Extracorporeal membrane oxygenation (ECMO) is increasingly being used as part of the algorithm for the management of patients with respiratory failure in whom conventional ventilatory strategies have failed to preserve gas exchange without use of settings that may result in ventilator-induced lung injury. ECMO for respiratory support may be required in critically ill patients with any of the following types of respiratory failure: a) acute respiratory distress syndrome (ARDS) of any aetiology (infectious or non-infectious, pulmonary or extrapulmonary), defined according to the Berlin criteria of ARDS, or the more recently proposed Kigali modification and the New Global definition of ARDS; b) acute reversible hypoxemic and/or hypercapnic respiratory failure of any infectious or non-infectious aetiology (including pulmonary embolism and primary graft failure in lung transplantation recipients); and c) chronic hypoxemic and/or hypercapnic respiratory failure, as a bridge to lung transplantation strategy. Right ventricular injury (RVI) may develop in the context of any of the aforementioned types of respiratory failure and is characterised by a spectrum of abnormal RV biomechanics which all have been linked to mortality. One of the main mechanisms of RVI in patients with respiratory failure is pulmonary vasoconstriction caused by hypoxaemia and/or hypercapnic acidaemia leading to elevated RV afterload. Respiratory ECMO supports or replaces pulmonary gas exchange and theoretically may reverse the aforementioned mechanism of RVI and unloads the RV. However, RVI may persist or worsen despite application of ECMO and is strongly associated with significant mortality.
There is currently no universally accepted definition for RVI in patients receiving ECMO for respiratory support or evidence-based RV-targeted therapies. This may result in underdiagnosis of this clinical entity and clinical practice variations and hence there is a need to standardise diagnostic criteria as well as clarify therapeutic management. The objective of the current investigation is to generate consensus statements by experts on the definition and management of RVI in adult patients receiving ECMO for respiratory support, using a Delphi process.
The Delphi process is a well-known mechanism for generating consensus on a specific topic by tapping into the "collective intelligence" of the panel members. The Steering Committee members conduct iterative Delphi rounds to obtain an agreement among the Experts after completing a literature search on the currently available evidence and preparing the opening statements. The members of the Steering Committee will not take part in the Delphi surveys.
The investigators will be using a modified Delphi-based methodology involving global experts from different disciplines (intensive care medicine, anaesthesia, cardiac surgery, cardiology, or a combination of two or more specialties) who meet pre-specified qualification criteria. A survey will be sent to all potential panel members prior to commencement of the Delphi rounds, to ascertain expertise in the field. The entire study will be conducted through approximately three or four rounds of Google Forms-based Delphi questionnaires. The Experts will provide opinion on the problem areas; definition and management of acute RVI in patients receiving ECMO for respiratory support. The survey is organised into three domains: Definition, RVI severity, Management strategies, and Research Priorities. The problem areas, domains and statements were generated by systematic literature review. Most of these statements require a 7-point Likert scale rating or selecting appropriate options in multiple-choice questions (MCQs). In round one, there is an option to collect feedback from participating Experts in the offered open area, which will be evaluated before the round two questionnaire. Rounds are repeated until consensus (or stable dissensus) is reached (≥70% for the Likert scale and ≥80% for MCQs). Experts will be presented with the summary results of each round, and the survey procedure will be repeated with the amended questionnaire. The Delphi rounds will continue until the required consensus (or lack thereof) and statement stability is obtained.
