Comments(1)

Interpretation of Goal-Directed Therapy

Greg Martin   (17 November 2005)  Emory University

I congratulate the authors on completing a scientifically important study that has the potential to change clinical practice. To apply these methods to clinical practice it is necessary to more fully understand the measurements and interventions. For instance, the groups are initially resuscitated according to central venous pressure (CVP, control group) and stroke volume (SV, goal-directed therapy [GDT] group). These goals are not necessarily consistent, as CVP does not accurately reflect preload or cardiac function, while stroke volume is a direct correlate of cardiac output. These different goals may have implications for the algorithm, as patients with insufficient cardiac function (defined as cardiac index < 2.5 mL/min/m²) are meant to receive intravenous epinephrine. The distribution of these patients is likely different between groups, as suggested by inter-group differences in SV in Table 2. Because the administration of epinephrine has adverse consequences (being arrhythmogenic and increasing myocardial oxygen demand), differences in the utilization of epinephrine between groups could influence the study results. Thus, in order to interpret the results and generalize the interventions, it would be useful for the authors to describe the proportion of patients in each group who failed to achieve an "adequate" cardiac index, the proportions who received epinephrine, and any difference in adverse events (i.e. cardiac arrhythmias) between groups.

Competing interests

None.

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