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.

Acute pulmonary thromboembolism (PTE) is a common cause of cardiovascular mortality. Right ventricular (RV) dysfunction is the most important cause of mortality. Computed Tomography Pulmonary Angiography (CTPA) can detect right ventricular enlargement which is an indicator of RV dysfunction at the time of diagnosis. This study aimed to determine the parameters indicating RV dysfunction in CTPA and correlation of early mortality findings. In this retrospective study, electronic files of patients diagnosed PTE with CTPA between January 2012 and December 2017 were evaluated. Measurements of heart chambers, IVC reflux, and IVS morphology were calculated. In-hospital mortality of the patients after acute PTE diagnosis was evaluated. There were 206 eligible patients. Among the evaluated radiological parameters, right atrium (RA) size (p= 0.002), PA size (p= 0.003), Ao size (p= 0.006), and the presence of IVC reflux (p= 0.001) were associated with mortality. No significant relationship was found between RV/LV ≥1 and mortality (p= 0.908). All patients with PTE-related mortality had RV/LV ratio ≥1 in CTPA and had IVC reflux. Patients with an RV/LV ratio of ≥1 had statistically significantly higher troponin levels (p= 0.004) and IVC reflux (p= 0.025) compared to patients with an RV/LV ratio of <1. In conclusion, RV/LV ratio should be evaluated together with cardiac biomarkers to define mortality risk.

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.

Background: Right ventricular dysfunction (RVD) is the main determinant of mortality in patients with pulmonary embolism (PE). Thus, guidelines recommend the assessment of RVD with transthoracic echocardiography (TTE) or computed tomography pulmonary angiography (CTPA) among these patients. In this study, we investigated the agreement between TTE and CTPA for the detection of RVD. Materials and Methods: This single-center retrospective study included patients who were diagnosed with CTPA and underwent TTE within the first 24 hours following the diagnosis. Results: Two hundred fifty-eight patients met the inclusion criteria. In 71.3% (184) of them, CTPA and TTE agreed on both the presence and absence of RVD. There was a moderate agreement between the 2 tests (Cohen’s kappa = 0.404, P < .001). The agreement between right ventricle dysfunction on TTE and the increased right ventricle/left ventricle (RV/LV) on CTPA was fair (Cohen’s kappa = 0.388, P < .001). Three patients died due to PE, and another 5 patients required urgent reperfusion therapy. Overall, adverse outcomes occurred in 4% (8) of patients. The sensitivity of modalities in the detection of adverse outcomes was 100%. Transthoracic echocardiography was more specific compared to CTPA (43% vs. 28%). Statistically, flattening/bulging of the interventricular septum on TTE was significantly associated with adverse outcomes. No individual CTPA parameter was related to adverse outcomes. Conclusion: Both CTPA and TTE are reliable imaging modalities in the detection of RVD. However, TTE is more specific, and this may help in the identification and appropriate management of patients at higher risk of decompensation. A combination of CTPA parameters rather than individual RV/LV ratios increases the sensitivity of CTPA.