Object:

1.    Evaluating the consumption of Sevofluran during low flow anesthesia with ecoflow at fresh gas flow 0.5 L/min for abdominal surgery in elderly patients.

2.    Describing changes in O2, CO2 during low flow anesthesia with ecoflow at fresh gas flow 0.5 L/min for abdominal surgery in elderly patients.

Materials and methods: 30 patients, ASA I, II,III aged ≥ 60 years undergoing opened abdominal surgery were included. The inhalation anesthetic maintenance was done with low flow at FGF 0.5L / min, FiO2 50%. A standardized anesthetic monitorings (MAC-Sevofluran, entropy, SPI, TOF, heart rate, MAP, SPO₂, EtCO₂,FiO2, blood gas) were utilized.

Results and conclusions: The average amount of Sevoflurane consumed during low flow anesthesia with ecoflow at fresh gas flow 0.5 L/min for abdominal surgery in elderly patients was 0.15ml/min. Of the 30 patients studied, 17 patients (57.6%) had a decrease in FiO2 to 25% (PaO2= 74.3±44.3 mmHg) after 75.8±27.4 minutes and five patients (16.7%) had EtCO2 increased to 45 mmHg after 82.2±36.4 minutes. FiO2 and EtCO2 at the time of the starting lowflow anesthesia to the end of lowflow anesthesia was statistically significantly increased with P <0.05.