Abstract
BACKGROUND: Accurate arterial pressure monitoring is critical in cardiac surgery to guide haemodynamic management and vasopressor therapy. Radial arterial pressure monitoring may systematically underestimate central aortic pressure compared with femoral monitoring, potentially leading to inappropriate vasopressor escalation and associated complications. Recent evidence demonstrates that excessive norepinephrine exposure is associated with acute kidney injury and increased mortality in cardiac surgery patients. OBJECTIVE: To determine whether femoral arterial pressure monitoring reduces norepinephrine use compared with radial monitoring in cardiac surgery patients. METHODS AND ANALYSIS: This is a prospective, randomised, controlled, single-blind, superiority trial conducted at two French university hospitals (CHU Besançon and CHU Dijon). Adult patients undergoing cardiac surgery with cardiopulmonary bypass will be randomised 1:1 to receive either femoral or radial arterial pressure monitoring. The primary endpoint is the proportion of patients treated with norepinephrine from anaesthetic induction to postoperative day 7. Secondary endpoints include acute kidney injury according to KDIGO criteria, cardiac complications, vasoactive-inotropic scores, duration of vasopressor therapy, vascular complications, and 7-day and 30-day mortality. Sample size calculation indicates 340 patients (170 per group) are needed to detect a 15% absolute reduction in norepinephrine use with 90% power and α=0.05, and an anticipated loss to follow-up rate of 5%. ETHICS AND DISSEMINATION: The study has been approved by the French Ethics Committee (Comité de Protection des Personnes Nord-Ouest II, no. 2024/897) and will be conducted according to the Declaration of Helsinki and Good Clinical Practice guidelines. Results will be submitted for publication in peer-reviewed journals and presented at international conferences. TRIAL REGISTRATION NUMBER: NCT06952907.