Hemodynamic assessment of different septic shock resuscitation strategies: a comparison of volume expansion versus norepinephrine administration, a prospective: Study protocol

Abstract

Background: Fluid resuscitation and vasopressors are the mainstays of septic shock management. However, individual hemodynamic responses vary significantly based on baseline cardiac function and preload status. Bedside echocardiography is a valuable tool for assessing these parameters, monitoring fluid responsiveness, and predicting vasopressor efficacy, which can ultimately improve patient outcomes. While recent studies have explored echocardiographic responses to vasopressin, evidence comparing hemodynamic responses to available vasopressors (like norepinephrine) versus fluid therapy in early septic shock remains limited, particularly in Thailand, where vasopressin is unavailable. This bedside echocardiography will help identify hemodynamic responders and guide individualized, precise management. Objective: To test the hypothesized assumption that hemodynamic response would differ between volume resuscitation and norepinephrine infusion resuscitation, in terms of cardiac index and stroke volume. Methods: This is a prospective cohort study conducted in the medical and surgical intensive care units of a tertiary care hospital in Thailand. We perform pre- and post-resuscitation echocardiography on patients with septic shock. Resuscitation strategies follow the Surviving Sepsis Campaign 2021 guidelines and are entirely directed by the attending physicians without blinding or randomization. To standardize the assessment, post-resuscitation echocardiography is performed 15 minutes after one of two physician-selected interventions: either fluid resuscitation with an intravenous bolus of isotonic fluid (≥4 mL/kg ideal body weight) or vasopressor resuscitation by norepinephrine with an infusion reaching 0.05 mcg/kg/min. The primary outcome is the change in the echocardiographic cardiac index from baseline to post-resuscitation. Conclusions: This study aims to evaluate pre- and post-intervention echocardiographic profiles in septic shock patients receiving either fluid boluses or norepinephrine infusion resuscitation. Ethics and Consideration: This study was approved by Siriraj institutional review board (IRB) on Certificate of approval (COA) no. Si 061/2025 Written informed consent was obtained from all participants or legally authorized representative (LAR) prior to inclusion in the study. Trial Registration: NCT07438301