Perfusion Efficiency-Guided MAP De-escalation in Elderly Septic Shock

This is a single-center, prospective, randomized crossover physiological trial conducted in elderly patients (≥65 years) with septic shock in the intensive care unit (ICU). All enrolled patients receive sequential titration of mean arterial pressure (MAP) to three predefined target ranges (60-65 mmHg, 65-70 mmHg, and 70-75 mmHg) in randomized order. The primary objective is to compare tissue perfusion pressure (TPP) between the low and intermediate MAP targets, and to test the non-inferiority hypothesis that the lower MAP target is non-inferior to the intermediate target. Multiple secondary microcirculatory, systemic perfusion, and safety indicators are collected during steady-state hemodynamic periods under each MAP target stage. Researchers will adopt linear mixed-effects models to analyze intra-individual differences across blood pressure targets and explore the MAP threshold for optimal peripheral perfusion. Safety outcomes including adverse hemodynamic events and long-term clinical follow-up data will also be assessed.