In patients on mechanical ventilation, positive end-expiratory pressure (PEEP) can decrease cardiac output through a decrease in cardiac preload and/or an increase in right ventricular afterload. Increase in central blood volume by fluid administration or passive leg raising (PLR) may reverse these phenomena through an increase in cardiac preload and/or a reopening of closed lung microvessels. We hypothesized that a transient decrease in PEEP (PEEP-test) may be used as a test to detect volume responsiveness.
Mechanically ventilated patients with PEEP ≥ 10 cmH2O (\"high level\") and without spontaneous breathing were prospectively included. Volume responsiveness was assessed by a positive PLR-test, defined as an increase in pulse-contour-derived cardiac index (CI) during PLR ≥ 10%. The PEEP-test consisted in reducing PEEP from the high level to 5 cmH2O for one minute. Pulse-contour-derived CI (PiCCO2) was monitored during PLR and the PEEP-test.
We enrolled 64 patients among whom 31 were volume responsive. The median increase in CI during PLR was 14% (11-16%). The median PEEP at baseline was 12 (10-15) cmH2O and the PEEP-test resulted in a median decrease in PEEP of 7 (5-10) cmH2O, without difference between volume responsive and unresponsive patients. Among volume responsive patients, the PEEP-test induced a significant increase in CI of 16% (12-20%) (from 2.4 ± 0.7 to 2.9 ± 0.9 L/min/m2, p < 0.0001) in comparison with volume unresponsive patients. In volume unresponsive patients, PLR and the PEEP-test increased CI by 2% (1-5%) and 6% (3-8%), respectively. Volume responsiveness was predicted by an increase in CI > 8.6% during the PEEP-test with a sensitivity of 96.8% (95% confidence interval (95%CI): 83.3-99.9%) and a specificity of 84.9% (95%CI 68.1-94.9%). The area under the receiver operating characteristic curve of the PEEP-test for detecting volume responsiveness was 0.94 (95%CI 0.85-0.98) (p < 0.0001 vs. 0.5). Spearman\'s correlation coefficient between the changes in CI induced by PLR and the PEEP-test was 0.76 (95%CI 0.63-0.85, p < 0.0001).
A CI increase > 8.6% during a PEEP-test, which consists in reducing PEEP to 5 cmH2O, reliably detects volume responsiveness in mechanically ventilated patients with a PEEP ≥ 10 cmH2O. Trial registration ClinicalTrial.gov (NCT 04,023,786). Registered July 18, 2019. Ethics Committee approval CPP Est III (N° 2018-A01599-46).

A 50-year-old patient with epilepsy, hypertension, loud snoring, recent 50-lb weight gain, and abrupt awakenings with a feeling of breathlessness but no headaches or excessive daytime sleepiness presented with concerns. What would you do next?

OBJECTIVE: Idiopathic pulmonary fibrosis (IPF) is a disease with a poor prognosis and a highly variable course. Pathologically increased ventilation-accessible by functional CT-is discussed as a potential predecessor of lung fibrosis. The purpose of this feasibility study was to investigate whether increased regional ventilation at baseline CT and morphological changes in the follow-up CT suggestive for fibrosis indeed occur in spatial correspondence.
METHODS: In this retrospective study, CT scans were performed at two time points between September 2016 and November 2020. Baseline ventilation was divided into four categories ranging from low, normal to moderately, and severely increased (C1-C4). Correlation between baseline ventilation and volume and density change at follow-up was investigated in corresponding voxels. The significance of the difference of density and volume change per ventilation category was assessed using paired t-tests with a significance level of p ≤ 0.05. The analysis was performed separately for normal (NAA) and high attenuation areas (HAA).
RESULTS: The study group consisted of 41 patients (73 ± 10 years, 36 men). In both NAA and HAA, significant increases of density and loss of volume were seen in areas of severely increased ventilation (C4) at baseline compared to areas of normal ventilation (C2, p < 0.001). In HAA, morphological changes were more heterogeneous compared to NAA.
CONCLUSIONS: Functional CT assessing the extent and distribution of lung parenchyma with pathologically increased ventilation may serve as an imaging marker to prospectively identify lung parenchyma at risk for developing fibrosis.
CONCLUSIONS: • Voxelwise correlation of serial CT scans suggests spatial correspondence between increased ventilation at baseline and structural changes at follow-up. • Regional assessment of pathologically increased ventilation at baseline has the potential to prospectively identify tissue at risk for developing fibrosis. • Presence and extent of pathologically increased ventilation may serve as an early imaging marker of disease activity.

India has been engaged in tuberculosis (TB) control activities for over 50 years and yet TB continues to remain India\'s important public health problem. The present study was conducted to compare the performance of GeneXpert MTB/RIF (GXpert) assay with composite reference standard in diagnosing cases of tubercular pleural effusion (TPE) and to evaluate the reliability of rifampicin resistance. A cross-sectional study was performed in a Department of Medicine of a rural teaching tertiary care hospital in central India. In all consecutive patients with pleural effusion on chest radiograph presenting to Department of Medicine, GXpert assay and composite reference standard was performed to evaluate the diagnostic accuracy of GXpert assay for detecting TPE in comparison to composite reference standard. Standard formulae were used to calculate the sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV), positive likelihood ratios (LR+) and negative likelihood ratios (LR-). Mc-Nemar\'s test was applied to compare variables. All comparisons were two-tailed. We considered the difference to be statistically significant if the P value was less than 0.05. The sensitivity of the GXpert assay in diagnosing TPE was 16.6% among 158 study participants, the specificity was 100% and diagnostic accuracy was 52.5% which was statistically significant (p value < 0.05). It had a PPV of 100% (95%CI: 88.3% - 100%) and a NPV of 47.5% (95%CI: 39.3% - 55.7%). The LR+ and LR-were 23.5 (95%CI: 1.43-38.6) and 0.83 (95%CI: 0.76-0.91) respectively. GXpert assay has a very high specificity in diagnosing TPE but has a low sensitivity. In comparison to composite reference standard Thus its clinical utility is limited when used as a standalone test. A physician\'s clinical acumen in combination with routine pleural fluid analysis should be the key factor in the diagnosis of TPE in clinically and radiologically suspected patients, especially in high TB burden countries.

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The Japanese Respiratory Society (JRS) has recommended spirometry for the diagnosis of respiratory diseases. It is indispensable for the confirmation of airflow obstruction by spirometry in chronic obstructive pulmonary disease (COPD) diagnosis. However, the coronavirus disease 2019 (COVID-19) pandemic has made it difficult for many clinics to perform spirometry as it may lead to possible aerosol infections. Thus, the diagnosis of COPD, especially in the early stage, has become difficult. To overcome this situation, JRS issued a \"Flowchart of Working Diagnosis and Management of COPD during the COVID-19 Pandemic\". This flowchart may help physicians provisionally diagnose COPD patients without performing spirometry, offering them appropriate intervention even in epidemic and pandemic situations.

Noninvasive sampling of the distal airspace in patients with acute respiratory distress syndrome (ARDS) has long eluded clinical and translational researchers. We recently reported that fluid collected from heat moisture exchange (HME) filters closely mirrors fluid directly aspirated from the distal airspace. In the current study, we sought to determine fluid yield from different HME types, optimal HME circuit dwell time, and reliability of HME fluid in reflecting the distal airspace. We studied fluid yield from four different filter types by loading increasing volumes of saline and measuring volumes of fluid recovered. We collected filters after 1, 2, and 4 h of dwell time for measurement of fluid volume and total protein from 13 subjects. After identifying 4 h as the optimal dwell time, we measured total protein and IgM in HME fluid from 42 subjects with ARDS and nine with hydrostatic pulmonary edema (HYDRO). We found that the fluid yield varies greatly by filter type. With timed sample collection, fluid recovery increased with increasing circuit dwell time with a median volume of 2.0 mL [interquartile range (IQR) 1.2-2.7] after 4 h. Total protein was higher in the 42 subjects with ARDS compared with nine with HYDRO [median 708 µg/mL (IQR 244-2017) vs. 364 µg/mL (IQR 136-578), P = 0.047], confirming that total protein concentration in HME is higher in ARDS compared with hydrostatic edema. These studies establish a standardized HME fluid collection protocol and confirm that HME fluid analysis is a novel noninvasive tool for the study of the distal airspace in ARDS.

COVID 19 pandemic has brought about a sea change in health care practices across the globe. All specialities have changed their way of working during the pandemic. In this study, we evaluated the impact of COVID-19 on the practice of interventional pulmonology at our centre. All interventional pulmonology procedures done during the three months after implementation of lockdown were evaluated retrospectively for patient demographics, clinical diagnosis, indication for procedure and diagnostic accuracy. The changes in practices, additional human resources requirement, the additional cost per procedure and impact on resident training were also assessed. Procedures done during the month of January 2020 were used as controls for comparison. Twenty-two flexible bronchoscopies (75.8%), four semirigid thoracoscopies (13.7%) and three EBUS-TBNAs (10.3%) were carried out during three month lockdown period as compared to 174 during January 2020. Twenty-three of the procedures were for the diagnostic indication (79%), and six were therapeutic (20.6%). The diagnostic yield in suspected neoplasm was 100% while for suspected infections was 58.3%. The percentage of independent procedures being done by residents reduced from 45.4% to 0%. The workforce required per procedure increased from 0.75 to 4-8, and the additional cost per procedure came out to be 135 USD. To conclude, COVID 19 has impacted the interventional pulmonology services in various ways and brought about a need to reorganize the services, while also thinking of innovative ideas to reduce cost without compromising patient safety.

Interventional treatment of emphysema offers a wide range of surgical and endoscopic options for patients with advanced disease. Multidisciplinary collaboration of pulmonology, thoracic surgery, and imaging disciplines in patient selection, therapy, and follow-up ensures treatment quality. The present joint statement describes the required structural and quality prerequisites of treatment centres. This is a translation of the German article \"Positionspapier der Deutschen Gesellschaft für Pneumologie und Beatmungsmedizin und der Deutschen Gesellschaft für Thoraxchirurgie in Kooperation mit der Deutschen Röntgengesellschaft: Strukturvoraussetzungen von Zentren für die interventionelle Emphysemtherapie\" Pneumologie. 2020;74:17-23.

OBJECTIVE: The purpose of the present study was to investigate the values of the serum (1,3)-β-D-glucan test (G test) alone, the galactomannan test (GM test) alone, and their combination in the diagnosis of invasive fungal rhinosinusitis (IFRS).
METHODS: The present study retrospectively analysed the clinical data of 98 patients who were preliminarily diagnosed with \"space-occupying lesions in nose\". Of these 98 patients, 88 received the G test, 55 received the GM test, and 45 received both. A pathology analysis was used as the gold standard to diagnose IFRS. All data were analysed using SPSS 19.0.
RESULTS: The sensitivities (Se) of the G and GM tests alone were 60.0% and 28.6%, respectively, whereas the specificities (Sp) were 92.3% and 93.8%, respectively. Moreover, the positive predictive values (PPV) of the G and GM tests alone were 50.0% and 40.0%, respectively, and the negative predictive values (NPV) were 94.7% and 90.0%, respectively. In addition, the diagnostic odds ratios (DOR) were 18.0 and 6.0, respectively, and the Kappa values were 0.48 (P < 0.05) and 0.25 (P > 0.05), respectively. When the G and GM tests were parallel combined, the Se was 66.7%, the Sp was 92.3%, the PPV was 57.1%, the NPV was 94.7%, the DOR was 24.0, and the Kappa value was 0.55 (P < 0.05). The present study was unable to evaluate the serial diagnosis due to the lack of patients testing positive.
CONCLUSIONS: The G/GM tests exhibited low Se and PPV when used to diagnose IFRS, while high Sp and NPV. Parallel diagnosis improved the diagnostic Se and DOR values.