Effect of magnesium sulfate on anesthesia depth, awareness incidence, and postoperative pain scores in obstetric patients. A double-blind randomized controlled trial

Comparison of adding magnesium sulfate, dexmedetomidine and ondansetron to lidocaine for gargling before laryngoscopy and endotracheal intubation to prevent sore throat: a randomized clinical trial

Postoperative sore throat is one well-recognized complication, occurring most frequently following tracheal intubation. Effective prevention of postoperative sore throat has been recognized as a top priority, bringing pleasant feelings and satisfaction to patients. This study aimed to assess the efficacy of magnesium sulfate, dexmedetomidine and ondansetron gargle with lidocaine administrated prior to laryngoscopy and tracheal intubation for postoperative sore throat prevention alongside hemodynamic management. This double-blind randomized clinical trial enrolled 105 general anesthesia-administered patients who had undergone laryngoscopy and endotracheal intubation, and they were equally randomized into three groups: magnesium sulfate, dexmedetomidine, and ondansetron groups. No significant intergroup difference was seen in oxygen saturation, non-invasive blood pressure, heart rate, duration of surgery, postoperative complications, analgesic consumption, and incidence of cough and hoarseness. The results showed statistically significant intergroup differences in pain scores and average pain intensity in the dexmedetomidine group was significantly lower than the other groups. Results suggest that dexmedetomidine gargle with lidocaine before general anesthesia induction could be recommended as an option depending on the patient's general condition and the anesthesiologist's discretion.

Magnesium Sulfate and Its Versatility in Anesthesia: A Comprehensive Review

In the field of general anesthesia, magnesium sulfate (MgSO4) has become a valuable adjunct because it provides a range of benefits that enhance and optimize conventional aesthetic procedures. This review highlights the various intra-anesthetic benefits of MgSO4 while examining its complex function in the treatment using anesthesia. Magnesium inhibits the release of acetylcholine at the motor endplate and blocks calcium channels at presynaptic nerve terminals. This reduces the amplitude of endplate potential and the excitability of muscle fibers, which increases the potency of a neuromuscular blockade by nondepolarizing neuromuscular blockers. This activity may lessen the need for primary muscle relaxants. Moreover, its capacity to potentially reduce the total amount of main aesthetic agents needed emphasizes its function in maximizing anesthesia dosage, ensuring sufficient depth while perhaps potentially reducing adverse effects linked with increased dosages. MgSO4's adaptable qualities present a viable path for improving anesthetic outcomes, possibly improving patient safety and improving surgical results.

[Accidental Awareness during General Anaesthesia]

Accidental awareness during general anaesthesia (AAGA) is a rare but severe complication. The reported incidence of AAGA may depend on the assessment of intraoperative awareness with explicit recall and there are substantial variations between subspecialties and groups of patients. The majority of prospective studies using structured interviews reported an incidence of AAGA at 0.1-0.2% during general anaesthesia, however, higher values were observed in paediatric (0.2-1.2%) and obstetric patients (0.47%). Risk factors that predispose to AAGA are patient conditions, ASA status, female gender, patient age, history of AAGA, surgical procedure, anaesthetic drug type, muscle relaxation, dosages of hypnotic or analgesic drugs, monitoring and malfunction of anaesthesia systems. Preventive strategies include careful assessment of risk factors, avoidance of underdosages of hypnotics and analgetics during general anaesthesia and monitoring of depth of anaesthesia in risk patients. The health-related consequences can be serious and psychopharmacological and psychotherapeutic interventions are indicated in patients who have experienced AAGA.

The use of processed electroencephalography (pEEG) in obstetric anaesthesia: a narrative review

Accidental awareness under general anaesthesia (AAGA) remains a major complication of anaesthesia. The incidence of AAGA during obstetric anaesthesia is high relative to other specialities. The use of processed electroencephalography (pEEG) in the form of "depth of anaesthesia" monitoring has been shown to reduce the incidence of AAGA in the non-obstetric population. The evidence for using pEEG to prevent AAGA in the obstetric population is poor and requires further exploration. Furthermore, pregnancy and disease states affecting the central nervous system, such as pre-eclampsia, may alter the interpretation of pEEG waveforms although this has not been fully characterised. National guidelines exist for pEEG monitoring with total intravenous anaesthesia and for "high-risk" cases regardless of technique, including the obstetric population. However, none of the currently available guidelines relates specifically to obstetric anaesthesia. Using pEEG monitoring for obstetric anaesthesia may also provide additional benefits beyond a reduction in risk of AAGA. These potential benefits include reduced postoperative nausea and vomiting, reduced anaesthetic agent use, a shorter post-anaesthetic recovery stay. In addition, pEEG acts as a surrogate marker of cerebral perfusion, and thus as an additional monitor for impending cardiovascular collapse, as seen in amniotic fluid embolism. The subtle physiological and pathological changes in EEG activity that may occur during pregnancy are an unexplored research area in the context of anaesthetic pEEG monitors. We believe that the direction of clinical practice is moving towards greater use of pEEG monitoring and individualisation of anaesthesia.

Intraoperative Awareness in Patients Undergoing Cardiac Surgery in an Academic Center in the North of Iran

Background

Coronary artery bypass grafting (CABG) has distinctive characteristics that may increase the risk of awareness during general anesthesia (AGA).

Objectives

This study was conducted to assess the incidence of AGA in cardiac surgery in an academic hospital in Guilan, Iran.

Methods

This descriptive cross-sectional study was performed in Dr. Heshmat Hospital in Rasht, Iran. Eligible patients candidates for CABG were enrolled in the survey in 2022. After surgery, when the patient was cooperative enough, a questionnaire including demographic data and specialized questions related to different stages of anesthesia was completed via face-to-face interviews. The data were analyzed using IBM SPSS Statistics 21 with chi-square, Fisher's exact, and t-test.

Results

The data from 322 patients were analyzed, of whom 14 (4.3%) experienced AGA. Among them, the "feeling of fear and anxiety" reported by 9 (39.1%) cases was the most common awareness state. "Dreaming during surgery and anesthesia" and "feeling unable to move during anesthesia,", each reported by 6 (26.1%) cases, were the other common types of awareness state. None of the demographic data had a significant association with the occurrence of AGA.

Conclusions

The incidence of AGA during CABG was almost acceptable according to the credible evidence.

Interactions between Ketamine and Magnesium for the Treatment of Pain: Current State of the Art

BACKGROUND

Over the past three decades, NMDA-receptor antagonists have been shown to be efficient drugs for treating pain, particularly pain resistant to conventional analgesics. Emphasis will be on the old-new drugs, ketamine and magnesium, and their combination as a novel approach for treating chronic pain.

METHODS

The MEDLINE database was searched via PubMed for articles that were published up to March 1, 2020, with the keywords 'ketamine', 'magnesium', and 'pain' (in the title/abstract).

RESULTS

Studies in animals, as well as humans, have shown that interactions of ketamine and magnesium can be additive, antagonistic, and synergistic. These discrepancies might be due to differences in magnesium and ketamine dosage, administration times, and the chronological order of drug administration. Different kinds of pain can also be the source of divergent results.

CONCLUSION

This review explains why studies performed with a combination of ketamine and magnesium have given inconsistent results. Because of the lack of efficacy of drugs available for pain, ketamine and magnesium in combination provide a novel therapeutic approach that needs to be standardized with a suitable dosing regimen, including the chronological order of drug administration.

Magnesium sulfate reduces postoperative pain in women with cesarean section: A meta-analysis of randomized controlled trials

OBJECTIVES

The use of magnesium sulfate (MgSO₄ ) as an adjunct in different anesthetic regimens for cesarean section (CS) delivery often reports conflicting results. This study aimed to review the effectiveness of MgSO₄ on improving postoperative analgesia after CS systematically.

METHODS

PubMed, Embase, and the Cochrane library were searched for randomized controlled trials (RCTs) published from inception to February 2020.

RESULTS

A total of 880 women were included (440 in each group). MgSO₄ had a statistically significant effect compared to the control group on the highest VAS (weighted mean difference [WMD] = -0.74, 95% confidence interval [CI] = -1.03 to -0.46, p < 0.001, I²  = 91.7%, p_{heterogeneity}  < 0.001) and the last VAS (WMD = -0.47, 95% CI = -0.71 to -0.23, p < 0.001, I²  = 95.0%, p_{heterogeneity}  < 0.001). MgSO₄ prolonged the time to the first use of analgesia compared to the control group (standardized mean difference [SMD] = -3.03 min, 95% CI = -4.32 to -1.74, p < 0.001, I²  = 96.3%, p_{heterogeneity}  < 0.001). MgSO₄ decreased the consumption of analgesia compared to the control group (SMD = -3.20 mg of IV morphine equivalent, 95% CI: -5.45 to -0.95, p = 0.005, I²  = 97.6%, p_{heterogeneity}  < 0.001).

DISCUSSION

MgSO₄ decreases the highest VAS in women who underwent general anesthesia, spinal anesthesia, or epidural for CS (all p < 0.05). Additional MgSO₄ significantly reduces postoperative pain in women undergoing CS.

Magnesium and Pain

In terms of antinociceptive action, the main mode of action of magnesium involves its antagonist action at the N-methyl-d-aspartate (NMDA) receptor, which prevents central sensitization and attenuates preexisting pain hypersensitivity. Given the pivotal function of NMDA receptors in pain transduction, magnesium has been investigated in a variety of pain conditions. The oral and parenteral administration of magnesium via the intravenous, intrathecal, or epidural route may alleviate pain and perioperative anesthetic and analgesic requirements. These beneficial effects of magnesium therapy have also been reported in patients with neuropathic pain, such as malignancy-related neurologic symptoms, diabetic neuropathy, postherpetic neuralgia, and chemotherapy-induced peripheral neuropathy. In addition, magnesium treatment is reportedly able to alleviate fibromyalgia, dysmenorrhea, headaches, and acute migraine attacks. Although magnesium plays an evolving role in pain management, better understanding of the mechanism underlying its antinociceptive action and additional clinical studies is required to clarify its role as an adjuvant analgesic.