GASTRIC INTRAMUCOSAL PH - A BETTER PREDICTOR OF MULTIORGAN DYSFUNCTION SYNDROME AND DEATH THAN OXYGEN-DERIVED VARIABLES IN PATIENTS WITH SEPSIS

Objective: To determine the value of tonometrically measured gastric intramucosal pH (pHi) and accepted indices of systemic oxygenation in predicting multiorgan dysfunction syndrome (MODS) and death in critically ill patients with sepsis. Design: Prospective, noninterventional study. Setting: Multidisciplinary ICU of a tertiary care, teaching hospital. Patients: Thirty critically ill ventilated patients with pulmonary artery catheters and nasogastric tonometers in place. Measurements and Main Results: The pHi, arterial lactate concentration, arterial and mixed venous pH, APACHE II score, and oxygen-derived variables, including oxygen delivery (DO2) and oxygen consumption (VO2) were determined within 24 h of the onset of sepsis. The patients were then followed until death or discharge from the ICU. The development of organ system dysfunction during the ICU stay was recorded. Fifteen patients developed MODS of whom 12 died. An additional three patients died. The pHi and arterial and mixed venous pH were significantly lower in those patients who developed MODS and in these patients who died. The VO2 and DO2, however, were higher in these patients. Using stepwise discriminant analysis, only the pHi contributed to the prediction of both MODS and death. Conclusions: In patients with sepsis, indices of tissue oxygenation are better predictors of outcome than the hemodynamic and oxygen-derived variables obtained by invasive hemodynamic monitoring. These indices should be used to direct therapy.