Nitroglycerine, esmolol and dexmedetomidine for induced hypotension during functional endoscopic sinus surgery: A comparative evaluation

Positive End-Expiratory Pressure in Rhinoplasty Surgery; Risks and Benefits

Aims

The aim of this study is to evaluate the effect of Positive End Expiratory Pressure (PEEP) on surgical field bleeding and its respiratory and hemodynamic consequences in rhinoplasty surgeries.

Materials and methods

This single-blind clinical trial performed in Amir Al-Momenin university Hospital in 2018. Seventy cases of rhinoplasty surgery patients Enrolled and were randomized into two groups; intervention (PEEP = 5) and comparison group (PEEP = 0). Surgical field bleeding and arterial oxygen saturation pulmonary dynamics and hemodynamic parameters were evaluated during operation and in post anesthesia care unit. Data were analyzed by SPSS software using descriptive and analytical statistics.

Results

PEEP applying had no negative effect on surgical bleeding as well as surgeon satisfaction, heart rate and blood pressure were similar in two groups. Pulmonary dynamics and oxygenation were stable and within normal values in all cases. The mean peak airway pressure was 17.87 ± 2.24 in the PEEP group and 16.08 ± 3.37 in the ZEEP group (P = 0.029).

Conclusion

applying low level PEEP during anesthesia improved recovery oxygen saturation but had no negative effects on the patient`s hemodynamics, and did not aggravate bleeding and visual clarity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03854-7.

Effects of smoking on controlled hypotension with nitroglycerin during ear-nose-throat surgery

Background and Aim

In this study, the aim was to research the effects of smoking habits on controlled hypotension administered with nitroglycerin during ear-nose-throat surgery.

Materials and Methods

This study administered controlled hypotension with nitroglycerin and total intravenous anesthesia to a total of 80 patients undergoing septoplasty operations. The patients were divided into two groups of 40 non-smokers (Group 1) and 40 smokers (Group 2). Intravenous propofol infusion was used for anesthesia maintenance. Nitroglycerin with 0.25-1 μg/kg/min dose was titrated to provide controlled hypotension. During this process, the hemodynamic parameters of patients, total propofol and nitroglycerin amounts used, operation duration, and duration of controlled hypotension were recorded at the end of the operation. At the end of the operation, the surgeon assessed the lack of blood in the surgical field with Fromme Scale.

Results

Fromme scale values were significantly higher in Group 2 compared to Group 1. The MAP values at 10, 20, 30 min, and end of operation were lower, while 10- and 20-min heart rate values were higher in Group 2 compared to Group 1.

Conclusion

Nitroglycerin, chosen for controlled hypotension to reduce hemorrhage in the surgical field during nasal surgery, was shown to cause more pronounced hypotension and reflex tachycardia due to endothelial dysfunction linked to nicotine in patients who smoke. Despite lower pressure values in the smoking group, the negative effects of nicotine on platelet functions combined with similar effects of nitroglycerin to increase bleeding amounts.

Dexmedetomidine vs. Fentanyl-Midazolam Combination to Mitigate the Stress Response in Microlaryngoscopy: A Randomized Double-blind Clinical Trial

Background

Laryngoscopy is the most painful noxious stimulus during anesthesia and surgery. Dexmedetomidine is increasingly used as a sedative in surgeries involving microlaryngoscopy.

Objectives

This study aimed to evaluate the effect of dexmedetomidine and a combination of fentanyl and midazolam on mitigating the stress response in patients scheduled for microlaryngoscopy.

Methods

This randomized, double-blind clinical trial enrolled 60 patients (28 males and 32 females) aged 18 - 65 years with the American Society of Anesthesiologists (ASA) physical status I - III. The patients were scheduled for microlaryngoscopy and equally divided into 2 groups. Group D received 1 μg/kg of dexmedetomidine and saline bolus dose over 10 minutes before general anesthesia (GA) induction, followed by 0.5 μg/kg/h of dexmedetomidine and saline infusions after GA induction. Group MF received 0.8 μg/kg of fentanyl plus 0.05 mg/kg of midazolam over 10 minutes before GA induction, followed by 1 μg/kg/h of fentanyl plus 0.05 mg/kg/h of midazolam as an infusion. The heart rate (HR) and mean arterial blood pressure (MAP) pressure were recorded from baseline until the end of surgery. Infusions were stopped at the end of the surgery.

Results

The number of patients requiring propofol and intraoperative supplemental propofol was significantly lower in group D than in group MF. The heart rate was significantly lower in group D than in group MF (P = 0.022, 0.048, 0.032, 0.045, 0.041, 0.026, 0.030, and 0.036) from induction until the end of surgery; in addition, it was comparable between both groups at baseline and before induction. MAP was comparable between both groups for all measurements.

Conclusions

Dexmedetomidine mitigates the hemodynamic changes related to microlaryngoscopy more effectively than the fentanyl-midazolam combination.

Management of Incidental Uncontrolled Elevation of Intraoperative Blood Pressure: A Comparative Study on Nitroglycerine Versus Dexmedetomidine Infusion

Background

Uncontrolled elevation of intraoperative blood pressure can result in deleterious effects with increased risk of morbidity and mortality.

Objectives

We aimed to compare nitroglycerine infusion with dexmedetomidine infusion in controlling accidental intraoperative uncontrolled hypertension.

Methods

This comparative study was conducted on 73 hypertensive patients undergoing cancer surgeries who experienced uncontrolled intraoperative hypertension. The data of 38 patients were retrieved from the medical records for the nitroglycerine group and 35 patients were prospectively enrolled for the dexmedetomidine group. Group N received nitroglycerine infusion (0.3 - 1 µg/kg/min), while group D received dexmedetomidine infusion (0.2 - 0.7 µg/kg/h).

Results

Both groups were comparable regarding their demographic data and clinical characteristics. Systolic, diastolic, and mean arterial pressure (MAP) values were significantly lower in group N compared to group D during the period between 60 and 120 minutes intraoperatively (P < 0.001). Heart rate values were significantly lower in group D than in group N (P < 0.001). Postoperative sedation scores were better for group D with lower analgesic requirements (P < 0.001).

Conclusions

Dexmedetomidine infusion can be used to manage the uncontrolled intraoperative elevation of blood pressure in selected patient population.

Evaluation of the Relationship between Baseline Autonomic Tone and Haemodynamic Effects of Dexmedetomidine

Dexmedetomidine, a central α-2 agonist, is used for procedural sedation and for conscious sedation influences on heart rate and blood pressure. Authors verified whether it is possible to predict bradycardia and hypotension with the use of heart rate variability (HRV) analysis for an autonomic nervous system (ANS) activity assessment. The study included adult patients of both sexes with an ASA score of I or II scheduled for ophthalmic surgery to be performed under sedation. The loading dose of dexmedetomidine was followed by a 15 min infusion of the maintenance dose. The frequency domain heart rate variability parameters from the 5-min Holter electrocardiogram recordings before dexmedetomidine administration were used for the analysis. The statistical analysis also included pre-drug heart rate and blood pressure as well as patient age and sex. The data from 62 patients were analysed. There was no relationship between the decrease in heart rate (42% of cases) and initial HRV parameters, haemodynamic parameters or sex and age of patients. In multivariate analysis, the only risk factor for a decrease in mean arterial pressure (MAP) > 15% from the pre-drug value (39% of cases) was the systolic blood pressure before dexmedetomidine administration as well as for a >15% decrease in MAP sustained at more than one consecutive time point (27% of cases). The initial condition of the ANS did not correlate with the incidence of bradycardia or hypotension; HRV analysis was not helpful in predicting the abovementioned side effects of dexmedetomidine.

Comparative evaluation of propofol versus dexmedetomidine infusion for hypotensive anesthesia during functional endoscopic sinus surgery: a prospective randomized trial

Background

During functional endoscopic sinus surgery (FESS), intranasal bleeding affects operative field visibility and increases the frequency of complications. Therefore, hypotensive anesthesia is a widely used technique to improve surgical outcomes. This study aimed to compare the efficacy of propofol and dexmedetomidine infusion for hypotensive anesthesia in patients undergoing FESS.

Methods

This prospective randomized trial was conducted in 80 adult patients who were scheduled for FESS under general anesthesia. Patients were randomly divided into two groups: group P (n = 40) received propofol infusion of 100–200 µg/kg/min and group D (n = 40) received dexmedetomidine infusion with a loading dose of 1 µg/kg over 10 min after induction, followed by maintenance infusion of 0.4–0.8 µg/kg/h. Intraoperative blood loss, quality of the surgical field (Fromme– Boezaart scale), hemodynamic control, and patient recovery were recorded. Statistical analysis was performed using Student’s t-test, chi-square test, and Mann– Whitney U test.

Results

The mean arterial pressure and heart rate were significantly lower in group D throughout the surgery than in group P. Blood loss was significantly higher in group P (100.73 ± 18.12 ml) than in group D (85.70 ± 18.56 ml). The average number of patients with Fromme’s score 1/2/3 was comparable between the groups. Intraoperatively, only one incidence of bradycardia and hypotension was observed in group D (2.5%) compared to group P.

Conclusions

Both dexmedetomidine and propofol are efficacious and safe drugs for facilitating controlled hypotension during FESS; however, dexmedetomidine provides better hemodynamic control and is associated with lesser blood loss without any significant adverse effects.

Effect of Dexmedetomidine infusion during hip fracture surgery on hemodynamic parameters and blood loss: A triple-blinded Randomized Clinical Trial

Introduction In this study, we aim to assess the intra-operative effect of dexmedetomidine administration on the hemodynamic parameters and bleeding volume during hip fracture surgery. Patients and methods we designed and implemented a triple-blinded randomized clinical trial to objectively compare the effects of 0.5 µg/kg/h infusion of dexmedetomidine with placebo (equal amount of normal saline) during hip fracture surgery. All included cases were between 30 and 70 years old and underwent surgery for fixation of a proximal femur fracture from September 26, 2020 until February 15, 2021. They were all ASA class I or II with preoperative hemoglobin levels of 10 mg/dL or higher. Surgical blood loss and hemodynamic parameters were documented. Results 76 patients were enrolled. There were no significant differences in baseline patient characteristics. The bleeding rate was 620 ± 190.0 mL for the normal saline group and 476 ± 177.98 mL in the dexmedetomidine group (P = 0.04). No significant effect on hemodynamic parameters was observed. Conclusion Based on the current study, intravenous infusion of dexmedetomidine during hip fracture surgery under general anesthesia reduced the amount of intraoperative bleeding without causing any significant hemodynamic disturbances. Registration number IRCT20191222045857N1 (Iranian Registry of Clinical Trials).

Effect of Different Concentrations of Esmolol on Perioperative Hemodynamics and Analgesia in Patients Undergoing Colectomy: A Prospective, Randomized Controlled Study

Purpose

The aim of this study was to investigate the efficacy of esmolol on intraoperative hemodynamic and perioperative analgesic management.

Methods

Totally, 125 patients undergoing colectomy were randomly divided into three groups. Group S (saline group) was administered 0.75 mL/kg/h of normal saline for 5 min before anesthesia induction and maintenance of 0.25 mL/kg/h; Group E₁ and Group E₂ were administered 0.5 mg/kg and 1.0 mg/kg esmolol for 5 min before anesthesia induction, and maintained of 0.5 mg/kg/h and 2.0 mg/kg/h, respectively. Several parameters including indexes of hemodynamics variation (primary outcome), intra- and postoperative analgesic usage, and pain score were measured.

Results

Group E₁ and Group E₂ had significantly lower intubation response than Group S (P = 0.007, P = 0.001), and extubation response of Group E₂ was significantly lower than Group S (P = 0.007). The opioid consumption in Group E₁ and Group E₂ was significantly lower than in Group S intraoperatively (P = 0.020 and 0.007). The incidence of postoperative adverse reactions among the three groups was not statistically significant (P = 0.368 and 0.772).

Conclusion

Esmolol 0.5 mg/kg and 1.0 mg/kg infusion before intubation both can effectively inhibit the intubation response, while only maintenance with 2.0 mg/kg/h of esmolol can reduce the incidence of extubation response. At the same time, esmolol can decrease intraoperative opioid requirement without increasing the risk of adverse reactions.

Trial Registration

ChiCTR1900024538 and the date of registration was July 15, 2019 at http://www.chictr.org.cn.

Comparison of hypotensive properties of dexmedetomidine versus clonidine for induced hypotension during functional endoscopic sinus surgery: A randomised, double-blind interventional study

Background and Aims

Excessive bleeding is a major concern in functional endoscopic sinus surgery (FESS) under general anaesthesia; this can be decreased by various hypotensive agents. This study was conducted to compare the hypotensive effectiveness and haemodynamic stability of dexmedetomidine and clonidine in patients undergoing elective FESS.

Methods

In this prospective double-blinded interventional study, 70 adult patients of either sex, 20-50 years of age, posted for elective FESS were randomly assigned to two groups. Group A received a loading dose of intravenous (IV) dexmedetomidine 1 μg/kg, followed by infusion of 1 μg/kg/h, and group B received a loading dose of IV clonidine 2 μg/kg, followed by 1 μg/kg/h infusion. Surgical field quality, emergence time, sedation score, visual analogue score, recovery profile and haemodynamic parameters were recorded. Statistical analysis was done by Student's unpaired t-test to evaluate the significance of normally distributed variables, whereas Mann-Whitney test and Chi-square test were used for ordinal data and categorical variables and proportions, respectively.

Results

In both the groups, target mean arterial pressure (MAP) of 65-70 mmHg and improved surgical field quality were achieved. MAP and heart rate (HR) were statistically significantly lower in the dexmedetomidine group with a longer duration of post-operative analgesia (P = 0.001). None of the groups showed any statistically significant adverse effects.

Conclusions

Both dexmedetomidine and clonidine can be used for controlled hypotension to improve surgical field quality in FESS. Dexmedetomidine provides more haemodynamic stability and an additional benefit of post-operative analgesia and conscious sedation.

Induced Hypotension in Functional Endoscopic Sinus Surgery: A Comparative Study of Dexmedetomidine and Esmolol

Introduction

Functional endoscopic sinus surgery (FESS) is one of the common surgical procedures requiring hypotensive anesthesia; many agents have been tried to reduce the amount of blood loss. This study aims at comparing the efficacy of two agents for providing deliberate hypotension.

Objectives

The aim of this study was to evaluate the efficacy of esmolol and of dexmedetomidine and compare which one of the two is a better agent to produce induced hypotension during FESS.

Materials and methods

This was a comparative study conducted in a tertiary care hospital in Odisha, India. There were two study groups with 30 participants each who were given either esmolol or dexmedetomidine (group E and group DEX, respectively).

Results

Esmolol is an anti-hypertensive agent with better hemodynamic stability. The amount of drug and dose requirement was low in group DEX. The emergence time, sedation score, and time to first analgesic request were found to be highly statistically significant in group DEX.

Conclusion

Dexmedetomidine was found to be a better agent at controlling intra-operative blood pressure than esmolol and had beneficial effects on recovery from anesthesia and analgesia.

To Compare the Efficacy of Dexmedetomidine Versus Labetalol in Providing Controlled Hypotension in Functional Endoscopic Sinus Surgery

Background

Functional endoscopic sinus surgery (FESS) is a surgical intervention for sinus diseases. Bleeding is a common concern during FESS. Hemodynamic stability and quality surgical field visibility help to achieve the best outcomes.

Objectives

The present study primarily intended to compare the effectiveness of dexmedetomidine versus labetalol in providing controlled hypotension during FESS and then to assess the quality of the surgical field.

Methods

The current research was conducted as a prospective randomized double-blinded clinical study. Sixty patients of the American Society of Anesthesiologists grade I or II status undergoing FESS under general anesthesia were divided into two groups, each with 30 members. Patients receiving dexmedetomidine and labetalol were named as group D and L, respectively. The study intended to manage mean arterial pressure (MAP) between 65 - 75 mmHg. The visibility of the operative field was evaluated using Fromme and Boezaart scoring system. Total intraoperative fentanyl consumption and postoperative first analgesic request time were recorded.

Results

The MAP target was achieved in both groups. Intergroup differences concerning MAP were observed in both D (75.0 ± 2.0) and L (82.4 ± 5.2) groups (P-value < 0.05). Scores for blood loss were significantly lower in the D group (1.3 ± 0.3) compared to the L group (2.1 ± 0.3) (P-value < 0.05). There was no intergroup difference concerning the mean heart rate (group D; 70.8 ± 4.2, and group L; 73.4 ± 4.4). The total dose of fentanyl consumed was found to be significantly lower in the group D (41.9 ± 5.8) compared to group L (59.9 ± 5.3) (P-value < 0.05). The first analgesic request time was significantly longer in the group D (50.2 ± 9.1) compared to group L (24.8 ± 5.1) (P-value < 0.05).

Conclusions

Dexmedetomidine provided better hemodynamic stability and operative field visibility as compared to labetalol during FESS.

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.

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.

Dexmedetomidine Efficacy in Quality of Surgical Field During Endoscopic Sinus Surgery

INTRODUCTION

Blood loss is a common concern during functional endoscopic sinus surgery (FESS). The present study aimed to evaluate the efficacy of dexmedetomidine (DEX) in intraoperative bleeding and surgical field in FESS.

MATERIALS AND METHODS

This double-blind randomized clinical trial was conducted on 72 patients within the age range of 16-60 years who underwent FESS. The subjects were randomly dividedinto two groups. The DEXgroup received 1 mic/kg DEX in 10 min at anesthesia induction followed by 0.4 to 0.8 mic/kg/hour during maintenance, while the control group received normal saline instead of DEX in bolus with the same volumemaintenance. Heart rate, systolic blood pressure, diastolic blood pressure (DBP),mean arterial pressure (MAP),and opioid requirement were evaluated in the 15^th, 30^th, 60^th, and 90^thmin of the induction. The surgeon's assessment of the field during surgery and intraoperative bleeding was also recorded in this study.

RESULTS

The DEX group had lower bleeding scores (P=0.001) than the control group.Surgeon's satisfaction based on a Likert scale (P=0.001) was lower in the control group. The mean of DBP was lower in the DEX group in the 30^th(P=0.001), 60^th(P=0.001), and 90^th(P=0.01) min of the induction. The MAP was lower in the DEX group in the 30^th(P=0.015), 60^th(P=0.052), and 90^th(P=0.046) min of the induction. There were no postoperative adverse effects in the DEX group.

CONCLUSION

It was observed that DEX improves the quality of the surgical field and hemodynamic stability. In addition, DEX might be safely and effectively used in surgeries in which deliberate hypotension is desirable.

Comparison of Intravenous Dexmedetomidine versus Esmolol for Attenuation of Hemodynamic Response to Tracheal Intubation after Rapid Sequence Induction: A Systematic Review and Meta-Analysis

The present study aims to investigate whether intravenous dexmedetomidine shows superiority to esmolol for hemodynamic response to tracheal intubation after rapid sequence induction. In the present meta-analysis, PubMed, EMBASE, and the Cochrane Library were searched for trials comparing dexmedetomidine with esmolol for the attenuation of the hemodynamic response to intubation. Ten trials were selected in the present meta-analysis. Compared to esmolol, the use of dexmedetomidine maintains stable heart rates (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) at 1 min, 3 min, and 5 min after tracheal intubation. Dexmedetomidine causes less hemodynamic response to tracheal intubation after rapid sequence induction compared with esmolol.

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.

Randomized Open-Labelled Comparative Evaluation of the Efficacy of Nitroglycerine, Esmolol and Dexmedetomidine in Producing Controlled Hypotension in Spine Surgeries

Aim:

This study was designed to evaluate the efficacy of nitroglycerine (NTG), esmolol, and dexmedetomidine (DEX) as hypotensive agents in decreasing intraoperative blood loss by producing controlled hypotension in posterior spine surgeries.

Materials and Methods:

Sixty patients aged 18–60 years, the American Society of Anesthesiologists physical status Classes I and II of either gender, were randomly assigned into three groups to receive either: NTG (0.01%) at the rate of 3–10 μg.kg^-1.min^-1 after positioning without a prior loading dose in Group N, esmolol 500 μg.kg^-1 loading dose over 1 min before induction of anesthesia followed by 50–300 μg.kg^-1.min^-1 infusion in Group E, and DEX 1 μg.kg^-1 over 10 min before induction followed by 0.2–0.7 μg.kg^-1.h^-1. infusion in Group D to maintain mean arterial blood pressure (MAP) between 60 and 65 mmHg. The three groups were compared for the achievement of target MAP, intraoperative blood loss, reversibility of hypotensive state, quality of surgical field, emergence time, and postextubation sedation score.

Statistical Analysis:

Analysis of variance was used for intergroup analysis, and for multiple comparisons, Bonferroni post hoc test was applied. P < 0.05 was considered statistically significant.

Results:

Patients in Group D and Group E achieved the target MAP with better heart rate control as compared to Group N. The intraoperative blood loss was significantly lesser in Group D (P < 0.001). The time to hypotension reversal and emergence time was prolonged in Group D (P < 0.001). The mean quality of surgical field score was statistically insignificant among the three groups. The mean Ramsay Sedation Scores were significantly higher in Group D compared to Groups N and E at 20^th and 40^th min postextubation (P < 0.001) with no significant intergroup difference at 60^th min postextubation (P = 0.130).

Conclusion:

Continuous infusion of DEX is an effective and safe method of producing controlled hypotension by achieving the target MAP, minimizing blood loss, and maintaining superior hemodynamics in comparison with NTG and esmolol in posterior spine surgeries.

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 Effect of Intravenous Infusion of Dexmedetomidine to Prevent Bleeding During Functional Endoscopic Sinus Surgery: A Clinical Trial

Background

Bleeding during surgery can lead to serious complications. Methods and drugs to control bleeding are always important both for the surgeon and anesthesiologist, especially in endoscopic procedures. A lot of efforts are made to optimize the surgical conditions for functional endoscopic sinus surgery. Induced hypotension is widely advocated to prevent bleeding and consequently to improve the quality of an operation . Amongst the pharmacological agents, dexmedetomidine is the most recently introduced drug to provide hypotensive anesthesia during functional endoscopic sinus surgery.

Objectives

The current study aimed at investigating the effects of intravenous infusion of dexmedetomidine on bleeding, nausea, awakening time, and other intravenous anesthetic doses during functional endoscopic sinus surgery.

Methods

Sixty patients aged 16 to 60 years with American society of anesthesiologists (ASA) class I or II in Imam Khomeini hospital of Ahvaz, Iran, who were the candidate for the elective functional endoscopic sinus surgery were enrolled in the current double-blind clinical trial. They were randomly divided into 2 groups: group D (receiving dexmedetomidine), and group N (receiving normal saline). Sampling was based on the block randomization method. In group D, a 1-μg/kg dexmedetomidine was injected during 10 minutes just before the induction. Then, 0.5 µg/ kg/ hour infusion was started. Both groups had the same induction and maintenance method as well as the drugs administered for general anesthesia induction. For maintenance, the patients received O₂ 50%: N₂O 50% and 100 μg/kg/minute of propofol and 0.2 μg/kg/minute of remifentanil. In group N, instead of dexmedetomidine in bolus and maintenance, normal saline was used with the same volume. Mean arterial pressure was maintained between 65 to 75 mmHg. The incidence of bleeding, nausea and vomiting after surgery, the amount of maintenance drugs, and awakening time were recorded in a checklist.

Results

The intravenous use of dexmedetomidine significantly reduced the amount of bleeding (P < 0.0001); in addition, the need for opioids (P < 0.0001) and intravenous anesthetics significantly decreased (P = 0.001). Awakening time was significantly longer (P = 0.001), but its effect on postoperative nausea and vomiting was not significant (P = 0.052).

Conclusions

The current study showed that although propofol and remifentanil compounds can control hemodynamic state, but intravenous infusion of dexmedetomidine during the functional endoscopic sinus surgery reduced the amount of bleeding more significantly. It also reduced the dosage of maintenance drugs.

Dexmedetomidine infusion as an anesthetic adjuvant to general anesthesia for appropriate surgical field visibility during modified radical mastectomy with i-gel®: a randomized control study

Background

Modified radical mastectomy is associated with appreciable blood loss, while endotracheal intubation leads to elevated hemodynamic responses. The present study aimed to evaluate the clinical efficacy of dexmedetomidine infusion as an anesthetic adjuvant to general anesthesia during modified radical mastectomy with I-Gel.

Methods

Sixty adult consenting female patients, of American Society of Anesthesiologists physical status 1 to 2 and aged 4,065 years, were blindly randomized into two groups of 30 patients each. The patients in Group I received intravenous dexmedetomidine at a loading dose of 1 µg/kg over 10 min, followed by maintenance infusion of 0.4 to 0.7 µg/kg/h, while patients in Group II were administered an identical amount of saline infusion until 15 min prior to the end of surgery. The primary end point was bleeding at the surgical field and hemodynamic changes; requirement of isoflurane, intraoperative fentanyl consumption and recovery time were assessed as secondary outcomes.

Results

The patients receiving dexmedetomidine infusion showed significantly less bleeding at the surgical field (P < 0.05). A statistically significant reduction was also observed in the percentage of isoflurane required (0.82 ± 0.80%) to maintain the systolic blood pressure between 100 and 110 mmHg in patients receiving dexmedetomidine infusion compared with the Group II (1.50 ± 0.90%). The mean intraoperative fentanyl consumption in patients in the Group I was also significantly lower compared with that of the Group II (38.43 ± 5.40 µg vs. 75.12 ± 4.60 µg). The mean recovery time from anesthesia did not show any clinically significant difference between the groups.

Conclusions

Dexmedetomidine infusion can be used safely to decrease the bleeding at the surgical field with smooth recovery from anesthesia.