The Association between Mortality and the Oxygen Saturation and Fraction of Inhaled Oxygen in Patients Requiring Oxygen Therapy due to COVID-19–Associated Pneumonia / 결핵및호흡기질환

Background@#The coronavirus disease (COVID-19) can manifest in a range of symptoms, including both asymptomatic systems which appear nearly non-existent to the patient, all the way to the development of acute respiratory distress syndrome (ARDS). Specifically, COVID-19–associated pneumonia develops into ARDS due to the rapid progression of hypoxia, and although arterial blood gas analysis can assist in halting this deterioration, the current environment provided by the COVID-19 pandemic, which has led to an overall lack of medical resources or equipment, has made it difficult to administer such tests in a widespread manner. As a result, this study was conducted in order to determine whether the levels of oxygen saturation (SpO2) and the fraction of inhaled oxygen (FiO2) (SF ratio) can also serve as predictors of ARDS and the patient’s risk of mortality. @*Methods@#This was a retrospective cohort study conducted from February 2020 to Mary 2020, with the study’s subjects consisting of COVID-19 pneumonia patients who had reached a state of deterioration that required the use of oxygen therapy. Of the 100 COVID-19 pneumonia cases, we compared 59 pneumonia patients who required oxygen therapy, divided into ARDS and non-ARDS pneumonia patients who required oxygen, and then investigated the different factors which affected their mortality. @*Results@#At the time of admission, the ratios of SpO2, FiO2, and SF for the ARDS group differed significantly from those of the non-ARDS pneumonia support group who required oxygen (p<0.001). With respect to the predicting of the occurrence of ARDS, the SF ratio on admission and the SF ratio at exacerbation had an area under the curve which measured to be around 85.7% and 88.8% (p<0.001). Multivariate Cox regression analysis identified that the SF ratio at exacerbation (hazard ratio [HR], 0.916; 95% confidence interval [CI], 0.846–0.991; p=0.029) and National Early Warning Score (NEWS) (HR, 1.277; 95% CI, 1.010–1.615; p=0.041) were significant predictors of mortality. @*Conclusion@#The SF ratio on admission and the SF ratio at exacerbation were strong predictors of the occurrence of ARDS, and the SF ratio at exacerbation and NEWS held a significant effect on mortality.

Clinical Characteristics of Community-Acquired Viridans Streptococcal Pneumonia / 결핵및호흡기질환

BACKGROUND: Viridans streptococci (VS) are a large group of streptococcal bacteria that are causative agents of community-acquired respiratory tract infection. However, data regarding their clinical characteristics are limited. The purpose of the present study was to investigate the clinical and radiologic features of community-acquired pneumonia (CAP) with or without parapneumonic effusion caused by VS. METHODS: Of 455 consecutive CAP patients with or without parapneumonic effusion, VS were isolated from the blood or pleural fluid in 27 (VS group, 5.9%) patients. Streptococcus pneumoniae was identified as a single etiologic agent in 70 (control group) patients. We compared various clinical parameters between the VS group and the control group. RESULTS: In univariate analysis, the VS group was characterized by more frequent complicated parapneumonic effusion or empyema and bed-ridden status, lower incidences of productive cough, elevated procalcitonin (>0.5 ng/mL), lower age-adjusted Charlson comorbidity index score, and more frequent ground glass opacity (GGO) or consolidation on computed tomography (CT) scans. Multivariate analysis demonstrated that complicated parapneumonic effusion or empyema, productive cough, bed-ridden status, and GGO or consolidation on CT scans were independent predictors of community-acquired respiratory tract infection caused by VS. CONCLUSION: CAP caused by VS commonly presents as complicated parapneumonic effusion or empyema. It is characterized by less frequent productive cough, more frequent bed-ridden status, and less common CT pulmonary parenchymal lesions. However, its treatment outcome and clinical course are similar to those of pneumococcal pneumonia.

Prognostic Value of Serum Growth Differentiation Factor-15 in Patients with Chronic Obstructive Pulmonary Disease Exacerbation / 결핵및호흡기질환

BACKGROUND: Information regarding prognostic value of growth differentiation factor 15 (GDF-15) and heart-type fatty acid-binding protein (H-FABP) in patients with chronic obstructive pulmonary disease (COPD) exacerbation is limited. The aim of this study was to investigate whether serum levels of GDF-15 and H-FABP predict an adverse outcome for COPD exacerbation. METHODS: Clinical variables, including serum GDF-15 and H-FABP levels were compared in prospectively enrolled patients with COPD exacerbation that did or did not experience an adverse outcome. An adverse outcome included 30-day mortality and need for endotracheal intubation or inotropic support. RESULTS: Ninety-seven patients were included and allocated into an adverse outcome (n=10) or a control (n=87) group. Frequencies of mental change and PaCO2>37 mm Hg were significantly higher in the adverse outcome group (mental change: 30% vs. 6%, p=0.034 and PaCO2>37 mm Hg: 80% vs. 22%, p1,600 pg/mL) was more common in the adverse outcome group (80% vs. 43%, p=0.041). However, serum H-FABP level and frequency of serum H-FABP elevation (>755 pg/mL) did not differ between the two groups. Multivariate analysis showed that an elevated serum GDF-15 and PaCO2>37 mm Hg were significant predictors of an adverse outcome (odds ratio [OR], 25.8; 95% confidence interval [CI], 2.7-243.8; p=0.005 and OR, 11.8; 95% CI, 1.2-115.3; p=0.034, respectively). CONCLUSION: Elevated serum GDF-15 level and PaCO2>37 mm Hg were found to predict an adverse outcome independently in patients with COPD exacerbation, suggesting the possibility that serum GDF-15 could be used as a prognostic biomarker of COPD exacerbation.

Clinical Utility of CT-Based Bronchial Aspirate TB-PCR for the Rapid Diagnosis of Pleural Tuberculosis / 결핵및호흡기질환

BACKGROUND: Thoracoscopic pleural biopsy is often required for rapid and confirmative diagnosis in patients with suspected pleural tuberculosis (PL-TB). However, this method is more invasive and costly than its alternatives. Therefore, we evaluated the clinical utility of the chest computed tomography (CT)-based bronchial aspirate (BA) TB-polymerase chain reaction (PCR) test in such patients. METHODS: Bronchoscopic evaluation was performed in 54 patients with presumptive PL-TB through diagnostic thoracentesis but without a positive result of sputum acid-fast bacilli (AFB) smear, pleural fluid AFB smear, or pleural fluid TB-PCR test. Diagnostic yields of BA were evaluated according to the characteristics of parenchymal lesions on chest CT. RESULTS: Chest radiograph and CT revealed parenchymal lesions in 25 (46%) and 40 (74%) of 54 patients, respectively. In cases with an absence of parenchymal lesions on chest CT, the bronchoscopic approach had no diagnostic benefit. BA TB-PCR test was positive in 21 out of 22 (95%) patients with early-positive results. Among BA results from 20 (37%) patients with patchy consolidative CT findings, eight (40%) were AFB smear-positive, 18 (90%) were TB-PCR-positive, and 19 (95%) were culture-positive. CONCLUSION: The BA TB-PCR test seems to be a satisfactory diagnostic modality in patients with suspected PL-TB and patchy consolidative CT findings. For rapid and confirmative diagnosis in these patients, the bronchoscopic approach with TB-PCR may be preferable to the thoracoscopy.

Sensitivity of Whole-Blood Interferon-Gamma Release Assay According to the Severity and the Location of Disease in Patients with Active Tuberculosis / 결핵및호흡기질환

BACKGROUND: The clinical manifestation of M. tuberculosis infection ranges from asymptomatic latent infection, to focal forms with minimal symptoms and low bacterial burdens, and finally to advanced tuberculosis (TB) with severe symptoms and high bacillary loads. We investigated the diagnostic sensitivity of the whole-blood interferon-gamma release assay according to the wide spectrum of clinical phenotypes. METHODS: In patients diagnosed with active TB that underwent QuantiFERON(R) (QFT) testing, the QFT results were compared with patients known to be infected with pulmonary tuberculosis (P-TB) and extra-pulmonary TB (EP-TB). In addition, the results of the QFT test were further analyzed according to the radiographic extent of disease in patients with P-TB and the location of disease in patients with EP-TB. RESULTS: There were no statistical differences in the overall distribution of QFT results between 177 patients with P-TB and 84 patients with EP-TB; the positive results of QFT test in patients with P-TB and EP-TB were 70.1% and 64.3%, respectively. Among patients with P-TB, patients with mild extents of disease showed higher frequency of positive results of QFT test than that of patients with severe form (75.2% vs. 57.1%, respectively; p=0.043) mainly due to an increase of indeterminate results in severe P-TB. Patients with TB pleurisy showed lower sensitivity by the QFT test than those with tuberculous lymphadenitis (48.8% vs. 78.8%, respectively; p=0.019). CONCLUSION: Although QFT test showed similar results between overall patients with P-TB and EP-TB, individual sensitivity was different according to the radiographic extent of disease in P-TB and the location of disease in EP-TB.

The clinical and microbial characteristics of healthcare-associated pneumonia / 대한내과학회지

BACKGROUND/AIMS: Healthcare-associated pneumonia (HCAP) occurs outside hospitals, but its characteristics are similar to those of hospital-acquired pneumonia (HAP). We evaluated the clinical and microbial characteristics of HCAP in Korea. METHODS: Of 130 subjects with suspected pneumonia, 49 were classified as HCAP and 81 as HAP. We retrospectively examined the clinical presentations, outcomes, pathogens, and drug resistance rates of Pseudomonas aeruginosae in both groups. RESULTS: The clinical presentations, including the symptoms and laboratory findings, at the time of hospitalization were comparable in both groups. The hospital mortalities of HCAP (28.6%) and HAP (34.6%) did not differ significantly; the length of the hospital stay was similar for all of the survivors (14 vs. 17 days, respectively). Of the identified pathogens, methicillin-resistant Staphylococcus aureus was significantly less common in HCAP than in HAP (two vs. 18 cases, respectively, p<0.01), whereas Klebsiella pneumoniae was more common in HCAP (five vs. zero cases, respectively, p<0.01). The frequency of other Gram-negative rods was similar in both groups. The rate of resistance to antibiotics in P. aeruginosae in both groups was substantial, with the highest resistant rate to ciprofloxacin (50% and 61.5% in HCAP and HAP, respectively). CONCLUSIONS: Although the clinical features and outcomes of HCAP were comparable to those of HAP in the study population, the frequency of methicillin-resistant S. aureus was significantly lower in HCAP compared to HAP.

Comparisons of Clinical Characteristics and Outcomes in COPD Patients Hospitalized with Community-acquired Pneumonia and Acute Exacerbation / 결핵및호흡기질환

BACKGROUND: Data comparing the clinical characteristics and outcomes in chronic obstructive pulmonary disease (COPD) patients hospitalized with community-acquired pneumonia (CAP-COPD) and acute exacerbation (AE-COPD) are very limited. METHODS: Eighty episodes of hospitalization in 65 CAP-COPD patients, and 111 episodes of hospitalization in 82 AE-COPD patients were included in this study. The baseline characteristics, clinical presentations, potential bacterial pathogens and clinical outcomes in these patients were retrospectively reviewed and compared. RESULTS: No significant differences were found between the two groups in parameters related to COPD and co-morbidities, except a higher rate of male among CAP-COPD patients. Clinical presentations by symptoms and laboratory findings on admission were significantly more severe in CAP-COPD patients, who showed higher rates of fever and crepitation, but less wheezing than AE-COPD patients. S. pneumoniae and P. aeruginosae were the most common bacterial pathogens in both groups. With no difference in the overall hospital mortality between both groups, the mean length of hospital stay was significantly longer in the CAP-COPD patients than in AE-COPD patients (15.3 vs. 9.8 days, respectively, p<0.01). Additional analysis on CAP-COPD patients showed that systemic steroid use did not influence the length of hospital stay. CONCLUSION: Although there was no significant difference in bacterial pathogens and overall hospital mortality between the two groups, CAP-COPD patients had more severe clinical symptoms and laboratory findings at presentation, and longer hospital stay than AE-COPD patients.

Comparisons of Clinical Characteristics and Outcomes in COPD Patients Hospitalized with Community-acquired Pneumonia and Acute Exacerbation / 결핵및호흡기질환

BACKGROUND: Data comparing the clinical characteristics and outcomes in chronic obstructive pulmonary disease (COPD) patients hospitalized with community-acquired pneumonia (CAP-COPD) and acute exacerbation (AE-COPD) are very limited. METHODS: Eighty episodes of hospitalization in 65 CAP-COPD patients, and 111 episodes of hospitalization in 82 AE-COPD patients were included in this study. The baseline characteristics, clinical presentations, potential bacterial pathogens and clinical outcomes in these patients were retrospectively reviewed and compared. RESULTS: No significant differences were found between the two groups in parameters related to COPD and co-morbidities, except a higher rate of male among CAP-COPD patients. Clinical presentations by symptoms and laboratory findings on admission were significantly more severe in CAP-COPD patients, who showed higher rates of fever and crepitation, but less wheezing than AE-COPD patients. S. pneumoniae and P. aeruginosae were the most common bacterial pathogens in both groups. With no difference in the overall hospital mortality between both groups, the mean length of hospital stay was significantly longer in the CAP-COPD patients than in AE-COPD patients (15.3 vs. 9.8 days, respectively, p<0.01). Additional analysis on CAP-COPD patients showed that systemic steroid use did not influence the length of hospital stay. CONCLUSION: Although there was no significant difference in bacterial pathogens and overall hospital mortality between the two groups, CAP-COPD patients had more severe clinical symptoms and laboratory findings at presentation, and longer hospital stay than AE-COPD patients.