Tissue oxygenation as a target for goal-directed therapy in high-risk surgery: a pilot study

BACKGROUND: Tissue hypoperfusion occurs frequently during surgery and may contribute to postoperative organ dysfunction. There is a need for perioperative treatment protocols aiming at improving tissue oxygenation (StO(2)). We hypothesised that intra-operative optimisation of StO(2) improves tissue perfusion and thus reduces postoperative complications. Furthermore, we evaluated the feasibility of the optimisation algorithm used. METHODS: We randomized 50 high-risk patients, all >65 years with ASA physical status III, who underwent major abdominal surgery under standardized balanced general anesthesia combined with epidural analgesia. Throughout surgery StO(2) was monitored at the thenar eminence using near-infrared spectroscopy. All patients were treated according to a standard care algorithm. In addition, patients in the intervention group were treated with dobutamine if necessary to keep or raise StO(2) ≥ 80%. Data were recorded continuously and complications were recorded during hospital stay with a maximum of 28 days. RESULTS: The number of complications was not significantly different between groups (11 vs 20; p = 0.23). Eleven patients in the intervention group had no complication, versus 7 in the control group. There was no significant difference between groups in length of stay in ICU or in hospital. Only ten patients in the intervention group received dobutamine. Administration of dobutamine resulted in a moderate 6 [-3 to 10] % increase of StO(2). The overall protocol adherence was 94%. CONCLUSIONS: No statistically significant difference in outcome was realized through intraoperative optimization of StO(2) values in this pilot study. The protocol used may be considered feasible for clinical practice. Further research is obligatory to define both the optimal StO(2) threshold and intervention to treat tissue hypoperfusion. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01342900. Registered 21 April 2011.