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

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.

To determine whether early hemodynamic responsiveness to dobutamine is associated with clinical outcomes and whether baseline echocardiographic parameters identify responders.

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.

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.

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.

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.