Dopexamine Test in septic shock with hyperlactatemia.

To evaluate the 6 hours haemodynamic effects of dopexamine (DPX) infusion in septic shock patients with persistent hyperlactatemia treated with high dose of norepinephrine (NE). Preliminary, prospective, uncontrolled study. Twenty-one septic shock with NE>0.5 μg/kg/min, venous mixed oxygen saturation (ScvO(2)/SvO(2))>70%, cardiac index (CI)>3.5 l/min/m(2) and lactate>3 mmol/l. Infusion of DPX at 0.5 μg/kg/min. After 6 hours, patients were classified as DPX-responders or DPX-non-responders according to the presence or not of a decrease ≥20% in lactatemia. DPX-responders and DPX-non-responders were compared with MAP, CI, central venous pressure (CVP), heart rate (HR) before infusion of DPX (h0), 30 minutes (h0.5) and 6 hours later (h6); and with NE infusion rate at h0 and h6. Eleven (52%) patients were DPX-responders and 10 (48%) DPX-non-responders. At H0.5, DPX-responders increased MAP more than DPX-non-responders (+21% versus +7%, P=0.01) with no change in CI, CVP and HR in both groups. At h0.5, an increase in MAP higher than 14%, compared to h0, could predict lactate clearance at h6 (sensitivity 91%, specificity 90%). From h0 to h6, increase in MAP (80±7 versus 70±8 mmHg, P<0.01) in DPX-responders allowed reduction in NE infusion (from 1.6±0.3 to 0.4±0.3 μg/kg/min, P<0.01); 28-day mortality was lower in DPX-responders than in DPX-non-responders (7 versus 90%, P<0.01). This study suggests that DPX did induce a decrease in lactatemia in 52% of septic shock, that could be predict by an increase in MAP (>14% within 30 minutes). Controlled studies are needed to confirm those preliminary results.