Bispectral index monitoring (BIS) is one of the major techniques used in monitoring depth of anaesthesia. The present study was carried out toevaluate and correlate the efficacy of BIS monitoring along with PRST score in assessment of depth of anaesthesia

A prospective clinical study was conducted on 160 patients undergoing surgery in various specialties. . This study was carried out on adult patients of ASA I/II posted for elective surgeries under general anaesthesia. Conditions and drugs likely to interfere with BIS values were excluded. Anaesthesia protocol was kept uniform.These patients were divided into two groups of 80 patients each by consecutive selection In Group 1- depth of anaesthesia will be assessed by Evan’s score or PRST score .Group 2- by BIS index monitoring and PRST score Before induction, all patients were premedicated using midazolam (0.05 mg / kg).For induction of anesthesiaInj.Propofolwas used with a dose of 1.5 to 2.5 mg/kg, for muscle relaxation appropriate dose of atracurium /vecuronium/rocuroniumwas used while the anaesthesia is maintained with oxygen, nitrous oxide and sevoflurane, and analgesia with opioids. Statistical analysis is performed by descriptive statistics to calculate the mean and standard deviation.The t-test, χ ² tests for calculating the materiality for establishing the results.

In Group -1 ( PRST ) group some patients experienced dreams but the difference with Group -2 was not statistically significant.Group-2 patients were found to have adequate depth of anaesthesia with no explicit recall. In laparoscopic surgeries Bi-spectaral index was found to be more reliable indicator of depth of anaesthesia than the PRST score ,though the bispectral index was between 40-60 PRST scores indicated inadequate depth of anaesthesia

Evaluation of intraoperative depth of anaesthesia is one of the main tasks of anaesthesiologist’s. The use of BIS monitoring with clinical assessment allows anaesthesiologists precise decision-making and balancing a dose of anaesthetics and other medications such as analgesics and cardio active agents, especially in patients with higher operative risk