The relation of lactate level and carbon dioxide pressure discrepancies between transcutaneous and arterial measurements.

Introduction: Partial carbondioxide pressure of the arterial blood (PaCO2) is used to evaluate alveolar ventilation. Transcutaneous carbon dioxide pressure (TcCO2) monitoring has been developed as a non-invasive (NIV) alternative to arterial blood gas analysis (ABG). Studies have shown that decreased tissue perfusion leads to increased carbondioxide (CO2). The use of transcutaneous capnometry may be unreliable in patients with perfusion abnormalities. In this study, we aimed to evaluate the relation between TcCO2-PaCO2 and lactate level which is recognized as a marker of hypoperfusion. Materials and Methods: In this prospective cohort study in critical care patients with hypercapnic respiratory failure (PaCO2 ≥45 mmHg) who received NIV between April 2019 and January 2020 in the intensive care unit were enrolled in the study. Patients' simultaneously measured TcCO2 and PaCO2 values of hypercapnic patients were recorded. Each paired measurement was categorized into two groups; normal lactate (<2 mmol/L) and increased lactate (≥2 mmol/L). Result: A total of 116 paired TcCO2 and PaCO2 measurements of 29 patients were recorded. Bland-Altman analysis showed the mean bias between the TcCO2 and PaCO2 and 95% limits of agreement (LOA) in all measurements (1.75 mmHg 95% LOA -3.67 to 7.17); in the normal lactate group (0.66 mmHg 95% LOA -1.71 to 3.03); and in the increased lactate group (5.17 mmHg 95% LOA -1.63 to 11.97). The analysis showed a correlation between lactate level and the difference between TcCO2 and PaCO2 (r= 0.79, p< 0.001) and a negative correlation between mean blood pressure and the difference between TcCO2 and PaCO2 (r= -0.54, p= 0.001). Multiple regression analysis results showed that lactate level was independently associated with increased differences between TcCO2 and PaCO2 (Beta= 0.875, p< 0.001). Conclusions: TcCO2 monitoring may not be reliable in patients with increased lactate levels. TcCO2 levels should be checked by ABG analysis in these patients.

Importance of mediastinal granulomatous/sarcoid-like lymphadenopathy in extrathoracic malignancies.

BACKGROUND: In patients with extrathoracic malignancies (ETM), granulomatous lymph adenopathy called sarcoid-like reactions (SLR) can be seen in the regional or draining lymph nodes. We hypothesized that SLR may be a sign of imminent metastasis and investigated the clinical course and rate of recurrence in patients with ETM and granulomatous mediastinal lymphadenopathy (MLN). METHODS: In this retrospective observational study, we reviewed the medical files of patients with known ETM and who underwent EBUS-TBNA for initial staging or detection of recurrence from 2011 to 2023. Patients with granulomatous MLN were included. RESULTS: Forty-one patients (29 female) enrolled in the study. Breast and colorectal carcinomas were the most common malignancies. A total of 81 lymph nodes were sampled. The final diagnosis of patients was five sarcoidosis, one tuberculosis, one second primary, one drug reaction, and 33 SLR. Among patients with SLR, in one patient lymph nodes progressed during the follow-up and were accepted as false-negative without confirmatory biopsy. The negative predictive value (NPV) of granulomatous MLN for metastasis was 97.05%. CONCLUSION: Granulomatous MLN may be due to tuberculosis, drug reaction, sarcoidosis, or SLR in patients with ETM. SLR has a high NPV in patients with ETM. Follow-up imaging rather than confirmatory biopsy is reasonable in these patients.

Immature platelet fraction as a systemic inflammation marker in patients with chronic obstructive pulmonary disease.

INTRODUCTION: Recently, there has been an increasing interest to find a simple, low cost, widely available biomarker for outcome predictors in chronic obstructive pulmonary disease (COPD). METHODS: Absolute immature platelet count (AIPC), the percentage of AIPC to the total platelet count (immature platelet fraction [IPF%]), symptoms, spirometry results, age-dyspne-airflow obstruction index, and C-reactive protein tests of COPD patients and control group were recorded. Neutrophil/lymphocyte, monocyte/lymphocyte, and platelet/lymphocyte ratios and Charlson comorbidity index scores were calculated. RESULTS: One hundred and thirty-four COPD patients and 30 healthy control subjects were included in the study. Eighty-nine patients were in exacerbation (AECOPD) and 45 of them were in stable COPD period. There was a difference between IPF% values and AIPC of COPD group and control group (3.45 ± 2.41 vs. 2.04 ± 1.12, p = 0.01; 5.87 ± 2.45 vs. 5.20 ± 3.02, p = 0.01). A positive correlation was observed between IPF% with white blood cell count and neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, monocyte/lymphocyte ratio in all patients (r = 0.352, p < 0.001; r = 0.399, p < 0.001; r = 0.186, p = 0.032; r = 0.200, p = 0.021) and AECOPD (r = 0.356, p < 0.001; r = 0.414, p < 0.001; r = 0.239, p = 0.025; r = 0.273, p = 0.010). At a cut-off of 3.4, IPF% showed the highest accuracy in identifying COPD (sensitivity: 80.3%, specificity: 82.5%) using receiver-operating characteristic analysis. CONCLUSION: This is the first study to examine the relationship between AIPC, IPF%, and COPD. The higher IPF% values in COPD and the positive correlation between IPF% and other inflammatory markers are suggested that IPF may be an indicator of systemic inflammation in COPD.

Intercostal Muscle Function During Noninvasive Ventilation and Acute Hypercapnic Respiratory Failure.

BACKGROUND: Noninvasive ventilation (NIV) is a widely used and well-established treatment modality for respiratory failure. In patients with increased respiratory work of breathing, accessory muscles are commonly activated along with the diaphragm. Whereas diaphragm ultrasound has been utilized to assess outcomes of mechanical ventilation, the data on intercostal muscle ultrasound remain limited. We aimed to investigate the association between intercostal muscle thickening fraction (TF) and NIV failure in critical care patients with hypercapnic respiratory failure. METHODS: Critical care subjects receiving NIV for hypercapnic respiratory failure were enrolled in the study. The intercostal muscle TF was measured on admission day (day 0) and the following day (day 1). NIV failure was defined as the need for invasive mechanical ventilation or death during NIV therapy. RESULTS: A total of 158 subjects were enrolled, and 30 experienced NIV failure. Age, sex, and body mass index (BMI) were similar in the NIV success and failure groups. Acute Physiology And Chronic Health Evaluation II (APACHE II) and the Sequential Organ Failure Assessment (SOFA) scores were higher in the NIV failure group. In terms of causes of respiratory failure, the COPD exacerbation rate was higher in the NIV success group. TF was higher in the NIV failure group on both day 0 and day 1. The increased TF on the ICU admission day, with a cutoff value of 12%, was associated with NIV failure after adjusting for age, sex, BMI, APACHE II, and SOFA. Persistence of a higher TF value on both day 0 and day 1 was also associated with NIV failure risk. CONCLUSIONS: There is a positive relation between intercostal muscle TF measured by ultrasound and NIV failure, even after adjusting for APACHE II and SOFA scores.

Interstitial lung disease associated with chronic liver disease.

It is important to make the differential diagnosis of restrictive changes associated with hepatic hydrothorax or hepatopulmonary syndrome seen in the later stages of chronic liver diseases and restrictive changes associated with interstitial lung disease. Lymphocytic interstitial pneumonia (LIP) is in the rare idiopathic interstitial pneumonia subgroup of interstitial lung diseases. LIP is a rare disease, and its incidence is unknown. LIP is characterized by infiltration of the alveolar interstitium with lymphocytes, plasma cells, and histiocytes. The etiology of LIP includes idiopathic causes, rheumatological diseases, immune deficiencies, viral infections, and drug-related causes. Chronic liver diseases are also rarely included in the etiology of LIP. A 75-year-old male patient who was followed up for liver cirrhosis presented with dyspnea. He had hypoxemia in the arterial blood gas. In the thorax and abdominal computed tomography, irregular reticulations in bilateral lungs, ground-glass opacities, and scattered air cysts in both lung parenchyma, chronic liver parenchymal disease, splenomegaly, chronic portal vein thrombosis were determined. Clinical and radiological changes in the patient were evaluated in favor of interstitial lung disease. Although histopathological diagnosis could not be made, the patient whose radiological pattern was compatible with LIP was evaluated together with clinical findings and was accepted as lymphocytic interstitial pneumonia. He was evaluated in terms of diseases that could cause LIP. He was accepted as LIP due to chronic liver disease. Although histopathological examination is the gold standard for the diagnosis, a biopsy could not be performed in our case. Radiological and clinical findings were considered sufficient for the diagnosis of LIP. Chronic viral hepatitis and cirrhosis are also present in the etiology of LIP. Our case is presented as an example in the literature because it is a case of LIP due to chronic liver disease, and it is rare.

Recovery from Respiratory Failure in Patients with Coronavirus Disease 2019.

OBJECTIVE: Coronavirus disease 2019 (COVID-19) can cause hypoxic respiratory failure; long-term oxygen therapy (LTOT) duration is unknown. MATERIAL AND METHODS: The aim was to investigate which patients would need LTOT after COVID-19 pneumonia. This single-center, prospective study was conducted at the Ankara University Faculty of Medicine, Department of Chest Diseases, between May 2021 and December 2021. The 70 patients hospitalized for COVID-19 pneumonia and discharged with LTOT due to hypoxemic respiratory failure were included. Patients were divided into 2 groups as group I (LTOT requirement <3 months) and group II (LTOT requirement continued ≥3 months). RESULTS: The mean age was 64.4 ± 13.5 years, and 44 (62.9%) of them were male. The most frequently encountered comorbidities were cardiovascular disease (57.1%) and lung disease (22.9%). While PaO2 levels increased in both groups during the follow-up period, this increment was significantly higher in group I (PaO2: 66.6 ± 9.9 mm Hg, P < .001). The factors affecting the LTOT requirement were evaluated using binary logistic regression. On multivariate analyses of lymphocytes, ferritin, C-reactive protein, PaO2, SaO2, subpleural reticulation, and number of lobes affected (≥3 lobes), the SaO2 level and presence of subpleural reticulation were significantly different between the 2 groups [odds ratio (OR) (95% CI): 0.853 (0.749-0.971), P = .016] and [OR (95% CI): 0.171 (0.042-0.733), P = .017], respectively. CONCLUSION: A significant proportion of patients who develop respiratory failure due to COVID-19 recover within the first 3 months. Factors determining the LTOT requirement for more than 3 months were SaO2 and the presence of subpleural reticulation.

[Prognosis of lung cancer patients followed in the intensive care unit: A cross-sectional study]. / Yogun bakim ünitesinde izlenen akciger kanseri hastalarinin prognozu: Kesitsel çalisma.

Introduction: Lung cancer is the most common solid organ malignancy requiring intensive care unit (ICU) admission. For many years, lung cancer patients were not considered in the priority patient category for admission to ICU because of their high mortality rate and poor response to therapy. Considering the developments in treatment modalities, we aimed to reevaluate the prognosis of patients with lung cancer in the ICU. Materials and Methods: Patients characteristics, date of diagnosis, the reason for ICU admission, the stage of cancer, histopathological type, history of chemotherapy, radiotherapy, or surgery for cancer, and APACHE-II and Charlson comorbidity index (CCI) were recorded retrospectively. Result: A total of 100 patients had a mean age of 69.7 ± 9.0 years. Among these patients, 18% had small cell lung cancer, while 82% had non-small cell lung cancer. The in-hospital mortality rate was 69% for all patients, while among those discharged from the ICU, the first 6-month mortality rate was 58.1%. The median survival time was 8.2 months. Advanced age, the need for mechanical ventilation, the need for vasopressors, a high APACHE -II, and the CCI all reduced survival in multivariate analysis, whereas chemotherapy and surgical history improved survival. Conclusions: Patients admitted to the ICU with lung cancer continue to experience a high mortality rate. However, identifying the factors that are associated with survival can be crucial in establishing care plans and prioritizing ICU admission for further therapy.

IS FLEXIBLE BRONCHOSCOPY A SAFE PROCEDURE FOR CRITICAL CARE PATIENTS WITH RESPIRATORY FAILURE?

Flexible bronchoscopy (FB) plays an important role in critical care patients. But, critical care patients with respiratory failure are at an increased risk of developing complications. Considering the developments in intensive care unit care in recent years, we aimed to evaluate the use of FB in these patients. We retrospectively reviewed patients who underwent FB in critical care between 2014 and 2020. A total of 143 patients underwent FB during the study period. Arterial blood gas measurement on the FB day revealed a mean PaO2/FiO2 of 186.94±28.47. Eighty-one (56.6%) patients underwent an fiberoptic bronchoscopy procedure under conventional oxygen supplementation, 10 (7%) on noninvasive ventilation, 13 (9.1%) on high flow nasal cannula, and 39 (27.3%) on invasive mechanical ventilation. During and immediately after bronchoscopy, none of the patients experienced life-threatening complications. Fifty-five (38.5%) patients developed complications that could be controlled. Multivariate analysis indicated that increased Apache-II score and presence of cardiovascular disease were significantly associated with an increased complication risk. Although critical care patients with respiratory failure are more prone to complications, diagnostic and therapeutic bronchoscopy may be performed following appropriate patient selection, without leading to major complications.

Allergic bronchopulmonary aspergillosis with endobronchial signs: Two cases.

Pulmonary aspergillosis may be classified under three categories depending on whether the patient is atopic or immunocompromised: invasive, chronic necrotizing, and allergic bronchopulmonary aspergillosis (ABPA), which is an immunological pulmonary disorder caused by hypersensitivity to Aspergillus spp., manifesting with poorly controlled asthma. ABPA is diagnosed using major and minor criteria. Herein, we present two ABPA cases with endobronchial signs on bronchoscopy. Asthmatic 31-year-old male and 59-year-old female patients were admitted with dyspnea and bilateral rhonchi. Total IgE levels were elevated. Peripheral eosinophilia was also present. Chest computed tomography revealed consolidated areas, peribronchial micronodules, ground-glass appearance, and increased nodular densities. Bronchoscopy showed brownish-yellow membranes on the bronchial mucosa of these patients. Aspergillus spp. growth was observed in bronchial lavage culture. ABPA is a curable disease only if diagnosed correctly. Notwithstanding the large number of cases reported to date, we aimed to emphasize the importance of bronchoscopic examination in endobronchial fungal infections.

A new device for bronchoscopy for better protection.

BACKGROUND: During the COVID-19 pandemic, the risk of transmission of SARS-CoV-2 has not been precisely known in bronchoscopy procedures. We have designed a cabinet device called Ankara University Bronchoscopy Cabinet (Aubrocab®) to protect healthcare. We aimed to evaluate preventing effect of Aubrocab® on aerosol spreading by measuring the particles in the bronchoscopy suite. METHODS: The patients were categorized into two groups as those who underwent bronchoscopy with and without Aubrocab®. We measured PM 0.5 levels before and after bronchoscopy in the bronchoscopy suite. RESULTS: A total of 82 patients, 62 of whom underwent bronchoscopy with Aubrocab®, were enrolled in the study. The PM 0.5 level measured before bronchoscopy was similar in both groups, whereas the PM 0.5 level measured after bronchoscopy was lower in the Aubrocab® group (42,603 ± 8,632 vs. 50,377 ± 10,487, p = 0.001). The percent of particle change (50.76 ± 19.91 vs 67.15 ± 24.24, p = 0.003) and the difference of the particle numbers between pre and postprocedure (13,638 ± 4,292 and 19,501 ± 5,891, p < 0.001) were lower in the Aubrocab® group. DISCUSSION: Our institution developed a barrier device named Aubrocab® which was shown to prevent excessive aerosol release in addition to routine precautions during bronchoscopy procedures.

Clinical, Functional, and Prognostic Evaluation of Idiopathic Pulmonary Fibrosis, Connective Tissue Disease-Associated Interstitial Lung Disease, Interstitial Pneumonia with Autoimmune Features: A Single-Center Prospective Study.

OBJECTIVE: Our study aimed to evaluate clinical, functional, and prognostic features and to determine the prognosis of idiopathic pulmonary fibrosis, connective tissue disease-associated interstitial lung diseases, and interstitial pneumonia with autoimmune features. MATERIAL AND METHODS: Sixty-nine cases with interstitial lung diseases were recruited in this study prospectively. Demographic features, symptoms, radiological findings, functional measurements, and immunological markers were recorded twice (at the time of initial admission and in the 12th month). Twenty-four of 69 cases were idiopathic pulmonary fibrosis, 32 were connective tissue diseaseassociated interstitial lung diseases, and 13 were interstitial pneumonia with autoimmune features . RESULTS: Most of the patients with idiopathic pulmonary fibrosis were male, while there were more female patients in connective tissue disease-associated interstitial lung diseases and interstitial pneumonia with autoimmune features groups. Female patients (65.0%) predominated in connective tissue disease-associated interstitial lung diseases group (P <.001). There was no significant difference in the mean ages of the disease groups, yet connective tissue disease-associated interstitial lung diseases patients were generally younger (min- max: 34-82 years). In the idiopathic pulmonary fibrosis group, only low titers of antinuclear antibody positivity were found. Antinuclear antibody positivity in the connective tissue disease-associated interstitial lung diseases group and interstitial pneumonia with autoimmune features group was high (P = .001). The long-term survival of idiopathic pulmonary fibrosis, connective tissue disease-associated interstitial lung diseases, and interstitial pneumonia with autoimmune features patients were 37%, 40 months (median) (95% CI, 5.193- 74.807), 48.6%, 80 months (median) (95% CI, 57.032-102.968), 30.8%, 46 months (median) (95% CI, 26.624-65.376), respectively. CONCLUSION: Although a consensus report describing interstitial lung diseases with autoimmune features has been published, diagnostic criteria for this group are still vague. Since the interstitial pneumonia with autoimmune features group had the worst results in terms of functional loss and survival rates, the follow-up parameters and follow-up algorithm should be established for this group. Clinical and immunological evaluation of the interstitial pneumonia with autoimmune features group should include detailed parameters because of follow-up and to estimate survival.

Evaluation of lung cancer biomarkers profile for the decision of targeted therapy in EBUS-TBNA cytological samples.

BACKGROUND: Guidelines recommend performing biomarker tests for epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), BRAF and ROS proto-oncogene-1(ROS1) genes and protein expression of programmed death ligand-1(PD-L1) in patients with non-small lung cell carcinoma (NSCLC). Studies reported that endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) can provide sufficient material for cancer biomarker analyses, but there are still concerns about the subject. AIM: The purpose of the study was to assess the adequacy of EBUS-TBNA for testing lung cancer biomarkers. METHODS: We retrospectively reviewed patients with NSCLC whose EBUS-TBNA was analysed for EGFR, ALK, ROS-1, BRAF and PD-L1 expression between December 2011 and December 2020. RESULTS: A total of 394 patients were enrolled in the study. EGFR mutation and ALK fusion were the most common studied biomarkers. EBUS-TBNA adequacy rate for biomarker tests was found 99.0% for EGFR, 99.1 for ALK, 97.2% for ROS1, 100% for BRAF and 99.3% for PD-L1 testing. Multivariate analysis revealed the histological type, history of treatment for NSCL, size, or 18-fluorodeoxyglucose uptake of sampled lesion did not show any association with TBNA adequacy for biomarker testing. CONCLUSION: EBUS-TBNA can provide adequate material for biomarker testing for EGFR, ALK, ROS-1, BRAF and PD-L1 expression.

Is endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) reliable and safe procedure in geriatric patients?

BACKGROUND: Even though studies have indicated the usefulness and safety of endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA), elderly patient data are limited due to the small sample sizes. AIM: We aimed to evaluate usage and safety of EBUS-TBNA in elderly population. METHODS: This single-center retrospective study was conducted with patients who underwent an EBUS-TBNA procedure between September 2011 and December 2019. The patients were categorized into two groups: those aged 65 years or older (elderly group) and those younger than 65 years (younger group). RESULTS: 2444 patient data, 1069 of which were in the elderly group, were analyzed. The cytological examination of EBUS-TBNA identified specimen adequacy in 96.8% of patients. One hundred and thirty patients (5.3%) experienced complications, with similar complication rates recorded in both the elderly and younger groups (5.4% vs 5.2%, p: 0.836). Logistic regression analyses revealed that age, and presence of hypertension, diabetes mellitus, coronary artery disease and malignancy are associated significantly with complication-related EBUS-TBNA. For the lymph nodes with a final diagnosis of malignancy, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of EBUS-TBNA revealed a diagnostic performance in excess of 90% except for metastasis and lymphoma. CONCLUSION: EBUS-TBNA can be considered a safe and effective technique in patients aged 65 years and over.

Can diaphragm excursion predict prognosis in patients with severe pneumonia?

INTRODUCTION: Although thorax ultrasound has been used to diagnose pneumonia in recent years, the role of ultrasonic diaphragm evaluation in the prognosis of pneumonia is unknown. This study aimed to assess the impact of diaphragmatic excursion (Dex) measured by ultrasound on the prognosis of severe pneumonia in critical care patients. MATERIALS AND METHODS: We prospectively recruited patients with severe pneumonia who were admitted to the intensive care unit (ICU) between January 2019 and July 2021. Patients' Dex values, vital signs, clinical features, laboratory parameters, APACHE-II scores on the first admission day of ICU, mortality and respiratory support status at follow-up were recorded. RESULT: There were 39 patients enrolled in the study. Mean Dex of the study patients was 30.66 ± 12.17 mm. Mean Dex was significantly lower in deceased patients than survivors (18.37 ± 8.12 vs 34.90 ± 10.36 p< 0.001). Dex was lower in patients who required invasive mechanical ventilation than those not (24.90 ± 10.93 vs 34.26 ± 11.70, p= 0.017). The cut-off value of Dex was found 19.0 mm for significantly predicted (p≤ 0.001) survival with the sensitivity of 96.6% and specificity of 70%. Among the study group, diaphragm excursion was negatively correlated with APACHE-II score (r= -0.688, p≤ 0.001) and respiratory rate (r= -0.531, p= 0.001). CONCLUSIONS: Dex measured on the day of ICU admission can be used to evaluate the prognosis of patients with severe pneumonia.

Is pulse oximeter a reliable tool for non-critically ill patients with COVID-19?

INTRODUCTION: Guidelines recommend using a pulse oximeter rather than arterial blood gas (ABG) for COVID-19 patients. However, significant differences can be observed between oxygen saturation measured by pulse oximetry (SpO2 ) and arterial oxygen saturation (SaO2 ) in some clinical conditions. We aimed to assess the reliability of the pulse oximeter in patients with COVID-19. METHODS: We retrospectively reviewed ABG analyses and SpO2 levels measured simultaneously with ABG in patients hospitalised in COVID-19 wards. RESULTS: We categorised total 117 patients into two groups, in whom the difference between SpO2 and SaO2 was ≤4% (acceptable difference) and >4% (large difference). A large difference group exhibited higher neutrophil count, C-reactive protein, ferritin, fibrinogen, D-dimer and lower lymphocyte count. Multivariate analyses revealed that increased fibrinogen, increased ferritin and decreased lymphocyte count were independent risk factors for a large difference between SpO2 and SaO2 . The total study group demonstrated the negative bias of 4.02% with the limits of agreement of -9.22% to 1.17%. The bias became significantly higher in patients with higher ferritin, fibrinogen levels and lower lymphocyte count. CONCLUSION: Pulse oximeters may not be sufficient to assess actual oxygen saturation, especially in COVID-19 patients with high ferritin and fibrinogen levels and low lymphocyte count with low SpO2 measurements.

Prognostic Significance of Red Cell Distribution Width in Idiopathic Pulmonary Fibrosis and Combined Pulmonary Fibrosis Emphysema.

OBJECTIVE: The red cell distribution width (RDW) is an inexpensive, readily available prognostic indicator of several diseases. RDW has been assessed as a prognostic biomarker in patients with idiopathic pulmonary fibrosis (IPF) in only one study; furthermore, the relationship between the RDW and combined pulmonary fibrosis emphysema (CPFE) has yet to be reported. SUBJECTS AND METHODS: This single-center study was conducted between January 2015 and December 2018 in the Atatürk Chest Diseases and Chest Surgery Education and Research Hospital. Baseline characteristics, laboratory results, and survival status of patients were recorded. RESULTS: The RDW value was significantly higher in the CPFE group than in the IPF group (median [IQR 25-75]; 16.8 [15.5-19] vs. 15.3 [13.7-16.8], p = 0.028). High RDW values were correlated with carbon monoxide diffusion capacity (DLCO) (r: -0.653 p = 0.001), 6-minute walking test (6MWT) distance (r: -0.361 p = 0.017), arterial partial oxygen pressure (PaO2) (r: -0.692 p < 0.001), and systolic pulmonary arterial pressure (SPAP) (r: 0.349 p = 0.022) in patients with fibrotic lung disease. The RDW value was significantly higher in the exitus group than in the survivors (median [IQR 25-75]; 18.4 [15.4-19] vs. 15.2 [13.5-17.2], p = 0.016). A univariate Cox regression analysis identified DLCO, SPAP, PaO2, and RDW as potential covariates of mortality. In a multivariate analysis, the DLCO (HR 1.21, 95% CI 1.11-1.47, p = 0.012) and RDW level (HR 1.65, 95% CI 1.09-2.47, p = 0.023) remained independent predictors of mortality. CONCLUSION: High RDW values appear to be a simple prognostic factor in patients with IPF or CPFE.

Prone positioning in non-intubated patients with COVID-19.

Prone positioning is a well-known supportive maneuver to improve oxygenation for patients with moderate to severe acute respiratory distress syndrome (ARDS). Although this technique is usually performed to sedated patients on invasive mechanical ventilation, it has been used in non-intubated patients frequently during the coronavirus diseases-2019 (COVID-19) pandemic. Favorable outcomes have been reported mainly in combining the prone positioning with high flow nasal cannula (HFNC) or non-invasive ventilation (NIV). Due to limited data, a standard approach for the awake prone positioning has not yet been defined. In this manuscript, we reviewed the literature data about prone positioning in non-intubated patients with COVID-19. According to available literature data, we concluded that prone positioning in non-intubated COVID-19 patients may improve oxygenation and prevent the need for invasive mechanical ventilation. But the efficacy is still controversial in the early stage of the disease due to pulmonary mechanics. Further studies are needed to the defined optimal approach of awake prone positioning in COVID-19 patients with hypoxemic respiratory failure.

High flow nasal cannula in COVID-19: a literature review.

In recent years, high flow nasal cannula (HFNC) is a respiratory support system that has become prominent in the treatment of respiratory failure. HFNC provides higher concentration and flow of oxygen, resulting in decreasing anatomic dead space by preventing rebreathing and ensure positive end-expiratory. However, in COVID-19, the usage of HFNC is much controversial due to concerns about the benefits and risk of aerosol-dispersion. Considering the debates about the use of HFNC, we reviewed the literature related to the usage of HFNC in COVID-19. The available reports suggest that HFNC provides high concentrations of oxygen to the patients, who can not reach with conventional devices. HFNC can reduce the requiring of intubation in patients with COVID-19, and it can decrease the length of intensive care unit stay, and complications related to mechanical ventilation. Also HFNC can in achieving apneic oxygenation in patients during airway management. Besides that, the use of high-flow oxygen cannulas can produce aerosols. So, HFNC treatment should be carried out in a negative pressure room; when it is not possible, devices should be undertaken in a single room.