Effects of small-dose remifentanil combined with index of consciousness monitoring on gastroscopic polypectomy: a prospective, randomized, single-blinded trial

Abstract

BackgroundWith the development of painless diagnosis and treatment, remifentanil, a synthetic opioid agonist, is increasingly used in gastroscopy for its rapid, short-term, and potent analgesic effect. However, the dosage of remifentanil used in endoscopy is unclear. Index of consciousness (IOC) is a new anesthesia depth-monitoring indicator that can be divided into index of consciousness 1 (IOC1) and index of consciousness 2 (IOC2); IOC1 is used for estimating a patient’s sedation state, whereas IOC2 reflects analgesic depth. We hypothesized that combining with IOC1 and IOC2 monitoring may be helpful to identify an optimal remifentanil dosage in gastroscopic polypectomy.MethodsOne hundred twenty patients scheduled for gastroscopic polypectomy were enrolled and were randomly assigned to remifentanil 2 ng/mL (group R2), 4 ng/mL (group R4), or 6 ng/mL (group R6), and 40 cases were in each group. During the anesthesia period, remifentanil was kept at the initial given concentration but propofol was adjusted according to IOC1. The primary outcomes were the dosage of propofol and remifentanil. The secondary outcomes were the variety of IOC1 and IOC2, patients’ awakening time, and peri-operative adverse reactions such as hypotension, hypertension, bradycardia, tachycardia, body movements, hypoxemia, therapy interruption, nausea, vomiting, aspiration, and intra-operative awareness.ResultsWith the increasing dosage of remifentanil, the propofol dosage and patients’ awakening time decreased significantly, the morbidity of hypertension and body movements also declined, but the incidence of hypotension, bradycardia, and hypoxemia rose. In group R2, the value of IOC2 remained above 50 during the treatment. However, IOC2 dropped to below 30 at the beginning of the gastroscopy in group R6, and there was statistical difference in hypoxemia between groups R2 and R6 (P <0.05).ConclusionsWith the help of IOC monitoring, we found that a target concentration of remifentanil 4 ng/mL is comparatively ideal in patients under gastroscopic polypectomy.Trial registrationChinese Clinical Trial Register: ChiCTR-OOD-16009489, on October 19, 2016.

Effects of Depth of Anesthesia Monitored by IoC on Patients Undergoing Laparoscopic Radical Resection of Colorectal Cancer

“…For example, it is reported that IoC is a better predictor than BIS for representing patient's consciousness during the anesthesia induction and maintenance with sevoflurane and remifentanil. 32 Monitoring anesthesia through IoC makes the whole procedure more controllable and effectively reduces adverse events during the operation. 33 The current clinical research on IoC mainly focuses on IoC1.…”

Comparison of propofol-esketamine versus propofol for anesthesia in gastroscopy: a double-blind, randomized controlled clinical trial

“…Tachycardia or bradycardia was defined as heart rate (HR) increased or decreased by more than 25% of the first recorded HR on the monitor screen ( 20 ) Urapidil (10–20 mg) or ephedrine (0.1–0.2 mg/kg) was administered IV to treat hypertension or hypotension, respectively. Esmolol (1 mg/kg) or atropine (0.005–0.01 mg/kg) was administered IV to treat tachycardia or bradycardia, respectively ( 16 , 21 ). Hypoxemia was defined as 75% < SpO 2 < 90% in 60 s or SpO 2 < 75% at any moment ( 20 , 22 ).…”