Effect Of Total Introvenous And Intravenous-inhalation Combined Anesthesia On Serum Levels Of γ-aminobutyric Acid

Emergence agitation in the awaking stage of general anesthesia is not a new phenomenon in clinical practice. In the early 1960s, Eckenhoff et al. were the first to report the signs of hyperexcitation, up to now, we still do not know much more about its etiology, nor do we have a reliable assessment tool or clear-cut preventive strategy for this short-lived but troublesome clinical event. Such a delirium can suddenlu become dangerous and have serious consequences such as injury, increased pain, haemorrhage, self-extubation and removal of catheters re quiring physical or chemical restraint. The incidence of emergence agitation is around 5.3%. Emergence agitation results in the significantly negative influence on the quality of recovery after surgery. Although Emergence delirium is mostly a self-limited phenomenon (last for about 5min-15min), the serious consequence should not be ignored. Given that the mechanism of the emergence agitation is not known well, no single etiology can be determined to explain this phenomenon, anesthetic and surgical factors may influence the incidence, Emergence agitation during anesthetic recovery stage has been a feature of general anesthesia with the development of our modern anesthetics (especially inhalational agents), Both sevoflurane and isoflurane are indisputably associated with a higher incidence of emergence agitation than propofol. emergence agitation may also be the consequence of other etiologies, including hypoxemia, pain, bladder distension, and nausea, et al. However, there are still many questions that deserve answers. What links the above mentioned inhaled anesthetics to EA/ED?Obviusly, further trials are necessary to discover the underlying causes of EA/ED and to determine which factors might help predict and potentially prevent it. For consistency, it seems reasonable for studies to target the same substrate that affected by both inhaled and introvenous anesthetics,γ-Aminobutyric acid (GABA) is a major inhibitory neurotransmitter in the CNS and also the common substrate of inhaled anesthetics and propofol. The purpose of the trial is to compare the effect of total introvenous anesthesia and intravenous-inhalation combined anesthesia on serum levels ofγ-aminobutyric acid (GABA) and to investigate the possible mechanism of emergence agitation during the awaking stage of general anesthesia. Thirty ASAⅠ~Ⅲpatients undergoing upper abdominal surgery were randomly divided into propofol group (A), isoflurane group (B) and sevoflurane group (C). Peripheral venous blood was drawn before induction and at 15min, 60min after operation. Serum levels of GABA were measured with enzyme linked immunosorbent assay. There was no significant difference among the three groups in the serum levels of GABA before induction. T he serum GABA level at all time points postoperatively was increased comparing to that before induction (P<0.05), in contrast to intravenous group (group A), the serum level of GABA of the inhalation group (group B and C) was increased more significantly. The results suggest that propofol, isoflurane or sevoflurane could increase the serum level of GABA, in addition, the effect of isoflurane and sevoflurane is more obviously than that of propofol. The results suggest that propofol, isoflurane or sevoflurane could increase the serum level of GABA,in addition, the effect of isoflurane and sevoflurane is more obviously than that of propofol. Such result is in accordance with the clinical phenomenon that inhalation general anesthetic is one of the most important causes for emergence agitation. Thus, we can presume the mechanism of inhalation general anesthetic inducing emergence agitation.