Median effective concentration of remifentanil for the inhibition of laryngoscope-induced cardiovascular responses

Abstract

Abstract. The aim of this study was to calculate the median effective concentration (EC 50 ) of remifentanil (Rem) for the inhibition of laryngoscope-induced cardiovascular responses, and to observe its effects on the cardiovascular system and stress system. The study included 20 patients, who underwent time-scheduled vocal cord polyp resection with monitoring of heart rate (HR), mean blood pressure (MBP) and auditory evoked potential (AEP)-based A-line ARX Index (AAI). The Rem concentration was initially 5 ng/ml in the first patient, and the concentration selected for each subsequent patient was calculated from the previous case on the basis of whether or not cardiovascular reactions occurred. The HR, MBP and AAI at baseline, after the induction of anesthesia, and before and after the insertion of a self-retaining laryngoscope were recorded, with a change >15% recorded as a positive cardiovascular response. The EC 50 sequential method was used to calculate the EC 50 of Rem for the inhibition of laryngoscope-induced responses. Cortisol, interleukin-6 and blood glucose levels before and after laryngoscope insertion were also measured. The target-controlled concentrations for the 20 patients were as follows: 2 cases at 5 ng/ml, 6 cases at 4.2 ng/ml, 6 cases at 3.5 ng/ml, 4 cases at 2.9 ng/ml and 2 cases at 2.4 ng/ml. The EC 50 of Rem for the inhibition of laryngoscope-induced responses was 3.5 ng/ml with a 95% confidence interval (CI) of 3.47-3.60 ng/ml. A reasonable dose for inhibiting laryngoscope-induced responses was within the range 2.9-4.2 ng/ml. In conclusion, Rem exhibited an EC 50 of 3.5 ng/ml for the inhibition of laryngoscope-induced cardiovascular responses, with a 95% CI of 3.47-3.60 ng/ml, and a reasonable dose for the inhibition of such responses was 2.9-4.2 ng/ml.

A review on advances in the development of electrochemical sensors for the detection of anesthetic drugs

“…The effective anesthetic concentration of remifentanil is found to be 2.9–4.2 ng ml −1 . 17 In addition to this, synthetic opioids like methadone, buprenorphine, oxycodone, and codeine are also used in a surgical setting for various purposes. The therapeutic ranges of these drugs are 100–1000 ng ml −1 , 10–40 ng ml −1 , 1–2 ng ml −1 , and 159 ng ml −1 , respectively.…”

Effect of sex differences in remifentanil requirements for inhibiting the response to a CO2 pneumoperitoneum during propofol anesthesia: an up-and-down sequential allocation trial

“…The onset and recovery time of propofol are rapid, making sedation easy to control [7,8]. Although there have been several studies investigating the median effective concentration (EC 50 ) of remifentanil during propofol anesthesia in different situations [9][10][11], the remifentanil required to inhibit the cardiovascular response to a CO 2 pneumoperitoneum combined with propofol remains unknown.…”