Effects of different remifentanil target concentrations on MAC _BAR of sevoflurane in patients with liver dysfunction under carbon dioxide pneumoperitoneum stimulus: A randomized controlled trial

Abstract

What is known and objective Remifentanil can effectively decrease the sevoflurane concentration to block sympathetic adrenergic response to CO2 pneumoperitoneum stimulus,and liver dysfunction will significantly reduce the MACBAR (minimum alveolar concentration for blocking adrenergic response) of sevoflurane. However, the effects of different remifentanil concentrations on the MACBAR of sevoflurane in patients with liver dysfunction are unclear. The aim of this study was to observe the effects of different remifentanil concentrations by intravenous target‐controlled infusion on the MACBAR of sevoflurane in patients with grade B liver dysfunction under carbon dioxide pneumoperitoneum stimulus. Methods Seventy‐five patients with grade B liver dysfunction undergoing elective laparoscopic surgery were selected, and randomly divided into three groups with remifentanil plasma target concentrations of 0 (group R0), 1 (group R1) and 2 (group R2) ng/ml. Anaesthesia was induced by intravenous injection of propofol 2–3 mg/kg, remifentanil 2 μg/kg and cisatracurium 0.15 mg/kg. All groups were inhaled different concentrations of sevoflurane. The determination of sevoflurane MACBAR in each group was used a method of sequential‐allocation technique, and venous blood samples were taken before and after the creation of carbon dioxide pneumoperitoneum to determine plasma adrenaline and noradrenaline concentrations. Results and discussions The MACBAR of sevoflurane in groups R0, R1 and R2 was 4.83%, 3.00% and 2.10%, respectively. The MACBAR of sevoflurane was significantly difference among the three groups. When a similar effect of MACBAR had achieved in each group, no significant differences were found in the changes of plasma adrenaline and noradrenaline concentrations before and after the creation of pneumoperitoneum. What is new and conclusion Target‐controlled infusion of different concentrations of remifentanil can reduce sevoflurane MACBAR during pneumoperitoneum stimulation in patients with liver dysfunction in some degree. However, the changes of plasma adrenaline and noradrenaline concentrations are consistent in the three groups when patient's stress response was inhibited at the same degree.

Effect of remimazolam on MACBAR of sevoflurane in gynecological laparoscopic surgery: a randomized controlled trial

“…It is often used to evaluate the potency of inhalational anesthetics. Pre-pilot studies by our research team have demonstrated that opioids signi cantly reduce the MACBAR of inhalation anesthetics (2)(3)(4)(5). Other sedatives and analgesics also reduce the MACBAR of inhalation anesthetics to varying degrees (6).…”