Perioperative effects of various anesthetic adjuvants with TIVA guided by bispectral index

Abstract

BackgroundThis prospective, randomized, double blinded, controlled study was designed to compare effects of intravenous co-administration of clonidine, magnesium, or ketamine on anesthetic consumption, intraoperative hemodynamics, postoperative analgesia and recovery indices during Bispectral Index (BIS) guided total intravenous anesthesia (TIVA).MethodsAfter ethical committee approval and written informed consent, 120 adult patients ASA I and II scheduled for open cholecystectomy were randomly assigned to one of 4 equal groups. Group CL received clonidine 3 µg/kg and maintained by 2 µg/kg/h. Group MG received magnesium sulphate 50 mg/kg and maintained by 8 mg/kg/h. Group KET received racemic ketamine 0.4 mg/kg and maintained by 0.2 mg/kg/h. Control group (CT) received the same volume of isotonic saline. Anesthesia was induced and maintained by fentanyl, propofol and rocuronium. Propofol infusion was adjusted to keep the BIS value between 45-55. Intraoperative hemodynamics, induction time, anesthetic consumption, recovery indices, and PACU discharge were recorded.ResultsInduction time, propofol requirements for induction and maintenance of anesthesia, intraoperative fentanyl and hemodynamic values were significantly lower with Groups CL and MG compared to Groups KET and CT (P < 0.05). Patients in Group MG showed significantly lower muscle relaxant consumption, delayed recovery and PACU discharge than other groups (P < 0.05). First, analgesic requirement was significantly longer and total postoperative analgesic consumption was significantly lower in the adjuvant groups versus Group CT (P < 0.05).ConclusionsClonidine, magnesium, and ketamine can be useful adjuvant agents to BIS-guided TIVA. Pharmacokinetic studies of such drug combinations were recommended to investigate their interaction.

Melatonin and clonidine premedication has similar impact on the pharmacokinetics and pharmacodynamics of propofol target controlled‐infusions

“…The patients who received clonidine had considerably lower values of their systolic (SYS) and diastolic (DIAS) arterial pressure and their heart rate (HR) than those who received melatonin (Table ). These results are in agreement with the data reported in the literature . However, it is noteworthy that the lower SYS/DIAS and HR values did not cause a decrease in propofol clearance.…”

“…Morris et al proved that clonidine (3 μg/kg) reduced the dose of propofol which was necessary to induce anesthesia in vascular surgery. The effect of clonidine saving the consumption of propofol was also confirmed by Ghosh et al, Khafagy et al, and Higuchi et al In our research, we assessed the influence of melatonin and clonidine on the hypnotic effect of propofol and the “anesthetic‐saving” effect on the basis of population modeling. The influence of premedication on individual PK/PD parameters was not statistically significant in either premedication medium ( P > 0.01).…”

“…These results are in agreement with the data reported in the literature. 23,[28][29][30][31] However, it is noteworthy that the lower SYS/DIAS and HR values did not cause a decrease in propofol clearance. According to the literature data, the pharmacokinetics of propofol is influenced by changes in the distribution of blood volume, cardiac output, and hepatic blood flow, 10 because the drug is characterized by a high hepatic extraction ratio (over 0.7).…”

Effect of clonidine on the target dose of propofol: bispectral index evaluation

“…Ketamine showed better post-operative pain relief, but also had a greater incidence of agitation and hypersalivation, [21] and magnesium sulphate showed no benefits with respect to clonidine. [22] All of the studies showed similar effects with respect to sedation level and patient satisfaction; however, only clonidine showed synergism with opioids and hypnotics [31,32].…”

“…[17] Clonidine's analgesic effects are difficult to evaluate perioperatively, due to a lack of specific devices that can evaluate pain. However, its synergism with propofol can be shown by BIS [22,33]. Clonidine used alone has a sedative effect, which in isolation alters the BIS values and the analgesic effect.…”