Clinical Utility of Surgical Lung Biopsy for Patients with Acute Respiratory Distress Syndrome: A Systematic Review and Meta-Analysis.

BACKGROUND: Surgical lung biopsy (SLB) is performed in patients with acute respiratory distress syndrome (ARDS); however, its clinical utility remains unclear. OBJECTIVES: We categorized the pathological diagnoses and investigated the predictive value for short-term mortality. METHOD: Three electronic databases (MEDLINE, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov) were searched for the included studies. The QUADAS-2 was used to evaluate the risk of bias and its applicability. The types and populations of pathological diagnoses were investigated. The pooled sensitivity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (DOR) were estimated at a fixed specificity. Hierarchical summary receiver operating characteristic curves were drawn. RESULTS: A total of 16 studies that enrolled 758 patients were included. The pathological diagnoses were as follows: diffuse alveolar damage (DAD) 29.9%; infection 24.7%; interstitial lung disease 17.2%; malignancy 3.6%; cardiovascular disease 3.6%; drug toxicity 2.3%; connective tissue disease 2.2%; allergic disease 1.1%; and nonspecific diagnosis 15.4%. To predict short-term mortality, 13 studies that enrolled 613 patients used DAD as an index test and recorded a mortality rate of 56.9% (349 of 613 patients). A total of 3 studies that used index tests other than DAD were excluded. The pooled sensitivity, fixed specificity, LR+, LR-, and DOR were 0.46 (95% confidence interval [CI]: 0.29-0.56), 0.69, 1.48 (95% CI: 0.92-1.81), 0.78 (95% CI: 0.63-1.03), and 1.90 (95% CI: 0.89-2.86), respectively. CONCLUSIONS: SLB is unlikely to provide a specific diagnosis and should not be recommended for confirming DAD or predicting ARDS prognosis.

Serum Krebs von den Lungen-6 levels are associated with mortality and severity in patients with coronavirus disease 2019.

BACKGROUND: The serum Krebs von den Lungen-6 (KL-6) level is a predictive factor for acute respiratory distress syndrome (ARDS). The development of ARDS has been reported in patients with coronavirus disease 2019 (COVID-19). This study aimed to determine whether serum KL-6 levels are associated with mortality and severity in patients with COVID-19. METHODS: Among 361 Japanese patients with COVID-19 who were hospitalized at Kanagawa Cardiovascular and Respiratory Center between February 2020 and December 2020, 356 patients with data on serum KL-6 levels were enrolled and their medical records were retrospectively analyzed. RESULTS: A negative correlation was observed between KL-6 levels and the ratio of the arterial partial pressure of oxygen to the fraction of inspired oxygen on admission. The KL-6 levels on admission and the maximal KL-6 levels were higher in patients with severe disease (n = 60) than in those with nonsevere disease (n = 296). Furthermore, the maximal KL-6 levels were higher in nonsurvivors (n = 6) than in survivors (n = 350). In nonsurvivors, the KL-6 levels increased as the disease progressed. The optimal cutoff value of the maximal KL-6 level for discriminating between survivors and nonsurvivors was 684 U/mL, with a sensitivity of 83.3%, a specificity of 90.5%, and an area under the curve of 0.89. CONCLUSIONS: The serum KL-6 level was associated with disease severity. Patients with KL-6 levels ≥684 U/mL had a significantly poorer outcome than those with KL-6 levels <684 U/mL.

Clinical characteristics of Japanese patients with moderate to severe COVID-19.

INTRODUCTION: Although several reports on the risk factors for severe disease of COVID-19 already exist, reports on effective early indicators are still limited, especially from Japan. This study was conducted to clarify the patient's characteristics whose disease progressed to severe status. METHODS: The medical records of all consecutive 300 Japanese patients hospitalized at our institution between February and November 2020 were retrospectively reviewed. The clinical characteristics were evaluated to compare between mild (no oxygen needed), moderate (oxygen needs of 1-4 L/min), and severe diseases (oxygen needs of 5 L/min or more). RESULTS: The median age was 68 years old, with 123 (41.0%) males and 177 (59.0%) females. Of these, 199 patients (66.3%), 55 patients (18.3%), 46 patients (15.3%) patients were in the mild disease, moderate disease, severe disease groups, respectively. Patients with severe disease were more likely to be older, have more comorbidities, and tended to have higher body mass index. In laboratory data, lymphocyte count, levels of C-reactive protein (CRP), LDH, and AST on admission were significantly associated with the severity. In multivariate analysis, age and CRP were the independent risk factors for severe disease (OR = 1.050, 1.130, respectively). The optimal cut-off value for age was 74 years old and that for CRP was 3.15 mg/dL. CONCLUSIONS: Age and CRP were independently associated with disease severity of COVID-19 in multivariate analysis. Additionally, the numbers of underlying disease, lymphocyte count, and inflammatory markers such as LDH and D-dimer may also be related to disease severity.