Antinociceptive effects of magnesium sulfate for monitored anesthesia care during hysteroscopy: a randomized controlled study

Effects of intra-operative magnesium sulfate infusion on orthognathic surgery: A prospective and randomized controlled trial

Purpose

To comprehensively understand the effects of intra-operative infusion of magnesium sulfate on patients who underwent orthognathic surgery, including remifentanil consumption, postoperative pain, postoperative nausea and vomiting (PONV), inflammatory response, and serum magnesium levels.

Methods

Seventy-five adult patients undergoing orthognathic surgery under general balanced anesthesia were randomly divided into two groups. One group (Group M) received 50 mg/kg of magnesium sulfate in 20 mL 0.9 % saline after intubation, followed by a continuous infusion at a rate of 15 mg/kg/h until 30 min before the anticipated end of surgery. The other group (Group C) received an equal volume of isotonic saline as a placebo. (Clinical trial registration number: chiCTR2100045981).

Results

The primary outcome was remifentanil consumption. The secondary outcomes included the pain score assessed using the verbal numerical rating scale (VNRS) and PONV assessed using a Likert scale. Remifentanil comsumption in Group M was lower than Group C (mean ± SD: 0.146 ± 0.04 μg/kg/min vs. 0.173 ± 0.04 μg/kg/min, P = 0.003). At 2 h after surgery, patients in Group C suffered more severe PONV than those in Group M (median [interquartile range, IQR]: 1 [3] vs. 1 [0], mean rank: 31.45 vs. 42.71, P = 0.040). At post-anesthesia care unit (PACU), postoperative pain in Group C was severe than Group M (3 [1] vs. 3 [0], mean rank: 31.45 vs. 42.71, P = 0.013). Changes in haemodynamics and surgical field scores did not differ between the groups (all P > 0.05). The levels of cytokines (IL-4, IL-6, IL-8, IL-10, TNF-a, and MIP-1β) were not significantly different between the groups after surgery (all P > 0.05). Postoperative serum magnesium levels in Group C were lower than those in Group M (0.74 ± 0.07 mmol/L vs. 0.91 ± 0.08 mmol/L, P = 0.000) and the preoperative level (0.74 ± 0.07 mmol/L vs. 0.83 ± 0.06 mmol/L, P = 0.219).

Conclusions

In orthognathic surgery, magnesium sulfate administration can reduce remifentanil requirement and relieve PONV and postoperative pain in the early postoperative phase.

Analgesic Effects of Magnesium Sulphate as an Adjuvant to Fentanyl for Monitored Anaesthesia Care During Hysteroscopy

BACKGROUND

Magnesium sulphate (MgSO4) is conventionally used in the treatment of eclampsia, refractive arrhythmias, asthma, etc. In our study, we aimed to study the analgesic effects of MgSO4 as an adjuvant to fentanyl and reduce the intraoperative opioid requirement to decrease their adverse effects.

METHODS

A total of 122 patients scheduled for hysteroscopy were randomly divided into two groups. Patients in the magnesium group (group A) received intravenous MgSO4 50 mg/kg in 100 ml of isotonic saline over 15 minutes before anaesthesia induction and then 15 mg/kg per hour by continuous intravenous infusion. Patients in the control group (group B) received an equal volume of isotonic saline as a placebo. All the patients were induced with fentanyl and propofol. Perioperative haemodynamic monitoring and postoperative assessment of pain were done.

RESULTS

Only 18% of the patients in group A required rescue analgesics as compared to 39.3% of patients in group B. The patients receiving MgSO4 displayed lower verbal numeric rating scale scores in the postoperative period. In addition, the intraoperative requirement of fentanyl (101 (21.33) vs. 144 (28.4) µg, mean (SD)) and propofol (121 (13.3) vs. 140 (16.5) mg, mean (SD)) was significantly lower in group A as compared to that in group B.

CONCLUSION

MgSO4, when administered as an adjuvant to opioids, provided effective postoperative analgesia thereby reducing the need for rescue analgesics. It also decreases intraoperative fentanyl consumption and its dose-related side effects.

Effects of intravenous administration of magnesium sulfate in propofol-based sedation for ERCP in elderly patients: a randomized, double-blind, placebo-controlled study

BACKGROUND

Propofol-based sedations are widely used in elderly patients for endoscopic retrograde cholangiopancreatography (ERCP) procedure, but respiratory depression and cardiovascular adverse events commonly occur. Magnesium administered intravenously can alleviate pain and decrease propofol requirements during surgery. We hypothesized that intravenous magnesium was used as adjuvant to propofol might be beneficial in elderly patients undergoing ERCP procedures.

METHODS

Eighty patients aged from 65 to 79 years who were scheduled for ERCP were enrolled. All patients were intravenously administered 0.1 µg/kg sufentanil as premedication. The patients were randomized to receive either intravenous magnesium sulfate 40 mg/kg (group M, n = 40) or the same volume of normal saline (group N, n = 40) over 15 min before the start of sedation. Intraoperative sedation was provided by propofol. Total propofol requirement during ERCP was the primary outcome.

RESULTS

The total propofol consumption were reduced by 21.4% in the group M compared with the group N (151.2 ± 53.3 mg vs. 192.3 ± 72.1 mg, P = 0.001). The incidences of respiratory depression episodes and involuntary movement were less in the group M than those in the group N (0/40 vs. 6/40, P = 0.011; 4/40 vs. 11/40, P = 0.045; respectively). In the group M, the patients experienced less pain than those in the group N at 30 min after the procedure (1 [0-1] vs. 2 [1-2], P < 0.001). Correspondingly, the patients' satisfaction was clearly higher in the group M (P = 0.005). There was a tendency towards lower intraoperative heart rate and mean arterial pressure in group M.

CONCLUSIONS

A single bolus of 40 mg/kg of intravenous magnesium can significantly reduce propofol consumption during ERCP, with higher sedation success and lower adverse events.

TRIAL REGISTRATION

ID UMIN000044737. Registered 02/07/2021.

Efficacy and safety of remimazolam tosylate in hysteroscopy: A randomized, single-blind, parallel controlled trial

WHAT IS KNOWN AND OBJECTIVE

To compare the effectiveness and safety of remimazolam tosylate and propofol for hysteroscopy.

METHODS

From November 2020 to June 2021, a total of 90 patients who underwent hysteroscopy were prospectively enrolled in this study. The patients were randomly assigned to three groups: propofol group (group A), low-dose remimazolam tosylate group (group B), and high-dose remimazolam tosylate group (group C), with 30 cases in each group. All cases received intravenous sufentanil 0.1ug/kg for analgesic preconditioning. Patients in group A were given 2 mg/kg propofol intravenously, and maintained at a rate of 5 mg/kg/h. Patients in groups B and C were given intravenous remimazolam tosylate 0.25 mg/kg. Group B was maintained with remimazolam tosylate at a rate of 0.48 mg/kg/h, while group C was at a rate of 0.6 mg/kg/h. The changes of heart rate (HR), mean arterial pressure (MAP) and saturation of peripheral oxygen (SpO2) were recorded after admission (T0), 1 min after anaesthesia (T1), dilation of the uterine cavity (T2), and the end of hysteroscopy (T3). In addition, Observer's Assessment of Alertness/Sedation Scale (OAA/S) at 1 min, 3 min, and 5 min after hysteroscopy, the incidence of adverse events, and the time from the end of the hysteroscopy to reach the discharge standard, were recorded.

RESULTS AND DISCUSSION

The success rate of sedation in each group was 100%. After administration, the adverse event incidence in group A was significantly higher than that in groups B and C (p < 0.05, respectively). Compared with propofol, remimazolam tosylate did not cause injection pain, had less impact on haemodynamics and caused less respiratory depression.

WHAT IS NEW AND CONCLUSION

Remimazolam tosylate and propofol have similar success rates for painless hysteroscopy, and both can provide safe and effective sedation. The safety of remimazolam tosylate for hysteroscopy appears to be better than that of propofol.