Effect of low-flow sevoflurane anesthesia on early postoperative renal function

Abstract

Objective To evaluate the effect of low-flow sevoflurane anesthesia on the early postoperative renal function in patients. Methods Sixty patients of both sexes, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, aged 18-64 yr, scheduled for elective non-urological surgery with general anesthesia, with an expected surgical duration>4 h, were divided into 2 groups (n=30 each) using a random number table method: middle-flow anesthesia group (groupⅠ) and low-flow anesthesia group (group Ⅱ). Anesthesia was induced with IV midazolam, sufentanil, propofol and cisatracurium besylate.Mechanical ventilation was performed after tracheal intubation.Pure oxygen served as carrier, the fresh gas flow of oxygen was set at 4-5 L/min, sevoflurane was inhaled for 10-15 min, and then fresh gas flow was decreased to 2 L/min(groupⅠ) and 0.5 L/min (group Ⅱ). End-tidal pressure of carbon dioxide was maintained at 35-45 mmHg.The end-tidal concentration of sevoflurane was set at 2.0%-2.4%, remifentanil and cisatracurium besylate were infused intravenously, and sufentanill or propofol was injected intermittently to maintain anesthesia.Bispectral index value was maintained at 40-60 during operation.Before anesthesia induction (T0), at 1, 2, 3 and 4 h after anesthesia induction (T1-4), immediately after operation (T5) and at 24 h after operation (T6), peripheral venous blood samples were collected for determination of serum fluoride ion concentrations.Peripheral venous blood samples and urine specimens were collected at T0, T5, T6, 48 h after operation (T7) and 72 h after operation (T8) for determination of creatinine (Cr), blood urea nitrogen (BUN) and cystatin C (Cys C) and serum and urine β2-microglobulin (β2-MG) concentrations. Results Compared with the baseline at T0, serum fluoride ion concentrations were significantly increased at T1-6 in two groups, the serum Cys C concentration was increased at T5, and serum and urine β2-MG concentrations were increased at T5 and T6 in groupⅠ, serum Cr and BUN concentrations and serum and urine β2-MG concentrations were increased at T5 and T6, and the serum Cys C concentration was increased at T5-T7 in groupⅡ (P<0.05). Compared with groupⅠ, serum fluoride concentrations were significantly increased at T1-6, serum Cr and BUN concentrations and serum and urine β2-MG concentrations were increased at T5, and serum Cys C concentrations at T5-T7 and urine β2-MG concentrations at T5 and T6 were increased in groupⅡ (P<0.05). Conclusion Low-flow sevoflurane anesthesia produces no marked effect on early postoperative renal function in patients. Key words: Anesthetics, inhalation; Kidney function tests; Fresh gas flow