High Flow Nasal Cannula Oxygenation Successfully Used as Bridge Therapy for Systemic Thrombolysis in COVID-19 Associated Intermediate-high Risk Pulmonary Embolism

Impact of Alteplase on Mortality in Critically Ill Patients with COVID-19 and Pulmonary Embolism

COVID-19 is an independent risk factor for pulmonary embolism (PE). Little is known about alteplase therapy in this patient group. A retrospective study analyzed 74 patients with PE and acute respiratory distress syndrome (ARDS) due to COVID-19 who were hospitalized in the intensive care unit in 2021. Patients with or without confirmed right heart thrombi (RHT) were treated with unfractionated heparin or alteplase. The mortality rate in patients with RHT treated with heparin was 100% compared to 37.9% and 55.2% in those treated with alteplase without RHT and alteplase with RHT, respectively. The risk of death in the alteplase group increased with delayed thrombolysis (p = 0.009, odds ratio (OR) = 1.73 95% CI (confidence interval) 1.14-2.62), increased D-dimer concentration (p = 0.02, OR = 1.43 95% CI 1.06-1.93), and decreased PaO₂/FiO₂ ratio (p = 0.001, OR = 0.56 95% CI 0.41-0.78). The receiver operating characteristic method determined that a 1-day delay in thrombolytic treatment, D-dimer concentration >5.844 mg/L, and PaO₂/FiO₂ <144 mmHg predicted a fatal outcome. The risk of death in patients with severe COVID-19 with ARDS and PE increases with higher D-dimer levels, decreased PaO₂/FiO₂, and delayed thrombolytic treatment. Thrombolysis seems to be treatment of choice in severe COVID-19 with PE and RHT. It should be carried out as soon as possible after the diagnosis is established.

Effectiveness of high-flow nasal cannula therapy on clinical outcomes in adults with COVID-19: A systematic review

Introduction/Background

Coronavirus disease 2019 (COVID-19) has high transmissibility and mortality rates. High-flow nasal cannula therapy (HFNC) might reduce the need for orotracheal intubation, easing the burden on the health system caused by COVID-19. The objective of the present study was to examine the effectiveness of HFNC in adult patients hospitalized with COVID-19. Specifically, the present study explores the effects of HFNC on rates of mortality, intubation and intensive care units (ICU) length of stay. The present study also seeks to define predictors of success and failure of HFNC.

Methods

A systematic literature search was conducted in the PubMed, EMBASE and SCOPUS databases, and the study was prepared according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Study quality was assessed using the National Heart, Lung, and Blood Institute's Study Quality Assessment Tools.

Results

The search identified 1,476 unique titles; 95 articles received full-text reviews and 40 studies were included in this review. HFNC was associated with a reduction in the rate of orotracheal intubation, notably when compared to conventional oxygen therapy. Studies reported inconsistency in whether HFNC reduced ICU length of stay or mortality rates. Among the predictors of HFNC failure/success, a ratio of oxygen saturation index of approximately 5 or more was associated with HFNC success.

Conclusion

In adult patients hospitalized with COVID-19, HFNC may prove effective in reducing the rate of orotracheal intubation. The ratio of the oxygen saturation index was the parameter most examined as a predictor of HFNC success. Low-level research designs, inherent study weaknesses and inconsistent findings made it impossible to conclude whether HFNC reduces ICU length of stay or mortality. Future studies should employ higher level research designs.

A brief review on failed hybrid treatment for massive pulmonary embolism: catheter-directed thrombolysis (CDT) and pharmaco-mechanical thrombolysis (PMT)

Acute massive or high-risk pulmonary embolism (PE), described as a lung arteries occlusion by an embolus, causes a significant compromise of hemodynamic stability and could lead to a lethal event. Systemic fibrinolytic therapy has been accepted as the standard reperfusion therapy in massive PE, except when there is an increased risk of bleeding. Catheter-based mechanical strategies (thrombofragmentation, thromboaspiration with catheter-guided thrombolysis) are described as options when there are absolute contraindications to systemic thrombolysis. We briefly reviewed clinical situations when patients with severe pneumonia due to COVID-19 are complicated by a high-risk saddle pulmonary embolism and underwent repeated pharmacomechanical thrombolysis and high-flow oxygen therapy. There are scarce reports of failed catheter-guided pharmacomechanical thrombolysis in patients with PE secondary to COVID-19. Re-administration of systemic thrombolysis and alteplase (15 mg dose) can show favorable results.