Abstract
Index of consciousness (IoC) consisting of IoC1 and IoC2, is a new analgesia monitoring indicator in anesthesia evaluation in the laparoscopic radical resection of colorectal cancer. Although the precise anesthetic dosage adjusted by IoC1 has been confirmed to enhance the recovery and reduce the complications of anesthesia, the most appropriate range of IoC2 during anesthesia remains unclear. To investigate the correlation between IoC2 and peri-operative indicators of patients during laparoscopic radical resection of colorectal cancer, the current randomized, controlled, and single-blinded clinical trial was performed. Participants were divided randomly into three groups with different anesthesia depth monitored by IoC2 during their laparoscopic radical resections. Primary outcomes included the dosage of remifentanil. Secondary outcomes included other physiological indexes and complications. The remifentanil dosage and the awakening time increased as IoC2 decreased. The incidences of hypotension and hypoxemia decreased with the elevated IoC2, but the risk of intra-operative awareness also increased. The impact caused by anesthesia to the immune system and health-related life quality of the patients descended with reduced anesthetic level. The IoC2 range of 35-45 could represent the most appropriate anesthetic depth during laparoscopic radical resection, which provides a new perspective for the clinical treatment of colon cancer.