Magnesium sulphate as a technique of hypotensive anaesthesia

The effect of intravenous magnesium sulphate infusion on total intravenous anesthesia with propofol in adult dogs: A randomized, blinded trial

OBJECTIVE

To evaluate cardiopulmonary, arterial blood gas and propofol-sparing effects of magnesium sulfate (MgSO4) constant rate infusion (CRI) in mechanically ventilated dogs maintained under total intravenous anesthesia with propofol.

STUDY DESIGN

Blinded, randomized, clinical trial.

ANIMALS

A total of 24 healthy adult dogs.

METHODS

Dogs were premedicated with intramuscular acepromazine (0.05 mg kg-1) and morphine (0.5 mg kg-1), followed by an intravenous (IV) bolus of saline or MgSO4 (50 mg kg-1 over 15 minutes) and propofol (given to effect to induce anesthesia). Anesthesia was maintained with an IV propofol infusion (beginning at 0.3 mg kg-1 minute-1, adjusted as necessary). Concurrently, one of three IV infusions were administered: GS (0.9% NaCl), GM30 (MgSO4, 30 mg kg-1 hour-1) or GM80 (MgSO4, 80 mg kg-1 hour-1). Propofol induction and maintenance doses were recorded. The following variables were recorded at baseline (T0), after bolus treatment (T1), after beginning mechanical ventilation (T5) and every 15 minutes until the end of the procedure (T15-T120): mean arterial pressure, heart rate, peripheral oxygen saturation, end-tidal partial pressure of CO2, temperature, blood gas variables, indirect calorimetry and extubation time. Values of p < 0.05 were considered significant.

RESULTS

Propofol induction bolus dose was lower in GM30 (31.2%, p = 0.04) and GM80 (38.9%, p = 0.003) than in GS. The maintenance propofol infusion rate in GM80 was 16.9% lower (p = 0.03), resulting in fewer propofol CRI rescues during the perioperative period. GM30 and GM80 exhibited faster extubation times than GS (46.2%, p = 0.002 and 48.9%, p = 0.001, respectively).

CONCLUSIONS AND CLINICAL RELEVANCE

Infusion of a 50 mg kg-1 bolus, followed by CRI of MgSO4 (30 and 80 mg kg-1 hour-1), reduces the propofol induction and maintenance (CRI) requirement, maintaining cardiorespiratory stability and reducing the time required to extubation.

Efficacy and safety of intraoperative controlled hypotension: a systematic review and meta-analysis of randomised trials

BACKGROUND

Intraoperative controlled hypotension improves surgical field visibility by reducing blood loss (efficacy) but poses potential risks linked to organ hypoperfusion (safety). The use of controlled hypotension persists despite increasing evidence of associations between intraoperative inadvertent hypotension and adverse outcomes. Therefore, we tested the hypothesis that the focus and results of intraoperative controlled hypertension research differ across anaesthesia and surgery investigators because of differing priorities.

METHODS

We systematically reviewed randomised trials comparing controlled hypotension with usual care with trials categorised by investigators' affiliation.

RESULTS

We identified 48 eligible trials, of which 37 were conducted by anaesthesia investigators and 11 by surgery investigators. For the primary outcome, 54% of the anaesthesia-led trials focused on safety, whereas all (100%) surgery-led trials focused on efficacy (P=0.004). Compared with usual care, mean arterial pressure in controlled hypotension was 23% (95% confidence interval [CI] 17-29%) lower in anaesthesia trials and 30% (95% CI 14-37%) lower in surgery trials; estimated blood loss was 44% (95% CI 30-55%) less in anaesthesia trials and 38% (95% CI 30-49%) less in surgery trials. Overall, blood loss was reduced by 43% (95% CI 32-53%), and trial sequential analysis supported an efficacy conclusion. Mean arterial pressure and estimated blood loss reductions were associated (R2=0.41, P=0.002). All trials were underpowered for safety outcomes, and none adequately evaluated myocardial or renal injury.

CONCLUSIONS

Anaesthesia researchers prioritised safety outcomes, whereas surgery researchers emphasised efficacy in controlled hypotension trials. Controlled hypotension significantly reduces blood loss. In contrast, safety outcomes were poorly studied. Given increasing observational evidence linking inadvertent hypotension to myocardial and renal injury, the safety of controlled hypotension remains to be addressed.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO (CRD42023450397).

The effect of pre-emptive oral pregabalin on opioid consumption in patients undergoing laparoscopic sleeve gastrectomy with an analysis of intraoperative hemodynamic stability and quality of recovery: study protocol for a randomized, prospective, double-blind study

BACKGROUND

Obese patients undergoing laparoscopic sleeve gastrectomy (LSG) are particularly at risk of opioid-related side effects. To reduce patient exposure to opioids, multimodal analgesia, which involves the use of drugs of different classes, may be utilized. One of the drugs under consideration is pregabalin. Despite an opioid-sparing potential, few studies assess the role of pregabalin as an element of multimodal analgesia in LSG. Considering the limited number and inconsistent results of available studies, we decided to conduct a randomized, prospective study on the effect of preemptive pregabalin administration in obese patients on opioid consumption, pain scores, the incidence of opioid side effects, and hemodynamical stability.

METHODS

The study is designed as a prospective randomized controlled trial with double-blinding. Randomization will be performed in a block with a parallel 1:1 allocation. The intervention will involve receiving a pregabalin 150 mg capsule 1-2 h before the surgery, whereas the control group will receive an identically looking placebo. The primary outcome measure will be total oxycodone consumption in the first 24 h following surgery. Secondary outcome measures will be pain severity assessed using the Numerical Rating Scale (NRS) 1, 6, 12, and 24 h after surgery, postoperative sedation on the Ramsay scale, PONV impact scale, the incidence of desaturation episodes < 94%, and episodes of blurred vision at 1, 6, 12, and 24 h after surgery, intraoperative hemodynamic parameters such as heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP), total fluid volume, and total ephedrine dose. Patient comfort will be additionally assessed using the QoR-40 questionnaire at discharge.

DISCUSSION

The study will explore the efficacy and safety of preemptive pregabalin in a dose of 150 mg as a co-analgesic used in multimodal analgesia for LSG. As studies on opioid-sparing regimes concern the safety of obese patients, we aim to contribute objective data with a relatively large study sample size. The result of the present clinical trial may support the reassessment of recommendations to use pregabalin in the studied population.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05804591. Registered on 07.04.2023.

Opioid-Free Anesthesia in Bariatric Surgery: Is It the One and Only? A Comprehensive Review of the Current Literature

Opioid-free anesthesia (OFA) is a heterogeneous group of general anesthesia techniques in which the intraoperative use of opioids is eliminated. This strategy aims to decrease the risk of complications and improve the patient's safety and comfort. Such potential advantages are particularly beneficial for selected groups of patients, among them obese patients undergoing laparoscopic bariatric surgery. Opioids have been traditionally used as an element of balanced anesthesia, and replacing them requires using a combination of coanalgesics and various types of local and regional anesthesia, which also have their side effects, limitations, and potential disadvantages. Moreover, despite the growing amount of evidence, the empirical data on the superiority of OFA compared to standard anesthesia with multimodal analgesia are contradictory, and potential benefits in many studies are being questioned. Additionally, little is known about the long-term sequelae of such a strategy. Considering the above-mentioned issues, this study aims to present the potential benefits, risks, and difficulties of implementing OFA in bariatric surgery, considering the current state of knowledge and literature.

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.

Effects of intravenous single-bolus lidocaine infusion versus intravenous single-bolus magnesium sulfate infusion on postoperative pain, emotional status, and quality of life in patients undergoing spine fusion surgery: a randomized study

BACKGROUND

We assessed the efficiency of intravenous adjuvants in decreasing opioid intake and pain scores after spine fusion surgery.

METHODS

This study included 120 patients aged 18-60 listed for spine fusion surgery under general anesthesia. Patients were randomly assigned to four groups: Group (Lidocaine): received IV lidocaine 4 mg/kg in 50 mL volume over 30 min. Group (Magnesium): received IV magnesium sulfate 30mg/kg in 50 mL volume over 30 min. Group (combined Lidocaine and Magnesium): received IV lidocaine 4 mg/kg in 50 mL volume over 30 min.+IV magnesium sulfate 30mg/kg in 50 mL volume over 30 min. Group (Control): received IV saline 50 mL. The time to the first request analgesia, the postoperative pain score, total analgesic use, patient satisfaction, anxiety, depression, mental state, quality of life, and side effects were measured.

RESULTS

The combined group had more extended time for the first analgesic request and fewer rescue analgesia doses than the other groups. NRS scores at rest or movement were statistically significantly lower in the lidocaine group and the combined group compared to the control group (P1, P3<0.05) at almost all times. This combination reduces anxiety and depression and improves overall health up to three months after a single infusion. The combined group had higher patient satisfaction.

CONCLUSIONS

A synergistic effect of a combination of lidocaine and magnesium sulfate on perioperative pain was found. It reduces analgesic consumption, depression, and anxiety and improves overall health up to three months after a single infusion dose.

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.

A Comprehensive Review of Magnesium Sulfate Infusion: Unveiling the Impact on Hemodynamic Stability During Laryngoscopy and Tracheal Intubation in Ear, Nose, and Throat Surgeries

This comprehensive review explores the potential of magnesium sulfate infusion in mitigating hemodynamic instability during laryngoscopy and tracheal intubation in ear, nose, and throat (ENT) surgeries. Hemodynamic fluctuations during these procedures pose challenges, and magnesium sulfate, with its vasodilatory, antiarrhythmic, and neuroprotective properties, emerges as a promising intervention. The review critically examines existing literature, emphasizing patient selection criteria, dosage protocols, and a comparative analysis with other hemodynamic stabilizers. Safety considerations, including known adverse effects and risk-benefit assessments, and monitoring and management strategies are elucidated. The implications for ENT surgery are discussed, highlighting the potential for enhanced hemodynamic management and individualized approaches. The review concludes with a call for continued research, emphasizing the ongoing evolution of understanding and practice incorporating magnesium sulfate into perioperative care. The insights offered aim to guide clinicians in navigating this dynamic landscape for improved patient outcomes in ENT surgeries.

Efficacy of intravenous magnesium sulfate infusion on postoperative pain and quality of recovery for septorhinoplasty: a randomized controlled study

BACKGROUND

The pain that occurs after septorhinoplasty is an important factor affecting the comfort of the patient.

OBJECTIVES

To investigate the effect of perioperative intravenous magnesium sulfate infusion on postoperative pain and quality of recovery in patients underwent septorhinoplasty surgery.

MATERIAL AND METHODS

One hundred twenty patients who underwent septorhinoplasty were randomly divided into two groups. Magnesium group received intravenous magnesium after induction of anesthesia (30 mg/kg), then infused until the end of the surgical procedure (9 mg/kg). The placebo group received the same volume of saline infusion. The VAS score was used for postoperative pain assessment, and the Quality of Recovery-40 (QoR-40) score was used for the assessment of recovery status.

RESULTS

The postoperative 30 min, 1st, 2nd, 4th (p < .001) and 24th hour (p < .05) VAS scores of the patients in the magnesium infusion group were significantly lower compared to the placebo group. Also; in terms of physical comfort (p < .001), emotional state (p < .05), psychological support, pain and total score values (p < .001), patients in magnesium group had significantly higher QoR-40 scores than those in placebo group.

CONCLUSION

Intraoperative magnesium infusion, which is widely used in many surgeries to provide controlled hypotension, also contributes significantly to patient comfort with its positive effect on postoperative pain and recovery scores.

Evaluation of the Efficacy of Magnesium Sulfate in Reducing Blood Loss in Functional Endoscopic Sinus Surgery: A Randomized Double-Blinded Controlled Trial

Objectives  The primary concern in functional endoscopic sinus surgery (FESS) is maintaining a clear and unobstructed surgical field. Achieving this objective necessitates controlled hypotension, which can aid in the surgical dissection process and reduce the overall duration of the operation. This study aims to evaluate the efficacy of a sole bolus injection of intravenous magnesium sulfate in FESS. The outcomes measured include blood loss, surgical field grading, the additional intraoperative requirement of fentanyl, stress attenuation during laryngoscopy and endotracheal intubation, and extubation time. Methods In this prospective, double-blinded, randomized control trial (CTRI/2021/04/033052), 50 patients scheduled for FESS were randomly divided into two groups: Group M received 50 mg/kg MgSO₄ in 100 ml normal saline, and Group N received 100 ml plain normal saline 15 min before induction. The study assessed total blood loss, measured by blood collected from the surgical field and weighing gauze. The surgical field grading was assessed by a six-point Fromme and Boezaart scale. We also observed stress attenuation during laryngoscopy and endotracheal intubation, additional intraoperative fentanyl requirements, and time taken for extubation. The sample size was estimated using the G power calculator 3.1.9.2 (http://www.gpower.hhu.de/). Data were entered in Microsoft Excel (Microsoft Corporation, Redmond, WA) and analyzed using Statistical Package for Social Sciences version 20.0 (IBM Corp., Armonk, NY). Results The demographic data and duration of the surgery were comparable in both groups. The total blood loss in Group M was 100.40 ml ±60.71 ml, which is lower than Group N (133.80 ml ±59.7 ml) with a p-value of 0.016. In addition, the surgical field grading was also better in Group M. The total vecuronium consumption was significantly lower in Group M, which was (7.23±0.84 mg); in Group N, it was (10.64±1.74 mg) with a p-value of 0.0001, respectively. The dosage of additional fentanyl in Group N was 38.46 mcg ± 8.99 mcg, more than in Group M (33.64 mcg ± 11.20 mcg). The time required for extubation was similar in both groups. The duration of the surgery was significantly more significant in Group M (150.0 ±31.36) than in Group N (205.0 ±32.79), with a p-value of 0.0001, respectively. Furthermore, the mean arterial pressure after induction, at 2 min and 4 min after laryngoscopy, was less in Group M, with p=0.001, p=0.003, and p<0.0001, respectively, when compared with Group N. The heart rate after induction, at 2 min and 4 min after laryngoscopy, was also less in Group M, with p=0.016, p=0.003, and p=0.003, respectively, when compared with Group N. The Ramsay Sedation Score was higher in Group M than in Group N's fourth, eighth, and sixteenth hour, with p=0.001, p=0.021, and p=0.001, respectively, in the postoperative period. The sedation score was statistically insignificant after that. No complications were encountered during the study. Conclusion We conclude that a single bolus dose of MgSO₄ reduced surgical blood loss more effectively than in the control group. The surgical field grading was also better in Group M, as was the stress attenuation during laryngoscopy and endotracheal intubation. The intraoperative fentanyl requirement was not statistically significant. The time for extubation was similar between the groups. No other adverse effects were encountered during the study.

Efficacy of intravenous magnesium for the management of non-post operative atrial fibrillation with rapid ventricular response: A systematic review and meta-analysis

BACKGROUND

Intravenous magnesium (IV Mg), a commonly utilized therapeutic agent in the management of atrial fibrillation (AF) with rapid ventricular response, is thought to exert its influence via its effect on cellular automaticity and prolongation of atrial and atrioventricular nodal refractoriness thus reducing ventricular rate. We sought to undertake a systematic review and meta-analysis of the effectiveness of IV Mg versus placebo in addition to standard pharmacotherapy in the rate and rhythm control of AF in the nonpostoperative patient cohort given that randomized control trials (RCTs) have shown conflicting results.

METHODS

Randomized controlled trials comparing IV Mg versus placebo in addition to standard of care were identified via electronic database searches. Nine RCTs were returned with a total of 1048 patients. Primary efficacy endpoints were study-defined rate control and rhythm control/reversion to sinus rhythm. The secondary endpoint was patient experienced side effects.

RESULTS

Our analysis found IV Mg in addition to standard care was successful in achieving rate control (odd ratio [OR] 1.87, 95% confidence interval [CI] 1.13-3.11, p = .02) and rhythm control (OR 1.45, 95% CI 1.04-2.03, p = .03). Although not well reported among studies, there was no significant difference between groups regarding the likelihood of experiencing side effects.

CONCLUSIONS

IV Mg, in addition to standard-of-care pharmacotherapy, increases the rates of successful rate and rhythm control in nonpostoperative patients with AF with rapid ventricular response and is well tolerated.

Controlled Hypotension for Functional Endoscopic Sinus Surgery With Two Different Doses of Fentanyl

Background and Objectives Functional endoscopic sinus surgery (FESS) is a type of minimally invasive surgery done for acute and chronic sinus diseases or paranasal illnesses. The idea of FESS is to preserve the normal anatomy, which is non-obstructing and mucous membrane while removing tissue obstructing OMC (osteo metal complex) and facilitating drainage. The critical structures, including the brain, orbit, and carotid veins, the lack of adequate operating room, and bleeding that obscures endoscopic vision throughout the procedure may increase the likelihood of unfavorable surgical results. This study seeks to examine the hemodynamic effects of intubation and extubation as well as the impact of fentanyl infusion on lowering blood pressure during FESS procedures. Materials and Methods Sixty-eight patients from the American Society of Anesthesiologists classes 1 and 2 who were planned for functional endoscopic sinus operations were randomly split into two groups for this randomized prospective trial. Group 1 patient belonging to the fentanyl 2 mcg per kg bolus 30 minutes before induction followed by 2 mcg per kg per hr infusion for 90 minutes of surgery, and Group 2 patient belonging to fentanyl 1 mcg per kg bolus 30 minutes before induction followed by 1 mcg per kg per hr infusion for 90 minutes of surgery. The significance of the difference in quantitative measures was measured using the student-t test, and the Chi-square test was used to measure up the difference in proportion. Statistically significant was set at P<0.05. Results Mean systolic blood pressure was higher in members of Group 2 than in Group 1. In contrast to Group 2, Group 1 had considerably better surgical field conditions, surgeon satisfaction on the AONO'S scale, post-operative nausea and vomiting, and a post-operative VAS Score during the first 24 hours. Conclusion Pre-induction Fentanyl with infusion can effectively control hypotension during functional endoscopic sinus surgery.

Intravenous Versus Wetting Solution Magnesium Sulphate to Counteract Epinephrine Cardiac Adverse Events in Abdominal Liposuction: A Randomized Controlled Trial

Background

The increased frequency of liposuction has resulted in more complications being reported. Adding epinephrine to the wetting solution could induce some cardiac adverse effects, some of which may be fatal. For instance, magnesium sulfate (MgSO₄) is known for its cardioprotective effects.

Objectives

This study aimed to evaluate the efficacy of intravenous (IV) versus wetting solution containing MgSO₄ in decreasing such cardiac adverse events during abdominal liposuction.

Methods

This randomized controlled study included 129 adult cases undergoing abdominal liposuction under general anesthesia. The participants were divided into 3 groups: Group I (control group) was only subjected to the injection of the wetting fluid (1 mL 1/1000 epinephrine added to every 1000 mL of normal saline), group II was subjected to IV MgSO₄ (40 mg/kg over 1 minute) at the same time of installing the wetting solution, and group III was subjected to MgSO₄ (40 mg/kg) added to the wetting solution.

Results

Intraoperative isoflurane consumption, intraoperative heart rate (HR), mean arterial pressure (MAP), and postoperative pain scores were significantly lower in the MgSO₄ groups (groups II and III) than group I. Cardiac adverse events (sinus tachycardia and premature ventricular contractions (PVCs)) were also significantly less frequent in groups II and III compared to group I.

Conclusions

Adding MgSO₄, either through IV or subcutaneous routes, is associated with lower intraoperative HR, MAP, and postoperative pain scores and a remarkable decrease in epinephrine-induced cardiac adverse events during liposuction.

Effects of Magnesium Sulfate on Intraoperative Blood Loss and Anesthetic Requirement in Meningioma Patients Undergoing Craniotomy with Tumor Removal: A Prospective Randomized Study

Background Meningioma brain tumor is associated with significant blood loss. Magnesium (Mg), a calcium blocker, can facilitate blood pressure control during surgery. This study aimed to evaluate effects of magnesium on blood loss, anesthetic requirement, and its neuroprotective effect in meningioma patients undergoing craniotomy.

Methods Eighty patients aged between 18 and 70, American Society of Anesthesiologists physical status I and II, diagnosed with meningioma and scheduled for craniotomy tumor removal were randomized into two groups. Group M (Mg) received intravenous magnesium sulfate 40 mg/kg over 30 minutes initiated at skin incision and followed by continuous infusion of 10 mg/kg/h until dura closure. Group N (NSS) received 0.9% NaCl as placebo. Anesthesiologists in charge, surgeons, and patients were all blinded. The assessed outcomes were perioperative blood loss, anesthetic requirement, and pre- and postoperative neurocognitive functions assessed by Montreal Cognitive Assessment (MoCA).

Results Thirty-eight patients in each group were analyzed. In group M, the intraoperative blood losses were 500 (70, 2300) mL, and 510 (100, 1600) mL in group N (p = 0.315). Patients who received blood within 24 hours were 39.5% in group M and 47.4% in group N (p = 0.644). No differences were observed in anesthetic requirement, intraoperative mean arterial pressure, hypotensive episodes, and vasopressor usages. There were no significant differences in postoperative MoCA score. Magnesium levels did not exceed acceptable levels.

Conclusions Magnesium administration in meningioma patients had no significant effects on blood loss, anesthetic requirement, and postoperative cognitive function.

Effects of magnesium sulphate on the onset time of rocuronium at different doses: a randomized clinical trial

Background and aims

Rocuronium may provide excellent onset time, but high doses are required for effective action. Several strategies have managed to shorten rocuronium onset time, including the use of Magnesium Sulphate (MgSO₄).

Methods

One hundred and eighty patients were randomized into six groups according to rocuronium dose received (0.3, 0.6 or 1.2 mg.kg^-1) and the administration of saline or MgSO⁴ (60 mg.kg^-1). Correlations between tissue perfusion and rocuronium onset time was determined by variations in perfusion index.

Results

Median (quartiles) rocuronium onset times were 85.5 (74.0–92.0); 76.0 (52.0–87.0) and 50.0 (41.0–59.5) seconds for 0.3, 0.6 mg.kg^-1 and 1.2 mg.kg^-1 doses, respectively. MgSO₄ decreased rocuronium onset at doses of 0.3 mg.kg^-1 (60.0 [48.0–74.3] seconds) and 0.6 mg.kg^-1 (44.0 [39.0–49.0] seconds) but not at 1.2 mg.kg^-1 (38.0 [33.5–56.3] seconds) (p < 0.001). Perfusion index variations in groups that received MgSO₄ were greater than in controls. A negative correlation between shorten onset and increased perfusion index was observed in rocuronium doses of 0.3 mg.kg^-1 (r = -0.50; p < 0.001) and 0.6 mg.kg^-1 (r = -0.424; p < 0.001), but not for 1.2 mg.kg^-1 dose (r = -0.25; p = 0.07).

Conclusion

MgSO₄ reduces rocuronium onset time at doses of 0.3 mg.kg^-1 and 0.6 mg.kg^-1 being that the latter has a similar effect when compared to the dose of 1.2 mg.kg^-1, with or without the use of MgSO₄.

Trial registry at

http://www.ensaiosclinicos.gov.br/

Registry Number

RBR-96CY3K

Reducing the dose of neuromuscular blocking agents with adjuncts: a systematic review and meta-analysis

BACKGROUND

Acute global shortages of neuromuscular blocking agents (NMBA) threaten to impact adversely on perioperative and critical care. The use of pharmacological adjuncts may reduce NMBA dose. However, the magnitude of any putative effects remains unclear.

METHODS

We conducted a systematic review and meta-analysis of RCTs. We searched Medline, Embase, Web of Science, and Cochrane Database (1970-2020) for RCTs comparing use of pharmacological adjuncts for NMBAs. We excluded RCTs not reporting perioperative NMBA dose. The primary outcome was total NMBA dose used to achieve a clinically acceptable depth of neuromuscular block. We assessed the quality of evidence using the GRADE (Grades of Recommendation, Assessment, Development, and Evaluation) criteria. Data are presented as the standardised mean difference (SMD); I² indicates percentage of variance attributable to heterogeneity.

RESULTS

From 3082 records, the full texts of 159 trials were retrieved. Thirty-one perioperative RCTs met the inclusion criteria for meta-analysis (n=1962). No studies were conducted in critically ill patients. Reduction in NMBA dose was associated with use of magnesium (SMD: -1.10 [-1.44 to -0.76], P<0.001; I²=85%; GRADE=moderate), dexmedetomidine (SMD: -0.89 [-1.55 to -0.22]; P=0.009; I²=87%; GRADE=low), and clonidine (SMD: -0.67 [-1.13 to -0.22]; P=0.004; I²=0%; GRADE=low) but not lidocaine (SMD: -0.46 [-1.01 to -0.09]; P=0.10; I²=68%; GRADE=moderate). Meta-analyses for nicardipine, diltiazem, and dexamethasone were not possible owing to the low numbers of studies. We estimated that 30-50 mg kg^-1 magnesium preoperatively (8-15 mg kg h^-1 intraoperatively) reduces rocuronium dose by 25.5% (inter-quartile range, 14.7-31).

CONCLUSIONS

Magnesium, dexmedetomidine, and clonidine may confer a clinically relevant sparing effect on the required dose of neuromuscular block ing drugs in the perioperative setting.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO: CRD42020183969.

Effects of perioperative magnesium sulfate with controlled hypotension on intraoperative bleeding and postoperative ecchymosis and edema in open rhinoplasty

PURPOSE

This randomized, double-blind study was planned to evaluate the effect of perioperative magnesium sulfate with controlled hypotension on intraoperative bleeding, postoperative ecchymosis and edema, and side-effects.

MATERIALS AND METHOD

Forty-nine patients undergoing open rhinoplasty were divided into two groups - magnesium sulfate and control. The magnesium sulfate group received 30-50 mg·kg^-1 intravenously as a bolus before induction of anesthesia, followed by 10-20 mg·kg^-1 h^-1 by continuous intravenous infusion during surgery. Anesthesia was induced with propofol 3 mg·kg^-1, fentanyl 15 μg·kg^-1 and cisatracurium 0.6 mg·kg^-1. Mean arterial pressure was maintained at 50 to 60 mmHg under controlled hypotensive anesthesia with magnesium sulfate titration. Hemodynamic variables, operational bleeding, early postoperative side-effects and postoperative first-, third- and seventh-day ecchymosis and edema were compared between the groups. Ecchymosis and edema were evaluated using a graded scale from 0 to 4.

RESULTS

In the magnesium sulfate group, mean arterial pressure decreased during most of the perioperative period. Intraoperative bleeding also decreased. A distinct reduction in ecchymosis and edema was observed in both the upper and lower eyelids on the first, third and seventh days. Patients in the magnesium sulfate group also had a more peaceful postoperative course with less postoperative nausea vomiting, and shivering.

CONCLUSION

Magnesium sulfate with controlled hypotension can lower ecchymosis and edema of the upper and lower eyelids in rhinoplasty surgery by reducing bleeding.

Effects of perioperative magnesium sulfate infusion on intraoperative blood loss and postoperative analgesia in patients undergoing posterior lumbar spinal fusion surgery: A randomized controlled trial

OBJECTIVE

Many studies have suggested the anti-nociceptive role for magnesium either as an adjunct for postoperative pain. Although several studies have been carried out to evaluate the anti-nociceptive effect of magnesium, there is still considerable uncertainty.

PATIENTS AND METHODS

Eighty patients who underwent posterior spinal fusion were randomly divided into two groups (magnesium and saline). Changes in cell count, magnesium concentration and coagulation status were assessed one hour after operation at both group and compared to baseline. At recovery room, their pain score was assessed according to 10 points visual analogue scale (VAS). Morphine consumption was evaluated at regular times after the surgery by patient controlled analgesia (PCA) device.

RESULTS

VAS scores were significantly lower in the magnesium group. Cumulative PCA morphine consumption after the surgery was significantly lower in the magnesium group. Pre and postoperative values for haemoglobin, platelet count, Prothrombin Time (PT), fibrinogen were not significantly different. There was a significant increase in activated Partial Thromboplastin Time (aPTT), International Normalized Ratio (INR), and bleeding time (BT), one hour after the operation in the magnesium group but intraoperative blood loss was similar in both groups.

CONCLUSIONS

Perioperative magnesium sulfate infusion improves the postoperative analgesia, decreases the amount of morphine consumption after the operation and does not change the intraoperative bleeding in patients undergoing posterior spinal fusion surgery.

Metoprolol Significantly Improves Visual Clarity and Hemodynamic Parameters during Functional Endoscopic Sinus Surgery

Background and Objectives

The success of functional endoscopic sinus surgery (FESS) depends on the visual clarity of the surgical field, which is understudied. Controlled hypotension has many advantages for FESS including reduction in blood loss and improved quality of the surgical field. This study determined whether the use of β-blockers as a premedication could improve the operative field in FESS. Methods : Sixty patients aged from 18 to 50 years, undergoing septoplasty and FESS were included in this prospective, randomized, double-blind, placebo-controlled study. Patients were randomly assigned to receive either metoprolol (100 mg, group 1) or a placebo (a vitamin tablet, group 2) 60 min before surgery.

Results

The average blood loss and surgery duration were not significantly higher in the placebo group. The surgical field was graded using the Fromme-Boezaart scale, and it was significantly clearer (p < 0.001) in metoprolol group. The mean arterial blood pressure was significantly lower in the metoprolol group after 30 min of induction until the end of surgery (p < 0.001). The heart rate was also significantly lower (p < 0.001) in those who received metoprolol from before induction of anesthesia up to the end of surgery. Conclusion : Metoprolol significantly improves visual clarity and hemodynamics during FESS. We would recommend the use of metoprolol in FESS and septoplasty.

Comparison of effects and safety in providing controlled hypotension during surgery between dexmedetomidine and magnesium sulphate: A meta-analysis of randomized controlled trials

Background

Effectiveness of controlled hypotension has been proven in alleviating intraoperative bleeding. Many recent studies emphasized the efficacy of dexmedetomidine and magnesium in providing controlled hypotension during various surgeries. The present meta-analysis of randomized controlled trials (RCTs) was performed to evaluate comprehensively the effects and safety of these two medications.

Methods

Literature search was performed in four databases from inception to April 2019. All RCTs that used dexmedetomidine and magnesium as hypotensive agents were enrolled. The outcomes contained bleeding condition of surgical site, hemodynamic parameters, duration of surgeries, number of patients requiring opioid/analgesia administration, recovery period, and adverse events emerged during surgeries.

Results

Ten studies with 663 patients met with our inclusion criteria. The results indicated that both bleeding score and values of mean arterial pressure (MAP) and heart rate (HR) were significantly lower in patients receiving dexmedetomidine (SMD 1.65 with 95% CI [0.90,2.41], P<0.00001) compared to the patients receiving magnesium. The effect in decreasing the necessity of using opioid/analgesia was affirmative in dexmedetomidine group (29.13% with magnesium vs 10.78% with dexmedetomidine), and the condition was more favorable in magnesium group in reducing recovery period (SMD -1.98 with 95% CI [-4.27,0.30], P = 0.09). Compared with magnesium, using of dexmedetomidine was associated with higher incidence of bradycardia but lower incidence of nausea and vomiting.

Conclusion

Compared with magnesium, dexmedetomidine is more effective to provide promising surgical field condition, favorable controlled hypotension, and less necessity of opioid or analgesia administration. But long recovery period and high-probability bradycardia should be deliberated.

The effect of magnesium sulfate on surgical field during endoscopic sinus surgery: A meta-analysis of randomized controlled trials

INTRODUCTION

The benefits of magnesium sulfate for surgical field during endoscopic sinus surgery remain controversial. We conduct a systematic review and meta-analysis to explore the influence of magnesium sulfate versus placebo on surgical field during endoscopic sinus surgery.

METHODS

We search PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through November 2018 for randomized controlled trials (RCTs) assessing the effect of magnesium sulfate versus placebo on surgical field during endoscopic sinus surgery. This meta-analysis is performed using the random-effect model.

RESULTS

Four RCTs and 404 patients are included in the meta-analysis. Overall, compared with control group endoscopic sinus surgery, magnesium sulfate has remarkably positive impact on surgical field scores (MD = -1.76; 95% CI = -2.33 to -1.18; P < .00001), and intraoperative blood loss (MD = -89.09; 95% CI = -163.20 to -14.97; P = .02), but shows no markedly effect on surgery duration (MD = -7.08; 95% CI = -21.38 to 7.22; P = .33), fentanyl (MD = -0.64; 95% CI = -1.97 to 0.70; P = .35), and vecuronium (MD = -3.64; 95% CI = -10.99 to 3.70; P = .33).

CONCLUSIONS

Magnesium sulfate exerts positive impact on surgical field and blood loss reduction for endoscopic sinus surgery.

Comparison of dexmedetomidine versus propofol-based anaesthesia for controlled hypotension in functional endoscopic sinus surgery

Background: Increased intraoperative bleeding during functional endoscopic sinus surgery (FESS) affects operative field visibility, which increases both duration of surgery and frequency of complications. Controlled hypotension is an anaesthetic technique in which there is deliberate reduction of systemic blood pressure during anaesthesia. The aim of the study was to compare the efficacy of dexmedetomidine against propofol infusion when used for controlled hypotension during FESS. Methods: A randomised, prospective, and single-blinded study was carried out, which included 80 patients of either sex of ASA grade І & ІІ who underwent elective FESS. Patients were randomly assigned to two groups: Group A (dexmedetomidine), Group B (propofol). Intraoperative mean arterial pressure (MAP), heart rate (HR), surgical grade of bleeding (based on the Fromme– Boezzart scale), and amount of bleeding were recorded. Results: Groups were well matched for their demographic data. There was a statistically significant difference (p < 0.05) between Group A and Group B in heart rate, mean arterial pressure (MAP) and mean total blood loss, with Group A being effectively in controlled on all three parameters during FESS. However, there was no significant difference (p > 0.05) in terms of surgical grade of bleeding between Group A and Group B. Conclusions: Both dexmedetomidine and propofol infusion are efficacious to facilitate controlled hypotension and haemodynamic stability intraoperatively.

Optimization of the Surgical Field in Endoscopic Sinus Surgery: an Evidence-Based Approach

PURPOSE OF REVIEW

The advent of endoscopic sinus surgery (ESS) has enabled the development of minimally invasive surgical procedures in Rhinology. However, proficiency with ESS techniques can still be hampered by poorly controlled bleeding limiting visibility of the surgical field (VSF). This can lead to increased operating time and, more importantly, increased risk of major and minor complications. To optimize the VSF and mitigate the risk of complications, many strategies have been explored.

RECENT FINDINGS

This is a narrative review of the relative risks and benefits of pre- and intra-operative interventions aimed at optimizing intraoperative conditions during ESS. The value of these interventions is determined based on their impact on intraoperative blood loss, time of surgery, and the VSF, and weighed against their adverse event profile. This review provides a comprehensive overview of the evidence relating to the safety and efficacy of interventions used to improve intraoperative conditions during ESS.

Comparative Study between Magnesium Sulfate and Lidocaine for Controlled Hypotension during Functional Endoscopic Sinus Surgery: A Randomized Controlled Study

Background:

Intraoperative bleeding impairs surgical field visibility during functional endoscopic sinus surgery (FESS); several methods have been used to decrease blood loss and improve surgical field, one of them is usage of hypotensive anesthetic agents.

Aim:

We intended to compare magnesium sulfate with lidocaine, regarding their efficiency in inducing controlled hypotension and providing a better surgical field exposure during FESS and the influence of their usage on extubation time.

Settings and Design:

This study design was a prospective randomized controlled double-blinded clinical study.

Patients and Methods:

Eighty adult patients with patients' physical status ASA Classes I and II, aged 20–50 years scheduled for FESS were randomly divided into two study groups; each group contains 40 patients: Group L received lidocaine 2 mg/kg/h with maximum of 200 mg/h starting at induction of anesthesia and continuing until the end of surgery and Group M received an iv bolus of magnesium sulfate 50mg/kg in a total of 100ml saline over 10 min followed by infusion of 15mg/kg/h until the end of surgery; patients were observed for the quality of the surgical field, blood loss, and extubation time.

Statistical Analysis Used:

Student's t-test or Mann–Whitney's U, Chi-square, or Fisher's exact tests were used.

Results:

Group L showed a significant decrease in blood loss (P = 0.01), better surgical field clarity (P = 0.002), and shorter extubation time (P = 0.001) than Group M, but there was no statistically significant difference between the two study groups as regards hemodynamics.

Conclusion:

We concluded that both magnesium sulfate and lidocaine successfully induced controlled hypotension in patients undergoing FEES, but lidocaine provided better surgical field clarity and shorter extubation time.

Antenatal magnesium sulfate is beneficial or harmful in very preterm and extremely preterm neonates: a new insight

AIMS

To evaluate whether antenatal MgSO₄ is beneficial or harmful in very preterm and extremely preterm neonates.

MATERIALS AND METHODS

We retrieved published literature through searches of PubMed or Medline, CINAHL, and the Cochrane Library. Results were restricted to systematic reviews, meta-analysis, randomized controlled trials (RCTs), and relevant observational studies.

RESULTS

Evidence revealed that antenatal MgSO₄ has neuroprotective role in preterm neonates and it decreased the risk of cerebral palsy and gross motor dysfunction. Evidences regarding association of antenatal MgSO₄ with feed intolerance, NEC and SIP were from cohort studies and controversial.

CONCLUSIONS

We should continue use antenatal MgSO₄ to all eligible patients according to protocol till the more robust evidence will suggest association with gastrointestinal complications. In the meantime, we should have a high index of suspicion of gastrointestinal complications in extremely preterms particularly <26 weeks of gestation.

Controlled Hypotension During Rhinoplasty: A Comparison of Dexmedetomidine with Magnesium Sulfate

Objective

The current study aimed at comparing the efficacy of dexmedetomidine and magnesium sulfate to control blood pressure (BP) during rhinoplasty and the resultant effects on the quality of surgical field in terms of bleeding and visibility.

Methods

The current randomized, prospective, double-blind study was conducted on 60 patients aged 18 to 50 years classified as ASA (American Society of Anesthesiologists) physical status I who were candidates for rhinoplasty. Patients were randomly divided into 2 groups: (1) group Dex, received 1 µg/kg dexmedetomidine in 10 minutes before induction of anesthesia, followed by 0.4 - 0.6 µg/kg/hour during the maintenance of anesthesia, and (2) group Mg, received 40 mg/kg in 10 minutes before anesthesia induction followed by 10 - 15 mg/kg/hour during anesthesia maintenance. In both groups, the goal was to achieve a mean arterial pressure (MAP) of 60 - 70 mmHg. Hemodynamic variables, anesthetic, opioid, muscle relaxant requirements, and surgical field condition were recorded. Sedation score, time to reach modified Aldrete score ≥ 9, and adverse effects including nausea and vomiting (N&V) and shivering were recorded.

Results

Controlled hypotension was achieved in both groups. There was no significant difference in MAP between the groups, but heart rate (HR) was significantly lower in the Dex group (P < 0.001), compared with that of the Mg group. Bleeding score was lower (P < 0.001) and surgeon's satisfaction score was higher (P < 0.001) in the Dex group. More patients required fentanyl (P < 0.001) or nitroglycerin (P < 0.001) and the mean fentanyl (P = 0.005) or nitroglycerin (P < 0.001) required doses were higher in the Mg group. Patients in the Dex group required more frequent administration of cisatracurium (P = 0.004). Five patients in the Dex group versus no patients in the Mg group received atropine (P = 0.023). Ramsay sedation score and time to reach modified Aldrete score ≥ 9 were significantly higher in the Dex group (P < 0.001 and P < 0.001, respectively). The incidence rate of N&V and shivering were similar in both groups.

Conclusion

Dexmedetomidine was more effective than magnesium to achieve controlled hypotension, and provide a favorable surgical field condition. However, dexmedetomidine also heightened the risk of induced bradycardia and prolonged sedation. These are 2 important points to consider when applying this drug as a hypotensive agent during operation.

Anesthetic Techniques in Endoscopic Sinus and Skull Base Surgery

Endoscopic sinus approach has become one of the most common surgical techniques for endoscopic sinus and skull base surgery. Anesthetic management has an important impact on the overall patient management, from the preoperative assessment and management to the quality of the surgical field and the postoperative recovery. Hemostasis is critical for adequate anatomical endoscopic visualization. Mild controlled hypotension seems to improve the visibility of the surgical field. Reduction of intraoperative bleeding should be considered during the treatment planning. Preoperative preparations include the optimization of comorbidities and cessation of drugs that may inhibit coagulation.

The effects of dexmedetomidine and magnesium sulphate in adult patients undergoing endoscopic transnasal transsphenoidal resection of pituitary adenoma: A double-blind randomised study

Background and Aim:

Transnasal transsphenoidal resection of pituitary tumours is associated with blood loss and wide fluctuations in haemodynamic parameters. The aim of the present study was to compare the effect of dexmedetomidine and magnesium sulphate during the transsphenoidal resection of pituitary tumours.

Methods:

The study was a double-blind, randomised study and included 152 patients classified randomly into two groups: Group D: Dexmedetomidine was given as a loading dose 1 μg/kg over 10 min before induction followed by an infusion at 0.5 μg/kg/h during the surgery. Group M: Magnesium sulphate was given as loading dose of 50 mg/kg over 10 min followed by an infusion at 15 mg/kg/h during the surgery. The systolic, diastolic and mean arterial blood pressures, in addition to the amount of blood loss were measured at specific timepoints. Data were described in terms of mean ± standard deviation, median, frequencies, 95% confidence of interval of mean and percentages.

Results:

Mean bleeding score was lower in Group D than Group M (1.36 ± 0.48 vs. 3.05 ± 0.65, respectively; P = 0.002). Mean blood loss was lower in Group D (157.43 ± 48.79 ml vs.299.47 ± 77.28 ml in Group M; P < 0.001)Heart rate, mean arterial pressure, fentanyl requirements, end-tidal sevoflurane concentration, and extubation and emergence times were lower, while incidence of bradycardia and hypotension were higher in Group D.

Conclusions:

During transsphenoidal pituitary resection, dexmedetomidine, compared to magnesium, is associated with lower blood loss and better operating conditions but with more hypotension and bradycardia

Magnesium in obstetric anesthesia and intensive care

Magnesium, one of the essential elements in the human body, has numerous favorable effects that offer a variety of possibilities for its use in obstetric anesthesia and intensive care. Administered as a single intravenous bolus dose or a bolus followed by continuous infusion during surgery, magnesium attenuates stress response to endotracheal intubation, and reduces intraoperative anesthetic and postoperative analgesic requirements, while at the same time preserving favorable hemodynamics. Applied as part of an intrathecal or epidural anesthetic mixture, magnesium prolongs the duration of anesthesia and diminishes total postoperative analgesic consumption with no adverse maternal or neonatal effects. In obstetric intensive care, magnesium represents a first-choice medication in the treatment and prevention of eclamptic seizures. If used in recommended doses with close monitoring, magnesium is a safe and effective medication.

Deliberate hypotension with propofol under anaesthesia for functional endoscopic sinus surgery (FESS)

BACKGROUND

Functional endoscopic sinus surgery (FESS) is a minimally invasive technique that is used to treat chronic sinusitis. Small bleeding areas can reduce operative visibility and result in destruction of surrounding structures. Deliberate hypotension (lowering the mean arterial blood pressure to between 50 and 65 mm Hg in normotensive patients) using a range of pharmacological agents during general anaesthesia reduces blood loss in many operations. This review was originally published in 2013 and updated in February 2016.

OBJECTIVES

We aimed to compare the use of propofol versus other techniques for achieving deliberate intraoperative hypotension during FESS procedures with regard to blood loss and operative conditions.

SEARCH METHODS

We searched the following databases in the updated review: the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 2), MEDLINE (1950 to February 2016), Embase (1980 to February 2016), LILACS (1982 to February 2016), and ISI Web of Science (1946 to February 2016). We also searched the reference lists of relevant articles and conference proceedings and contacted the authors of included trials.

SELECTION CRITERIA

We sought all randomized controlled trials comparing propofol with other techniques for deliberate hypotension during FESS with regard to blood loss and operative conditions in both adults and children. Our primary outcome was total blood loss (TBL). Other outcomes included surgical field quality, operation time, mortality within 24 hours, complications, and failure to reach target blood pressure.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Two review authors independently extracted details of trial methodology and outcome data from the reports of all trials considered eligible for inclusion. We made all analyses on an intention-to-treat basis where possible. When I2 was less than 40% and the P value from the Chi2 test was higher than 0.10, we pooled data using the fixed-effect model. Otherwise, we pooled data using the random-effects model.

MAIN RESULTS

We found no new studies. This updated review therefore includes four studies with 278 participants. Most analyses were based on data from few participants and low-quality evidence, so our results should be interpreted with caution. Deliberate hypotension with propofol did not decrease TBL (millilitres) when compared with inhalation anaesthetics in either children (1 study; 70 participants; very low-quality evidence), or adults (1 study; 88 participants; moderate-quality evidence). Propofol improved the quality of the surgical field by less than one category on a scale from 0 (no bleeding) to 5 (severe bleeding) (mean difference -0.64, 95% CI -0.91 to -0.37; 4 studies; 277 participants; low-quality evidence), but no difference in operation time was reported (3 studies; 214 participants; low-quality evidence). Failure to lower blood pressure to target was less common in the propofol group (risk ratio of failure with propofol 0.24, 95% CI 0.09 to 0.66; 1 study; 88 participants; moderate-quality evidence).

AUTHORS' CONCLUSIONS

Using propofol to achieve deliberate hypotension probably improves the surgical field, but the effect is small. Deliberate hypotension with propofol did not decrease TBL and the operation time. However, due to the very low quality of the evidence, this conclusion is not definitive. Randomized controlled trials with good-quality methodology and large sample size are required to investigate the effectiveness of deliberate hypotension with propofol for FESS.

Comparison of quality of the surgical field after controlled hypotension using esmolol and magnesium sulfate during endoscopic sinus surgery

Background and Aims:

Most vital aspect of Endoscopic Sinus Surgery (ESS) is an optimal visibility in the surgical field. This invariably requires controlled hypotension to facilitate surgical dissection and to decrease operative time. We used esmolol and magnesium sulfate to achieve controlled hypotension and assessed the quality of the surgical field in ESS.

Material and Methods:

A total of 30 patients undergoing ESS, were enrolled in three parallel groups of 10 patients each in a prospective randomized double-blind study. “Magnesium Sulfate group” received magnesium sulfate 40 mg/kg intravenously (i.v.) as a bolus over 10 min before induction of anesthesia, followed by 15-30 mg/kg/h through infusion. “Esmolol group” received 0.5 mg/kg i.v. bolus over 10 min after induction followed by 150-300 μg/kg/min infusion and “control group” received normal saline in same volume schedule. The primary aim was to assess the quality of surgical field, using Fromme scale. Category Scale values of all the three groups were compared using Kruskal-Wallis analysis of variance (ANOVA) test. Hemodynamic data was compared using ANOVA test.

Results:

Quality of the surgical field was better in both magnesium sulfate and esmolol groups as compared to the control group. Durations of anesthesia and surgery were significantly lower in esmolol group as compared to the control group. Blood loss was comparable in all the three groups.

Conclusion:

Quality of the surgical field was better in esmolol and magnesium sulfate groups as compared to control group. Duration of surgery was significantly less in esmolol group as compared to other two groups.

Magnesium sulfate or diltiazem as adjuvants to total intravenous anesthesia to reduce blood loss in functional endoscopic sinus surgery

STUDY OBJECTIVE

This study was designed to know whether addition of magnesium sulfate (MgSO4) or diltiazem to total intravenous anesthesia (TIVA) (propofol) aided reduction in blood loss during functional endoscopic sinus surgery (FESS). The secondary outcomes measured were surgeon's assessment of the surgical field and hemodynamics.

DESIGN

Randomized, double-blinded, placebo-controlled trial.

SETTING

Operating room.

PATIENTS

Forty-five American Society of Anesthesiologists I and II adult patients (18-60years) undergoing FESS.

INTERVENTIONS

All groups received propofol-fentanyl TIVA. Patients were randomly allocated to 1 of the 3 groups (MgSO4 group, n=15; diltiazem group, n=15; saline group, n=15).

MEASUREMENTS

Intraoperative bleeding was quantified, and quality of surgical field was graded. Hemodynamic parameters were recorded.

MAIN RESULTS

Addition of both MgSO4 and diltiazem significantly reduced blood loss (240 and 350mL) in comparison to control group (415mL) (P=.003). The surgical field was significantly better in the MgSO4 group compared with the diltiazem (P=.028) and saline groups (P=.0001).

CONCLUSION

It was concluded that the addition of both MgSO4 and diltiazem to TIVA propofol results in significant reduction in blood loss and significant improvement in the quality of surgical field during FESS without causing any adverse effects on the hemodynamics or on the recovery from anesthesia. The surgical field in the MgSO4 group was significantly better than that in the diltiazem group (P=.04).