THE EFFECTS OF PROSTACYCLIN ON GASTRIC INTRAMUCOSAL PH IN PATIENTS WITH SEPTIC SHOCK

Objective: To investigate whether infusing prostacyclin (PGI,) in pati ents 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 consecuti ve patients with septic shock according to the criteria of the ACCP/SC CM consensus conference all requiring norepinephrine to maintain arter ial blood pressure. Interventions: All patients received PGI(2) (10 ng /kg . min) after no further increase in oxygen delivery could be obtai ned by volume expansion, red cell transfusion and dobutamine infusion. The results were compared with those before and after conventional re suscitation. The patients received continuous PGI(2) infusion for 3-32 days. Measurements and results: O-2 uptake was measured directly in t he respiratory gases, pHi was determined by tonometry. Baseline O-2 de livery, O-2 uptake and pHi were 466 +/- 122 ml/min . m(2), 158 +/- 38 ml/min . m(2), and 7.29 +/- 0.09, respectively. While O-2 uptake remai ned unchanged, infusing PGI(2) increased O-2 delivery (from 610 +/- 14 0 to 682 +/- 155 ml/min . m(2), p < 0.01) and pHi (from 7.32 +/- 0.09 to 7.38 +/- 0.08, p < 0.001) beyond the values obtained by conventiona l resuscitation. While 9 of 11 patients with final pHi > 7.35 survived , all patients with final pHi < 7.35 died (p < 0.01). Conclusions: Inf using PGI(2) in patients with septic shock increases pHi probably by e nhancing blood flow to the splanchnic bed and thereby improves splanch nic oxygenation even when conventional resuscitation goals have been a chieved.