LAUSR

PurposeThe purpose of this study was to assess the changes in regional cerebral oxygen saturation (rScO2) in response to different ventilation strategies: inspired oxygen concentration (FiO2), end-tidal carbon dioxide (EtCO2), and positive end expiratory pressure (PEEP) in addition to optimizing mean arterial pressure (MAP) in obese patients subjected to laparoscopic bariatric surgery in the reverse trendelenburg position.Methods50 obese patients were randomly assigned into one of two groups. Each group is 25 patients. Control patients subjected to a ventilation strategy aimed to maintain FiO2 0.4 and EtCO2 30 mmHg without PEEP. Study patients were assigned to specific protocol; T0, baseline rScO2; T1, 5 min following induction; T2, PP/RTP (10 min after pneumoperitoneum and reverse trendelenburg position); T3, PEEP 10 cmH2O; T4, FiO2 1.0; T5, EtCO2 40 mmHg and T6, MAP/BL; MAP back to baseline in both groups.Main results10 min after PP/RTP, there was a significant decrease in rScO2 in both groups. At T4, with FiO2 1.0, there was significant improvement in rScO2 when compared to T2. At T5, with EtCO2 40 mmHg, rScO2 significantly enhanced when compared to EtCO2 30 mmHg. At T4 and T5, we observed highly significance difference between both groups. At the end of the procedure and when MAP increased back to baseline (T6) in both groups, rScO2 statistically increased in both groups when compared to T2.ConclusionIn obese patients, subjected to laparoscopic bariatric surgery in reverse trendelenburg position, adjustment of ventilation strategies and hemodynamic optimization succeeded to improve rScO2.