Comparison of hemodynamic effects with thoracic electrical bioimpedance monitoring in desfiumne anaesthesia applied with low and high flow

Abstract

Background and Goal of Study: After the removal of exhaled CO2, rebrcathing of 50% or more of exhaled gases is possible during low flow anaesthesia. The purpose of this study is to compare the thoracic electrical bioimpedancc (TEB) method for hcmodynamic monitoring under low flow and high flow desfluranc anaesthesia. Material and Methods: After Institutional Ethics Committee approval, 40 ASA I-II patients scheduled for elective surgery were included into the study. For all patients, anaesthesia was induced with 1.5 ?g kg-1 fentanyl and 5-7 mg kg-1 thiopcnthal. The trachea was intubated after 0,1 mg kg-1 vecuronium, Patients were randomly divided into two groups to receive low flow (1 L min-1 50% N2O+O2) in group I or high flow (4 L min-1 50% N2O+O2) in group II with 4-6%. Ejection fractions (EF), end-diastolic indexes (EDI), cardiac indexes (CI), stroke indexes (SI) were monitored and recorded with noninvasivc TEB for basal, induction, intubations and 15 min. intervals. The level of anaesthesia was adjusted by the concentration of dnsflurane to achieve a target BIS in the range of 40-60. Postoperative Aldrete Recovery Score (ARS) was recorded. Student-t test and repeated measures of variance were used to statistical analysis. p<0.05 was accepted statistiealy significant. Results: The concentrations of end-tidal desfluranc in group II were significantly higher than group I at the 45 th and 60th minutes (p<0,05). The EDI at 45 th and 60th minutes in group I were significantly higher than group II (p<0.05). The values of CI, SVI and EF were similar in group I and II. The ARS at 5th and 10th minutes were significantly higher in group I. Conclusion: We concluded that low flow or high flow anaesthesia technique by desfluranc has similar hemodynamic effects by using TEB method.