Related Experiment Video
Updated: Aug 13, 2026

Application of Dixon's Up-and-Down Design to Estimate the Minimum Alveolar Concentration of Sevoflurane in Rats with Refined Movement Classification
Published on: July 25, 2025
The effects of magnesium sulphate on sevoflurane minimum alveolar concentrations and haemodynamic responses
1Inonu University, School of Medicine, Department of Anaesthesiology, Malatya, Turkey.
Background And Objective:
Magnesium administered before anaesthesia induction results in a significant reduction in intravenous anaesthetic consumption. The purpose of this study was to evaluate whether the dose of intravenous magnesium sulphate reduces the minimum alveolar anaesthetic concentration of sevoflurane for endotracheal intubation (MACEI) and skin incision (MAC), and attenuates haemodynamic responses.
Methods:
We studied 60 patients who were scheduled for elective surgery. Patients were not premedicated before induction of anaesthesia and were randomly assigned to receive intravenous saline 0.9% (Group I, n = 20) or magnesium sulphate 30 mg kg(-1) bolus + 10 mg kg(-1) h(-1) continuous infusion (Group II, n = 20) or 50 mg kg(-1) bolus + 10 mg kg(-1) h(-1) continuous infusion (Group III, n = 20).
Results:
Median and 95% confidence limits for sevoflurane MACEI were 2.68 (2.48-2.85), 2.88 (2.70-3.06) and 2.96 (2.70-3.16), and for sevoflurane MAC were 2.08 (1.76-2.40), 2.26 (2.08-2.47) and 2.40 (2.19-2.68) in Groups I, II and III, respectively. The differences in MACEI and MAC among groups were not statistically significant, except Group III in MAC study (P < 0.05). Mean arterial pressures and heart rate did not increase in Groups II and III after endotracheal intubation and skin incision.
Conclusions:
Magnesium sulphate administered before induction of anaesthesia increases MAC of sevoflurane and reduces cardiovascular responses to intubation.
Related Concept Videos
Inhalational Anesthetics: Overview
Skeletal Muscle Relaxants: Adverse Effects
Unlike...
Stages of General Anesthesia
Parenteral Anesthetics: Overview
Skeletal Muscle Relaxants: Therapeutic Uses
