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).

Use of dexmedetomidine for controlled hypotension in middle ear surgery: A systematic review and meta-analysis.

BACKGROUND: Microsurgical operations such as middle ear surgery rely heavily on visibility of the surgical field. Anesthetic techniques such as controlled hypotension have been developed to improve surgical field visibility by attempting to decrease bleeding. Many agents have been utilized to achieve controlled hypotension intraoperatively. Dexmedetomidine is a relatively newer agent which works on alpha-2 receptors to decrease sympathetic tone. This paper sought to determine the efficacy of dexmedetomidine for optimizing surgical field visibility in MES. METHODS: A comprehensive search strategy was used in PubMed, SCOPUS, CINAHL, and CENTRAL through August 9, 2022 for this systematic review and meta-analysis. INCLUSION CRITERIA: adult patients undergoing middle ear surgery with dexmedetomidine used for controlled hypotension to improve surgical field visibility. Risk of bias was assessed via Cochrane RoB 2. Meta-analysis of mean difference for surgical field scores and risk ratios for positive surgical field scores were used to compare dexmedetomidine with placebo or other agents. RESULTS: Fourteen studies were included in this review. Statistically significant mean difference was found to favor dexmedetomidine over placebo for Fromme-Boezaart surgical field scores. Statistically significant results were also demonstrated favoring dexmedetomidine over other agents in risk ratio for receiving positive surgical field scores, as well as surgeon and patient satisfaction scores. CONCLUSIONS: Controlled hypotension is an invaluable tool for surgical field visibility. Improved surgical field visibility was observed with dexmedetomidine compared with placebo and various other agents. Risk of sub-optimal bleeding scores was significantly lower with dexmedetomidine. Dexmedetomidine is effective at improving surgical field visibility in middle ear surgery.

Does preoperative administration of hypotensive agents affect the quality of the surgical field during endoscopic sinus surgery? A triple-blind randomized controlled trial.

PURPOSE: Endoscopic sinus surgery (ESS) is a surgical procedure widely used in the treatment of various sinonasal conditions. Excessive bleeding during ESS leads to potentially major complications. The primary aim of this trial was to explore any different effects of bisoprolol and nifedipine on the intraoperative surgical field. In addition, the correlations regarding surgical field state, total blood loss (TBL), mean arterial pressure (MAP), and heart rate (HR) were also examined. METHODS: A prospective, triple-blinded, randomized, placebo-controlled trial was conducted, including 72 patients between 18 and 65 years of age who underwent ESS. As an indicator of the worst state of the intraoperative surgical field, the Boezaart scale score was used, as evaluated by two surgeons. Appropriate statistical analysis was conducted to explore score comparisons across groups and correlations between vital signs, bleeding, and the operative field state. RESULTS: No statistically significant difference was found among different intervention groups regarding the worst state of the surgical field (p = 0.367 > 0.05). The Boezaart scale score was positively correlated with TBL (rxy = 0.619, p = 0.000 < 0.001) and MAP (rxy = 0.259, p = 0.028 < 0.05). Furthermore, MAP was positively correlated with HR (rs = 0.254, p = 0.32 < 0.05). CONCLUSION: Our study demonstrates that preoperative administration of bisoprolol and nifedipine does not affect the worst state of the operative field. However, vital signs seem to either directly or indirectly affect bleeding and operative field state, and agents affecting them are worth exploring further.

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 induced hypotension and hemostatic markers.

Background and Aims: The hemostatic system undergoes extensive alterations following surgical trauma leading to a hypercoagulable state. We assessed and compared the changes in platelet aggregation, coagulation, and fibrinolysis status during normotensive and dexmedetomidine-induced hypotensive anesthesia in patients undergoing spine surgery. Material and Methods: Sixty patients undergoing spine surgery were randomly allocated into two groups: normotensive and dexmedetomidine-induced hypotensive groups. Platelet aggregation was assessed preoperatively, 15 min after induction, 60 min, and 120 min after skin incision, at the end of surgery, 2 h and 24 h postoperatively. Prothrombin time (PT), activated partial thromboplastin time (aPTT), platelet count, antithrombin III, fibrinogen, and D-dimer levels were measured preoperatively, 2 h and 24 h postoperatively. Results: Preoperative platelet aggregation (%) was comparable between both groups. Platelet aggregation significantly increased intraoperative at 120 min after skin incision and postoperatively in the normotensive group compared to the preoperative value (P < 0.05) but it was insignificantly decreased during the intraoperative induced hypotensive period in the dexmedetomidine-induced hypotensive group (P > 0.05). Postoperative PT, aPTT significantly increased and platelet count, and antithrombin III significantly decreased in the normotensive group compared to the preoperative value (P < 0.05) but they were not significantly changed in the hypotensive group (P > 0.05). Postoperative D-dimer significantly increased in the two groups compared to the preoperative value (P < 0.05). Conclusion: Intraoperative and postoperative platelet aggregation significantly increased in the normotensive group with significant alterations of the coagulation markers. Dexmedetomidine-induced hypotensive anesthesia prevented the increased platelet aggregation that occurred in the normotensive group with better preservation of platelet and coagulation factors.

Controlled arterial hypotension during resection of cerebral arteriovenous malformations.

BACKGROUND: Resection of cerebral arteriovenous malformations (AVM) is technically demanding because of size, eloquent location or diffuse nidus. Controlled arterial hypotension (CAH) could facilitate haemostasis. We performed a study to characterize the duration and degree of CAH and to investigate its association with blood loss and outcome. METHODS: We retrospectively analysed intraoperative arterial blood pressure of 56 patients that underwent AVM-resection performed by the same neurosurgeon between 2003 and 2012. Degree of CAH, AVM size, grading and neurological outcome were studied. Patients were divided into two groups, depending on whether CAH was performed (hypotension group) or not (control group). RESULTS: The hypotension group consisted of 28 patients, which presented with riskier to treat AVMs and a higher Spetzler-Martin grading. CAH was achieved by application of urapidil, increasing anaesthetic depth or a combination thereof. Systolic and mean arterial blood pressure were lowered to 82 ± 7 and 57 ± 7 mmHg, respectively, for a median duration of 58 min [25% percentile: 26 min.; 75% percentile: 107 min]. In the hypotension group, duration of surgery (4.4 ± 1.3 h) was significantly (p <  0.001) longer, and median blood loss (500 ml) was significantly (p = 0.002) higher than in the control group (3.3 ± 0.9 h and 200 ml, respectively). No case fatalities occurred. CAH was associated with a higher amount of postoperative neurological deficits. CONCLUSIONS: Whether CAH caused neurological deficits or prevented worse outcomes could be clarified by a prospective randomised study, which is regarded as ethically problematic in the context of bleeding. CAH should only be used after strict indication and should be applied as mild and short as possible.

Comparison of the Effect of Dexmedetomidine and Remifentanil on Controlled Hypotension During Rhinoplasty: A Clinical Trial Study.

INTRODUCTION: One of the most important problems during cosmetic nose surgery is excessive bleeding. Controlled hypotension is an appropriate technique for reducing intraoperative bleeding as well as satisfactory and non-bloody surgical field. Different drugs, such as dexmedetomidine and remifentanil, are used to control hypotension. The aim of this study was to compare the effect of dexmedetomidine and remifentanil on the creation of control hypotension during rhinoplasty. MATERIAL AND METHOD: This study is a randomized, double-blind clinical trial which was performed on 60 patients randomly divided into two groups D (Dexmedetomidine) and R (Remifentanil). In group D (0.5 mg / kg / h) Dexmedetomidine infusion and in group R (50-100 µg / kg / h) Remifentanil infusion. The study groups were compared in terms of hemodynamics and intraoperative bleeding. The data obtained from completed questionnaires were analyzed using SPSS software, T-test and ANOVA statistical tests and were presented in tables and statistical charts. RESULTS: The results of this study showed that the mean MAP (Mean Arterial Pressure) was significantly lower in remifentanil group patients than in dexmedetomidine group, while the intraoperative bradycardia rate was different at various time. CONCLUSION: During rhinoplasty surgery, both dexmedetomidine and remifentanil were effective in controlling hypotension and reducing intraoperative bleeding, but the effect of remifentanil was more pronounced than dexmedetomidine.

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 the nontourniquet combined with controlled hypotension technique on pain and long-term prognosis in elderly patients after total knee arthroplasty: a randomized controlled study.

PURPOSE: The aim of this study was to confirm the alleviating effects of the nontourniquet technique on the postoperative acute and chronic pain of patients after total knee arthroplasty (TKA). METHODS: 122 elderly patients undergoing TKA were randomly divided into two groups: group T (n = 58) and group H (n = 64). An electronic inflatable tourniquet was used during TKA in group T. The patients in group H received controlled hypotension but without tourniquet use during the operation. The numeric rating scale (NRS) score was used to evaluate pain level on day 1, day 2, day 3 and day 7 after the operation, and the incidence of chronic pain was judged at 3-month and 1-year follow-ups, and functional recovery of the knee joint was estimated by the active range of knee joint motion (AROM) at the same time points. Cognitive function was assessed by the montreal cognitive assessment scale (MoCA) for 7 days after operation. RESULTS: There were no significant differences in the NRS scores and AROM for 7 days after surgery. The incidence rate of chronic pain in group H (25.0%) was lower than that in group T (41.4%) and the AROM in group H was greater at one year follow-up. The MoCA score in group H was lower than that in group T on day 1 and day 2. CONCLUSION: The nontourniquet combined with controlled hypotension technique can alleviate chronic pain and promote the long-term rehabilitation of patients after TKA.

[Practical potentials of using dexmedetomidine in oral and maxillofacial surgery]. / Prakticheskie vozmozhnosti primeneniia sovremennogo sedativnogo preparata pri anesteziologicheskom posobii v stomatologii i cheliustno-litsevoi khirurgii.

Dexmedetomidine is a selective α2 adrenoreceptor agonist. The drug has a set of useful properties due to wide prevalence of the receptors in a body. The article presents review of the literature of using dexmedetomidine in anesthetic practice of various surgery fields which positive results may be extrapolated to dentistry and maxillofacial surgery to solve important anesthesiologic problems. Inclusion of the drug in routine oral and maxillofacial surgery anesthesia can bring a significant amount of benefits: safe sedation for dental interventions, sedation for compromised airways without respiratory depression, improvement of intraoperative and postoperative analgesia, reduction of postoperative nausea, vomiting and postoperative shivering incidence, nephroprotection and stability of hypotensive hemodynamics, decrease of intraoperative blood loss. Thus, the dexmedetomidine may be a useful agent for anesthesia in oral and maxillofacial surgery that increases anesthesia safety and quality of medical care.

Transvenous embolization of brain arteriovenous malformations: a review of techniques, indications, and outcomes.

Endovascular embolization of brain arteriovenous malformations (AVMs) is conventionally performed from a transarterial approach. Transarterial AVM embolization can be a standalone treatment or, more commonly, used as a neoadjuvant therapy prior to microsurgery or stereotactic radiosurgery. In contrast to the transarterial approach, curative embolization of AVMs may be more readily achieved from a transvenous approach. Transvenous embolization is considered a salvage therapy in contemporary AVM management. Proposed indications for this approach include a small (diameter < 3 cm) and compact AVM nidus, deep AVM location, hemorrhagic presentation, single draining vein, lack of an accessible arterial pedicle, exclusive arterial supply by perforators, and en passage feeding arteries. Available studies of transvenous AVM embolization in the literature have reported high complete obliteration rates, with reasonably low complication rates. However, evaluating the efficacy and safety of this approach is challenging due to the limited number of published cases. In this review the authors describe the technical considerations, indications, and outcomes of transvenous AVM embolization.

Risk factors for intraoperative bradycardia during ear, nose, throat and maxillofacial surgery.

Intraoperative bradycardia (IOB) is one of the most common cardiac arrhythmias observed in clinical anaesthetic practice. Controlled hypotension, as a strategy of lowering patient's blood pressure during anesthesia has been practiced for decades in head and neck surgery. The aim of our study was to determine the incidence and the risk factors for intraoperative bradycardia in maxillofacial, ear, nose and throat surgery, as well as to determine whether controlled hypotension affects the occurrence of IOB. The retrospective study included 2304 patients who underwent maxillofacial, ear, nose or throat surgery. We studied the influence of: sex, age, comorbidity, type of surgery, duration of anesthesia and controlled hypotension on the occurrence of IOB. IOB was registered in 473 patients (20.5%). Patients with controlled hypotension had IOB significantly more often than patients without controlled hypotension (33.9 vs 15.1%) (p = 0.000). The significant predictors of IOB were: age (OR = 1.158; 95% CI = 1.068-1.256; p = 0.000), sex (OR = 0.786; 95% CI = 0.623-0.993; p = 0.043), ischemic heart disease (OR = 2.016; 95% CI = 1.182-3.441; p = 0.010); ear surgery (OR = 1.593; 95% CI = 1.232-2.060; p = 0.000), anesthesia duration, (OR = 1.006; 95% CI = 1.004-1.007; p = 0.000) and controlled hypotension (OR = 2.204; 95% CI = 1.761-2.758; p = 0.000). IOB is common in maxillofacial, ear, nose and throat surgery, particularly in male, older age and patients with ishemic heart disease. The ear surgery, longer anesthesia duration and controlled hypotension raise the risk for occurrence of IOB.

Range of S-100ß levels during functional endoscopic sinus surgery with moderately controlled hypotension.

The aim of this study is to determine the range of S-100ß levels during functional endoscopic sinus surgery (FESS) when the mean arterial pressure (MAP) was controlled within 60-70 mmHg. After anesthesia induction with propofol and remifentanil, the patient was positioned in the reverse Trendelenburg position and MAP was controlled within 60-70 mmHg during surgery. For the S-100ß assay, blood was taken from a radial arterial catheter before (baseline) and at 20 (T 20) and 60 (T 60) min after setting the reverse Trendelenburg position and controlled hypotension, and at 60 (T post60) min after the end of the operation. In total, 34 patients completed the study. Baseline S-100ß was 0.00837 ± 0.00785 ng/mL. The levels at T 20 and T 60 were 0.02057 ± 0.01739 and 0.01987 ± 0.01145 ng/mL, respectively. The level of T post60 was 0.05436 ± 0.02318 ng/mL. The level at T 20 increased significantly versus the baseline level (P < 0.001); there were no significant differences between T 20 and T 60. The level at T post60 was significantly different versus T 20 and T 60 (P < 0.001). However, all S-100ß levels were within the normal range. S-100ß-a sensitive biomarker of cerebral ischemia-was within the normal range during FESS when moderate hypotension (MAP >60 mmHg) was provided. Thus, moderate hypotension would be seemed to be a safe and effective anesthetic technique for FESS without risk for cerebral ischemia.

Surgical conditions during FESS; comparison of dexmedetomidine and remifentanil.

To compare dexmedetomidine with remifentanil in functional endoscopic sinus surgery (FESS) in regards to intra-operative bleeding, anesthetic consumption and post-operative recovery. Randomized, double blind study. Tertiary care medical center. Fifty patients with nasal polyposis who had been scheduled for FESS were randomly divided into two groups. In group D (n = 25), dexmedetomidine 1 µg/kg infused intravenous (IV) over 10 min before anesthesia induction, followed by a continuous of 0.7 µg/kg/h infusion during operation. In group R (n = 25), 1 µg/kg remifentanil IV bolus, was administered with induction of anesthesia and continued 0.25-0.50 µg/kg/min during operation. Heart rates, mean arterial pressure, end tidal CO2, end tidal sevoflurane were recorded. The amount of bleeding, surgical field condition for bleeding and the time to reach Aldrete recovery score 9-10 were recorded. Postoperative nausea, vomiting, pain, shivering, sedation were followed up over 24 h. There was no significant difference between groups according to the amount of bleeding during surgery, assessment of surgical field condition, consumption of sevoflurane, scores of postoperative VAS, rates of nausea and vomiting, shivering, demands of additional analgesic medication (P > 0.05). The time to reach Aldrete recovery score 9-10, sedation scores at the postoperative first hour were significantly higher in group D (P = 0.001). We concluded that in comparison to remifentanil, dexmedetomidine during FESS for controlled hypotension is of limited value as it has no additional benefits in terms of control of hypotension and amount of bleeding in the surgical field and it is associated with higher recovery time and first-hour postoperative sedation scores.

Comparative Induction of Controlled Hypotension by Electroacupuncture at DU20 Acupoint and Remifentanil in Lumbar Laminectomy.

Hypotensive anesthesia is utilized to reduce bleeding during orthopedic surgery. One of the various drugs that have been used to reduce blood pressure is remifentanil. This study was an attempt to compare the effect of remifentanil with that of electroacupuncture (EA) at DU20 on reducing blood pressure. In this randomized controlled clinical trial, 54 patients undergoing lumbar laminectomy were allocated to two groups. Hypotensive anesthesia was performed through infusion of remifentanil 100 µg/kg/min for the control group, and EA at DU20 acupoint with a frequency of 2-10 Hz and intensity of 1-5 mA for the intervention group. Blood pressure, pulse rate, volume of blood lost and the quality of surgical field were evaluated every 10 min. There were no statistically significant differences between the two groups in terms of the changes in mean arterial pressure (MAP), pulse rate, and the quality of surgical field (P > 0.05). Therefore, EA can be as effective as remifentanil to reduce blood pressure in the patients undergoing lumbar laminectomy.

Effect of controlled hypotension on regional cerebral oxygen saturation during rhinoplasty: a prospective study.

The aim of this study was to investigate the effect of controlled hypotension on cerebral oxygen saturation (rSO2) using near infrared spectroscopy (NIRS) and evaluation of postoperative cognitive function in patients undergoing rhinoplasty. Fifty adult patients who were scheduled for elective rhinoplasty surgery and required controlled hypotension were enrolled in this prospective study. Controlled hypotension was provided using a combination of propofol and remifentanil infusion supplemented with nitroglycerin infusion as necessary. rSO2 was evaluated during controlled hypotension by NIRS. Cerebral desaturation was observed in 5 out of 50 patients (10 %) during hypotensive anesthesia. The greatest decrease from baseline was 28 % when MAP was 57 mmHg. In both non-desaturated and desaturated patients, postoperative MMSE scores were significantly lower than preoperative scores. There was a 4 % decrease in the non-desaturated patients and a 7 % decrease in the desaturated patients when preoperative and postoperative MMSE scores were compared. A decline in cognitive function 1 day after surgery was observed in 23 patients (46 %) and in all patients with intraoperative cerebral desaturation. The current study showed that even if SpO2 is in the normal range, there might be a decrease of more than 20 % in cerebral oxygen saturation during controlled hypotension.

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.

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

BACKGROUND AND AIM: Induced hypotension limits intra-operative blood loss to provide better visibility of the surgical field and diminishes the incidence of major complications during functional endoscopic sinus surgery (FESS). We aimed at comparing nitroglycerine, esmolol and dexmedetomidine for inducing controlled hypotension in patients undergoing FESS. MATERIAL AND METHODS: One hundred and fifty American Society of Anesthesiologists physical status I or II adult patients undergoing FESS under general anesthesia were randomly allocated to three groups of 50 patients each. Group E received esmolol in a loading and maintenance dose of 1 mg/kg over 1 min and 0.5-1.0 mg/kg/h, respectively. Group D received a loading dose of dexmedetomidine 1 µg/kg over 10 min followed by an infusion 0.5-1.0 µg/kg/h, and group N received nitroglycerine infusion at a dose of 0.5-2 µg/kg/min so as to maintain mean arterial pressure (MAP) between 60 and 70 mmHg in all the groups. The visibility of the surgical field was assessed by surgeon using Fromme and Boezaart scoring system. Hemodynamic variables, total intra-operative fentanyl consumption, emergence time and time to first analgesic request were recorded. Any side-effects were noted. The postoperative sedation was assessed using Ramsay Sedation Score. RESULT: The desired MAP (60-70 mmHg) could be achieved in all the three study groups albeit with titration of study drugs during intra-operative period. No significant intergroup difference was observed in Fromme's score during the intra-operative period. The mean total dose of fentanyl (µg/kg) used was found to be significantly lower in group D compared to groups E and N (1.2 ± 0.75 vs. 3.6 ± 1.3 and 2.9 ± 1.1 respectively). The mean heart rate was significantly lower in group D compared to groups E and N at all times of measurement (P < 0.05). The MAP was found to be significantly lower in group D compared to groups E and N after infusion of study drugs, after induction, just after intubation and 5 min after intubation (P < 0.05). The Ramsay Sedation Scores were significantly higher in group D (score 3 in 46%) when compared to group E (score 2 in 50%) and group N (score 2 in 54%) (P < 0.001). The emergence time was significantly lower in group E and group N compared to group D. Time to first analgesic request was significantly longer in group D. CONCLUSION: Dexmedetomidine and esmolol provided better hemodynamic stability and operative field visibility compared to nitroglycerin during FESS. Dexmedetomidine provides an additional benefit of reducing the analgesic requirements and providing postoperative sedation.