006 and August 2016. Seventeen (44.7%) had acute acalculous cholecystitis, while 21 (55.3%) had acute calculous cholecystitis. The median age was 73 years (interquartile range = 63-81 years), and 22 (57.9%) patients were male. The most common reason for ICU admission was pneumonia or sepsis. The median interval from ICU admission to diagnosis of AC was 11 days (interquartile range = 4.8-22.8 days). Before AC diagnosis, almost 90% of patients used total parenteral nutrition, 68% used opioids, 76% were mechanically ventilated, and 42% received vasoactive drugs. More than half of patients underwent cholecystectomy, and all surgically resected gallbladders had pathology results for cholecystitis. Gangrenous cholecystitis was observed in five patients with acute calculous cholecystitis. The overall mortality was 42.1%, and 1/3 of these deaths were directly associated with AC. The average length of stay in the ICU and hospital was 26.5 and 44.5 days, respectively. CONCLUSION: The development of AC in the ICU should be carefully monitored, especially in patients who have been infected and admitted to the ICU for more than 10 days. Proper diagnosis and treatment at a critical time could be lifesaving.

Life-threatening pulmonary embolism that occurred immediately after acute carbon monoxide poisoning in the emergency department.

The risk of thromboembolism is higher in those with carbon monoxide (CO) poisoning than in the general population. Pulmonary embolisms (PE) usually develop during admission for acute CO poisoning. We report the first case of a life-threatening PE that occurred immediately after acute CO poisoning and was treated with a thrombolytic agent. A 38-year-old woman presented at the emergency department with a stuporous mental status immediately after acute CO poisoning. She was started on hyperbaric oxygen therapy (HBOT), which maintained her hemodynamic stability. After completing the first HBOT session, profound shock occurred. The results of focused cardiac ultrasound performed by an emergency physician were completely different from those of the ultrasound conducted before HBOT; hyperdynamic left ventricle systolic function and right ventricle enlargement with dysfunction were detected. We administered a thrombolytic agent as she was suspected with acute PE based on ultrasound findings; computed tomography could not be performed because of impending arrest. She recovered after the treatment. We should consider that PE is also an important differential cause in patients with hypotension. In these patients, bedside ultrasound performed by emergency physicians can act as the only diagnostic examination.

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.

Clinical Features and Outcomes of Respiratory Complications in Patients with Thoracic Hyperkyphosis.

INTRODUCTION: There are few data about thoracic hyperkyphosis which focused on respiratory events and prognoses. We investigated the clinical features and outcomes of respiratory complications requiring hospitalization in patients with thoracic hyperkyphosis. METHODS: Following a retrospective review of the medical records between 2002 and 2011, we included 51 patients with thoracic hyperkyphosis who had visited the respiratory department due to respiratory symptoms. RESULTS: Of total 51 patients, 35 patients were hospitalized due to respiratory events. Among 56 total hospitalized events, acute respiratory failure (ARF) (n = 18) and exacerbation of a chronic airway disorder (n = 18) were the most common causes. Respiratory events related mortality was 13.7 % (7/51). The median value of the thoracic kyphosis angle was 89.0°. The ratio of the measured kyphosis angle to the normal value according to age and sex showed the median value of 2.38 (interquartile range 1.61-2.87). This ratio was negatively correlated with both predicted forced vital capacity (γ = -0.647, p < 0.0001) and predicted forced expiratory volume for 1 s (γ = -0.518, p = 0.008). After adjustments for age and sex, hyperkyphosis (angle ≥90°) was not found to influence the development of ARF (hazard ratio 3.2; 95 % confidence interval, 0.86-12.14; p = 0.082). CONCLUSIONS: Patients with thoracic hyperkyphosis presenting to a respiratory department with respiratory issues commonly experienced respiratory events requiring hospitalization and had a poor prognosis. In addition, the severity of the kyphosis angle was correlated with respiratory insufficiency although it was not a risk factor for the development of ARF.

Prognosis and Predictors of Rebleeding After Bronchial Artery Embolization in Patients with Active or Inactive Pulmonary Tuberculosis.

INTRODUCTION: The aim of this study was to characterize the prognosis and identify factors that contribute to rebleeding after bronchial artery embolization (BAE) in patients with active or inactive pulmonary tuberculosis (PTB). METHODS: Following a retrospective review, 190 patients had hemoptysis requiring BAE due to PTB in one hospital between 2006 and 2013. RESULTS: The median age at the time of diagnosis of PTB was 37 years and 54 years at the time of first episode of hemoptysis. Among 47 patients (24.7 %) who experienced rebleeding after BAE during the median follow-up period of 13.9 months [interquartile range (IQR) 2.3-36.0 months], bleeding recurred in 12 patients (6.3 %) within 1 month and in 15 patients (7.9 %) after 1 year. The median non-recurrence time was 8.6 months (IQR 1.2-27.6 months). Independent predictors of rebleeding after BAE were tuberculous-destroyed lung [hazard ratio (HR) 3.0; 95 % confidence interval (CI) 1.5-6.2; p = 0.003], the use of anticoagulant agents and/or antiplatelet agents (HR 2.6; 95 % CI 1.1-5.8; p = 0.022), underlying chronic liver disease (HR 2.7; 95 % CI 1.1-4-6.9; p = 0.033), elevated pre-BAE C-reactive protein (CRP) (mg/dL) (HR 2.4; 95 % CI 1.0-5.5; p = 0.048), and the existence of fungal ball (HR 2.1; 95 % CI 1.0-4.3; p = 0.050). CONCLUSIONS: The risk of rebleeding after BAE in active or inactive PTB was high, particularly in patients with tuberculous-destroyed lung, chronic liver disease, the use of anticoagulant agents and/or antiplatelet agents, elevated pre-BAE CRP, and the existence of fungal ball.

Image quality assessment of ultra low-dose chest CT using sinogram-affirmed iterative reconstruction.

OBJECTIVES: To assess the image quality of ultra-low-dose computed tomography (ULDCT) using sinogram-affirmed iterative reconstruction (SAFIRE) compared to reduced dose CT (RDCT). METHODS: Eighty-one consecutive patients underwent non-enhanced ULDCT using 80 kVp and 30 mAs and contrast-enhanced RDCT using automated tube potential selection and tube current modulation. CT images were reconstructed with SAFIRE. Image noise and subjective image quality of normal structures and various pulmonary lesions were assessed. RESULTS: The mean effective doses were 0.29 ± 0.03 and 2.88 ± 1.11 mSv for ULDCT and RDCT, respectively. ULDCT had significantly higher noise (p < 0.001). Image quality of five normal structures was diagnostic in 91.1 % of ULDCT and 100 % of RDCT. With ULDCT, the frequencies of non-diagnostic image quality were 2.0 (1/50), 4.6 (13/280), 25.5 (14/55), and 40.0 (8/20)% for BMIs of < 20, 20-25, 25-30, and >30. In the assessment of pulmonary lesions, non-diagnostic image quality was observed for 11.2 % of all lesions, 60.9 % of decreased attenuation (significantly more frequent for upper lung lesions), and 23.5 % of ground-glass nodules. CONCLUSION: ULDCT generates diagnostic images in patients with a BMI ≤25, but is of limited use for lesions with decreased attenuation, ground-glass nodules, or those located in the upper lobe. KEY POINTS: • Iterative reconstruction enables ultra-low-dose CT (ULDCT) with very low radiation doses. • Image quality of ULDCT depends on the patient body mass index (BMI). • Selection of kVp and mAs depends on both BMI and lesion type. • Diagnosis of pulmonary emphysema or ground-glass nodules requires higher radiation doses.

The impact of low subcutaneous fat in patients with nontuberculous mycobacterial lung disease.

BACKGROUND: Nontuberculous mycobacteria (NTM) are pathogens that cause chronic respiratory disease, even in immunocompetent patients. We hypothesized that low subcutaneous fat is a predisposing factor for NTM lung disease. METHODS: Following a retrospective review of medical records from between 2005 and 2012, a total of 148 patients with NTM lung disease and 142 age- and sex-matched controls were enrolled. We evaluated subcutaneous fat using chest computed tomography (CT) scans at the midpole level of the left kidney. RESULTS: The median age of the patients was 62 years and 60.8 % were female. Approximately 71 % were classified into a nodular bronchiectatic group. The patient group had significantly less subcutaneous fat than the control group (39.3 vs. 53.0 cm(2), p = 0.001). Patients with both localized disease (43.5 vs. 53.0 cm(2), p = 0.042) and extensive disease (35.9 vs. 53.0 cm(2), p < 0.0001) had less subcutaneous fat compared with the control group. No difference in subcutaneous fat was observed with respect to the increasing bacterial load in sputum (p = 0.246). In 20 patients with prominent disease progression during the follow-up period, no significant difference was observed between subcutaneous fat at the initial diagnosis and that at the follow-up CT (36.2 vs. 42.0 cm(2), p = 0.47). CONCLUSION: Our results suggest that lower subcutaneous fat may contribute to host susceptibility to NTM lung disease.

Risk of lung diseases in patients with previous carbon monoxide poisoning: a nationwide population-based cohort study in the Republic of Korea.

INTRODUCTION: Carbon monoxide poisoning is associated with severe damage to various organs. In this study, we aimed to determine if previous carbon monoxide poisoning was associated with an increased risk of lung diseases. METHODS: The study population was derived from the National Health Insurance Service database of Korea between 1 January 2002 and 31 December 2021. Adults with carbon monoxide poisoning, with at least one visit to medical facilities between 2002 and 2021, were included. For comparison, an equal number of matched controls with the same index date were selected from the database. RESULTS: A total of 28,618 patients with carbon monoxide poisoning and 28,618 matched controls were included in this study. Approximately 42.8 per cent of the patient and control groups were female, with a mean age of 51.3 years. In patients with carbon monoxide poisoning, there was a significant increase in the risk of lung cancer (adjusted hazard ratio, 1.84; 95 per cent confidence interval, 1.42-2.39; P < 0.001), chronic obstructive pulmonary disease (adjusted hazard ratio, 1.60; 95 per cent confidence interval, 1.36-1.89; P < 0.001), pulmonary tuberculosis (adjusted hazard ratio, 1.46; 95 per cent confidence interval, 1.13-1.88; P = 0.003), and non-tuberculous mycobacterial infection (adjusted hazard ratio, 1.54; 95 per cent confidence interval, 1.01-2.36; P = 0.047). DISCUSSION: In this retrospective cohort study, previous carbon monoxide poisoning was associated with an increased risk of lung cancer, chronic obstructive pulmonary disease, pulmonary tuberculosis, and non-tuberculous mycobacterial infection. Further studies are needed to confirm such an association in other populations and the risk of lung diseases due to the toxic effect of carbon monoxide from different sources. CONCLUSIONS: Previous carbon monoxide poisoning was associated with an increased risk of lung diseases, but the relative importance of the causes and sources of exposure was not known. The long-term management of survivors of acute carbon monoxide poisoning should include monitoring for lung cancer, chronic obstructive pulmonary disease, pulmonary tuberculosis, and non-tuberculous mycobacterial infection.

Inhaled Corticosteroids May Not Affect the Clinical Outcomes of Pneumonia in Patients with Chronic Obstructive Pulmonary Disease.

BACKGROUND: Although inhaled corticosteroids (ICS) is reportedly associated with a higher risk of pneumonia in chronic obstructive pulmonary disease (COPD), the clinical implications of ICS have not been sufficiently verified to determine their effect on the prognosis of pneumonia. METHODS: The electronic health records of patients hospitalized for pneumonia with underlying COPD were retrospectively reviewed. Pneumonia was confirmed using chest radiography or computed tomography. The clinical outcomes of pneumonia in patients with COPD who received ICS and those who received long-acting bronchodilators other than ICS were compared. RESULTS: Among the 255 hospitalized patients, 89 met the inclusion criteria. The numbers of ICS and non-ICS users were 46 and 43, respectively. The CURB-65 (confusion, uremia, respiratory rate, blood pressure, age ≥65 years) scores at the initial presentation of pneumonia were comparable between the two groups. The proportions of patients with multilobar infiltration, pleural effusion, and complicated pneumonia in the radiological studies did not vary between the two groups. Additionally, the defervescence time, proportion of mechanical ventilation, intensive care unit admission, length of hospital stays, and mortality rate at 30 and 90 days were not significantly different between the two groups. ICS use and blood eosinophils count were not associated with all pneumonia outcomes and mortality in multivariate analyses. CONCLUSION: The clinical outcomes of pneumonia following ICS use in patients with COPD did not differ from those in patients treated without ICS. Thus, ICS may not contribute to the severity and outcomes of pneumonia in patients with COPD.

Incidence, Prevalence, and Mortality of Eosinophilic Granulomatosis With Polyangiitis in Korea: A Nationwide Population-Based Study.

PURPOSE: Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare form of vasculitis with multiorgan involvement. The incidence and prevalence of EGPA vary geographically and ethnically. This study investigated the incidence, prevalence, and mortality of EGPA in a nationwide population-based cohort in Korea. METHODS: This retrospective cohort study used data from the National Health Insurance database that covers almost all Korean residents. EGPA was identified using relevant diagnostic codes from 2007 to 2018. Newly diagnosed EGPA cases since 2007 and patients who visited outpatient clinics for EGPA at least three times were included. Age- and sex-adjusted standardized incidence and prevalence rates were analyzed. RESULTS: A total of 843 patients with EGPA were identified. The mean annual standardized incidence between 2007 and 2018 was 1.2 (per 1,000,000 individuals). The incidence of EGPA has increased from 1.1 (per 1,000,000 individuals) in 2007 to 1.6 (per 1,000,000 individuals) in 2017. The standardized prevalence of EGPA has increased from 1.1(per 1,000,000 individuals) in 2007 to 11.2 (per 1,000,000 individuals) in 2018. The incidence and prevalence of EGPA were higher in women than in men. The standardized mortality rate was 1.61 (95% confidence interval [CI], 1.34-1.93) in total population, 1.59 (95% CI, 1.23-2.02) in males, and 1.63 (95% CI, 1.22-2.13) in females. CONCLUSIONS: The incidence of EGPA has increased over the past decade. Incidence and prevalence rates were higher in females than in males. The overall mortality rate associated with EGPA was higher than that in the general population.

Risk of Cardiovascular Events Associated with Chronic Obstructive Pulmonary Disease and/or Metabolic Syndrome: A Large-Scale Nationwide Population-Based Cohort Study.

Purpose: Chronic obstructive pulmonary disease (COPD) and metabolic syndrome (MetS) are among the most prevalent conditions that might predispose individuals to life-threatening events. We aimed to examine their associations with cardiovascular (CV) events and mortality using a large-scale population dataset from the National Health Information Database in Korea. Patients and Methods: This population-based cohort study enrolled adults aged ≥40 years who had undergone more than two health examinations between 2009 and 2011. They were divided into four groups based on the presence of COPD and MetS. Analysis of the outcomes and CV events or deaths was performed from 2014 to 2019. We compared CV event incidence and mortality rates using a multivariate Cox proportional hazards model and Kaplan-Meier curves. Results: Totally, 5,101,810 individuals were included, among whom 3,738,458 (73.3%) had neither COPD nor MetS, 1,193,014 (23.4%) had only MetS, 125,976 (2.5%) had only COPD, and 44,362 (0.9%) had both. The risk of CV events was significantly higher in individuals with both COPD and MetS than in those with either COPD or MetS alone (HRs: 2.4 vs 1.6 and 1.8, respectively; all P <0.001). Similarly, among those with both COPD and MetS, all-cause and CV mortality risks were also elevated (HRs, 2.9 and 3.0, respectively) compared to the risks in those with either COPD (HRs, 2.6 and 2.1, respectively) or MetS (HRs, 1.7 and 2.1, respectively; all P <0.001). Conclusion: The comorbidity of MetS in patients with COPD increases the incidence of CV events and all-cause and cardiovascular mortality rates.

Inhaled Corticosteroids and the Risk of Nontuberculous Mycobacterial Pulmonary Disease in Chronic Obstructive Pulmonary Disease: Findings from a Nationwide Population-Based Study.

Studies have shown increased nontuberculous mycobacterial pulmonary disease (NTM) incidence with inhaled corticosteroid (ICS) use in patients with chronic respiratory diseases; however, this association in chronic obstructive pulmonary disease (COPD) remains insufficiently studied. Using a nationwide population-based database of the Korean National Health Insurance Service, newly diagnosed COPD patients (2005-2018) treated with inhaled bronchodilators were selected. An NTM case was defined by the presence of the first diagnostic code following inhaled bronchodilator use. Results indicated that ICS users did not have an increased risk of NTM disease compared to non-ICS users (hazard ratio (HR), 1.121; 95% confidence interval (CI), 0.950-1.323; p = 0.176). However, in a subgroup analysis, the highest quartile of the cumulative ICS dose was associated with the development of NTM (1.200, 0.950-1.323, p = 0.050). Medium (1.229, 1.008-1.499, p = 0.041) and high daily doses of ICS (1.637, 1.241-2.160, p < 0.001) were associated with an increased risk of NTM disease. There was no difference in the risk of NTM according to ICS type. ICS use may increase the risk of developing NTM disease in patients with COPD. Physicians should weigh the potential benefits and risks of ICS, especially when using high doses and prolonged durations.

Outstanding Characteristics of Birt-Hogg-Dube Syndrome in Korea.

Birt-Hogg-Dube (BHD) is a rare genetic disorder characterized by multiple lung cysts, typical skin manifestations, and renal tumors. We prospectively enrolled thirty-one subjects from four South Korean institutions with typical lung cysts, and next-generation sequencing was conducted. We prospectively enrolled thirty-one subjects from four Korean institutions with typical lung cysts. Next-generation sequencing was performed to investigate mutations in the following genes: FLCN, TSC1, TSC2, CFTR, EFEMP2, ELN, FBLN5, LTBP4, and SERPINA1. BHD was diagnosed in 11 of the 31 enrolled subjects (35.5%; FLCN mutations). Notably, we identified three novel mutations (c.1098G>A, c.139G>T, and c.1335del) that have not been previously reported. In addition to FLCN mutations, we also observed mutations in CFTR (16.1%), LTBP4 (9.7%), TSC2 (9.7%), TSC1 (3.2%), ELN (3.2%), and SERPINA1 (3.2%). According to a systematic review of 45 South Korean patients with BHD, the prevalence of pneumothorax (72.7%) was greater in South Korea than in the rest of the world (50.9%; p = 0.003). The prevalence of skin manifestations (13.6%) and renal tumors (9.1%) was lower in Korea than in the rest of the world, at 47.9% [p < 0.001] and 22.5% [p = 0.027], respectively). This study confirmed a significant prediction model for BHD based on age, number of lung cysts (>40), and maximal diameter of lung cysts (>2 cm) regardless of skin manifestations and renal tumors. Importantly, three novel mutations (c.1098G>A, c.139G>T, and c.1335del) were identified. In conclusion, South Korean patients with BHD display characteristics that are different from those observed in patients of other nationalities. Detailed characterization of lung cysts is needed to define BHD, especially in South Korea, even if patients do not present with skin or renal lesions.