Gastroduodenal perfusion and mortality in mechanical ventilation-dependent patients with systemic inflammatory response syndrome

The role of gastrointestinal blood flow determination in predicting mortality is not known. We tested the hypothesis that when mechanical ventilation-dependent (MVD) patients with systemic inflammatory response syndrome (SIRS) develop a significant reduction in gastroduodenal blood flow, high mortality will ensue. The design was a prospective, observational study at the intensive care unit (study patients) and outpatient endoscopy suite (controls) of a tertiary care Veterans Affairs Hospital. There were 6 study patients and 10 control subjects. Interventions were endoscopic reflectance spectrophotometry recorded indexes of gastroduodenal mucosal oxygen saturation (ISO2) and hemoglobin concentration (IHB). Data for Acute Physiologic and Chronic Health Evaluation (APACHE) II scores were gathered. All study patients had septic SIRS at enrollment. Gastroduodenal blood flow measurements ranged from 32 to 55% (ISO2) and from 42 to 51% (IHB) of those in control subjects. The significant hypoperfusion upgraded diagnosis to severe sepsis. The APACHE II score of 16.8 +/- 2.8 (mean +/- SE) predicted approximately 25% mortality. Observed in-hospital mortality was 83%. Our study confirmed that MVD patients with severe sepsis have a significant impairment of gastroduodenal blood flow. Such a dramatic reduction is associated with a grave prognosis. The impact of these measurements on physicians' predictions of the likelihood of survival in patients receiving intensive care deserves to be assessed.