Effect of magnesium infusion on thoracic epidural analgesia

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

Objectives:

To assess the effects of magnesium on the depth of anesthesia and to determine the effects of magnesium on incidence of awareness and postoperative pain after caesarean section.

Methods:

The study was designed as a double-blind, controlled, randomized study and conducted in Hacettepe University Hospital, Ankara, Turkey between January 2015 and March 2016. A total of 100 pregnant healthy women who were between 17 and 41 years old, ASA II, and scheduled for an elective cesarean section with general anesthesia were included in the study. After induction, sevoflurane was used for maintenance in Group S and desflurane in Group D (control groups). At Group S-M and Group D-M (study groups), magnesium infusion was started with sevoflurane and desflurane anesthesia respectively. Minimum alveolar concentration of sevoflurane and desflurane were kept constant. Bispectral index scores (BIS), fentanyl consumption and postoperative visual analogue scale (VAS) values were recorded. All of the patients had been followed-up for awareness until the postoperative first year.

Results:

Demographic variables of the patients were similar. BIS values were significantly higher in control groups throughout the operation (p<0.001). No significant difference was detected for intraoperative fentanyl consumption and awareness incidence. VAS values were significantly lower in study groups (p<0.05).

Conclusion:

Magnesium infusion provided significantly lower intraoperative BIS values and lower postoperative VAS scores. We believe that magnesium can be useful as an adjuvant to general anesthesia.

Magnesium interscalene nerve block for the management of painful shoulder disorders

Shoulder pain is a common and distressing disorder. Systemic multimodal analgesia may be ineffective, but interscalene nerve block provides effective therapy. Magnesium may increase the efficacy and duration of systemic or regional analgesia. This case series examines the utility of magnesium interscalene nerve block for the management of painful shoulder disorders. Six elderly patients with shoulder pain and dysfunction received interscalene nerve block with injection of bupivacaine and magnesium. The patients subsequently reported significant improvement in sleep, shoulder pain, and physical function for 16 weeks. This report highlights that magnesium interscalene nerve block provides safe, effective, and prolonged shoulder analgesia.

Single bolus dose of epidural magnesium prolongs the duration of analgesia in cardiac patients undergoing vascular surgeries

Background and Aims:

Magnesium, a physiological antagonist of calcium and N-methyl-d-aspartate, has a role in the prevention of pain in patients undergoing surgery for peripheral vascular diseases with cardiac comorbidities such as ischaemic heart disease and coronary artery disease. The objective of our study was assessment of effects of epidural magnesium in cardiac patients undergoing vascular surgery.

Methods:

Sixty patients of either sex American Society of Anesthesiologists physical status III undergoing surgeries for peripheral vascular diseases were enrolled. The control group had 30 patients who received levobupivacaine 0.25% 10 ml with fentanyl 50 μg while 30 patients in study group received levobupivacaine 0.25% 10 ml with fentanyl 50 μg and magnesium 100 mg. The primary outcome was duration of analgesia. Sedation score, pain assessment using visual analogue scale (VAS), systolic blood pressure (SBP) and diastolic blood pressure (DBP), heart rate (HR), respiratory rate (RR) and fentanyl consumption were also recorded. Statistical analyses were performed using Minitab 15 statistical software.

Results:

Both groups were similar demographically and with respect to baseline HR, SBP, DBP and RR. In the study group, compared to the control group, duration of analgesia was 4.17 ± 1.07 h versus 1.55 ± 0.47 h (P < 0.01), sedation score were\ better (P = 0.003) and the VAS scores was lower (P < 0.01).

Conclusion:

Epidural magnesium, added to levobupivacaine and fentanyl as a single bolus dose effectively prolongs the duration of analgesia in high-risk cardiac patients undergoing peripheral vascular surgery.

Magnesium Therapy in Pre-eclampsia Prolongs Analgesia Following Spinal Anaesthesia with Fentanyl and Bupivacaine: An Observational Study

BACKGROUND

Magnesium has anti-nociceptive effects and potentiates opioid analgesia following its systemic and neuraxial administration. However, there is no study evaluating the effects of intravenous (IV) magnesium sulphate (MgSO4) therapy on spinal anaesthesia characteristics in severely pre-eclamptic patients.

AIMS

The aim of this study was to compare spinal anaesthesia characteristics in severely pre-eclamptic parturients treated with MgSO4 and healthy preterm parturients undergoing caesarean section. Thus, our primary outcome was regarded as the time to first analgesic request following spinal anaesthesia.

STUDY DESIGN

Case-control Study.

METHODS

Following approval of Institutional Clinical Research Ethics Committee and informed consent of the patients, 44 parturients undergoing caesarean section with spinal anaesthesia were enrolled in the study in two groups: Healthy preterm parturients (Group C) and severely pre-eclamptic parturients with IV MgSO4 therapy (Group Mg). Following blood and cerebrospinal fluid (CSF) sampling, spinal anaesthesia was induced with 9 mg hyperbaric bupivacaine and 20 μg fentanyl. Serum and CSF magnesium levels, onset of sensory block at T4 level, highest sensory block level, motor block characteristics, time to first analgesic request, maternal haemodynamics as well as side effects were evaluated.

RESULTS

Blood and CSF magnesium levels were higher in Group Mg. Sensory block onset at T4 were 257.1±77.5 and 194.5±80.1 sec in Group C and Mg respectively (p=0.015). Time to first postoperative analgesic request was significantly prolonged in Group Mg than in Group C (246.1±52.8 and 137.4±30.5 min, respectively, p<0.001; with a mean difference of 108.6 min and 95% CI between 81.6 and 135.7). Side effects were similar in both groups. Group C required significantly more fluids.

CONCLUSION

Treatment with IV MgSO4 in severe pre-eclamptic parturients significantly prolonged the time to first analgesic request compared to healthy preterm parturients, which might be attributed to the opioid potentiation of magnesium.

Intrathecal injection of magnesium sulfate: shivering prevention during cesarean section: a randomized, double-blinded, controlled study

Background

Regional anesthesia is known to significantly impair thermoregulation and predispose patients to hypothermia. We hypothesized that the addition of an intrathecal injection of magnesium sulfate (MgSO₄) to bupivacaine would improve perioperative shivering in female patients undergoing elective caesarean section.

Methods

In a block-randomized, double-blinded, controlled trial 72 patients scheduled for elective caesarean section with spinal anesthesia were separated into two groups. In the treatment group, 2 ml of 0.5% bupivacaine plus 25 mg MgSO₄ (0.5 ml) were injected intrathecally, and in the control group 2 ml of 0.5% bupivacaine plus 0.5 ml normal saline were injected intrathecally. Core temperature was measured before and after drug injection at predetermined intervals. Sedation was graded using the Ramsay sedation scale.

Results

No significant intergroup differences in appearance of shivering were seen immediately or at 5, 30, 40, 50, 60, and 90 min after block administration. However, at 10, 15, and 20 min post block, there was a significant difference in shivering. The group administered MgSO₄ showed lower shivering grades compared with the control group. Core temperature was significantly reduced in the MgSO₄ group compared to the normal saline group 30 min after blocking.

Conclusions

Intrathecal injection of MgSO₄ improved perioperative shivering in female patients undergoing elective caesarean section.

Comparison of non-divided intercostal muscle flap and intercostal nerve cryoanalgesia treatments for post-oesophagectomy neuropathic pain control

OBJECTIVES

Oesophagectomy is at present considered to be the optimal curative treatment for patients with severe oesophageal disease. Postoperative pain, both acute and chronic, plays a significant role in the quality of life for post-oesophagectomy patients. The present study compared the effects of two methods-application of a non-divided intercostal muscle flap (NIMF) and intercostal nerve cryoanalgesia (INC) treatment-in reducing neuropathic pain in post-oesophagectomy patients.

METHODS

From June 2009 to June 2010, a total of 160 patients who underwent posterolateral thoracotomy and oesophagectomy were subsequently recruited to our study and divided into NIMF groups and INC groups at random. Patient follow-up studies were conducted for one year on all the subjects and the resultant postoperative pain, chronic pain, rehabilitation and complication scored were measured and documented.

RESULTS

INC treatment was more time-intensive than NIMF treatment (P < 0.05). Also, additional chest tube drainage and subsequent extubation were often necessary in the INC group (P < 0.001). No statistically significant differences were found between the two groups regarding the number of subjects who required oral medication one month postoperative with respect to pain score. The chronic pain level, as well as the number of patients requiring oral pain medication, increased significantly by the sixth month following operation and notably increased until the 12th postoperative month in the INC group (P < 0.05).

CONCLUSIONS

Both NIMF and INC treatments were effective and safe for the treatment of acute pain after oesophagectomy. NIMF was the better technique in reducing chronic postoperative pain.