OBJECTIVE: Investigation of the hypothesis that the infusion of 10 ng/kg/min prostacyclin (epoprostenol) (PGI2) improves O2 uptake in patients with hyperdynamic septic shock. DESIGN: Prospective, single cohort design. SETTING: ICU, university hospital. PATIENTS: Fifteen postoperative patients with septic shock. INTERVENTIONS: Infusion of 10 ng/kg/min of PGI2 for 60 min. MEASUREMENTS: Complete hemodynamic profile with O2 transport-related variables (simultaneous measurements of VO2 from the respiratory gases and by cardiovascular Fick) and blood lactate levels before start of the PGI2-infusion and 60 min thereafter. MAIN RESULTS: Oxygen delivery increased significantly (14 percent) from its already high value, 750 +/- 238 to 852 +/- 214 ml/min/m2. The O2 extraction ratio remained unchanged. When VO2 was measured from the respiratory gases, it was unchanged. When VO2 was measured by cardiovascular Fick, it increased slightly (p < 0.05). CONCLUSIONS: We conclude that in this O2 challenge test with PGI2 in patients with septic shock, an increase in O2 delivery was not matched by an increase in VO2. We believe that the adequate conventional support of these patients may have prevented the PGI2 from revealing a "covert" O2 debt. The PGI2 test did not predict mortality by O2 supply dependency. The small increase in VO2 as calculated indirectly suggests a degree of mathematical coupling of O2 delivery and uptake.
OBJECTIVE: Investigation of the hypothesis that the infusion of 10 ng/kg/min prostacyclin (epoprostenol) (PGI2) improves O2 uptake in patients with hyperdynamic septic shock. DESIGN: Prospective, single cohort design. SETTING: ICU, university hospital. PATIENTS: Fifteen postoperative patients with septic shock. INTERVENTIONS: Infusion of 10 ng/kg/min of PGI2 for 60 min. MEASUREMENTS: Complete hemodynamic profile with O2 transport-related variables (simultaneous measurements of VO2 from the respiratory gases and by cardiovascular Fick) and blood lactate levels before start of the PGI2-infusion and 60 min thereafter. MAIN RESULTS:Oxygen delivery increased significantly (14 percent) from its already high value, 750 +/- 238 to 852 +/- 214 ml/min/m2. The O2 extraction ratio remained unchanged. When VO2 was measured from the respiratory gases, it was unchanged. When VO2 was measured by cardiovascular Fick, it increased slightly (p < 0.05). CONCLUSIONS: We conclude that in this O2 challenge test with PGI2 in patients with septic shock, an increase in O2 delivery was not matched by an increase in VO2. We believe that the adequate conventional support of these patients may have prevented the PGI2 from revealing a "covert" O2 debt. The PGI2 test did not predict mortality by O2 supply dependency. The small increase in VO2 as calculated indirectly suggests a degree of mathematical coupling of O2 delivery and uptake.
Authors: Elizabeth L Cureton; Terry J Chong; Rita O Kwan; Kristopher C Dozier; Javid Sadjadi; Brian Curran; Gregory P Victorino Journal: Shock Date: 2010-06 Impact factor: 3.454