GASTRIC TONOMETRY SUPPLEMENTS INFORMATION PROVIDED BY SYSTEMIC INDICATORS OF OXYGEN-TRANSPORT

Hypothesis. Assessment of splanchnic perfusion by gastric intramucosal pH (pHi) adds to the information provided by systemic indicators of oxygen transport. Setting. University Hospital level I trauma center. Design. Prospective study in 20 critically ill trauma patients comparing pHi with base deficit, lactate, oxygen delivery, and oxygen consumption (indexed to body surface area), mixed venous oxygen saturation (SVO2), oxygen utilization coefficient, and arterial pH. All measurements were obtained at admission, 1, 2, 4, 8, 16, and 24 hours, or at death. Main Outcome Measures. Correlation of pHi with the measured systemic variables, prediction of organ dysfunction, development of multiple organ dysfunction syndrome, and mortality. Results. There was a poor correlation between pHi and the systemic hemodynamic and oxygen transport variables. Patients with a low pHi (<7.32) on admission who did not correct within the initial 24 hours had a higher mortality (50% vs. 0.0%, p = 0.03) and incidence of organ dysfunction (2.6 organs/patient vs. 0.62 organs/patient, p = 0.02) than those who did. Using logistic regression analysis, only pHi, base deficit, and SVO2 were significantly associated with mortality during the study period. At 24 hours, only pHi was different between patients who developed multiple organ dysfunction syndrome and those who did not. There was a threshold value for pHi (7.10) which identified those patients who would go on to develop multiple organ dysfunction syndrome. Conclusions. Uncorrected splanchnic malperfusion is associated with a higher incidence of organ dysfunction and mortality. Gastric tonometry supplements information provided by systemic indicators of oxygen transport during resuscitation of critically ill trauma patients.