[Comparison between magnesium sulfate and dexmedetomidine in controlled hypotension during functional endoscopic sinus surgery]

The Efficacy of Hypotensive Agents on Intraoperative Bleeding and Recovery Following General Anesthesia for Nasal Surgery: A Network Meta-Analysis

OBJECTIVES

A systematic review of the literature was conducted to evaluate hypotensive agents in terms of their adverse effects and associations with perioperative morbidity in patients undergoing nasal surgery.

METHODS

Two authors independently searched databases (Medline, Scopus, and Cochrane databases) up to February 2020 for randomized controlled trials comparing the perioperative administration of a hypotensive agent with a placebo or other agent. The outcomes of interest for this analysis were intraoperative morbidity, operative time, intraoperative bleeding, hypotension, postoperative nausea/vomiting, and postoperative pain. Both a standard pairwise meta-analysis and network meta-analysis were conducted.

RESULTS

Our analysis was based on 37 trials. Treatment networks consisting of six interventions (placebo, clonidine, dexmedetomidine, beta-blockers, opioids, and nitroglycerine) were defined for the network meta-analysis. Dexmedetomidine resulted in the greatest differences in intraoperative bleeding (-0.971; 95% confidence interval [CI], -1.161 to -0.781), intraoperative fentanyl administration (-3.683; 95% CI, -4.848 to -2.518), and postoperative pain (-2.065; 95% CI, -3.170 to -0.960) compared with placebo. The greatest difference in operative time compared with placebo was achieved with clonidine (-0.699; 95% CI, -0.977 to -0.421). All other agents also had beneficial effects on the measured outcomes. Dexmedetomidine was less likely than other agents to cause adverse effects.

CONCLUSION

This study demonstrated the superiority of the systemic use of dexmedetomidine as a perioperative hypotensive agent compared with the other five tested agents. However, the other agents were also superior to placebo in improving operative time, intraoperative bleeding, and postoperative pain.

Surgical Field Visualization during Functional Endoscopic Sinus Surgery: Comparison of Propofol- vs Desflurane-Based Anesthesia

OBJECTIVE

To assess if the type of general anesthetic affects bleeding and field visualization during endoscopic sinus surgery.

STUDY DESIGN

Prospective, randomized, controlled trial.

SETTING

Academic teaching hospital and Veterans Affairs hospital in the United States.

SUBJECTS AND METHODS

Seventy patients were randomized to 1 of 3 anesthetic regimens: (1) the volatile anesthetic desflurane (n = 22), (2) intravenous anesthesia with propofol (n = 25), or (3) a combination of propofol and desflurane (n = 23). Intravenous remifentanil was titrated to decrease the mean arterial pressure to 60 to 70 mm Hg but not ≥30% from baseline. Surgical bleeding scores were recorded along with bleeding rates and hemodynamic parameters, including cardiac output and systemic vascular resistance through pulse contour analysis from a radial arterial line. Statistics: multiple comparison tests and regression analyses; α = .05.

RESULTS

There were no differences in bleeding rate (median, 0.58, 0.85, 0.57 mL min^-1), bleeding score (2.1, 2.0, 2.0), surgery duration (79, 81, 86 minutes), extubation time (9, 7, 8 minutes), recovery room time (65, 61, 61 minutes), or any hemodynamic parameters among groups 1 through 3, respectively. Group 1 required lower remifentanil infusions than group 2 (0.11 vs 0.26 µg kg^-1 min^-1; P = .01). The bleeding score correlated positively with height (P = .014) and the Lund-MacKay score (P = .013). Bilateral vs unilateral surgery led to longer surgery duration (P = .001) and recovery room time (P = .004).

CONCLUSION

When remifentanil is used for controlled hypotension, propofol has no advantage over desflurane to improve surgical field visualization during functional endoscopic sinus surgery.

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.

Controlled hypotension for FESS: A randomised double-blinded comparison of magnesium sulphate and dexmedetomidine

Background and Aims:

Intense bleeding during general anaesthesia (GA) is the major limitation during functional endoscopic sinus surgery (FESS). This study was aimed to compare the efficacy of dexmedetomidine and magnesium sulphate (MgSO₄) for controlled hypotension in FESS.

Methods:

Sixty eight patients undergoing FESS were randomised to receive either dexmedetomidine 1 μg/kg over 10 min followed by infusion at 0.2 to 0.7 μg/kg/h (Group D) or MgSO₄ 40 mg/kg over 10 min followed by an infusion at 10 to 15 mg/kg/h (Group M). Anaesthesia and infusion rates for study drugs were maintained with sevoflurane to keep MAP between 60–70 mmHg throughout the surgery. The time to reach the target MAP, the number of patients requiring a minimum and maximum infusion doses of study drugs were noted.

Results:

The mean time to achieve target mean arterial pressure (MAP) was less in group D (10.59 ± 2.04) as compared with (21.32 ± 4.65 min) group M (P < 0.001). The target MAP was achieved between 5–15 min in 73.52% patients (Group D) with an infusion dose of 0.2–0.4 μg/kg/h of dexmedetomidine without the use of sevoflurane, while 82.35% patients in group M required 4% sevoflurane along with >12–15 mg/kg/hr infusion of MgSO₄ to achieve target MAP in 10–20 min.

Conclusion:

Dexmedetomidine is superior to MgSO₄ in achieving target MAP in lesser time with minimum infusion dose.

Use of α2-Adrenergic Agonists to Improve Surgical Field Visibility in Endoscopy Sinus Surgery: A Systematic Review of Randomised Controlled Trials

PURPOSE

We assessed the evidence for the use of α₂-adrenergic agonists (A2AAs) in bleeding control and field quality in endoscopic sinus surgery.

METHODS

We systematically reviewed randomized clinical trials (RCTs) assessing A2AAs in endoscopic sinus surgery. Abstracts were reviewed by 2 investigators for eligibility, and selected articles were fully reviewed. Data on study design, population, A2AA drug and control groups, bleeding and surgical field quality outcomes, and adverse effects were extracted and synthesized.

FINDINGS

A total of 13 RCTs that included 896 individuals (7 double-blind trials, 5 single-blind trials, and 1 open-label trial) were selected that assessed the efficacy of clonidine (6 RCTs, 407 patients), dexmedetomidine (6 RCT, 423 patients), or both (1 RCT, 66 patients). Clonidine was compared with placebo (3 RCTs), midazolam (1 RCT), and remifentanil (2 RCTs). Dexmedetomidine was compared with esmolol (2 RCTs), remifentanil (2 RCTs), nitroglycerin and esmolol (1 RCT), and magnesium sulfate (1 RCT). Clonidine and dexmedetomidine were compared in 1 RCT. Clonidine reduced the proportion of individuals with an impaired surgical field by 23% vs placebo (number needed to treat = 4). Clonidine was better than midazolam and remifentanil in 2 trials, and dexmedetomidine was better than magnesium sulfate and esmolol in 2 trials but was not superior to esmolol, remifentanil, or nitroglycerin in 4 trials. Dexmedetomidine produced significantly better differences in bleeding outcomes versus clonidine. Adverse events were infrequent and mainly caused by hypotension or bradycardia.

IMPLICATIONS

RCTs consistently report that A2AAs reduce bleeding and improve surgical field quality during endoscopic sinus surgery. Adverse event reporting was often omitted in RCTs. Well-designed RCTs with appropriate sample sizes are desirable to identify the best A2AAs and confirm their potential effects on clinical outcomes.

Comparing remifentanil, magnesium sulfate, and dexmedetomidine for intraoperative hypotension and bleeding and postoperative recovery in endoscopic sinus surgery and tympanomastoidectomy

The study aimed to compare remifentanil, magnesium sulfate, and dexmedetomidine for intraoperative hypotension, bleeding volume, and recovery time in endoscopic sinus surgery and tympanomastoidectomy (TM). A double-blind clinical trial enrolled the patients undergoing endoscopic nasal sinus surgery and TM at Amirkabir Hospital (Arak, Iran), who were randomly assigned into three groups dexmedetomidine (DEX), remifentanil (REM), and magnesium sulfate (MgSO₄) to which we intravenously administered 1 μg/kg DEX, an intravenous dose of 1 μg/kg REM, and 40 mg/kg of intravenous MgSO₄, respectively. The blood loss, blood pressure (BP), heart ratio (HR), oxygen saturation (SaO₂), and recovery time were recorded. Significant differences were found statistically in bleeding rates among all groups (P = 0.0001). The least amount of blood loss (very mild bleeding) was observed at 82.85% in the DEX group. BP and HR were lower in this group than those in the other groups. While recovery score was significantly different in the three groups (P = 0.007), the recovery time was the highest in the DEX group, while the least in the REM group. Based on the present results Dexmedetomidine seems to better prevent from bleeding than the others. Moreover, DEX can cause lower BP and HR in subjects with lower propofol administration, but the recovery time is longer. This study was registered by IRCT2017021114056N11 in Iranian Registry Clinical Center.

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.

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

Controlled hypotension in day care functional endoscopic sinus surgery: A comparison between esmolol and dexmedetomidine: A prospective, double-blind, and randomized study

Background:

Functional endoscopic sinus surgery (FESS) is the cornerstone of therapeutic management for nasal pathologies. This study is to compare the ability of preoperative and intraoperative esmolol versus dexmedetomidine for producing induced hypotension during FESS in adults in a day care setting.

Materials and Methods:

Sixty patients (20-45 years) posted for FESS under general anesthesia were randomly divided into Group E (n = 30) receiving esmolol, loading dose 1 mg/kg over 1 min followed by 0.5 mg/kg/h infusion during maintenance and Group D (n = 30) receiving dexmedetomidine 1 μg/kg over 15 min before induction of anesthesia followed by 0.5 μg/Kg/h infusion during maintenance, respectively. Nasal bleeding and Surgeon's satisfaction score; amount and number of patients receiving fentanyl and nitroglycerine for analgesia and deliberate hypotension, Postanesthesia Care Unit (PACU) and hospital stay; hemodynamic parameters and side effects were recorded for each patient.

Results:

Significantly less number and dosage of nitroglycerine was required (P = 0.0032 and 0.0001, respectively) in Group D compared to that in Group E. Again the number and dosage of patients requiring fentanyl were significantly lower in Group D. However, the duration of controlled hypotension was almost similar in both the groups. Group D patients suffered from significantly less nasal bleeding, and surgeon's satisfaction score was also high in this group. Discharge from PACU and hospital were significantly earlier in Group D. Intraoperative hemodynamics were quite comparable (P > 0.05) without any appreciable side effects.

Conclusion:

Dexmedetomidine found to be providing more effectively controlled hypotension and analgesia and thus allowing less nasal bleeding as well as more surgeons’ satisfaction score.

Induced hypotension in ambulatory functional endoscopic sinus surgery: A comparison between dexmedetomidine and clonidine as premedication. A prospective, double-blind, and randomized study

Background:

Functional endoscopic sinus surgery (FESS) is the mainstay of a therapeutic technique for nasal pathologies. This study is to compare the ability of preoperative dexmedetomidine versus clonidine for producing controlled hypotensive anesthesia during FESS in adults in an ambulatory care setting.

Materials and Methods:

Sixty patients (25-50 years) posted for ambulatory FESS procedures under general anesthesia were randomly divided into Group C and D (n = 33 each) receiving dexmedetomidine 1 μg/kg and clonidine 1.5 μg/kg, respectively; both diluted in 100 ml saline solution 15 min before anesthetic induction. Nasal bleeding and surgeon's satisfaction score; amount and number of patients receiving fentanyl and nitroglycerine for analgesia and deliberate hypotension, duration of hypotension, post anesthesia care unit (PACU) and hospital stay; hemodynamic parameters and side effects were recorded for each patient.

Results:

Number and dosage of nitroglycerine used was significantly (P = 0.034 and 0.0001 respectively) lower in Group D compared to that in Group C. Similarly, number of patients requiring fentanyl and dosage of same was significantly lower in Group D. But, the duration of controlled hypotension was almost similar in both the groups. Group D patients suffered from significantly less nasal bleeding and surgeon's satisfaction score was also high in this group. Discharge from PACU was significantly earlier in Group D, but hospital discharge timing was quite comparable among two groups. Intraoperative hemodynamics was significantly lower in Group D (P < 0.05) without any appreciable side effects.

Conclusion:

Dexmedetomidine found to be providing more effectively controlled hypotension and analgesia, and thus, allowing less nasal bleeding as well as more surgeons’ satisfaction score.