scholarly journals Double Trouble: Airflow and Pulmonary Vascular Obstruction

2021 ◽  
Author(s):  
Michael H. Lee ◽  
Brian B Graham ◽  
Todd M. Bull
Keyword(s):  
Vascular Obstruction ◽  
Pulmonary Vascular Obstruction

scholarly journals Residual pulmonary vascular obstruction and recurrence after acute pulmonary embolism: protocol for a systematic review and meta-analysis of individual participant data

BMJ Open ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. e023939 ◽  
Author(s):  
Philippe Robin ◽  
Maggie Eddy ◽  
Lindsey Sikora ◽  
Pierre-Yves Le Roux ◽  
Marc Carrier ◽  
...  
Keyword(s):  
Acute Pulmonary Embolism ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Randomized Controlled ◽  
Individual Participant ◽  
Recurrent Vte ◽  
Vascular Obstruction ◽  
The Relationship ◽  
Acute Pe ◽  
Pulmonary Vascular Obstruction

BackgroundIn patients with a first, unprovoked venous thromboembolism (VTE), the optimal duration of anticoagulant therapy (AT) is controversial due to tightly balanced risks and benefits of indefinite anticoagulation. The objective of this study is to assess among patients with a first acute pulmonary embolism (PE) who received ≥3 months of AT and thereafter had a planar lung scan, whether residual pulmonary vascular obstruction (RPVO) is associated with VTE recurrence after discontinuation of AT.Methods and analysisWe will conduct a systematic review with a meta-analysis of individual participant data of contemporary studies evaluating the prognostic significance of RPVO in patients with a first acute PE. We will search from inception to 24 January 2018, PubMed, Medline, Embase and Cochrane’s Central Registry for Randomized Controlled Trials, CENTRAL for randomized controlled trials and prospective cohort studies. Two reviewers will conduct all screening and data collection independently. The methodological quality and risk of bias of eligible studies will be carefully and rigorously assessed using the Risk Of Bias In Non-randomised Studies of Interventions tool. The primary objective will be to assess the relationship between RPVO on ventilation–perfusion scan after completion of at least 3 months of AT after an acute PE event, and the risk of an objectively confirmed symptomatic recurrent VTE (including deep vein thrombosis or PE) or death due to PE. The secondary objectives will include the assessment of the optimal RPVO cut-off and the risk of recurrent VTE, as well as the relationship between the relative change in RPVO between PE diagnosis and at discontinuation of AT (≥3 months) and risk of recurrent VTE.Ethics and disseminationThis study of secondary data does not require ethics approval. It will be presented internationally and published in the peer-reviewed literature.PROSPERO registration numberCRD42017081080.

Ultrasound-Assisted Catheter-Directed Thrombolysis for Submassive Pulmonary Embolism

2018 ◽  
Vol 52 (3) ◽  
pp. 195-201 ◽  
Author(s):  
Prasoon P. Mohan ◽  
John J. Manov ◽  
Francisco Contreras ◽  
Michael E. Langston ◽  
Mehul H. Doshi ◽  
...  
Keyword(s):  
Risk Factors ◽  
Pulmonary Embolism ◽  
Bleeding Risk ◽  
Right Heart ◽  
Systemic Thrombolysis ◽  
Catheter Directed Thrombolysis ◽  
Ultrasound Assisted ◽  
Vascular Obstruction ◽  
The Right ◽  
Pulmonary Vascular Obstruction

Purpose: Catheter-directed thrombolysis (CDT) is a relatively new therapy for pulmonary embolism that achieves the superior clot resolution compared to systemic thrombolysis while avoiding the high bleeding risk intrinsically associated with that therapy. In order to examine the efficacy and safety of CDT, we conducted a retrospective cohort study of patients undergoing ultrasound-assisted CDT at our institution. Methods: The charts of 30 consecutive patients who underwent CDT as a treatment of pulmonary embolism at our institution were reviewed. Risk factors for bleeding during thrombolysis were noted. Indicators of the right heart strain on computed tomography and echocardiogram, as well as the degree of pulmonary vascular obstruction, were recorded before and after CDT. Thirty-day mortality and occurrence of bleeding events were recorded. Results: Nine (30%) patients had 3 or more minor contraindications to thrombolysis and 14 (47%) had major surgery in the month prior to CDT. Right ventricular systolic pressure and vascular obstruction decreased significantly after CDT. There was a significant decrease in the proportion of patients with right ventricular dilation or hypokinesis. Decrease in pulmonary vascular obstruction was associated with nadir of fibrinogen level. No patients experienced major or moderate bleeding attributed to CDT. Conclusion: Catheter-directed thrombolysis is an effective therapy in rapidly alleviating the right heart strain that is associated with increased mortality and long-term morbidity in patients with pulmonary embolism with minimal bleeding risk. Catheter-directed thrombolysis is a safe alternative to systemic thrombolysis in patients with risk factors for bleeding such as prior surgery. Future studies should examine the safety of CDT in patients with contraindications to systemic thrombolysis.

Lung water measurements with the mean transit time approach

1985 ◽  
Vol 59 (3) ◽  
pp. 673-683 ◽  
Author(s):  
R. M. Effros
Keyword(s):  
Transit Time ◽  
Mean Transit Time ◽  
Tissue Perfusion ◽  
Time Data ◽  
Lung Water ◽  
Thermal Signal ◽  
The Mean ◽  
Points Of View ◽  
Vascular Obstruction ◽  
Pulmonary Vascular Obstruction

The potential usefulness and limitations of the double-indicator mean transit time approach for measuring lung water are evaluated from both theoretical and empirical points of view. It is concluded that poor tissue perfusion is the most serious factor that can compromise the reliability of this approach. Replacement of the conventional water isotopes with a thermal signal enhances indicator delivery to ischemic areas but the diffusion of heat is not sufficiently rapid to permit measurements of water in macroscopic collections of fluid which remain unperfused. The frequency of pulmonary vascular obstruction in patients with pulmonary edema related to lung injury suggests that interpretation of transit time data will be complicated by uncertainties concerning perfusion. Thermal-dye measurements of lung water may prove more helpful in situations where pulmonary blood flow remains relatively uniform.

scholarly journals The Cardiovascular, Coagulation and Haematological Effects of Tiger Snake (Notechis scutatus) Venom

1998 ◽  
Vol 26 (5) ◽  
pp. 529-535 ◽  
Author(s):  
J. Tibballs
Keyword(s):  
Degradation Products ◽  
Pulmonary Artery Occlusion Pressure ◽  
Artery Occlusion ◽  
Low Cardiac Output ◽  
Mechanically Ventilated ◽  
Systemic Hypotension ◽  
Fibrin Degradation Products ◽  
Vasoactive Substances ◽  
Vascular Obstruction ◽  
Pulmonary Vascular Obstruction

The cardiovascular, coagulation and haematological effects of Tiger Snake (Notechis scutatus) venom were investigated in anaesthetized, mechanically ventilated dogs. Intravenous infusion of venom caused dose-related systemic hypotension, low cardiac output, pulmonary hypertension and raised pulmonary artery occlusion pressure. These effects occurred within several minutes of venom administration but recovered over 30 to 40 minutes. They were accompanied by prolongation of prothrombin and activated partial thromboplastin times and by depletion of serum fibrinogen. Fibrin degradation products were not detected. Thrombocytopenia and leucopenia were observed within minutes of venom administration but recovered over 30 to 40 minutes. The mechanism of systemic hypotension is probably pulmonary vascular obstruction and coronary ischaemia caused by disseminated intravascular coagulation, although the existence of a myocardial depressant in venom or release of vasoactive substances by venom cannot be excluded.

Early diagnosis of chronic pulmonary vascular obstruction

1968 ◽  
Vol 44 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Jay A. Nadel ◽  
Warren M. Gold ◽  
John H. Burgess
Keyword(s):  
Early Diagnosis ◽  
Vascular Obstruction ◽  
Pulmonary Vascular Obstruction

scholarly journals Dead Space Ventilation Parallels Changes in Scintigraphic Vascular Obstruction at Recurrence of Pulmonary Embolism and after Thrombolytic Therapy: A Case Report

1998 ◽  
Vol 5 (3) ◽  
pp. 215-218 ◽  
Author(s):  
Marc A Rodger ◽  
Gwynne Jones ◽  
Francois Raymond ◽  
Daniel Lalonde ◽  
Mike Proulx ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Thrombolytic Therapy ◽  
Dead Space ◽  
Heparin Therapy ◽  
Alveolar Dead Space ◽  
Right Heart ◽  
Vascular Obstruction ◽  
Right Heart Dysfunction ◽  
Pulmonary Vascular Obstruction ◽  
Dead Space Ventilation

Physiological and alveolar dead space ventilation both increase in pulmonary embolism (PE) in proportion to the severity of vascular obstruction. The case of a patient with recurrent PE while on heparin therapy is presented. The recurrence was characterized clinically by severe pulmonary vascular obstruction and right heart dysfunction. The patient was treated with thrombolytic therapy, with excellent clinical and scintigraphic resolution. Dead space ventilation measurements at baseline, at the time of recurrence and after thrombolytic therapy are presented. The potential utility of dead space ventilation measurements for PE diagnosis and management are discussed.

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