Influência da adequação anestésica controlada pelo eeg sobre o estresse oxidativo e metabolismo anaeróbico em operações pelo acesso videolaparoscópico

Abstract

The present study evaluated the influence EEG-monitored depth of anesthesia (BIS, SEF 95%, pEMG and TS) on the blood levels of the metabolites (lactate, piruvate and glucose) of thiobarbituric acid-reactive substances (TBARS) and glutathione in patients submitted to laparascopic surgery. Twenty adult subjects (ASA I, body mass index 20–26, age 20–40 years) were randomly assigned to one of two groups: Group I – BIS maintained in the range 45–60 during surgery; Group II – BIS maintained in the range 30–45. The patients were evaluated at six different moments: M1 (immediately before induction of anesthesia), M2 (immediately before tracheal intubation), M3 (immediately after tracheal intubation), M4 (immediately before pneumoperitoneum), M5 (immediately after pneumoperitoneum) and M6 (one hour after surgery). BIS levels were adjusted according to the end tidal concentration of sevoflurane. The parameters PAS, PAD, FC, BIS, TS, SEF 95%, CEsevo, TBARS, glutathione, lactate, piruvate and glycemia were measured at all six moments. The groups were comparable with regard to anthropometric variables, duration of surgery, anesthesia and pneumoperitoneum (p>0.05), and the hemodynamic variables were within the normal range. Lactate, piruvate, glycemia, TBARS and glutathione levels increased significantly at M5 in both groups (p<0.05), but especially in Group II (deeper levels of anesthesia). Burst supression was observed for three patients in Group II after pneumoperitoneum. The observed increase in plasma concentrations for all parameters in Group I indicates increased anaerobic metabolism in the splanchnic circulation, while the high concentrations observed for Group II (GII>GI at M5; p<0.05) suggests the interference of another factor (deep anesthesia) inducing anaerobic metabolism, probably through increased depression of the autonomous nervous system and decreased splanchnic autoregulation.