Abstract
Background:
Reducing bleeding in lumbar vertebrae fusion surgery is essential to maintain the patient’s hemodynamic stability and create a favorable view. This study aims to compare and contrast the effects of dexmedetomidine and magnesium sulfate on lumbar laminectomy surgery.
Materials and Methods:
This double-blind randomized clinical trial was conducted on 70 patient underwent lumbar fusion surgery. They were randomly divided into two groups of 35. After inducing general anesthesia with an infusion pump, the first group (MgSO4 group) received an intravenous injection of 60 mg/kg of 50% magnesium sulfate, diluted in 100 cc of normal saline, for 15 minutes. In the second group (DEX group), a dexmedetomidine infusion was started before anesthesia with a dose of 1 μg/kg every 10 minutes. Dexmedetomidine infusion at a rate of 0.5 μg/kg/hour was continued until the end of the surgical procedure. Systolic and diastolic pressure (SBP, DBP), mean atrial pressure (MAP), heart rate (HR), and SPO2, was recorded before surgery and every 30 minutes during surgery. Also, the intraoperative bleeding and side effect were recorded.
Results:
The results of this study showed that SBP and MAP of the DEX group at 30 and 60 minutes were significantly lower than the MgSO4 group. The DBP of the DEX group was significantly lower than the MgSO4 group only in the 30th minute. Intraoperative bleeding, packed-cell transfusion, tachycardia, and quality of the surgical field were significantly lower in the DEX group.
Conclusions:
Considering that the administration of DEX has been more effective in controlling intraoperative bleeding and better quality of surgical field, it seems that the administration of DEX is more preferable than MgSO4.
Keywords: Dexmedetomidine, intraoperative bleeding, lumbar laminectomy, magnesium sulfate
INTRODUCTION
Lumbar vertebrae fusion surgery is often associated with a lot of bleeding, sometimes to such an extent that the need for blood transfusions and blood products is necessary.[1] Bleeding can be a problem in not only major surgeries but also in smaller fusions.[2] Reducing bleeding is essential to maintain the patient’s hemodynamic stability and create a blood-free field with a favorable view for the surgeon.[3] The latter aspect is especially sensitive for nerve surgeries due to its proximity to vulnerable nerve structures.[4] The surgeon’s ease of visibility into the surgical field not only shortens the procedure duration, but also decreases bleeding.[5] Cutting down on bleeding also cuts down on the need for blood products, which lowers the risk of complications like hemolytic and nonhemolytic reactions, acute lung damage, the spread of viral and bacterial infections, hypothermia, coagulation disorders, and more.[5]
We can divide intraoperative bleeding control methods into two groups based on their mechanism: those that reduce bleeding hemodynamically (with controlled hypotension, local vasoconstrictors, epidural block) or chemically/biologically (such as desmopressin, aprotinin, transamine, aminocaproic acid, estrogens, hemostatic sponges, or fibrin glues), and those that reduce the need for homologous transfusion (such as acute hemodilution, autologous transfusion, cell saver, erythropoietin).[6] In orthopedic surgery, controlled hypotension has been associated with excellent success.
Some procedures that require injectable anesthesia, such as intubation in patients admitted to the intensive care unit, use the injectable drug dexmedetomidine.[7] In cases where rapid anesthesia induction is required, we use this drug. Dexmedetomidine works in two ways: first, it selectively binds to and relaxes alpha-2 adrenoceptors in the brain stem, which stops norepinephrine from being released, and second, it narrows blood vessels by activating the peripheral alpha-2B adrenoceptor in a high dose of drug or a rapid intravenous injection of drug. Some studies have shown that the use of alpha-2 agonists such as dexmedetomidine, either orally or intravenously, reduces bleeding during surgery.[8]
Magnesium has an indirect effect on cardiac muscle cells by inhibiting the absorption of calcium into troponin-C inside the myocyte. In fact, it exerts negative inotropism on the myocardium in a dose-dependent manner. Magnesium infusion dilates coronary arteries and increases coronary blood flow. Also, magnesium stops the adrenal gland and adrenergic sympathetic nerve endings from releasing catecholamine. This lowers the excitability of heart muscle cells and nodal tissue, preventing arrhythmia. Some studies have suggested using magnesium sulfate as a vasodilator drug with minimal myocardial effects to induce controlled hypotension.[9,10]
Because both magnesium sulfate and dexmedetomidine may help stop bleeding during spinal surgeries, and because no previous research has looked at how these two drugs work in lumbar perfusion surgery, this study aims to compare and contrast the effects of two drugs on lumbar laminectomy surgery.
MATERIALS AND METHODS
This study was a double-blind randomized clinical trial. Study population includes all patients underwent lumbar fusion surgery who referred to Al-Zahra and Kashani Hospitals in Isfahan from 2023 to 2024. This study has been registered in www.irct.ir with the clinical trial code (IRCT code: IRCT20160307026950N59).
The sample size, with a 95% confidence level and 80% power, considering the standard deviation of bleeding in previous studies[11] equal to 5.2 and the error level obtained from the mean of two groups equals 3.72, and accounting for a 10% potential dropout rate, the sample size in each group calculated 35 patient.
The inclusion criteria included having a lumbar fusion indication and being aged 18 to 60 years. Exclusion criteria include heart diseases (arrhythmias, heart valve diseases, uncontrolled hypertension), respiratory diseases, preoperative coagulation disorders, hepatitis and renal failure, diabetes mellitus, neuromuscular diseases, seizures, any drug allergy during the study, the onset of a dangerous arrhythmia (ventricular arrhythmia), or occurrence of ventricular arrhythmia or heart block during the operation.
After obtaining the ethics code from the Ethics Committee of Isfahan University of Medical Sciences and receiving written consent from eligible patients, a total of 70 patients were randomly selected. Then, using random allocation software, these patients were divided into two groups of 35 [Figure 1]. Demographic and clinical information of the patients, including gender, age, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean atrial pressure (MAP), heart rate (HR), and SPO2 was recorded, at the beginning of the study.
Figure 1.
Consort flowchart of patients
All patients were placed in the prone position and administered the same anesthesia protocol (sodium thiopental 5 mg/kg, fentanyl 2 g/kg, morphine 0.01 mg/kg, and atracurium 0.5 mg/kg) for maintenance. In addition, we prescribed atracurium 0.2 mg/kg every 30 to 40 minutes, based on peripheral nerve stimulator monitoring and a maximum of two responses in four.
Left radial cannulation to directly monitor arterial pressure and measure serum magnesium levels were performed. Also, the function of vital organs using various intraoperative monitoring techniques, including echocardiography for the heart, peripheral nerve stimulation for the neuromuscular system, pulse oximetry and capnography for the respiratory system, and urine output for the urinary system was checked.
After inducing general anesthesia with an infusion pump, the first group (MgSO4 group) received an intravenous injection of 60 mg/kg of 50% magnesium sulfate, diluted in 100 cc of normal saline, for 15 minutes, as the starting dose. The injection was continued at a rate of 20 mg/kg/h until 30 minutes before the end of the operation, achieving an average arterial pressure of 55 to 60 mmHg. If the desired average pressure is not achieved, a higher concentration of isoflurane (maximum 1.2%) or nitroglycerin injection at a rate of 5 to 50 μg/min is used. If the mean arterial pressure decreased to less than 50 mm Hg, magnesium and nitroglycerin infusions were stopped, and crystalloid fluid (Ringer’s) was prescribed at a rate of 5 mL/kg/h. Intravenous ephedrine was administered at a rate of 5 mg/dose every 3 to 5 minutes. If a dangerous arrhythmia (stable ventricular arrhythmia) or a second-degree heart block (or higher) occurred during the recording, the patient was excluded from the study.
In the second group (DEX group), a dexmedetomidine infusion was started before anesthesia with a dose of 1 μg/kg every 10 minutes (precedex 200 μg/2 mL, diluted in 50 mL 0.9% saline). Dexmedetomidine infusion at a rate of 0.5 μg/kg/hour was continued until the end of the surgical procedure. We conducted all the monitoring in the magnesium sulfate group.
To achieve a double-blind study, two daily medications, dexmedetomidine and magnesium sulfate, were prepared by the operating room nurse (without the researcher’s knowledge) before the operation and placed in a bag labeled A and B. These bags were given to the anesthesiologist (researcher) daily. Therefore, the patient, the researcher, and the person collecting the clinical and initial patient information would not be aware of the type of intervention.
Note that all surgeries were performed in the same hospital by a single skilled surgical team to avoid the influence of any confounding factors and to ensure uniformity of the anesthesia protocol in the two groups.
Hemodynamic parameters including SBP, DBP, MAP, HR, and SPO2 were recorded every 30 minutes during surgery and at the end of surgery.
The amount of intraoperative bleeding was recorded by measuring the blood in the high-precision suction device, measuring potential blood gases. Also, the quality of the surgical field was assessed and scored by the surgeon based on Boezaart criteria scale [Table 1].
Table 1.
Boezaart criteria grading system for scoring the quality and bleeding of surgical field during surgery
| Grade | Surgical field status |
|---|---|
| 0 | There is no bleeding—cadaveric conditions |
| 1 | Slight bleeding—no need for suction |
| 2 | Slight Bleeding – sometimes suction is required |
| 3 | Slight bleeding—repeated suction is needed—the bleeding of the surgical site removed for a few seconds after the end of the suction. |
| 4 | Moderate bleeding requires frequent suctioning, and bleeding at the surgical site starts immediately after the end of suctioning but removes during the suctioning. |
| 5 | Severe bleeding, continuous suction is needed, bleeding is too fast to remove with suction. The surgical field is heavily involved and surgery is usually not possible. |
The required dose of propofol, ephedrine, the duration of the surgery, and the occurrence of side effects (such as tachycardia and bradycardia) was recorded.
Statistical analysis
The statistical analysis was conducted using statistical software version 27. The data were presented as mean ± standard deviation (SD) or n (%). Based on the results of the Shapiro–Wilk test, it was determined that the data followed a normal distribution. Therefore, the independent sample t-test was used to compare the mean values of the quantitative variables between the two groups at each time. Furthermore, repeated-measure ANOVA was used to assess the changes in the quantitative variables between the two groups by passing time. In addition, the Chi-square test was used to compare the frequency distribution of qualitative variables between the two groups. In all analyses, a significance level of less than 0.05 was considered.
RESULTS
This study was conducted on 70 people for both MgSO4 and DEX groups (35 people for each group). The demographic variables were no significant difference between two groups (P > 0.05). Also, the mean maintenance fluid therapy in the MgSO4 group was 15.02 ± 2.15 mL/kg/h, and in the DEX group, it was 14.76 ± 2.59 mL/kg/h, and there was no significant difference in this case (P = 0.922). Urinary output in the MgSO4 group was 692.73 ± 180.12 mL/h, and in the DEX group, it was 741.91 ± 230.55 mL/h (P = 0.323) [Table 2].
Table 2.
Demographic and clinical characteristics of patients in the two groups
| Characteristics | MgSO4 group (n=35) | DEX group (n=35) | P | |
|---|---|---|---|---|
| Age; year | 44.68±13.69 | 48.34±12.02 | 0.238 | |
| Sex | Male | 26 (74.2%) | 15 (42.8%) | 0.440 |
| Female | 9 (25.8%) | 20 (57.2%) | ||
| BMI; kg/m2 | 27.78±1.69 | 28.20±2.40 | 0.400 | |
| Duration of surgery; hours | 1.98±0.62 | 1.33±0.54 | 0.081 | |
| Volume of fluids consumed; mL/kg/h | 15.02±2.15 | 14.76±2.59 | 0.922 | |
| Urinary output; mL/h | 692.73±180.12 | 741.91±230.55 | 0.323 | |
In the evaluation of hemodynamic parameters, it was found that the DEX group exhibited significantly lower SBP at 30 and 60 minutes compared with the MgSO4 group (P < 0.05). Only in the 30th minute did the DEX group have significantly lower DBP than the MgSO4 (P < 0.05). The DEX group showed significantly lower MAP at 30 and 60 minutes compared with the MgSO4 group (P < 0.05). At all follow-up times, the HR in the DEX group was significantly lower than the MgSO4 group (P value < 0.001). However, during extubation, none of the hemodynamic parameters were significantly different between the two groups (P value > 0.05) [Table 3].
Table 3.
Comparison the mean of hemodynamic parameters in the follow-up times in the two groups
| Parameters | Time | MgSO4 group (n=35) | DEX group (n=35) | P 1 |
|---|---|---|---|---|
| SBP; mmHg | Baseline | 110.06±5.37 | 109.89±5.26 | 0.894 |
| 30th minute during surgery | 98.08±8.57 | 94.05±7.40 | 0.038 | |
| 60th minute during surgery | 98.15±8.13 | 93.61±8.51 | 0.025 | |
| 90th minute during surgery | 90.23±9.44 | 91.96±6.45 | 0.373 | |
| End of surgery | 111.00±9.67 | 108.63±8.34 | 0.276 | |
| P 2 | 0.012 | 0.025 | ||
| DBP; mmHg | Baseline | 73.23±12.13 | 76.23±11.41 | 0.276 |
| 30th minute during surgery | 65.39±10.26 | 59.05±10.40 | 0.012 | |
| 60th minute during surgery | 64.33±13.32 | 60.32±13.41 | 0.213 | |
| 90th minute during surgery | 63.00±11.68 | 59.61±11.35 | 0.222 | |
| End of surgery | 81.16±8.32 | 80.76±14.96 | 0.890 | |
| P 2 | 0.005 | 0.004 | ||
| MAP; mmHg | Baseline | 85.11±8.69 | 87.20±6.17 | 0.250 |
| 30th minute during surgery | 78.39±7.62 | 71.58±8.40 | <0.001 | |
| 60th minute during surgery | 75.33±7.23 | 71.23±6.14 | 0.012 | |
| 90th minute during surgery | 72.00±8.86 | 70.16±7.53 | 0.352 | |
| End of surgery | 91.16±6.49 | 89.67±9.69 | 0.452 | |
| P 2 | 0.026 | 0.014 | ||
| SPO2; % | Baseline | 96.80±0.53 | 96.97±0.82 | 0.094 |
| 30th minute during surgery | 97.29±0.95 | 97.03±0.82 | 0.120 | |
| 60th minute during surgery | 97.54±0.74 | 97.29±0.75 | 0.315 | |
| 90th minute during surgery | 97.77±0.64 | 97.71±0.57 | 0.103 | |
| End of surgery | 95.49±0.70 | 95.66±0.99 | 0.530 | |
| P 2 | 0.154 | 0.078 | ||
| HR; bpm | Baseline | 87.20±8.65 | 84.13±7.25 | 0.112 |
| 30th minute during surgery | 83.72±9.91 | 63.30±10.28 | <0.001 | |
| 60th minute during surgery | 83.34±9.59 | 62.18±10.64 | <0.001 | |
| 90th minute during surgery | 82.56±10.94 | 62.16±10.21 | <0.001 | |
| End of surgery | 84.49±10.07 | 62.99±11.03 | <0.001 | |
| P 2 | 0.042 | 0.014 | ||
SBP=Systolic blood pressure, DBP=Diastolic blood pressure, MAP=Mean arterial pressure, SPO2=Saturation of peripheral oxygen, HR=Heart rate. 1The significance level obtained from the independent sample t-test comparing the variable mean between two groups at each time. 2The significance level obtained from the repeated measure ANOVA, comparing the variable mean over time in each of the two groups
Finally, the DEX group significantly reduced the amount of intraoperative bleeding, packed cell transfusion, tachycardia incidence, and quality of the surgical field (based on Boezaart score) compared with the MgSO4 group (P < 0.001). In contrast, the incidence of bradycardia and the need for ephedrine to increase BP were significantly higher in the DEX group (P < 0.001) [Table 4].
Table 4.
Comparison the outcomes and side effect in the two groups
| Outcome | MgSO4 group (n=35) | DEX group (n=35) | P |
|---|---|---|---|
| Intraoperative bleeding; mL | 686.11±100.6 | 633.33±180.84 | <0.001 |
| Blood transfusion; mL | 500.50±79.19 | 377.00±50.00 | <0.001 |
| Dose of propofol used; μg/kg/min | 976.15±15.22 | 653.22±16.08 | <0.001 |
| Side effect | |||
| Tachycardia | 11 (31.4%) | 5 (14.2%) | <0.001 |
| Bradycardia | 10 (28.5%) | 25 (71.4%) | <0.001 |
| Need for ephedrine | 9 (25.7%) | 20 (57.1%) | <0.001 |
| quality of the surgical field† | 2.57±0.36 | 2.43±0.43 | 0.033 |
†Boezaart criteria scoring was determined in Table 1
DISCUSSION
In spine surgery, hemodynamic stability is very important because sudden episodes of blood pressure can cause intraoperative bleeding, impair the quality of the surgical field of view, and lead to increased complications. Anesthesiologists’ goal is to improve the surgical field’s clarity by reducing bleeding during the procedure. This study tested the effectiveness of two drugs, magnesium sulfate and dexmedetomidine, in maintaining hemodynamic stability and reducing anesthesia consumption.
Recent research has focused on the effectiveness of dexmedetomidine as an adjunct to neuraxial anesthesia, demonstrating its effectiveness as a sedative in cases of critical illness. Dexmedetomidine has several favorable clinical effects, including hemodynamic stability, neuroprotection, and nonrespiratory interference, all without interfering with intraoperative neurophysiological monitoring. This suggests that dexmedetomidine may be useful in treating neurosurgery patients. Dexmedetomidine was associated with a higher incidence of hypotension and bradycardia, which was dose-dependent. Magnesium sulfate is safe to use as an adjuvant, but there have been cases of magnesium toxicity leading to cardiac arrest and death.
Most previous studies were consistent with our findings. In 2016, Srivastava et al.[10] demonstrated that intraoperative use of dexmedetomidine and magnesium sulfate was associated with hemodynamic stability and reduced anesthetic use. Nasreen et al.[11] reported an increase in surgeon satisfaction and a decrease in the need for inhaled medication to reduce mean arterial pressure by 30% in patients prescribed dexmedetomidine. Dexmedetomidine causes a secondary decrease in heart rate and blood pressure, which is considered the cause of this condition.
Vali et al.[12] found that dexmedetomidine had better control over vital parameters such as heart rate, mean arterial pressure, systolic blood pressure, and diastolic blood pressure than nitroglycerin. Rokhtabnak et al.[13] found that in the DEX group, blood pressure control was easier, and the number of patients requiring nitroglycerin or analgesia was lower. Similar to our own study, the DEX group experienced a shorter surgery duration compared with the magnesium sulfate and nitroglycerin group. In addition, dexmedetomidine facilitated a better visual field, resulting in less blood loss and a reduced need for blood transfusion.
Bayram et al.[14] also observed a significant reduction in bleeding scores in the DEX group in 2015. Modir et al.[15] also acknowledged that, based on the results of their study, dexmedetomidine seems to prevent intraoperative bleeding better than other drugs.
In 2024, Campos et al.[16] performed a systematic review and meta-analysis and stated that magnesium sulfate significantly reduced pain and opioid consumption at 24 hours compared with placebo. However, its extubation time and verbal response were longer compared with dexmedetomidine. Dexmedetomidine’s central and peripheral effects, such as reduced sympathetic outflow and blockade of peripheral ganglia, explain its protective effect on hemodynamic changes during neurosurgical procedures. In such cases, it is important to consider dexmedetomidine as an adjunct to general anesthesia because it reduces the occurrence of hypotensive episodes that can lead to bleeding, edema, surgical field deterioration, and increased intracranial pressure.
Ahmed’s[17] study revealed a significant reduction in the Boezaart score in the DEX group compared with the magnesium sulfate group, and a significant improvement in the surgical field quality in the DEX group. DEX administration was associated with greater surgeon satisfaction due to better blood pressure anesthesia, which reduces tissue leakage during surgical dissection. Intraoperative bleeding was minimal, and the surgeon satisfaction score was higher in the DEX group compared with the MgSO4 group.
In this study, the DEX group consumed significantly less isoflurane than the MgSO4 group because dexmedetomidine reduces the need for inhalation anesthesia due to its alpha-II agonist action, which suppresses the transmission of norepinephrine. This leads to a faster and better recovery from anesthesia and allows for early assessment of the patient’s neurological functions after the operation.
Also, this study showed that dexmedetomidine injection was associated with a significant reduction in the prescription of antihypertensive drugs, including beta blockers and hydralazine. In conclusion, both this study and ours have demonstrated that administering dexmedetomidine enhances the surgical field’s quality, minimizes blood loss, and decreases the prescription of antihypertensive drugs. According to all these interpretations, both our study and the vast majority of previous studies suggest that DEX has a greater and better effect on reducing bleeding during surgery than MgSO4.
We should acknowledge the limitations of our study. First, the small sample size (70 people) may affect the generalizability of the obtained results. Second, this comparison could also incorporate other drugs like remifentanil. Finally, it seems that future studies can help to clarify more in this field.
CONCLUSIONS
Although with the administration of DEX, the hemodynamic parameters became a little more unstable, so that in the middle of the surgery, it was associated with a decrease in blood pressure and heart rate. However, this unstable situation improved over time and at the end of the surgery, there was no significant difference with the MgSO4 group. Therefore, considering that the administration of DEX has been more effective in controlling intraoperative bleeding and better quality of surgical field, it seems that the administration of DEX is more preferable than MgSO4.
Ethics approval and consent to participate
All the experimental procedures were carried out according to the principles and guidelines of the Ethics Committee of Isfahan University of Medical Sciences (approval code: IR.MUI.MED.REC.1403.093).
Conflicts of interest
There are no conflicts of interest.
Funding Statement
Nil.
REFERENCES
- 1.Huang Y-H, Ou C-Y. Significant blood loss in lumbar fusion surgery for degenerative spine. World neurosurg. 2015;84:780–5. doi: 10.1016/j.wneu.2015.05.007. [DOI] [PubMed] [Google Scholar]
- 2.Xu D, Ren Z, Chen X, Zhuang Q, Hui S, Sheng L, et al. The further exploration of hidden blood loss in posterior lumbar fusion surgery. Orthop Traumatol Surg Res. 2017;103:527–30. doi: 10.1016/j.otsr.2017.01.011. [DOI] [PubMed] [Google Scholar]
- 3.Lu VM, Ho Y-T, Nambiar M, Mobbs RJ, Phan K. The perioperative efficacy and safety of antifibrinolytics in adult spinal fusion surgery: A systematic review and meta-analysis. Spine (Phine Pa 1976) 2018;43:E949–58. doi: 10.1097/BRS.0000000000002580. [DOI] [PubMed] [Google Scholar]
- 4.Nagabhushan RM, Shetty AP, Dumpa SR, Subramanian B, Kanna RM, Shanmuganathan R. Effectiveness and safety of batroxobin, tranexamic acid and a combination in reduction of blood loss in lumbar spinal fusion surgery. Spine (Phine Pa 1976) 2018;45:E267–73. doi: 10.1097/BRS.0000000000002315. [DOI] [PubMed] [Google Scholar]
- 5.Ren Z, Li S, Sheng L, Zhuang Q, Li Z, Xu D, et al. Topical use of tranexamic acid can effectively decrease hidden blood loss during posterior lumbar spinal fusion surgery: A retrospective study. Medicine (Baltimore) 2017;96:e8233. doi: 10.1097/MD.0000000000008233. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Akolkar AR, Kulkarni DG, Gangwani KD, Shetty L, Channe SP, Sarve PH. Bleeding control measures during oral and maxillofacial surgical procedures: A systematic review. J Dent Res Rev. 2017;4:79–89. [Google Scholar]
- 7.Lee S. Dexmedetomidine: Present and future directions. Korean J Anesthesiol. 2019;72:323–30. doi: 10.4097/kja.19259. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Janatmakan F, Nesioonpour S, Zadeh FJ, Teimouri A, Vaziri M. Comparing the effect of clonidine and dexmedetomidine on intraoperative bleeding in spine surgery. Anesth Pain Med. 2019;9:e83967. doi: 10.5812/aapm.83967. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Kosucu M, Tugcugil E, Arslan E, Omur S, Livaoglu M. Effects of perioperative magnesium sulfate with controlled hypotension on intraoperative bleeding and postoperative ecchymosis and edema in open rhinoplasty. Am J Otolaryngol. 2020;41:102722. doi: 10.1016/j.amjoto.2020.102722. [DOI] [PubMed] [Google Scholar]
- 10.Srivastava VK, Mishra A, Agrawal S, Kumar S, Sharma S, Kumar R. Comparative evaluation of dexmedetomidine and magnesium sulphate on propofol consumption, haemodynamics and postoperative recovery in spine surgery: A prospective, randomized, placebo controlled, double-blind study. Adv Pharm Bull. 2016;6:75–81. doi: 10.15171/apb.2016.012. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Nasreen F, Bano S, Khan RM, Hasan SA. Dexmedetomidine used to provide hypotensive anesthesia during middle ear surgery. Indian J Otolaryngol Head Neck Surg. 2009;61:205–7. doi: 10.1007/s12070-009-0067-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Vali LF, Gedam NT, Vali AH. editors Anesthesia management in a giant congenital undifferentiated orbital teratoma: A challenging, rare entity. Indian Anaesth Forum. 2017;18:28. [Google Scholar]
- 13.Rokhtabnak F, Motlagh SD, Ghodraty M, Pournajafian A, Delarestaghi MM, Banihashemi AT, et al. Controlled hypotension during rhinoplasty: A comparison of dexmedetomidine with magnesium sulfate. Anesth Pain Med. 2017;7:e64032. doi: 10.5812/aapm.64032. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Bayram A, Ülgey A, Günes I, Ketenci I, Çapar A, Esmaoglu A, et al. Comparison between magnesium sulfate and dexmedetomidine in controlled hypotension during functional endoscopic sinus surgery. Rev Bras Anestesiol. 2015;65:61–7. doi: 10.1016/j.bjan.2014.04.003. [DOI] [PubMed] [Google Scholar]
- 15.Modir H, Modir A, Rezaei O, Mohammadbeigi A. Comparing remifentanil, magnesium sulfate, and dexmedetomidine for intraoperative hypotension and bleeding and postoperative recovery in endoscopic sinus surgery and tympanomastoidectomy. Med Gas Res. 2018;8:42–7. doi: 10.4103/2045-9912.235124. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Campos J, Bas JL, Campos C, Mariscal G, Bas T, Bas P. Efficacy and safety of intravenous magnesium sulfate in spinal surgery: A systematic review and meta-analysis. J Clin Med. 2024;13:3122. doi: 10.3390/jcm13113122. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Ahmed SG. Comparative evaluation of dexmedetomidine versus magnesium sulphate on the adequacy of hypotensive anesthesia and post-operative recovery for patients undergoing endoscopic transnasal transsphenoidal pituitary tumor resection. Egypt J Hosp Med. 2021;86:59–65. [Google Scholar]