Objective: To measure the clinical effects of dopexamine on systemic and splanchnic perfusion in critically ill patients.
Design: Prospective study.
Setting: General intensive care unit.
Patients: Ten patients with sepsis syndrome, acute respiratory failure, and at least one other organ system in failure. The median age of the patients was 62.5 yrs (range 29 to 78), and the median admission Acute Physiology and Chronic Health Evaluation (APACHE) II score was 24 points (range 14 to 38).
Interventions: Timed infusion of dopexamine to a maximum dose of 6 micrograms/kg/min.
Measurements and main results: Systemic hemodynamics and oxygen transport variables were obtained from measurements after arterial and pulmonary artery catheterization. Gastric intramucosal pH and hepatic blood flow/function measurements were made by tonometry and indocyanine green clearance, respectively. All measurements were made before dopexamine infusion, after 1 hr of dopexamine infusion, and again 1 hr after the infusion ended. Cardiac index increased with dopexamine from a baseline median of 4.0 L/min/m2 (range 1.2 to 5.5) to 4.8 L/min/m2 (range 1.5 to 8.03) (p < .01), and returned to its previous level 1 hr after the infusion ended (median 4.0 L/min/m2 [range 1.4 to 5.8], p < .01). During dopexamine infusion, gastric intramucosal pH improved significantly from a median baseline level of 7.21 (range 7.04 to 7.50) to 7.28 (range 7.13 to 7.46, p < .05). This improvement in gastric intramucosal pH was maintained (median 7.36 [range 7.13 to 7.46]) after the infusion ended. Indocyanine green half-life decreased but not significantly with dopexamine (medians before and during the infusion were 6.6 and 6.3 mins, respectively). Indocyanine green half-life increased significantly 1 hr after the infusion ended (median 7.4 mins [range 4.4 to 14.8], p < .05), and changes in cardiac index correlated with changes in indocyanine green half-life (Rs2 = 0.60, p < .001). Changes in gastric intramucosal pH were unrelated to all other measurements.
Conclusions: Dopexamine improves gastric intramucosal pH, and thus, splanchnic oxygenation. This improvement in gastric intramucosal pH appears to be independent of dopexamine's systemic effects.