Response to Dobutamine in Septic Shock With Myocardial Dysfunction: A Single-Center Retrospective Study.

IMPORTANCE: Dobutamine is recommended for septic shock with myocardial dysfunction and persistent hypoperfusion despite preload and mean arterial pressure optimization; however, supporting evidence is limited, and predictors of response remain unclear. OBJECTIVES: To determine whether early hemodynamic responsiveness to dobutamine is associated with clinical outcomes and whether baseline echocardiographic parameters identify responders. DESIGN, SETTING, AND PARTICIPANTS: Single-center retrospective cohort study at a quaternary academic medical center. Adults with septic shock who received concomitant dobutamine with vasopressor therapy and underwent transthoracic echocardiography within 12 hours before dobutamine initiation. MAIN OUTCOMES AND MEASURES: Hemodynamic responsiveness was defined as the combination of an increase in central venous oxygen saturation (ScvO2) of at least five percentage points and a reduction in norepinephrine-equivalent (NEE) dose measured at 2 hours after dobutamine initiation. The primary outcome was 28-day ICU mortality. Secondary outcomes included ICU-free days and renal replacement therapy (RRT) requirement. RESULTS: Of 104 patients, 37 (36%) met the composite definition of hemodynamic response. Baseline demographics, illness severity, lactate, and baseline vasopressor dose were similar between groups. Beyond the 2-hour window used to define response, separation persisted at 6 hours: responders showed a greater reduction in NEE dose (ΔNEE, -0.13 vs. 0.04 µg/kg/min; p < 0.001) and a higher MAP/NEE ratio (380 vs. 166; p = 0.003), and a greater increase in ScvO2 (+12% vs. +6%; p = 0.014). 28-day ICU mortality was 41% in responders and 58% in nonresponders (p = 0.13); after multivariable adjustment, hemodynamic response was associated with lower 28-day ICU mortality (odds ratio, 0.18; 95% CI, 0.04-0.68; p = 0.018). Responders had more ICU-free days (17 [0-22] vs. 0 [0-15]; p = 0.017); RRT requirement did not differ (43% vs. 37%; p = 0.7). No baseline echocardiographic parameter was associated with hemodynamic responsiveness. CONCLUSIONS AND RELEVANCE: In septic shock with myocardial dysfunction, early hemodynamic responsiveness to dobutamine identified a subgroup with a more favorable clinical trajectory. Resting echocardiographic parameters did not identify responders. These findings are hypothesis-generating and require prospective confirmation.