Knowledge and Attitudes Toward Obstructive Sleep Apnea Among Korean Pulmonologists: A Nationwide Survey.

BACKGROUND: Obstructive sleep apnea (OSA) significantly impacts cardiovascular, metabolic, and respiratory health. In Korea, OSA patients are treated by specialists in internal medicine, otolaryngology, neurology, and psychiatry, but the participation rate of pulmonologists in OSA management is relatively low compared to other specialties. This study investigated the knowledge and attitudes about OSA among Korean pulmonologists. MATERIALS AND METHODS: An online survey was conducted, targeting respiratory specialists listed in the Korean Academy of Tuberculosis and Respiratory Diseases directory. The survey used the validated "Obstructive Sleep Apnea Knowledge and Attitudes" (OSAKA) questionnaire, which consists of questions about knowledge and attitudes on OSA. To maximize participation, email invitations were sent three times to the target audience. RESULTS: Out of 634 queried pulmonologists, 127 (20%) responded to the survey. The mean age of respondents was 45.4 ± 8.6 years. The respondents' years of specialty acquisition ranged from the 1980s to the 2010s. Additionally, 74 (58.3%) held a doctor's degree, and 96 (75.6%) worked in hospitals with a sleep center. Furthermore, 71 (55.9%) of the pulmonologists reported having experience with OSA patients. Pulmonologists with experience managing OSA patients had significantly higher knowledge and attitude scores compared to those without such experience. Interestingly, older respondents and those who completed their pulmonology training earlier had higher attitude scores. In addition, the knowledge score significantly correlated with responses to the five items of the attitude questionnaire. CONCLUSION: This study provides valuable insights into the knowledge and attitudes of Korean pulmonologists regarding OSA. The findings indicate that their knowledge levels are comparable to or better than those in previous studies. These results underscore the need for targeted educational programs and practical training, especially for younger pulmonologists, to enhance their proficiency in managing OSA and to encourage a more active role in its treatment.

Impact of lipopolysaccharide-induced acute lung injury in aged mice.

Study Aim: As the geriatric population rapidly expands, there has been a concurrent increase in elderly admissions to intensive care units (ICUs). Acute lung injury (ALI) is a prevalent reason for these admissions and carries poorer survival rates for the aged population compared to younger counterparts. The aging lung is subject to physiological, cellular, and immunological changes. However, our understanding of how aging impacts the clinical progression of ALI is limited. This study explored the effect of aging using a murine model of ALI. Methods: Female C57BL/6J mice, aged 7-8 wk (young) and 18 months (aged), were divided into four groups: young controls, aged controls, young with ALI (YL), and aged with ALI (AL). ALI was induced via intratracheal administration of lipopolysaccharide (LPS, 0.5 mg/kg). The animals were euthanized 72 h after LPS exposure. Results: The AL group exhibited a significantly increased wet/dry ratio compared to the other three groups, including the YL group. The bronchoalveolar lavage (BAL) fluid in the AL group had more cells overall, including more neutrophils, than the other groups. Inflammatory cytokines in BAL fluid showed similar trends. Histological analyses demonstrated more severe lung injury and fibrosis in the AL group than in the other groups. Increased transcription of senescence-associated secretory phenotype markers, including PAI-1 and MUC5B, was more prominent in the AL group than in the other groups. This trend was also observed in BAL samples from humans with pneumonia. Conclusions: Aging may amplify lung damage and inflammatory responses in ALI. This suggests that physicians should exercise increased caution in the clinical management of aged patients with ALI.

Effects of aging on accompanying intermittent hypoxia in a bleomycin-induced pulmonary fibrosis mouse model.

BACKGROUND/AIMS: Obstructive sleep apnea (OSA) is prevalent in older patients with idiopathic pulmonary fibrosis (IPF); however, it is underrecognized. OSA is characterized by intermittent hypoxia (IH) and sleep fragmentation. In this study, we evaluated the effects of IH in an older mouse model of bleomycin-induced lung fibrosis. METHODS: Bleomycin-induced mice (C57BL/6, female) were randomly divided into four groups of young vs. old and room air (RA)-exposed vs. IH-exposed. Mice were exposed to RA or IH (20 cycles/h, FiO2 nadir 7 ± 0.5%, 8 h/day) for four weeks. The mice were sacrificed on day 28, and blood, bronchoalveolar lavage (BAL) fluid, and lung tissue samples were obtained. RESULTS: The bleomycin-induced IH-exposed (EBI) older group showed more severe inflammation, fibrosis, and oxidative stress than the other groups. The levels of inflammatory cytokines in the serum and BAL fluid increased in the EBI group. Hydroxyproline levels in the lung tissue increased markedly in the EBI group. CONCLUSION: This study demonstrates the possible harmful impact of OSA in an elderly mouse model of lung fibrosis. This study further suggests that older patients with IPF and OSA may be more of a concern than younger patients with IPF. Further research is required in this area.

Associations among sleep-disordered breathing, sleep quality, and lung cancer in Korean patients.

PURPOSE: Intermittent hypoxia and sleep fragmentation, two main features of sleep-disordered breathing (SDB), have been shown to increase the aggressiveness of lung cancer, mainly in animal and in vitro studies. However, the association between SDB and lung cancer has not been well described in human studies. In this study, we investigated the associations among SDB, sleep quality, and lung cancer in Korean patients. METHODS: Patients with histologically diagnosed lung cancer performed a home sleep apnea test. Sleep questionnaires including the Epworth Sleepiness Scale (ESS), Insomnia Severity Index, and Pittsburgh Sleep Quality Index were also administered. Clinical information related to lung cancer was collected during the study. RESULTS: Sixty-nine patients were enrolled, 31 of whom were poor sleepers. The overall prevalence of SDB was 57% and that of moderate to severe SDB was 27%. Underlying chronic obstructive pulmonary disease (COPD) and smoking history were significantly more frequent in patients with moderate to severe SDB compared to patients without or with mild SDB. No significant differences were observed in the apnea-hypopnea index (AHI), oxygen desaturation index (ODI), or time with oxygen saturation < 90% (T90) according to cancer cell types, mutations, stages, and survival. However, small-cell lung cancer patients showed a trend toward higher AHI, ODI, and T90 values. CONCLUSION: The prevalence of SDB and proportion of poor sleepers were high in Korean patients with lung cancer. Paying more attention to sleep status may be helpful for patients with COPD, a smoking history, and small-cell lung cancer.

Monocyte distribution width (MDW) as a useful indicator for early screening of sepsis and discriminating false positive blood cultures.

BACKGROUND: Severe sepsis and septic shock are the leading cause of in-hospital death. As sepsis progresses, expression and activity of endogenous mediators of inflammation change. Early detection of biomarkers can play a role in sepsis screening and in improvement of patient outcomes. Recent studies suggest that increase in monocyte volume may be helpful in early detection of sepsis. Therefore, we evaluated the utility of monocyte distribution width (MDW) for the early assessment of sepsis compared with the blood culture and other inflammatory biomarkers. METHODS: Medical records of 1,404 patients (aged ≥19 years) who were admitted to the emergency department owing to clinically suspected infectious disease and requested blood cultures from Oct 2019 to Jan 2021 were reviewed. The patients were grouped based on Sepsis-3 criteria. They had undergone other laboratory tests to evaluate their clinical status. MDW was analyzed using DxH900 hematology analyzer (Beckman Coulter, Brea, California, USA). To determine the diagnostic performance of MDW, C-reactive protein (CRP), and procalcitonin (PCT) for sepsis, the area under the curve (AUC) of receiver operating characteristics curves and their sensitivity and specificity were measured. RESULTS: Among 1,404 patients, 520 patients were designated the sepsis group based on Sepsis-3 criteria. In the sepsis group, MDW value was 24.1 (median, IQR 21.6-28.1); AUC values for MDW, CRP, and PCT were 0.67 (95% CI, 0.64-0.69), 0.66 (95% CI, 0.63-0.68), and 0.75 (95% CI, 0.72-0.77), respectively. For diagnosis of the sepsis, the cut-off value of MDW was 21.7 (sensitivity 74% and specificity 54%). Measured values of MDW were higher for the blood culture positive group than that of the blood culture contamination group (P<0.001, 95% CI, -5.9 to -3.0) or blood culture negative group (P<0.001, 95% CI = -5.8 to -4.2). CONCLUSIONS: MDW is a new hematological parameter that is simultaneously calculated during complete blood cell counting by Beckman Coulter hematology analyzer. MDW is expected to serve as a useful indicator for early screening of sepsis in conjunction with CRP and PCT. MDW is especially useful for sepsis assessment in patients with a suspected infection. MDW can also assist in discriminating false positive blood cultures.

Simple Saliva Sample Collection for the Detection of SARS-CoV-2 Variants Compared With Nasopharyngeal Swab Sample.

CONTEXT.­: The use of saliva samples for diagnosis of SARS-CoV-2 infection offers several advantages, including ease of sample collection, feasibility of self-collection, and minimization of medical staff exposure to infection. The emergence of new SARS-CoV-2 variants has had an impact on the viral load of specimens and the results of real-time reverse transcription-polymerase chain reaction (rRT-PCR). OBJECTIVE.­: To compare nasopharyngeal swab and saliva samples for the diagnosis of SARS-CoV-2 using rRT-PCR. DESIGN.­: In this study, participants were recruited prospectively, and paired nasopharyngeal swab and saliva samples were collected simultaneously from each participant. After adding universal transport medium, RNA was extracted in an identical manner for both sample types, and samples were tested using rRT-PCR. In addition, samples with positive results were tested for SARS-CoV-2 variants. RESULTS.­: Of the 338 paired samples, 100 nasopharyngeal swab and 101 saliva samples tested positive for SARS-CoV-2. The rRT-PCR results of the saliva and nasopharyngeal swab samples showed a positive percent agreement of 95.0% (95% CI, 88.7%-98.4%), a negative percent agreement of 97.9% (95% CI, 95.2%-99.3%), and an overall percent agreement of 96.8% (95% CI, 94.3%-98.4%). SARS-CoV-2 was detected in the saliva samples of 6 participants with negative nasopharyngeal sample results. In addition, the sensitivity of saliva samples was similar to that of nasopharyngeal samples for detecting various SARS-CoV-2 variants, including the Omicron variant. CONCLUSIONS.­: Saliva samples can be used as an alternative to nasopharyngeal samples for convenient and effective detection of various SARS-CoV-2 variants.

Usefulness of monocyte distribution width and presepsin for early assessment of disease severity in COVID-19 patients.

Early predictors of severe coronavirus disease 2019 (COVID-19) would identify patients requiring intensive care. Recently, the monocyte distribution width (MDW) and presepsin level have been used for the early diagnosis of sepsis. Here, we assessed the utility of MDW and presepsin for the early assessment of COVID-19 severity. Eighty-seven inpatients with confirmed COVID-19 were enrolled and divided into 3 groups by the type of respiratory support: (1) mechanical ventilation or high-flow nasal cannula oxygen therapy (MVHF-OT), (2) conventional oxygen therapy, and (3) no oxygen therapy. We measured the complete blood count; MDW; erythrocyte sedimentation rate; and the levels of presepsin, C-reactive protein, procalcitonin, lactate dehydrogenase, ferritin, Krebs von den Lungen-6 (KL-6), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing antibody. Thirteen (14.9%) patients on MVHF-OT exhibited a significantly higher mortality and a longer hospital stay than did the others. The MDW and presepsin levels were significantly elevated on admission, and correlated with COVID-19 severity (both P < .001). Notably, only the MDW correlated significantly with symptoms in the no oxygen therapy group (P < .012). In the first week after admission, the MDW fell and no longer differed among the groups. The KL-6 level did not differ by disease severity at any time. Neutralizing antibodies were detected in 74 patients (91.4%) and the level of neutralization correlated significantly with COVID-19 severity (P < .001). The MDW and presepsin are useful indicators for early assessment of disease severity in COVID-19 patients.

Randomized Trial of Molnupiravir or Placebo in Patients Hospitalized with Covid-19.

BACKGROUND: Molnupiravir is an oral prodrug of ß-D-N4-hydroxycytidine, active against SARS-CoV-2 in vitro and in animal models. We report data from the phase 2 component of MOVe-IN, a clinical trial evaluating molnupiravir in patients hospitalized with Covid-19. METHODS: We conducted a randomized, placebo-controlled, double-blind phase 2/3 trial in patients 18 years old and older requiring in-hospital treatment for laboratory-confirmed Covid-19 with symptom onset 10 or fewer days before randomization. Participants were randomly assigned to placebo or molnupiravir 200 mg, 400 mg, or 800 mg (1:1:1:1 ratio), twice daily for 5 days. Primary end points were safety and sustained recovery (participant alive and either not hospitalized or medically ready for discharge) through day 29. RESULTS: Of 304 randomly assigned participants, 218 received at least one dose of molnupiravir and 75 of placebo. At baseline, 74.0% had at least one risk factor for severe Covid-19. Adverse events were reported in 121 of 218 (55.5%) molnupiravir-treated and 46 of 75 (61.3%) placebo-treated participants, with no apparent dose effect on adverse event rates and no evidence of hematologic toxicity based on prespecified adverse events. Of 16 confirmed deaths, most were in participants with severe Covid-19 (75.0%), with underlying comorbidities (87.5%), older than 60 years of age (81.3%), and/or symptom duration longer than 5 days (75.0%) at randomization. Median time to sustained recovery was 9 days in all groups, with similar day 29 recovery rates ranging from 81.5% to 85.2%. CONCLUSIONS: In this phase 2 trial of patients hospitalized with Covid-19, a 5-day course of molnupiravir up to 800 mg twice daily was not associated with dose-limiting side effects or adverse events, but did not demonstrate clinical benefit. (Funded by Merck Sharp & Dohme; ClinicalTrials.gov NCT04575584.)

Impacts of the COVID-19 pandemic on sleep center operations and sleep apnea treatment in Korea: A multicenter survey.

ABSTRACT: The coronavirus disease-2019 (COVID-19) pandemic has not only changed the lives of people around the world but also affected all areas of the healthcare system, including sleep medicine. However, no studies in Korea have investigated the status of domestic sleep centers and their challenges during the pandemic.An online survey was performed from December 2020 to January 2021. Hospitals that belonged to sleep-related academic societies and were considered well managed were included in this survey. The questionnaire focused on changes in sleep center operations, infection control policies, and patient treatment since the start of the COVID-19 pandemic. Telemedicine and future directions for sleep medicine services were also investigated.Of the 20 sleep centers that responded, 80% were at university hospitals with more than 500 inpatient beds. During the third wave of the COVID-19 pandemic in Korea (November-December 2020), the routine operating schedule of the sleep study room was reduced in 30% of the sleep centers compared to November-December 2019 (before COVID-19). The number of type 1 polysomnographies performed decreased in 85% of the sleep centers. In contrast, in-lab positive airway pressure (PAP) titrations decreased in 40%, remained unchanged in 35%, and increased in 25%. With respect to prescriptions, 30% of the sleep centers increased the number of prescriptions for auto-titrating continuous PAP. However, 60% of the sleep centers reported no change in the rate of fixed continuous PAP and auto-titrating continuous PAP prescriptions. All sleep centers that participated in this survey agreed that the need for documented infection control regulations will continue after the COVID-19 pandemic. Since the beginning of the pandemic, 30% of the centers have tried telemedicine. However, respondents expressed concern about telemedicine, citing a number of practical issues.Compared to countries where the COVID-19 pandemic was severe, Korea had less impact of COVID-19 on the sleep center operations and sleep apnea treatment. Infection and quality control in the sleep study room are important and inevitable issues, and regulation within each institution is necessary. Further research and discussion are needed regarding telemedicine and home sleep apnea test in Korea.

Serial Screening for SARS-CoV-2 in Rectal Swabs of Symptomatic COVID-19 Patients.

We used serial rectal swabs to investigate the amount and duration of virus secretion through the gastrointestinal tract and assessed the association between fecal shedding and gastrointestinal symptoms and to clarify the clinical usefulness testing rectal swabs. We enrolled ten adult patients hospitalized with symptomatic coronavirus disease 2019 (COVID-19). Respiratory and stool specimens were collected by physicians. The presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was confirmed using real-time reverse-transcription polymerase chain reaction. All ten patients had respiratory symptoms, six had diarrhea, and seven were positive for SARS-CoV-2 on rectal swabs. The viral loads in the respiratory specimens was higher than those in the rectal specimens, and no rectal specimens were positive after the respiratory specimens became negative. There was no association between gastrointestinal symptoms, pneumonia, severity, and rectal viral load. Rectal swabs may play a role in detecting SARS-CoV-2 in individuals with suspected COVID-19, regardless of gastrointestinal symptoms.

Cross-sectional survey on home mechanical ventilator use: major deficiencies in a home care system in South Korea.

BACKGROUND: Despite the increased use of home mechanical ventilation (HMV), data on home care services for HMV users in Asian countries are scarce. This study investigated the current status of HMV use in the Seoul metropolitan area. METHODS: This cross-sectional study involved three university-affiliated hospitals. Subjects who were receiving HMV at home for >3 months were included, and door-to-door visits were done to collect data (e.g., on devices, caregivers, and healthcare service use) from the subjects or their families. RESULTS: Among the 140 individuals who were initially screened, 38 adults and 26 children were finally enrolled; the duration of HMV use was 14.5 (8.8-37.5) months and 20.5 (7.0-28.0) months, respectively. Tracheostomy ventilation was performed in 36.8% of the adults and 61.5% of the children, and life-support ventilator in 55.3% and 96.2%, respectively. Regarding ancillary devices, 42.1% of the adults and 80.8% of the children had an oxygen monitoring device, while only one member of each group had a cough assist device. Among those with a tracheostomy, 64.3% of adults and 81.3% of children had an AMBU-bag. Reliance on a family member for care was determined in 65.8% of adults and 88.5% of children, but a home visit by a hospital nurse during the previous year occurred in only 26.3% of the adults and 3.8% of the children. Emergency incidents at home occurred in 39.5% of the adults and 50.0% of the children, with dyspnea being the most common cause. Out-of-pocket expenses tended to be higher in the tracheostomy (vs. non-tracheostomy) group and in children (vs. adults). CONCLUSIONS: Our study highlights the challenges faced by adults and children dependent on HMV, and their families. There is an urgent need for nationwide standardization of care for patients receiving HMV at home.

Utilization of pain and sedation therapy on noninvasive mechanical ventilation in Korean intensive care units: a multi-center prospective observational study.

BACKGROUND: The use of sedative drugs may be an important therapeutic intervention during noninvasive ventilation (NIV) in intensive care units (ICUs). The purpose of this study was to assess the current application of analgosedation in NIV and its impact on clinical outcomes in Korean ICUs. METHODS: Twenty Korean ICUs participated in the study, and data was collected on NIV use during the period between June 2017 and February 2018. Demographic data from all adult patients, NIV clinical parameters, and hospital mortality were included. RESULTS: A total of 155 patients treated with NIV in the ICUs were included, of whom 26 received pain and sedation therapy (sedation group) and 129 did not (control group). The primary cause of ICU admission was due to acute exacerbation of obstructed lung disease (45.7%) in the control group and pneumonia treatment (53.8%) in the sedation group. In addition, causes of NIV application included acute hypercapnic respiratory failure in the control group (62.8%) and post-extubation respiratory failure in the sedation group (57.7%). Arterial partial pressure of carbon dioxide (PaCO2) levels before and after 2 hours of NIV treatment were significantly decreased in both groups: from 61.9±23.8 mm Hg to 54.9±17.6 mm Hg in the control group (P<0.001) and from 54.9±15.1 mm Hg to 51.1±15.1 mm Hg in the sedation group (P=0.048). No significant differences were observed in the success rate of NIV weaning, complications, length of ICU stay, ICU survival rate, or hospital survival rate between the groups. CONCLUSIONS: In NIV patients, analgosedation therapy may have no harmful effects on complications, NIV weaning success, and mortality compared to the control group. Therefore, sedation during NIV may not be unsafe and can be used in patients for pain control when indicated.

The Effects of Chronic Intermittent Hypoxia in Bleomycin-Induced Lung Injury on Pulmonary Fibrosis via Regulating the NF-κB/Nrf2 Signaling Pathway.

BACKGROUND: Obstructive sleep apnea (OSA) is associated with pulmonary fibrosis. Chronic intermittent hypoxia (CIH) is considered to be a surrogate of OSA. However, its exact role in pulmonary fibrosis remains uncertain. Therefore, we investigated the mechanism underlying CIH-induced pulmonary fibrosis and the role of the anti-fibrotic agent in bleomycin (BLE) induced lung injury. METHODS: Mice were divided into eight groups: the normoxia (NOR), CIH, NOR plus BLE, CIH plus BLE, NOR plus pirfenidone (PF), CIH plus PF, NOR plus BLE and PF, and CIH plus BLE and PF groups. BLE was administered intratracheally on day 14 following CIH or NOR exposure. Subsequently, the mice were exposed to CIH or NOR for an additional 4 weeks. PF was administered orally on day 5 after BLE instillation once daily for 3 weeks. RESULTS: In the BLE-treated groups, CIH-induced more collagen deposition in lung tissues than NOR, and significantly increased hydroxyproline and transforming growth factor-ß expression. The CIH and BLE-treated groups showed increased lung inflammation compared to NOR or CIH groups. Following CIH with BLE treatment, nuclear factor-κB (NF-κB) protein expression was significantly increased, whereas nuclear factor-erythroid-related factor 2 (Nrf2) and heme oxygenase-1 protein levels were decreased. After PF treatment, NF-κB and Kelch-like ECH-associated protein 1 expression were suppressed, and Nrf2 expression was increased. CONCLUSION: CIH accelerated lung fibrosis in BLE-induced lung injury in mice, potentially by regulating the NF-κB/Nrf2 signaling pathway. Our results implicate PF as a potential therapeutic agent for treating pulmonary fibrosis in individuals with OSA and idiopathic pulmonary fibrosis.

Effects of chronic intermittent hypoxia caused by obstructive sleep apnea on lipopolysaccharide-induced acute lung injury.

AIM OF THE STUDY: Obstructive sleep apnea (OSA) is a common disease associated with significant morbidity and mortality. Sleep quality is an important issue; some patients with acute lung injury (ALI) have underlying OSA. However, the potential influences of OSA on ALI have not been reported until now. In this study, we evaluated the impact of preceding intermittent hypoxia (IH), a typical characteristic of OSA, on lipopolysaccharide (LPS)-induced ALI in a mouse model. METHODS: C57BL/6J mice were randomly divided into four groups: room air-control (RA-CTL), intermittent hypoxia-control (IH-CTL), room air-lipopolysaccharide (RA-LPS), and intermittent hypoxia-lipopolysaccharide (IH-LPS) groups. The mice were exposed to RA or IH (20 cycles/h, FiO2 nadir 7 ± 0.5%, 8 h/day) for 30 days. The LPS groups received intratracheal LPS on day 28. RESULTS: The IH-LPS group tended to exhibit more severe inflammation, fibrosis, and oxidative stress compared to the other groups, including the RA-LPS group. Total cell, neutrophil, and eosinophil counts in bronchoalveolar lavage fluid increased significantly in the IH-LPS group compared to the RA-LPS group. Compared to the RA-LPS group, the hydroxyproline level increased significantly in the IH-LPS group. In addition, the IH-LPS group exhibited significantly more terminal deoxynucleotidyl transferase dUTP nick end labeled-positive cells compared to the RA-LPS group. CONCLUSIONS: We found that prior IH may negatively impact LPS-induced ALI in a mouse model. This result suggests that ALI in patients with OSA may be more of a concern. Further research into the mechanisms underlying the effects of IH on ALI is needed.

Containment of a healthcare-associated COVID-19 outbreak in a university hospital in Seoul, Korea: A single-center experience.

BACKGROUND: Our hospital experienced the first healthcare-associated COVID-19 outbreak in Seoul at the time the first COVID-19 cases were confirmed in Korea. The first confirmed COVID-19 patient was a hospital personnel who was in charge of transferring patients inside our hospital. To contain the virus spread, we shutdown our hospital, and tested all inpatients, medical staff members, and employees. METHODS: We retrospectively analyzed the results of SARS-CoV-2 RT-PCR testing according to the contact history, occupation, and presence of respiratory symptoms. Closed-circuit television (CCTV) was reviewed in the presence of an epidemiologist to identify individuals who came into contact with confirmed COVID-19 patients. RESULTS: A total of 3,091 respiratory samples from 2,924 individuals were obtained. Among 2,924 individuals, two inpatients, and one caregiver tested positive (positivity rate, 0.1%). Although all confirmed cases were linked to a general ward designated for pulmonology patients, no medical staff members, medical support personnel, or employees working at the same ward were infected. Contact with confirmed COVID-19 cases was frequent among inpatients and medical support personnel. The most common contact area was the general ward for pulmonology patients and medical support areas, including clinical and imaging examination rooms. Finally, the total number of hospital-associated infections was 14, consisting of four diagnosed at our hospital and ten diagnosed outside the hospital. CONCLUSIONS: The robust control of the COVID-19 outbreak further minimized the transmission of SARS-CoV-2 in the hospital and local communities. However, there was also a debate over the appropriate period of hospital shutdown and testing of all hospital staff and patients. Future studies are required to refine and establish the in-hospital quarantine and de-isolation guidelines based on the epidemiological and clinical settings.

Association between triglyceride glucose index and obstructive sleep apnea risk in Korean adults: a cross-sectional cohort study.

BACKGROUND: Triglyceride glucose (TyG) index is a reliable marker of insulin resistance, which is linked to obstructive sleep apnea (OSA). However, the relationship between TyG index and OSA has not been adequately assessed. This study aimed to evaluate the association between TyG index and OSA. METHODS: TyG index was assessed in 180 (mean age: 48.6 ± 13.8 years; 73.9% male) consecutive Korean adults with suspected OSA admitted to the sleep clinic at St. Paul's Hospital between 2010 and 2012. The occurrence of more than 5 apnea-hypopnea index (AHI) events/h was used to define OSA. TyG index was calculated using the following equation: In [fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2]. All participants were grouped according to TyG index tertiles. Multivariate logistic regression analysis was used to determine factors associated with increased OSA risk. RESULTS: The overall prevalence of OSA in study participants was determined to be 83.9%. The prevalence of OSA increased (I [lowest]: 71.6%; II: 88.7%; III [highest]: 91.4%), and lowest peripheral oxygen saturation (SpO2) levels decreased (I: 83.3 ± 8.5%; II: 79.9 ± 8.7%; III: 79.0 ± 8.3%), as TyG index tertile increased (P < 0.05). TyG index was correlated with AHI (r = 0.179) and lowest SpO2 (r = - 0.188) (P < 0.05, respectively). Univariate linear regression analysis revealed an association between TyG and AHI (ß = 10.084; P = 0.016). Multivariate logistic regression analysis showed that TyG index (odds ratio [OR]: 3.348; 95% confidence interval [CI]: 1.081-10.372), age ≥ 55 years (OR: 5.426; 95% CI: 1.642-17.935), and obesity (OR: 3.801; 95% CI: 1.468-9.842) were associated with increased OSA risk (all P < 0.05). The optimal TyG index cut-off value for predicting OSA was 8.83 (sensitivity: 61.6%; specificity: 69.0%; area under the curve: 0.688; P = 0.001). The predictive value of the OSA cut-off value improved when age ≥ 55 years and obesity were considered. CONCLUSION: Increased TyG index was independently associated with increased OSA risk.

Non-invasive ventilation for acute respiratory failure: pressure support ventilation vs. pressure-controlled ventilation.

BACKGROUND: The best ventilator mode for patients receiving non-invasive ventilation (NIV) has not been clarified. This study compared the effectiveness of two pressure-targeted modes, i.e., pressure support ventilation (PSV) and pressure-controlled ventilation (PCV), in patients receiving NIV. METHODS: This was a prospective multicentre observational study of NIV use for acute respiratory failure (ARF) in adult patients. We compared the two pressure-targeted modes in terms of NIV success and complication rates. RESULTS: Among 176 patients receiving NIV, 88 patients were included in the study (PCV mode, n=29; PSV mode, n=59). The study population had a median age of 73.0 years and median body mass index of 20.8 kg/m2. The applied inspiratory positive airway pressure (IPAP) was higher in patients with PCV than in those with PSV [18.0 cmH2O (15.0-20.5 cmH2O) vs. 15.0 cmH2O (12.0-17.0 cmH2O), respectively, P=0.001]. More patients with PCV received sedatives and experienced dry mouth than those with PSV; however, the incidences of large leaks were low in both groups (n=5 vs. n=2, respectively). With regard to NIV outcomes, 24 (27.2%) patients experienced NIV failure and 13 (14.8%) died in hospital. PSV mode was a significant factor for NIV success [odds ratio (OR), 2.303; 95% confidence interval (CI), 1.216 to 4.360] in multivariate analyses and this association remained significant in a 1:1 matched cohort (n=29 per group). CONCLUSIONS: In contrast to PCV mode, PSV mode was significantly associated with NIV success in the intensive care unit setting, particularly when large leaks were not a major concern. Nevertheless, further well-designed multicenter, protocol-driven randomized controlled trials are warranted.