The effects of prostacyclin on gastric intramucosal pH in patients with septic shock

Objective To investigate whether infusing prostacyclin (PGI₂) in patients with septic shock improves splanchnic oxygenation as assessed by gastric intramucosal pH (pHi).Design Interventional clinical study.Setting Surgical ICU in a university hospital.Patients 16 consecutive patients with septic shock according to the criteria of the ACCP/SCCM consensus conference all requiring norepinephrine to maintain arterial blood pressure.Interventions All patients received PGI₂ (10 ng/kg·min) after no further increase in oxygen delivery could be obtained by volume expansion, red cell transfusion and dobutamine infusion. The results were compared with those before and after conventional resuscitation. The patients received continuous PGI₂ infusion for 3–32 days.Measurements and results O₂ uptake was measured directly in the respiratory gases, pHi was determined by tonometry. Baseline O₂ delivery, O₂ uptake and pHi were 466±122 ml/min·m², 158±38 ml/min·m², and 7.29±0.09, respectively. While O₂ uptake remained unchanged, infusing PGI₂ increased O₂ delivery (from 610±140 to 682±155 ml/min·m²,p<0.01) and pHi (from 7.32±0.09 to 7.38±0.08,p<0.001) beyond the values obtained by conventional resuscitation. While 9 of 11 patients with final pHi>7.35 survived, all patients with final pHi<7.35 died (p<0.01).Conclusions Infusing PGI₂ in patients with septic shock increases pHi probably by enhancing blood flow to the splanchnic bed and thereby improves splanchnic oxygenation even when conventional resuscitation goals have been achieved.Presented in part at the 13th International Symposium on Intensive Care and Emergency Medicine, Brussels, March 1993