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

Adjuvants for balanced anesthesia in ambulatory surgery

Balanced anesthesia relies on the simultaneous administration of different drugs to attain an anesthetic state. The classic triad of anesthesia is a combination of a hypnotic, an analgesic, and a neuromuscular blocker. It is predominantly the analgesic pillar of this triad that became more and more supported by adjuvant therapy. The aim of this approach is to evolve into an opioid-sparing technique to cope with undesirable side effects of the opioids and is fueled by the opioid epidemic. The optimal strategy for balanced general anesthesia in ambulatory surgery must aim for a transition to a multimodal analgesic regimen dealing with acute postoperative pain and ideally reduce the most common adverse effects patients are faced with at home; sore throat, delayed awakening, memory disturbances, headache, nausea and vomiting, and negative behavioral changes. Over the years, this continuum of "multimodal general anesthesia" adopted many drugs with different modes of action. This review focuses on the most recent evidence on the different adjuvants that entered clinical practice and gives an overview of the different mechanisms of action, the potential as opioid-sparing or hypnotic-sparing drugs, and the applicability specifically in ambulatory surgery.

Surgical Field Quality in Trans-Nasal Endoscopic Surgeries Using Lignocaine Infusion and Dexmedetomidine Infusion. A Prospective Randomized Control Study

Trans-nasal endoscopic surgery (TNES) is a helpful diagnostic and therapeutic modality in otorhinolaryngology surgeries and requires controlled hypotension for better visualization of the surgical field. Recent literature shows evidence of intravenous Lignocaine infusion to produce the controlled hypotension. The study aims to assess and compare the effects of Lignocaine (LIG) and Dexmedetomidine (DEX) infusion with respect to surgical field quality. 101 Consenting adult patients undergoing elective TNES were double-blinded, randomly allocated in one of the two groups and received either DEX infusion of 0.5ug/kg/hr (n = 51) or LIG infusion of 1.5 mg/kg/h (n = 50) after a loading dose. Surgical field score (SVF) as the primary outcome and secondary outcomes such as variations in hemodynamic parameters, the requirement for rescue agents and total blood loss were recorded. Both the groups were comparable with respect to patient demographics, total duration of anesthesia and surgery. SVF scores were significantly better in the LIG group during the first 105 min of the surgery (p < 0.05). In response to intubation, hemodynamic parameters were lower in LIG group. The requirement of other adjuvant drugs, total blood loss (166.40 ml vs. 251.17 ml) and extubation time were also significantly lower in the LIG group. The study concludes that intravenous Lignocaine gives a better surgical field in the first 105 min of surgery, comparable hemodynamics and decreased blood loss in patients undergoing TNES as compared to Dexmedetomidine infusion. Hence its role as an agent for controlled hypotension during TNES surgery is promising.

Premedication for Induced Hypotension in Functional Endoscopic Sinus Surgeries: Intravenous Dexmedetomidine Infusion vs Oral Metoprolol vs Placebo: A Comparative Study

Background:

Controlled hypotension has been used to reduce bleeding and the need for blood transfusions and provide a satisfactory bloodless surgical field. In this double-blind, randomized controlled trial, we are comparing intravenous (i.v.) dexmedetomidine infusion and oral metoprolol as a premedication for controlled hypotension in functional endoscopic sinus surgery (FESS) for evaluating surgical field visibility.

Subjects and Methods:

A total of 90 patients undergoing FESS were randomly divided into three groups of 30 each. Group A received intraoperative i.v. infusion of dexmedetomidine (loading 1 μg.kg⁻¹ over 10 min followed by the maintenance of 0.2–0.5 μg.kg⁻¹.h⁻¹), Group B received oral metoprolol 50 mg on night and 2 h before surgery as a premedication, and Group C was taken as a control group and patients received oral placebo tablet as premedication and intraoperative normal saline infusion. General anesthesia was given using sevoflurane. Intraoperative target mean arterial blood pressure was set 55–65 mmHg. Various parameters were recorded and statistically compared.

Results:

The three groups were statistically comparable in demographics. Quality of surgical field was better in Group A compared to other two groups. Total blood loss was also less in Group A. The incidence of adverse reactions was more in Group A.

Conclusion:

Dexmedetomidine provides a better surgical field compared to oral metoprolol in FESS along with the desired hemodynamics with lesser blood loss and better outcome.

Effect of intraoperative dexmedetomidine infusion during functional endoscopic sinus surgery: a prospective cohort study

Background

Dexmedetomidine, an α2 agonist, has well-known anesthetic and analgesic-sparing effects. We designed this study to evaluate the effect of intraoperative dexmedetomidine infusion on intra operative blood loss and postoperative pain in functional endoscopic sinus surgery.

Methods

This prospective cohort study included 90 patients planning to undergo endoscopic sinus surgery, who were randomly divided into three groups. 2 to 2.5 mg/kg of propofol was used in all groups to induce anesthesia. One group received dexmedetomidine 0.2 μg/kg per hour infusion whereas the other group received dexmedetomidine 0.5 μg/kg per hour infusion. The control group received normal saline infusion.

Results

The mean age of patients was 41.02 ± 11.93. 33 patients in the dexmedetomidine 0.2 μg/kg/h group, 30 patients in the dexmedetomidine 0.5 μg/kg/h group and 27 patients in the placebo group. The lowest amount of bleeding was related to the dexmedetomidine 0.5 μg/kg/h group. The volume of bleeding between the three groups was significantly different (p = 0.012). The satisfaction of the surgeon in the dexmedetomidine 0.5 μg/kg/h group was more than other groups. There was a significant relationship between the satisfaction of the surgeon and the treatment groups (p < 0.001). The lowest duration of surgery was related to the dexmedetomidine 0.2 μg/kg/h group. The most Trinitroglycerin (TNG) consumption was in the placebo group and the highest dose of labetalol was in the dexmedetomidine 0.5 μg/kg/h group. There was no significant difference in the TNG and labetalol consumption between three groups. The lowest consumption of morphine and pethidine in the dexmedetomidine 0.5 μg/kg/h group.

Conclusions

Infusion of dexmedetomidine 0.5 μg/kg/h decreased blood loss and consumption of morphine and pethidine in patients who underwent endoscopic sinus surgery.

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.

Effect of Clonidine on Hemodynamic Responses During Laparoscopic Cholecystectomy: A Systematic Review and Meta-Analysis

BACKGROUND

Clonidine might be beneficial to the patients undergoing laparoscopic cholecystectomy. This meta-analysis focused on the influence of clonidine on hemodynamic responses in patients undergoing laparoscopic cholecystectomy.

METHODS

We searched several databases including PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases. This meta-analysis included randomized controlled trials regarding the influence of clonidine versus placebo on laparoscopic cholecystectomy. The primary outcomes were mean arterial pressure (MAP) and heart rate (HR) at pneumoperitoneum. The random-effect model was applied for this study.

RESULTS

Compared with control intervention, clonidine intervention was found to significantly reduce the MAP at pneumoperitoneum [standard mean difference=-2.58; 95% confidence interval (CI),-4.63 to -0.53; P=0.01), HR at pneumoperitoneum (standard mean difference=-3.67; 95% CI, -6.57 to -0.76; P=0.01), MAP at intubation (standard mean difference=-2.40; 95% CI, -4.75 to -0.06; P=0.04), HR at intubation (standard mean difference=-3.39; 95% CI, -5.75 to -1.02; P=0.005), propofol requirement (standard mean difference=-2.25; 95% CI, -4.01 to -0.48; P=0.01), as well as postoperative nausea and vomiting (risk ratio, 0.35; 95% CI, 0.19-0.63; P=0.0005).

CONCLUSIONS

Compared with control intervention, clonidine intervention was found to significantly reduce MAP and HR at pneumoperitoneum and intubation, propofol requirement, as well as postoperative nausea and vomiting in patients undergoing laparoscopic cholecystectomy.

Is It Time for an Expanded Role of Dexmedetomidine in Contemporary Anesthesia Practice? - A Clinician's Perspective

Since its approval by US Food and Drug Administration in 1999 the clinical use of dexmedetomidine has been gaining in popularity. The indications and clinical applications of this drug have been expanded significantly. In this paper we reviewed its pharmacokinetics, pharmacodynamics, mechanisms of action and mainly focused on its clinical uses and outcomes. Common clinical uses of dexmedetomidine include pre-operative anxiolysis, heart rate control during intubation, treatment of bronchospasm, prevention of laryngospasm and avoiding opioid-induced post-operative respiratory depression and nausea and vomiting. Avoiding opioid induced respiratory depression has been especially beneficial in patients with sleep apnea syndrome. Other problems that can be prevented with dexmedetomidine are tachydysrhythmias, myocardial ischemia, delirium and acute kidney injury. Dexmedetomidine is an excellent sedative drug for intubated patients and it greatly facilitates neurological evaluation. It has been used successfully as a patient-controlled anesthesia drug and to prevent shivering. It is also used as an adjuvant to local anesthetics. It has been suggested that dexmedetomidine is a drug that has many beneficial effects and should be used more frequently by anesthesia care providers to prevent common problems in the peri-operative period. With judicious titration to effect during the intravenous administration of this drug the occurrence of side effects can be minimized. It is very likely that this drug will ascend to take a much more prominent role in future anesthesia practice.

Evaluation of Preoperative Flupirtine in Ambulatory Functional Endoscopic Sinus Surgery: A Prospective, Double-Blind, Randomized Controlled Trial

Background:

Functional endoscopic sinus surgery (FESS) is the mainstay therapeutic management for nasal pathologies. We evaluated flupirtine, a centrally acting analgesic, for producing perfect perioperative conditions in FESS for adults in a day-care setting.

Materials and Methods:

Sixty-two patients (25–40 years) scheduled for FESS under general anesthesia were randomly divided into Group F (n = 31) receiving preoperative flupirtine (100 mg) and Group C (n = 31) receiving identical-looking placebo capsule per oral 60 min before induction of anesthesia. Perioperative Nasal bleeding and surgeon's satisfaction score during operation; amount and number of patients receiving fentanyl, propofol, and esmolol infusion for analgesia; maintenance of desired bispectral index (BIS) and deliberate hypotension, respectively. Postanesthesia Care Unit (PACU) and hospital stay, hemodynamic parameters, and side effects were all recorded for each patient.

Results:

Significantly, less number of patients and less dosage of esmolol were required (P = 0.0040 and 0.0001, respectively) in Group F as compared to that in Group C. Again, number of patients requiring fentanyl and dosage of the same drug was significantly lower in Group F. Dose of propofol for the maintenance of BIS was significantly lower in Group F. However, the duration of controlled hypotension was almost similar in both groups. Group F patients suffered significantly less nasal bleeding and surgeon's satisfaction score was also high in this group. Discharge time from PACU and hospital was similar between two groups without any appreciable side effects.

Conclusion:

Flupirtine as a premedication found to be providing more favorable perioperative hemodynamic conditions, analgesia and thus allowing less nasal bleeding as well as more surgeons’ satisfaction score.

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.