Use, physiological effects and safety of pulmonary vasodilator therapy in thoracic surgical patients: a scoping review protocol

Introduction Thoracic surgery requiring one-lung ventilation is associated with acute increases in right ventricular (RV) afterload, which may contribute to perioperative RV dysfunction and long-term functional limitation. Pulmonary vasodilator therapy represents a potential strategy to attenuate these effects however, the breadth, characteristics and implications of pulmonary vasodilator therapy in the thoracic surgical population have not been comprehensively synthesised. This scoping review aims to map the existing evidence base on the use, physiological effects and safety of pulmonary vasodilator therapy in adult thoracic surgery.Methods and analysis This protocol has been developed in accordance with Joanna Briggs Institute (JBI) methodology and reported in line with the PRISMA Extension for Scoping Reviews (PRISMA-ScR). A comprehensive search of Ovid MEDLINE and Embase will be conducted from 1946 to 2026. Eligible studies will include original research (including case reports and case series) involving adult patients (≥18 years) undergoing thoracic surgery with perioperative administration of pulmonary vasodilator or inodilator therapy. Cardiac surgery, transplantation, non-surgical populations and paediatric studies will be excluded. Two independent reviewers will perform study selection, with disagreements resolved by consensus or third reviewer adjudication. Data extraction will be conducted by one reviewer and independently verified by a second. Extracted data will include study characteristics, patient population, surgical context, pharmacological interventions and reported physiological and safety outcomes. Data will be summarised descriptively using tabulated and narrative synthesis. Consistent with scoping review objectives, formal critical appraisal will not be undertaken, as the aim is to map the evidence rather than assess effect size or certainty. Methodological characteristics will be described to contextualise interpretation of results.Ethics and dissemination Ethical approval is not required. Findings will be disseminated through peer-reviewed publication and conference presentation, informing future clinical trial design.