Effects of epinephrine compared to dobutamine-norepinephrine on gastric perfusion in septic shock

In septic shock, the effects of catecholamines on gastrointestinal blood flow remain controversial. The aim of our study was to compare epinephrine (E) to the combination dobutamine-norepinephrine (D–N) on gastric perfusion in septic shock patients.

Methods

The study was prospective, randomized, on two parallel groups. Systemic and pulmonary hemodynamics, gastric mucosal blood flow (GMBF, laser Doppler), hepatic function (indocyanine green clearance) and blood gases were evaluated just before catecholamines infusion and as soon as mean arterial pressure reached 70–80 mmHg. E or N were titrated (from 0.1 μg/kg/min with 0.2 μg/kg/min increases every 5 min). D was continuously infused at 5 μg/kg/min.

Results

Twenty-two patients were included (11 in each group). At randomization, there was no significant difference between groups. At time of evaluation, mean arterial pressure was 78 ± 3 and 77 ± 5 mmHg in E and D–N groups, respectively. There was no significant difference between groups whichever the systemic and pulmonary hemodynamic or blood gas variable considered. Nevertheless, compared to D–N, E tended to induce greater values of cardiac index (5.0 ± 1.6 vs 4.2 ± 1.5 l/min/m², P = 0.078) and oxygen transport (617 ± 166 vs 481 ± 229 ml/min/m², P = 0.068), induced significantly greater values of GMBF (662 ± 210 vs 546 ± 200 units, P = 0.011) but did not modify indocyanine green clearance.

Conclusion

In septic shock patients, at the same mean arterial pressure, E enhances more GMBF than the combination of D at 5 μg/kg/min and N (see Fig Figure 1. overleaf). This effect, which probably results from higher cardiac index, emphasizes the crucial importance of doses in the pharmacodynamic profile of catecholamines.

Figure 1