INTRODUCTION
The technique of non-invasive monitoring of the depth of anesthesia (index of depth of anesthesia, qCON) and analgesia (index of nociception, qNOX (quantium (quantity) and “NOX” from the Latin noxious stimulus)) and using the Conox monitor, allows you to evaluate the hypnotic and analgesic effect during conducting general anesthesia based on electroencephalogram registration. Intraoperative monitoring of these indicators makes it possible to determine the optimal balance between the required dose of opiates and a sufficient level of analgesia for surgical intervention, which in turn leads to a reduction in the risks associated with excessive or insufficient levels of general anesthesia and analgesia.
OBJECTIVE
To evaluate the information content of the qCON and qNOX indicators for objectifying the depth of anesthesia and analgesia in patients undergoing laparoscopic cholecystectomy under general anesthesia.
MATERIALS AND METHODS
The study included 80 patients aged 35-80 years with physical status ASA I-III who underwent laparoscopic cholecystectomy under general anesthesia. The patients were divided into two groups: in the 1st group (n=40), intraoperative control of the depth of anesthesia and analgesia was carried out by assessing the main hemodynamic parameters — systolic blood pressure (mmHg), heart rate (beats/min), cardiac index (l/min/m2), total peripheral vascular resistance (din·s·cm–5); in the 2nd group (n=40), in addition to monitoring the main hemodynamic parameters, general anesthesia was carried out under the control of qCON and qNOX indicators. In the postoperative period, the level of pain was assessed 1, 4, 8 hours after the end of the surgical intervention and transfer to the surgical department — using a Visual Analogue Scale (VAS) (from 0 to 10). On the 2nd day after surgery, the need for narcotic analgesics and the frequency of postoperative nausea and vomiting (PONV) were assessed.
RESULTS
Hemodynamic parameters in both groups at all stages of the operation were not statistically significantly different. The minimum alveolar concentration (MAC) of sevoflurane in both groups was the same and amounted to 0.9-1.0 MAC, while the dose of fentanyl was statistically significantly lower (p<0.05) in the 2nd group than in the 1st group (0.2 [0.2; 0.3] mg and 0.4 [0.2; 0.5] mg, respectively). No patient from both groups required the administration of narcotic analgesics for postoperative pain relief. The incidence of PONV was 37.5% in the 1st group and 12.5% in the 2nd group.
CONCLUSION
The qCON and qNOX indices provided objectification of the depth of anesthesia and analgesia, and their dynamic assessment in patients undergoing laparoscopic cholecystectomy under general anesthesia made it possible to reduce the dose of opiates by an average of 2 times (without reducing the quality of general anesthesia) and reduce the incidence of PONV by 25%.
