Attenuation of pressor response and dose sparing of opioids and anaesthetics with pre-operative dexmedetomidine

Identification of an effective and safe bolus dose and lockout time for patient-controlled sedation (PCS) using dexmedetomidine in dental treatments: a randomized clinical trial

Background

This study investigated a safe and effective bolus dose and lockout time for patient-controlled sedation (PCS) with dexmedetomidine for dental treatments. The depth of sedation, vital signs, and patient satisfaction were investigated to demonstrate safety.

Methods

Thirty patients requiring dental scaling were enrolled and randomly divided into three groups based on bolus doses and lockout times: group 1 (low dose group, bolus dose 0.05 µg/kg, 1-minute lockout time), group 2 (middle dose group, 0.1 µg/kg, 1-minute), and group 3 (high dose group, 0.2 µg/kg, 3-minute) (n = 10 each). ECG, pulse, oxygen saturation, blood pressure, end-tidal CO2, respiratory rate, and bispectral index scores (BIS) were measured and recorded. The study was conducted in two stages: the first involved sedation without dental treatment and the second included sedation with dental scaling. Patients were instructed to press the drug demand button every 10 s, and the process of falling asleep and waking up was repeated 1-5 times. In the second stage, during dental scaling, patients were instructed to press the drug demand button. Loss of responsiveness (LOR) was defined as failure to respond to auditory stimuli six times, determining sleep onset. Patient and dentist satisfaction were assessed before and after experimentation.

Results

Thirty patients (22 males) participated in the study. Scaling was performed in 29 patients after excluding one who experienced dizziness during the first stage. The average number of drug administrations until first LOR was significantly lower in group 3 (2.8 times) than groups 1 and 2 (8.0 and 6.5 times, respectively). The time taken to reach the LOR showed no difference between groups. During the second stage, the average time required to reach the LOR during scaling was 583.4 seconds. The effect site concentrations (Ce) was significantly lower in group 1 than groups 2 and 3. In the participant survey on PCS, 8/10 in group 3 reported partial memory loss, whereas 17/20 in groups 1 and 2 recalled the procedure fully or partially.

Conclusion

PCS with dexmedetomidine can provide a rapid onset of sedation, safe vital sign management, and minimal side effects, thus facilitating smooth dental sedation.

Comparative evaluation of lignocaine nebulization with and without dexmedetomidine for flexible videoendoscopic guided awake nasal intubation for general anaesthesia

Background and Aims

Awake fibreoptic intubation is considered a safe approach in airway management of a patient with difficult airway. Awake fibreoptic endoscopy needs appropriate anaesthesia of airway to suppress airway reflexes and prevent discomfort. We planned this study to evaluate effect of adding dexmedetomidine to lignocaine nebulization on conditions for awake videoendoscopic intubation.

Material and Methods

In this prospective randomized double blind controlled study, ninety six ASA grade I, II patients of either gender, aged 18-65 years, scheduled for elective surgeries under general anaesthesia, were randomly allocated into two groups, Group D and L to receive nebulization with 4% Lignocaine 5 ml + Dexmedetomidine 2 mcg/kg and 4% Lignocaine alone respectively, 20 min before procedure. Time taken to intubate the patient, ease of intubation assessed by cough severity score, patient comfort score, post-intubation patient satisfaction and hemodynamic changes were recorded and compared.

Results

Group D and L had comparable intubation time (196.8 ± 61.2 s) and (205.8 ± 52.2 s) (p = 0.437). Cough severity, patient comfort and quality of procedure with post intubation patient satisfaction score were significantly better in Group D. Haemodynamics parameters were better post nebulization in group D as compared to group L.

Conclusion

Addition of Dexmedetomidine 2 mcg/kg with 4% Lignocaine during nebulization improves intubating conditions during awake flexible videoendoscopy in terms of ease of intubation, cough severity, patients comfort and satisfaction along with providing stable Haemodynamics profile.

Recovery and post-operative analgesic efficacy from fentanyl- versus dexmedetomidine-based anesthesia in head and neck cancer surgery: A prospective comparative trial

Background

Opioids such as fentanyl are being used frequently in the management of postoperative period, whereas non-opioid drugs such as dexmedetomidine are now commonly being used as adjuvants during the perioperative period to hasten the fast recovery and better outcome in the post-operative period because of their anesthetic and analgesic property. The recovery profile was measured by the emergence of anesthesia and pain characteristics. We aimed to evaluate and compare the efficacy of dexmedetomidine and fentanyl in the surgery of head and neck cancer patients.

Methods

Prospective double-blind study on 60 patients with the American Society Anesthesiologists (ASA) grade I and II were randomly divided into two groups. Group DM received a loading dose of dexmedetomidine 1 µg/kg over 10 min followed by a maintenance dose of 0.5 µg/kg/h and Group FM received a loading dose of fentanyl 2 µg/kg/h for over 10 min followed by 1 µg/kg/h maintenance dose. Data were analyzed using a Chi-square test or Student's 't' test.

Results

The group DM was hemodynamic stable as compared to group FM. The perturbation during extubation emergence was significantly lower in group DM as compared to that in group FM. A total of four patients were severely agitated in group FM, whereas it was absent in group DM. Severe agitation was significantly different between Group FM and Group DM. The visual analog scale (VAS) was lower among patients of Group DM as compared to Group FM at all times except at 4 h.

Conclusions

The infusion of dexmedetomidine was better in controlling emergence agitation, postoperative pain, and achieving peri-operative hemodynamic stability as compared to fentanyl.

Comparison of Fentanyl and Dexmedetomidine in Preventing an Increase in Heart Rate During Intubation Among Patients Undergoing General Anesthesia: A Meta-Analysis

General anesthesia induction, tracheal intubation, extubation, and laryngoscopy are associated with specific hemodynamic changes. Tracheal intubation and laryngoscopy are related to sympathetic stimulation and lead to hypertension and tachycardia. Recent studies have shown that dexmedetomidine is safe and effective as it does not depress respiratory function. This meta-analysis aims to compare the efficacy of dexmedetomidine and fentanyl in preventing an increase in heart rate (HR) during intubation among patients undergoing general anesthesia. A systematic literature search was done using PubMed, Cochrane Library, and Embase to assess studies comparing the efficacy of dexmedetomidine and fentanyl in preventing an increase in HR during intubation. A meta-analysis was done utilizing a random-effects model, and mean differences of HR were determined between fentanyl and dexmedetomidine at baseline, one minute, five minutes, and 10 minutes of intubation. In this meta-analysis, eight randomized control trials were included, involving 548 patients (274 in the fentanyl group and 274 in the dexmedetomidine group). The findings showed that significant difference of HR was significantly lower in the dexmedetomidine group than the fentanyl group at one minute of intubation (mean difference = -8.46; P-value = 0.003), at five minutes of intubation (mean difference = -7.51; P-value = 0.001), and at 10 minutes of intubation (mean difference = -5.15; P-value = 0.030). In the current meta-analysis, dexmedetomidine was better than fentanyl in preventing tachycardia following endotracheal intubation. HR was significantly lower at one minute, five minutes, and 10 minutes after intubation in the dexmedetomidine group compared to the fentanyl group.

A randomized comparison between interscalene block and dexmedetomidine for arthroscopic shoulder surgery

Introduction: Management of intraoperative hemodynamics and postoperative analgesia during arthroscopic shoulder surgeries remains a challenge. Although interscalene brachial plexus block (ISB) is considered ideal for shoulder anesthesia it requires skill and proficiency unlike intravenous (IV) dexmedetomidine. Objective: This randomized trial was performed to observe the efficacy of dexmedetomidine infusion which is less invasive and demands lesser skills than plexus block. Methodology: All patients scheduled for elective arthroscopic shoulder surgery under general anesthesia were assigned either to group DEX, which received an IV dexmedetomidine bolus of 0.5 mcg/kg over 20 minutes, followed by an infusion of 0.5 mcg/kg/hour that was stopped 30 minutes before surgery the end of surgery or to group BLOCK which received ultrasound guided ISB with 20ml of 0.25% bupivacaine. The primary outcome assessed was intraoperative hemodynamics; the secondary outcomes were immediate postoperative pain, operating condition as assessed by the surgeon, recovery time, and patient satisfaction after 24 hours. Blinded investigator and composite scores were used for the assessment. Results: Both groups displayed equivalent scores for intraoperative hemodynamics whereas ISB resulted in a better post-operative analgesia (p < 0.001). Surgeon’s opinion and recovery time were comparable. Overall, the patients had a satisfactory experience with both techniques, according to the quality assessment. Conclusion: IV dexmedetomidine infusion is an effective alternative to ISB for reconstructive shoulder surgeries under general anesthesia.

Effects of Dexmedetomidine Infusion in Low Dose on Dose Reduction of Propofol, Intraoperative Hemodynamics, and Postoperative Analgesia in Patients Undergoing Laparoscopic Cholecystectomy

Background:

Dexmedetomidine, alpha 2 agonist, with its anxiolytic, sympatholytic and sedative property can be good adjuvant in anesthesia by modifying stress response to various stimuli during laparoscopic cholecystectomy including laryngoscopy, intubation, pneumoperitoneum, and extubation. We aimed to evaluate low dose dexmedetomidine for reducing hemodynamic perturbations to stressful events with secondary aim of evaluating propofol dose reduction and postoperative analgesia.

Methods:

Sixty patients of American Society of Anesthesiologists Physical Status (ASA PS) Classes I and II were randomized to two groups of 30 each to receive dexmedetomidine infusion (0.5 mcg.kg⁻¹.h⁻¹) starting 15 min before induction (Group A) and normal saline (Group B). Patient induced and maintained with propofol infusion to keep BIS value 55–60 in both groups and heart rate (HR) and mean arterial pressure (MAP) were recorded. We stopped infusions at surgical closure. VAS score recorded till 24 h of surgery. Total propofol required in both groups were recorded. Data were statistically analyzed using the SPSS software version 15.0.

Results:

MAP and HR remain elevated following intubation in Group B and remain so throughout procedure and during all stressful events including CO₂ insufflation and tracheal extubation and were statistically significant. Significantly lower doses (almost 30%) of Propofol required in Group A to achieve similar BIS values compared to Group B. Visual Analog Scale score remained on the lower side in Group A for 24 h than Group B.

Conclusion:

Low dose dexmedetomidine (0.5 mcg.kg⁻¹.h⁻¹) can effectively maintain hemodynamics during stressful events, reduces propofol requirement and improves postoperative analgesia in patients undergoing laparoscopic cholecystectomy.

Comparison between dexmedetomidine and fentanyl bolus in attenuating the stress response to laryngoscopy and tracheal intubation: a randomized double-blind trial

Background and objectives

Laryngoscopy and tracheal intubation lead to a sympathoadrenal response. We compared the efficacy of dexmedetomidine with fentanyl bolus to attenuate this response.

Methods

One hundred patients admitted for routine surgical procedures under general anesthesia were enrolled in this double blind, randomized, controlled study. Patients were randomly assigned to two groups: Group F received injection of fentanyl 2 μg.kg^-1 and Group D received injection of dexmedetomidine 0.5 μg.kg^-1 diluted up to 5 mL by adding normal saline intravenously over 60 seconds. Five minutes thereafter, following induction with propofol and vecuronium, tracheal intubation was performed after 3 minutes of mask ventilation. Hemodynamic parameters were observed at an interval of 2 minutes before tracheal intubation and at an interval of 1 minute for 5 minutes after tracheal tube cuff inflation. Continuous variables are presented as mean with 95% confidence interval, and t-test was applied for comparing the difference of means between two groups after checking the normality condition. Chi-square test was applied to test the independence of attributes of categorical variables. Repeated measures two-way ANOVA was performed to compare the outcome variables between the two groups.

Results

The difference in heart rate and mean arterial pressure of patients in two groups after laryngoscopy and intubation was not statistically significant at any point of time. The hemodynamic changes did not require any intervention in the form of administration of rescue medication.

Conclusions

Dexmedetomidine 0.5 μg.kg^-1 is as effective as fentanyl 2 μg.kg^-1 in attenuating the hemodynamic response accompanying laryngoscopy and tracheal intubation.

Clinical trial number & registry URL

CTRI/2017/09/009857 [ctri.nic.in]

Evaluation of nebulised dexmedetomidine in blunting haemodynamic response to intubation: A prospective randomised study

Background and Aim:

The process of laryngoscopy and endotracheal intubation is associated with intense sympathetic activity, which may precipitate intra-operative complications. Taking the advantage of dexmedetomidine's good bioavailability and rapid absorption through nasal mucosa; we contemplated this study to evaluate the effects of nebulised dexmedetomidine as a premedication in blunting the haemodynamic response to laryngoscopy and tracheal intubation.

Methods:

This prospective, randomised, comparative study was conducted in 100 American Society of Anesthesiologists (ASA) I, II patients. The primary outcome was to evaluate the effects of dexmedetomidine nebulisation in blunting the stress response to laryngoscopy and intubation. The secondary outcome was to study its adverse effects. The study population was divided randomly into two groups. Control group C (n = 50) received nebulisation with 5 ml of normal saline and group D (n = 50) received 1 μg/kg dexmedetomidine 5 ml 10 min before induction in sitting position.

Results:

Demographics were comparable. Following laryngoscopy and intubation, systolic (SBP), diastolic (DBP) and mean arterial pressure (MAP), response entropy (RE) and state entropy (SE) were markedly increased in the control group whereas in group D there was a fall in SBP (at 1 min-126.64 ± 26.37; P 0.01, 5 min-109.50 ± 16.83; P 0.02, 10 min-106.94 ± 17.01; P 0.03), DBP (at 1 min-83.18 ± 17.89; P 0.001, 5 min-66.40 ± 13.88; P 0.001, 10 min- 62.56 ± 14.91; P 0.01) and MAP (at 1 min-99.68 ± 19.22; P 0.001, 5 min- 84.08 ± 13.66; P 0.003, 10 min- 81.74 ± 14.79; P 0.008), RE and SE which was statistically significant (P 0.002). There was a dose sparing effect of propofol in group D; sedation score was comparable.

Conclusion:

Nebulised dexmedetomidine effectively blunts the stress response to laryngoscopy and intubation with no adverse effects.

Effect of dexmedetomidine on attenuation of hemodynamic response to intubation, skin incision, and sternotomy in coronary artery bypass graft patients: A double-blind randomized control trial

Background and Aims:

Coronary artery bypass grafting (CABG) surgery involves various noxious stimuli resulting in stress response, which in turn increases the risk of perioperative myocardial ischemia. The present study was conducted to evaluate the effect of dexmedetomidine on the attenuation of hemodynamic response to intubation, skin incision, and sternotomy in CABG surgery.

Material and Methods:

Sixty patients were randomized into two groups of 30 each. Group D patients received dexmedetomidine 1 μg/kg as loading dose over 10 min, followed by continuous infusion of 0.5 μg/kg/h. In group P, normal saline was infused as loading and maintenance dose at similar rate. Hemodynamic parameters, total induction dose of thiopentone, and adverse effects were recorded. Statistical analysis was performed using SPSS version 20.0. Chi-square test and ANNOVA test were used and P < 0.05 was considered significant.

Results:

The percentage increase in heart rate was significantly lesser in group D than group P after intubation (7.04% v/s 15.08%), skin incision (5.91% v/s 10.11%), and sternotomy (5.33% v/s 11.65%). Similarly increase in systolic, diastolic, and mean blood pressure were significantly lesser in group D than group P after intubation, skin incision, and sternotomy. There was a significant reduction of mean total of thiopentone in group D in comparison to group P. (1.16 mg/kg v/s 2.44 mg/kg) (P<0.001).

Conclusion:

Dexmedetomidine resulted in significant attenuation of hemodynamic response to intubation, skin incision, and sternotomy in CABG surgery without significant adverse effects. It also significantly reduced the dose of thiopentone required for induction.

[Impact of post-thoracotomy analgesia with dexmedetomidine and morphine on immunocytes: a randomized clinical trial]

OBJECTIVE

This study aimed to investigate the impact of post-thoracotomy analgesia with dexmedetomidine and morphine on immunocytes.

METHODS

A total of 118 patients with post-thoracotomy Patient-Controlled Intravenous Analgesia (PCIA) in our hospital from March 2016 to July 2018 were randomly selected and divided into the Composite (COM) Group (57 patients administered with dexmedetomidine [1.0 μg.kg^-1 body weight] and morphine [0.48 mg.kg^-1 body weight]) and the Morphine (MOR) Group (61 patients administered with morphine [0.48 mg.kg^-1]). The values of lymphocyte subsets (CD3+, CD4+, and CD8+) and Natural Killer cells in the peripheral blood of these two groups were detected by FACSCalibur flow cytometry at different time points (before anesthesia induction [T0], immediately after tracheal extubation [T1], 12 hours after surgery [T2], 24 hours after surgery [T3], 48 hours after surgery [T4], 72 hours after surgery [T5], and 7 days after surgery [T6]). The doses of morphine at T3 to T5 and the adverse reactions between the two groups were also recorded and compared.

RESULTS

The CD3+ level and the CD4+/CD8+ ratio at T2 to T5 and the CD4+ level and NK cells at T3 to T5 were significantly higher in the COM Group than in the MOR Group (p < 0.05). The postoperative morphine dose and the incidence of postoperative itching, nausea, and vomiting were significantly lower in the COM Group than in the MOR Group (p < 0.05).

CONCLUSIONS

Dexmedetomidine combined with morphine for post-thoracotomy PCIA can improve the function of immunocytes, reduce morphine consumption, and reduce the adverse reactions during analgesia induction.

Impact of post-thoracotomy analgesia with dexmedetomidine and morphine on immunocytes: a randomized clinical trial

Objective

This study aimed to investigate the impact of post-thoracotomy analgesia with dexmedetomidine and morphine on immunocytes.

Methods

A total of 118 patients with post-thoracotomy Patient-Controlled Intravenous Analgesia (PCIA) in our hospital from March 2016 to July 2018 were randomly selected and divided into the Composite (COM) Group (57 patients administered with dexmedetomidine [1.0 μg.kg^-1 body weight] and morphine [0.48 mg.kg^-1 body weight]) and the Morphine (MOR) group (61 patients administered with morphine [0.48 mg.kg^-1]). The values of lymphocyte subsets (CD3+, CD4+, and CD8+) and Natural Killer cells in the peripheral blood of these two groups were detected by FACSCalibur flow cytometry at different time points (before anesthesia induction [T0], immediately after tracheal extubation [T1], 12 hours after surgery [T2], 24 hours after surgery [T3], 48 hours after surgery [T4], 72 hours after surgery [T5], and 7 days after surgery [T6]). The doses of morphine at T3 to T5 and the adverse reactions between the two groups were also recorded and compared.

Results

The CD3+ level and the CD4+/CD8+ ratio at T2 to T5 and the CD4+ level and NK cells at T3 to T5 were significantly higher in the COM Group than in the MOR Group (p< 0.05). The postoperative morphine dose and the incidence of postoperative itching, nausea, and vomiting were significantly lower in the COM Group than in the MOR Group (p< 0.05).

Conclusions

Dexmedetomidine combined with morphine for post-thoracotomy PCIA can improve the function of immunocytes, reduce morphine consumption, and reduce the adverse reactions during analgesia induction.

The comparison of dexmedetomidine, esmolol, and combination of dexmedetomidine with esmolol for attenuation of sympathomimetic response to laryngoscopy and intubation in patients undergoing coronary artery bypass grafting

Background:

The aim of this study was to compare the effects of dexmedetomidine, esmolol, and combination of both on control of sympathetic response to laryngoscopy and tracheal intubation in coronary artery disease patients.

Material and Methods:

A prospective, randomized, double-blinded clinical study included 90 patients scheduled for elective coronary artery bypass surgery. Patients were randomly allocated into three groups of 30 each: dexmedetomidine group (Group D) 1 μg/kg, esmolol group (Group E) 2 mg/kg, and group dexmedetomidine with esmolol (Group DE) 0.5 μg/kg of dexmedetomidine with 1 mg/kg of esmolol. Each drug was diluted with 0.9% normal saline to 20 ml volume and infused in 10 min before induction of anesthesia. Hemodynamic changes (heart rate [HR], arterial blood pressure, and pulmonary artery pressure) were compared at various time intervals as follows-baseline, after study drug, after induction, and 1, 3, and 5 min after intubation. Statistical analysis included analysis of variance, Chi-square, and Fisher's exact test.

Results:

In Group DE, there was no significant increase in HR at all-time intervals, and the HR was stable compared to Group D and Group E. Blood pressure values were comparable in all groups except in Group E at 5 min. The pulmonary arterial pressures were statistically less in DE group except at 3 and 5 min.

Conclusions:

The combination of dexmedetomidine and esmolol group has beneficial effect on HR and pulmonary arterial pressures but has no additional advantage with respect to arterial blood pressure when compared with dexmedetomidine and esmolol groups in patients undergoing elective coronary artery bypass grafting.

Dexmedetomidine for the prevention of postoperative delirium in elderly patients undergoing noncardiac surgery: A meta-analysis of randomized controlled trials

BACKGROUND

Postoperative delirium (POD) among the elderly population that undergoes noncardiac surgery is significantly associated with adverse clinical outcomes. We conducted this meta-analysis to evaluate the effectiveness and safety of dexmedetomidine for the prophylaxis of POD among the elderly population after noncardiac surgery.

METHODS

We searched Embase, PubMed, and the Cochrane Library from inception date to March 2019 for randomized controlled trials (RCTs) that compared dexmedetomidine and placebo for the prevention of POD and evaluated the major cardiovascular outcomes among elderly people after noncardiac surgery. Two authors independently screened the studies and extracted data from the published articles. The main outcome was the incidence of POD. The secondary outcomes included the occurrence of bradycardia, hypotension, hypertension, tachycardia, myocardial infarction, stroke, hypoxaemia, and all-cause mortality.

RESULTS

A total of 6 RCTs with 2102 participants were included. Compared with placebo, dexmedetomidine significantly reduced the prevalence of POD (RR = 0.61, 95% CI 0.34-0.76, P = 0.001, I2 = 66%), and the risk of tachycardia (RR = 0.48, 95% CI 0.30-0.76, P = 0.002, I2 = 0%), hypertension (RR = 0.59, 95% CI 0.44-0.79, P < 0.001, I2 = 20%), stroke (RR = 0.22, 95% CI 0.06-0.76, P = 0.02, I2 = 0%), and hypoxaemia (RR = 0.50, 95% CI 0.32-0.78, P = 0.002, I2 = 0%) in elderly patients who underwent noncardiac surgery. However, dexmedetomidine accelerated the occurrence of bradycardia (RR = 1.36, 95% CI 1.11-1.67, P = 0.003, I2 = 0%). Furthermore, no significant differences were observed in the incidence of hypotension, myocardial infarction, and all-cause mortality between the dexmedetomidine and placebo groups.

CONCLUSIONS

Among elderly patients after noncardiac surgery, the prophylactic use of dexmedetomidine, compared with the use of placebo, was related to a decline in the incidence of POD.

Time course of psychomotor recovery after intravenous dexmedetomidine infusion as a part of balanced anaesthetic technique: A randomised, double-blind study

Background and Aims:

Dexmedetomidine is a drug that is being widely used as an adjuvant to anaesthesia because of its unique pharmacodynamic and pharmacokinetic properties. We aimed to assess the recovery of psychomotor function from balanced anaesthesia including intravenous dexmedetomidine infusion as adjunct.

Methods:

Ninety American Society of Anesthesiologists I and II patients were randomised to group D (n = 45), to receive 1 μg/kg of dexmedetomidine loading dose over 10 min, with maintenance infusion of 0.5 μg/kg/h, and group S (n = 45), to receive an equal volume of 0.9% normal saline. Objective parameters were recovery of psychomotor function assessed by Trieger dot test (TDT), digit symbol substitution test (DSST) and intraoperative opioid requirement. the total fentanyl used intraoperatively in the two groups. Statistical analysis was performed using unpaired Student's t-test, Chi-squareor Fisher's exact test.

Results:

Psychomotor recovery assessed by TDT showed statistically significant early recovery in group D compared with group S. This was seen in the maximum distance of dots missed at 30 min, 60 min, 90 min and 120 min as well as in the average distance of dots missed at identical time points. Similarly, DSST revealed early recovery at 30 min (12.4 ± 5.3 vs. 10.4 ± 3.9 P = 0.04) postoperative interval but not at other time intervals. There was significant decrease in the intraoperative opioid requirement in group D compared with group S.

Conclusion:

The addition of dexmedetomidine to balanced anaesthetic technique significantly hastened the psychomotor recovery compared with placebo.

Alpha-2 adrenergic agonists for the prevention of cardiac complications among adults undergoing surgery

BACKGROUND

The surgical stress response plays an important role on the pathogenesis of perioperative cardiac complications. Alpha-2 adrenergic agonists attenuate this response and may help prevent postoperative cardiac complications.

OBJECTIVES

To determine the efficacy and safety of α-2 adrenergic agonists for reducing mortality and cardiac complications in adults undergoing cardiac surgery and non-cardiac surgery.

SEARCH METHODS

We searched CENTRAL (2017, Issue 4), MEDLINE (1950 to April Week 4, 2017), Embase (1980 to May 2017), the Science Citation Index, clinical trial registries, and reference lists of included articles.

SELECTION CRITERIA

We included randomized controlled trials that compared α-2 adrenergic agonists (i.e. clonidine, dexmedetomidine or mivazerol) against placebo or non-α-2 adrenergic agonists. Included trials had to evaluate the efficacy and safety of α-2 adrenergic agonists for preventing perioperative mortality or cardiac complications (or both), or measure one or more relevant outcomes (i.e. death, myocardial infarction, heart failure, acute stroke, supraventricular tachyarrhythmia and myocardial ischaemia).

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality, extracted data and independently performed computer entry of abstracted data. We contacted study authors for additional information. Adverse event data were gathered from the trials. We evaluated included studies using the Cochrane 'Risk of bias' tool, and the quality of the evidence underlying pooled treatment effects using GRADE methodology. Given the clinical heterogeneity between cardiac and non-cardiac surgery, we analysed these subgroups separately. We expressed treatment effects as pooled risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

We included 47 trials with 17,039 participants. Of these studies, 24 trials only included participants undergoing cardiac surgery, 23 only included participants undergoing non-cardiac surgery and eight only included participants undergoing vascular surgery. The α-2 adrenergic agonist studied was clonidine in 21 trials, dexmedetomidine in 24 trials and mivazerol in two trials.In non-cardiac surgery, there was high quality evidence that α-2 adrenergic agonists led to a similar risk of all-cause mortality compared with control groups (1.3% with α-2 adrenergic agonists versus 1.7% with control; RR 0.80, 95% CI 0.61 to 1.04; participants = 14,081; studies = 16). Additionally, the risk of cardiac mortality was similar between treatment groups (0.8% with α-2 adrenergic agonists versus 1.0% with control; RR 0.86, 95% CI 0.60 to 1.23; participants = 12,525; studies = 5, high quality evidence). The risk of myocardial infarction was probably similar between treatment groups (RR 0.94, 95% CI 0.69 to 1.27; participants = 13,907; studies = 12, moderate quality evidence). There was no associated effect on the risk of stroke (RR 0.93, 95% CI 0.55 to 1.56; participants = 11,542; studies = 7; high quality evidence). Conversely, α-2 adrenergic agonists probably increase the risks of clinically significant bradycardia (RR 1.59, 95% CI 1.18 to 2.13; participants = 14,035; studies = 16) and hypotension (RR 1.24, 95% CI 1.03 to 1.48; participants = 13,738; studies = 15), based on moderate quality evidence.There was insufficient evidence to determine the effect of α-2 adrenergic agonists on all-cause mortality in cardiac surgery (RR 0.52, 95% CI 0.26 to 1.04; participants = 1947; studies = 16) and myocardial infarction (RR 1.01, 95% CI 0.43 to 2.40; participants = 782; studies = 8), based on moderate quality evidence. There was one cardiac death in the clonidine arm of a study of 22 participants. Based on very limited data, α-2 adrenergic agonists may have reduced the risk of stroke (RR 0.37, 95% CI 0.15 to 0.93; participants = 1175; studies = 7; outcome events = 18; low quality evidence). Conversely, α-2 adrenergic agonists increased the risk of bradycardia from 6.4% to 12.0% (RR 1.88, 95% CI 1.35 to 2.62; participants = 1477; studies = 10; moderate quality evidence), but their effect on hypotension was uncertain (RR 1.19, 95% CI 0.87 to 1.64; participants = 1413; studies = 9; low quality evidence).These results were qualitatively unchanged in subgroup analyses and sensitivity analyses.

AUTHORS' CONCLUSIONS

Our review concludes that prophylactic α-2 adrenergic agonists generally do not prevent perioperative death or major cardiac complications. For non-cardiac surgery, there is moderate-to-high quality evidence that these agents do not prevent death, myocardial infarction or stroke. Conversely, there is moderate quality evidence that these agents have important adverse effects, namely increased risks of hypotension and bradycardia. For cardiac surgery, there is moderate quality evidence that α-2 adrenergic agonists have no effect on the risk of mortality or myocardial infarction, and that they increase the risk of bradycardia. The quality of evidence was inadequate to draw conclusions regarding the effects of alpha-2 agonists on stroke or hypotension during cardiac surgery.

Comparison of Esmolol and Dexmedetomidine for Suppression of Hemodynamic Response to Laryngoscopy and Endotracheal Intubation in Adult Patients Undergoing Elective General Surgery: A Prospective, Randomized Controlled Double-blinded Study

Context:

Laryngoscopy and endotracheal intubation lead to strong sympathetic response which may precipitate arrhythmias, myocardial ischemia and cerebrovascular accidents in patients with preexisting cardiovascular disease.

Aims:

This study was aimed to compare the effect of dexmedetomidine and esmolol on hemodynamic response to laryngoscopy and endotracheal intubation in patients undergoing elective surgery under general anesthesia.

Settings and Design:

This was a prospective, randomized controlled double-blinded study.

Materials and Methods:

A total of ninety patients were selected and randomized into three groups of thirty patients each: Group C received infusion of 20 mL 0.9% normal saline (NS) over 10 min, Group D received infusion of dexmedetomidine 1 μg/kg diluted in 20 mL NS over 10 min, and Group E received infusion of esmolol 1.5 mg/kg diluted in 20 mL NS over 10 min. Three minutes after the completion of infusion, patients were induced with general anesthesia. Baseline parameters such as heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), and rate pressure product (RPP) were recorded before administration of study drugs and at 1, 3, 5, 7, and 10 min after intubation.

Statistical Analysis Used:

One-way ANOVA was used for comparison among the groups and unpaired t-test was used for comparison within the groups along with Tukey's test for post test analysis.

Results:

Mean HR, SBP, DBP, MAP, and RPP values remained significantly lower in Group D than that of Group C and Group E at all time intervals up to 10 min after intubation.

Conclusions:

Both dexmedetomidine and esmolol suppressed the hemodynamic response to intubation when compared to control group, but dexmedetomidine is more effective than esmolol in maintaining hemodynamic stability following laryngoscopy and intubation.

Effect of adjunctive dexmedetomidine on anesthesia and analgesia requirement and recovery characteristics during Bispectral Index-guided anesthesia for cerebello-pontine angle surgeries: A randomized clinical trial

Background and Aims

The study was conceived to elucidate the effects of dexmedetomidine as an anesthetic adjunct to propofol (total intravenous anesthesia) on anesthetic dose reduction and anesthesia recovery parameters in cerebello-pontine angle (CPA) surgeries.

Material and Methods

This prospective randomized study was conducted on 49 patients (25 with dexmedetomidine, 24 without). After standardized anesthetic induction, anesthesia was maintained using propofol (via target controlled infusion, titrated to maintain BIS between 40 and 60), fentanyl (0.5 μg/kg/hour) and either dexmedetomidine (0.5 μg/kg/hour) or a sham infusion. Neuromuscular blocking agents were excluded to allow cranial nerve EMG monitoring. Adverse hemodynamic events, recovery parameters (time to opening eyes, obeying commands, and extubation) and postoperative sedation score, shivering score, nausea, and vomiting score were recorded.

Results

Propofol and fentanyl utilization (as total dose, adjusted for duration of surgery and body weight, and number of extra boluses) was significantly lower in the dexmedetomidine group. There was no difference in any of the recovery parameters between the two groups. Incidence of bradycardia was significantly higher with dexmedetomidine, while no difference was found for hypotension, hypertension, and tachycardia.

Conclusion

Dexmedetomidine-fentanyl-propofol anesthesia compares favorably with fentanyl-propofol anesthesia during CPA neurosurgical procedures with regard to anesthesia recovery times, but with lower intraoperative opioid and hypnotic utilization rates.

Effect of Two Different Doses of Dexmedetomidine on Stress Response in Laparoscopic Pyeloplasty: A Randomized Prospective Controlled Study

Background

Clonidine, opioids, β-blockers, and dexmedetomidine have been tried to attenuate stress responses during laparoscopic surgery. We evaluated the efficacy of dexmedetomidine in two different doses in attenuating stress responses on patients undergoing laparoscopic pyeloplasty.

Subjects and Methods

Ninety patients were assigned to one of the three groups: Group A, Group B, and Group C. Group B received dexmedetomidine 1 mcg/kg as loading dose, followed by 0.7 mcg/kg/h for maintenance; Group C received dexmedetomidine 0.7 mcg/kg as a loading dose, followed by 0.5 mcg/kg/h for maintenance. Group A received normal saline. Stress responses were assessed by the variations in heart rate (HR), mean arterial pressure (MAP), blood glucose levels, and serum cortisol levels. One-way analysis of variance test was applied. Multiple comparisons between groups were done with post hoc Bonferroni test.

Results

The HR and MAP were found to be higher in Group A. The difference was statistically significant (P < 0.05) during intubation, carbon dioxide insufflation, and extubation when compared with Groups B and C. Blood glucose levels at postintubation and at extubation were higher in Group A and statistically significant (P < 0.05) when compared with Groups B and C. Serum cortisol levels at postintubation, during midsurgery, and 2 h after extubation were higher in Group A and statistically significant (P < 0.05) when compared with Groups B and C. However, HR, MAP, blood glucose levels, and serum cortisol levels were similar in dexmedetomidine groups.

Conclusions

Dexmedetomidine decreases stress response and provides good condition for maintenance of anesthesia. Dexmedetomidine when used in lower dose in Group C decreases stress response comparable to higher dose in Group B.

Effects of Dexmedetomidine on Intraoperative Hemodynamics and Propofol Requirement in Patients Undergoing Laparoscopic Cholecystectomy

Background

Despite multiple benefits, laparoscopic surgery always poses anesthetic challenge due to significant alteration of hemodynamics. Various pharmacological agents have been used for the same with variable response. Dexmedetomidine, in addition to sympatholytic effect, diminishes intraoperative requirement of anesthetics including propofol. The present study was conducted to evaluate the effects of intravenous dexmedetomidine on intraoperative hemodynamics and propofol requirement using bispectral index (BIS) in laparoscopic cholecystectomy.

Methods

Forty patients undergoing laparoscopic cholecystectomy were randomly allocated to receive either dexmedetomidine (Group A; n = 20) or normal saline (Group B; n = 20). In Group A, dexmedetomidine was loaded (1 μg/kg) before anesthesia induction and infused (0.6 μg/kg/h) during surgery. Anesthesia was induced with propofol, and maintenance infusion rate was adjusted to a BIS of 55-60 in both groups. Mean arterial pressure (MAP) and heart rate (HR) were recorded at baseline and at various time points from loading of drugs to just after tracheal extubation. All infusions were stopped with removal of scope from abdominal cavity. Recovery time (time from end of all infusions to BIS = 80) and extubation time (time from end of all infusions to extubation) were noted.

Results

After intubation, MAP and HR values in Group A were significantly lower than Group B at various time points of study. To achieve similar BIS values, significantly low doses of propofol were required in Group A during induction and intraoperatively. Doses were reduced by 36% and 31%, respectively. Mean recovery time and mean extubation time in Group A were also significantly less.

Conclusion

During propofol-based anesthesia for laparoscopic cholecystectomy, dexmedetomidine provides stable intraoperative hemodynamics and reduces propofol requirement for induction as well as maintenance, without compromising recovery profile.

A Comparative Evaluation of Intravenous Dexmedetomidine and Fentanyl in Breast Cancer Surgery: A Prospective, Randomized, and Controlled Trial

Background and Aim:

Recent studies have advised narcotic less anaestheic techniques for breast cancer surgeries due to altered immune system by use of opioids. So we planned this study to compare the efficacy of dexmedtomidine with fentanyl in breast cancer surgery in terms of haemodynamic stability, anaesthetic sparing effects, recovery profile and postoperative analgesia.

Material and Methods:

In this randomized prospective controlled trial, a total of 60 female patients were randomly assigned into two groups. Patients in group F (n = 30) received a loading dose of fentanyl 2 μg/kg with maintenance dose of 0.5 μg/kg/h and in group D (n = 30) received dexmedetomidine 1 μg/kg as loading dose with maintenance dose of 0.25 μg/kg/h till the end of surgery. Hemodynamic parameters, desflurane requirement, recovery profile and postoperative analgesia were monitored and compared in both the groups.

Results:

Mean HR was less in group D compared to group F intraoperatively, before and after extubation with a significant p value. The mean MAP was also lower in group D compared to group F at all the time points. MAC requirements were found lower in group D compared to group F with a significant P < 0.001. Cognitive recovery in the form of time to respond to verbal commands, time to extubation, time to orientation was early in dexmedetomidine group.

Conclusion:

Dexmedtomidine can be used as suitable alternative to fentanyl in breast cancer surgeries due to better hemodynamic stability, anaesthetic sparing effects and better recovery profile.

Influence of different menstrual phases on the Bispectral Index during dexmedetomidine sedation

To investigate the influence of different menstrual phases on the Bispectral Index (BIS) during dexmedetomidine (Dex) sedation, 40 patients with regular menstrual cycle, American Society of Anesthesiologists I-II, aged 18-40 years, undergoing selective gynecologic laparoscopic surgery, were enrolled. According to different menstrual phases and the serum progesterone concentration, they were divided into two groups: the follicular phase group (Group F) and the luteal phase group (Group L), and each group had 20 patients. Before anesthesia induction, patients were infused with an initial loading dose of Dex (1 μg/kg) for 10 minutes and then 0.5 μg/kg/h for 20 minutes. BIS and the changes in hemodynamic and respiratory parameters were recorded within those 30 minutes. Time to lower BIS to 70 and 60 in Group L was shorter than that in Group F (9.4 ± 1.3 minutes vs. 11.3 ± 2.1 minutes, p = 0.005; 11.3 ± 2.4 minutes vs. 14.0 ± 3.6 minutes, p = 0.021). The number of patients whose BIS reached 50 in Group L was greater than that in Group F (15 vs. 8, p < 0.05). The lowest BIS value in the Group L was lower than that in Group F (46.8 ± 6.3 vs. 55.3 ± 5.5, p = 0.006), and the heart rate of patients in both groups showed a decrease (p < 0.05). The sedative effect of Dex was more significant in patients during the luteal phase than during the follicular phase.

Magnesium in obstetric anesthesia and intensive care

Magnesium, one of the essential elements in the human body, has numerous favorable effects that offer a variety of possibilities for its use in obstetric anesthesia and intensive care. Administered as a single intravenous bolus dose or a bolus followed by continuous infusion during surgery, magnesium attenuates stress response to endotracheal intubation, and reduces intraoperative anesthetic and postoperative analgesic requirements, while at the same time preserving favorable hemodynamics. Applied as part of an intrathecal or epidural anesthetic mixture, magnesium prolongs the duration of anesthesia and diminishes total postoperative analgesic consumption with no adverse maternal or neonatal effects. In obstetric intensive care, magnesium represents a first-choice medication in the treatment and prevention of eclamptic seizures. If used in recommended doses with close monitoring, magnesium is a safe and effective medication.

Comparison of the efficacy of lornoxicam and fentanyl in attenuating the hemodynamic response to laryngoscopy and intubation

BACKGROUND AND OBJECTIVES

Laryngoscopy and intubation elicits huge spectrum of stress response which is hazardous in high-risk patients. Many drugs and techniques have been used to attenuate the stress response. Lornoxicam 16 mg is a potent nonsteroidal anti-inflammatory drug agent with analgesic potency equivalent to morphine 10 mg, fentanyl 100 μg and tramadol 100 mg. Lornoxicam has been found to attenuate stress response in some studies. We compared the lornoxicam with fentanyl in attenuating stress response.

MATERIALS AND METHODS

A double blind randomized controlled study was conducted on 60 adult patients of American Society of Anesthesiologist physical status 1 and 2. Group L (n = 30) receives injection lornoxicam 16 mg intravenous 30 min before induction, Group F (n = 30) receives injection fentanyl 2 μg/kg during induction. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and heart rate (HR) were recorded baseline (BL), before induction, every minute up to 5 min and at 10 min after intubation.

RESULTS

After intubation, there is a gradual decrease in SBP and DBP in both groups. The MAP was also comparable between the two groups except at 5 min and 10 min during which MAP recovered toward BL in Group L where as it remained low in Group F which was statistically significant (P < 0.05). Both the drugs have successfully attenuated the HR response.

CONCLUSION

Lornoxicam successfully attenuated the hemodynamic response to laryngoscopy and endotracheal intubation and is equally efficacious as fentanyl.

Oral Clonidine vs Oral Pregabalin Premedication to Attenuate Pressor Response to Direct Laryngoscopy in Patients Undergoing Laparoscopic Cholecystectomy: A Randomized Double Blind Study

INTRODUCTION

Direct laryngoscopy and tracheal intubation has adverse effects like tachycardia, hypertension, myocardial ischemia and cerebral haemorrhage. There are several studies on various pharmacological agents to attenuate this response.

AIM

This study was designed to compare efficacy and safety of oral clonidine and oral pregabalin premedication to attenuate stress response in patients undergoing laparoscopic cholecystectomy.

MATERIALS AND METHODS

Total 80 patients of ASA grade I and II, aged between 20-60 years of both sexes scheduled for elective laparoscopic cholecystectomy were included in the study. All the patients were randomized into two groups. Group A received oral clonidine 0.3mg and group B received oral pregabalin 150mg, 60 minutes before surgery. Anaesthesia technique was standardized. Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), mean arterial pressure (MAP) and heart rate were recorded preoperatively, after premedication, immediately after intubation, then at 1 min, 3 min, 5 min, 10 min and 15 min after intubation. Level of sedation, postoperative pain scores and any adverse effects were also noted and compared.

RESULTS

Oral clonidine 0.3mg as well as oral pregabalin 150mg were effective in blunting haemodynamic stress response to laryngoscopy and tracheal intubation. Clonidine was found to be better than pregabalin in lowering of systolic blood pressure, diastolic blood pressure, mean arterial pressure and heart rate changes associated with laryngoscopy. We also found that bradycardia was common with both the drugs, more so in clonidine group. Post-operative analgesia was better in pregabalin group as compared to clonidine group. Both the drugs cause sedation, but it was more with the use of pregabalin.

CONCLUSION

Both the drugs can be used as an effective premedicant to attenuate the sympathetic response to laryngoscopy and tracheal intubation without much side effects and the added advantage of intraoperative and postoperative analgesia.

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.

Comparison of dexmedetomidine with fentanyl for maintenance of intraoperative hemodynamics in hypertensive patients undergoing major surgery: A randomized controlled trial

Background:

The objective of this study was to study and compare the effects of intravenous dexmedetomidine and fentanyl on intraoperative hemodynamics, opioid consumption, and recovery characteristics in hypertensive patients.

Methods:

Fifty-seven hypertensive patients undergoing major surgery were randomized into two groups, Group D (dexmedetomidine, n = 29) and Group F (fentanyl, n = 28). The patients received 1 μg/kg of either dexmedetomidine or fentanyl, followed by 0.5 μg/kg/h infusion of the same drug, followed by a standard induction protocol. Heart rate (HR), mean arterial pressures (MAPs), end-tidal isoflurane concentration, and use of additional fentanyl and vasopressors were recorded throughout.

Results:

Both dexmedetomidine and fentanyl caused significant fall in HR and MAP after induction and dexmedetomidine significantly reduced the induction dose of thiopentone (P = 0.026). After laryngoscopy and intubation, patients in Group D experienced a fall in HR and a small rise in MAP (P = 0.094) while those in Group F showed significant rise in HR (P = 0.01) and MAP (P = 0.004). The requirement of isoflurane and fentanyl boluses was significantly less in Group D. The duration of postoperative analgesia was longer in Group D (P = 0.015) with significantly lower postoperative nausea and vomiting (PONV) (P < 0.001).

Conclusion:

Infusion of dexmedetomidine in hypertensive patients controlled the sympathetic stress response better than fentanyl and provided stable intraoperative hemodynamics. It reduced the dose of thiopentone, requirement of isoflurane and fentanyl boluses. The postoperative analgesia was prolonged, and incidence of PONV was less in patients who received dexmedetomidine.

Comparision of clonidine and dexmedetomidine for attenuation of laryngoscopy and intubation response - A randomized controlled trial

BACKGROUND

Clonidine and dexmedetomidine are alpha-2 agonists with beneficial effect on the hemodynamic response to laryngoscopy and intubation. The present study was designed to evaluate and compare the efficacy of intravenous clonidine 1 μg/kg, and dexmedetomidine in doses of 0.5 μg/kg and 1 μg/kg, for blunting the hemodynamic changes during laryngoscopy and intubation.

METHOD

Adult patients of ASA physical grade I/II scheduled for surgery under general anaesthesia with endotracheal tube were randomly divided into three groups using a computer generated random number table, each group receiving one of the following drugs prior to induction of anaesthesia, by a blinded anaesthesiologist in a volume of 100 mL infused intravenously over 20 minutes: clonidine 1 μg/kg, or dexmedetomidine 0.5 μg/kg, or dexmedetomidine 1 μg/kg. General anaesthesia was induced using standard technique and intubations performed by same anaesthesiologist. Heart rate and mean blood pressure were recorded in pre-operative room (baseline) and again at 1 minute, 3 minutes, 5 minutes and 10 minutes after intubation. An increase in heart rate and/or mean blood pressure by >20% above baseline values during observation period was taken to indicate a positive intubation response.

RESULTS

The incidence of intubation response was similar in all three groups (P>.05). The number of patients developing hypotension was significantly higher in group receiving dexmedetomidine1μg/kg group (P<.005) as compared to other two groups. Both the groups receiving dexmedetomidine had higher number of patients developing bradycardia as compared to patients receiving clonidine.

DISCUSSION & CONCLUSION

Dexmedetomidine 0.5 μg/kg, 1 μg/kg and clonidine 1 μg/kg attenuate the laryngoscopy and intubation response but Clonidine 1 μg/kg was associated with lesser side effects.

Comparative Evaluation of Dexmedetomidine and Magnesium Sulphate on Propofol Consumption, Haemodynamics and Postoperative Recovery in Spine Surgery: A Prospective, Randomized, Placebo Controlled, Double-blind Study

PURPOSE

Dexmedetomidine and magnesium sulfate have been used in anesthesia as adjuvant to provide hemodynamic stability and anesthetic agents sparing effect. We compared these effects of dexmedetomidine and magnesium sulfate in spine surgeries.

METHODS

Ninety patients were randomly assigned to three groups. Group D received dexmedetomidine loading dose 1 µg/kg over a period of 15 minutes and maintenance 0.5 µg/kg/h throughout the surgery. Group M received magnesium sulfate loading dose 50 mg/kg over a period of 15 minutes and maintenance 15 mg/kg/h throughout the surgery. Group C received same volume of normal saline. Heart rate (HR) and blood pressure values were recorded at various intervals. The induction and maintenance doses of anesthetics and recovery parameters were also recorded.

RESULTS

Heart rate in group D and group M were significantly decreased (p<0.05) during the whole intraoperative period compared to preoperative values. There was a significant difference in HR values between group C, D and M, during the whole intraoperaive period (p<0.05). Blood pressure values were statistically significantly lower in the group D and group M compared to group C after intubation and all time observations of surgery (p<0.05). Both drugs reduced the anesthetic agent's requirement during surgery. However, the recovery parameters were statistically significant increase with magnesium sulphate compared to dexmedetomidine and control groups.

CONCLUSION

Dexmedetomidine is more effective than magnesium sulfate for maintaining the hemodynamic stability in spine surgeries. Both these drugs also reduce the requirements of anesthetic agents. Recovery from dexmedetomidine is as rapid as control group compared to magnesium sulfate.

Anaesthesia for laparoscopic surgery: General vs regional anaesthesia

The use of laparoscopy has revolutionised the surgical field with its advantages of reduced morbidity with early recovery. Laparoscopic procedures have been traditionally performed under general anaesthesia (GA) due to the respiratory changes caused by pneumoperitoneum, which is an integral part of laparoscopy. The precise control of ventilation under controlled conditions in GA has proven it to be ideal for such procedures. However, recently the use of regional anaesthesia (RA) has emerged as an alternative choice for laparoscopy. Various reports in the literature suggest the safety of the use of spinal, epidural and combined spinal-epidural anaesthesia in laparoscopic procedures. The advantages of RA can include: Prevention of airway manipulation, an awake and spontaneously breathing patient intraoperatively, minimal nausea and vomiting, effective post-operative analgesia, and early ambulation and recovery. However, RA may be associated with a few side effects such as the requirement of a higher sensory level, more severe hypotension, shoulder discomfort due to diaphragmatic irritation, and respiratory embarrassment caused by pneumoperitoneum. Further studies may be required to establish the advantage of RA over GA for its eventual global use in different patient populations.

Multimodal versus Conventional Approach for Postoperative Pain Relief in Oral Cancer Patients

INTRODUCTION

Multimodal analgesia includes regional anaesthesia in the form of nerve block may improve recovery along with optimal rehabilitation and early resumption of day-to-day activity following major surgery. Conventional general anaesthesia consists of premedication, induction, intubation and maintenance.

AIM

The aim of the study is to compare the multimodal versus conventional approach in oral cancer surgery.

MATERIALS AND METHODS

The patients were randomly allocated into three groups, 30 patients in each group using the computer generated random table to one of the following groups: Group A: Fentanyl 1 μg/kg, Group B: Fentanyl 1 μg/kg + bupivacaine local infiltration, Group C: Fentanyl 1 μg/kg + bupivacaine local infiltration + Dexemedetomidine infusion (Loading 0.5 μg/kg, Maintenance 0.2μg/kg/hr).

RESULTS

No significant (p>0.05) difference was found in mean arterial pressure and heart rate at different time intervals among the groups. The VAS was lower in Group C than Group B and A. The ramsay sedation scale was higher in Group C than Group B and A. The rescue analgesic for 24 hour was lower in Group C than Group B and A. The time of first time analgesia requirement was significantly (p=0.001) higher in Group C than Group B and A. The rescue analgesic was significantly (p=0.001) lower in Group C (39.29±19.67) than Group B (68.33±18.49) and A (160.83±35.16).

CONCLUSION

Multimodal analgesia has beneficial haemodynamic effects during oral cancer surgery with reliable postoperative analgesia and sedation and less postoperative complication. Dose of drugs used in our study is not associated with any major adverse effect.

A randomised comparative study of the effect of Airtraq optical laryngoscope vs. Macintosh laryngoscope on intraocular pressure in non-ophthalmic surgery

BACKGROUND

We compared intraocular pressure changes following laryngoscopy and intubation with conventional Macintosh blade and Airtraq optical laryngoscope.

METHODS

Ninety adult patients were randomly assigned to study group or control group. Study group (n=45) - Airtraq laryngoscope was used for laryngoscopy. Control group (n=45) - conventional Macintosh laryngoscope was used for laryngoscopy. Preoperative baseline intraocular pressure was measured with Schiotz tonometer. Laryngoscopy was done as per group protocol. Intraocular pressure and haemodynamic parameters were recorded just before insertion of the device and subsequently three times at an interval of one minute after insertion of the device.

RESULTS

Patient characteristics, baseline haemodynamic parameters and baseline intraocular pressure were comparable in the two groups. Following insertion of the endotracheal tube with Macintosh laryngoscope, there was statistically significant rise in heart rate and intraocular pressure compared to Airtraq group. There was no significant change in MAP. Eight patients in Macintosh group had tongue-lip-dental trauma during intubation, while only 2 patients received upper airway trauma in Airtraq group.

CONCLUSION

We conclude that Airtraq laryngoscope in comparison to Macintosh laryngoscope results in significantly fewer rises in intraocular pressure and clinically less marked increase in haemodynamic response to laryngoscopy and intubation.

Dexmedetomidine as an adjuvant to levobupivacaine in supraclavicular brachial plexus block: A novel anesthetic approach

Aims and Objectives:

Supplementation of dexmedetomidine produces a dose-dependent sedation, anxiolysis and analgesia without respiratory depression. This study was conducted to evaluate the possible effect of dexmedetomidine as an adjuvant to levobupivacaine for supraclavicular brachial plexus block in upper limb surgery.

Settings and Design:

Tertiary care institute, Department of Anaesthesiology and Intensive Care, a placebo-controlled study.

Materials and Methods:

After obtaining Ethical Committee approval, a randomized, double-blind, placebo-controlled study was conducted on sixty American Society of Anesthesiologists physical status I and II patients in the age group of 18–60 years, divided randomly into two groups, Group I received 30 ml of 0.5% levobupivacaine with 1 ml of isotonic sodium chloride solution and Group II received 30 ml of 0.5% levobupivacaine and 1 ml (100 mcg) of dexmedetomidine for supraclavicular brachial plexus block. The onset and duration of sensory and motor blockade, duration of analgesia (DOA) and any adverse effects were noted. At the end of the study, data were compiled and analyzed using appropriate statistical tests. The value of P < 0.05 was considered significant.

Results:

Demographic profile was comparable in both the groups. The time to onset of sensory and motor block was 10.54 ± 2.333 min and 12.21 ± 2.529 min in Group I while it was 3.24 ± 0.951 min and 2.83 ± 1.197 min in Group II, respectively. The duration of sensory and motor block was 7.79 ± 2.007 h and 9.18 ± 1.701 h in Group I, and it was 16.31 ± 2.606 h and 17.52 ± 2.098 h in Group II, respectively. The DOA was 678.68 ± 20.492 min in Group I and 1273.79 ± 83.139 min in Group II. On statistical comparison, these values were highly significant (P < 0.001). Side effects such as nausea, vomiting, hypoxemia, pruritis, or urinary retention were not observed in either of the groups.

Conclusion:

Dexmedetomidine shortens the onset time for sensory and motor block significantly and prolongs DOA as well when used with levobupivacaine for supraclavicular brachial plexus block, without increasing the incidence of any adverse effects.

Efficacy of dexmedetomidine and fentanyl on pressor response and pneumoperitoneum in laparoscopic cholecystectomy

Background:

The advent of laparoscopic surgeries has proved to be beneficial for both patient and surgeon although increased morbidity may result from hemodynamic changes associated with laryngoscopy, intubation, and pneumoperitoneum (PNP).

Aim:

The present study was prospective, randomized, double-blind conducted to evaluate the efficacy of dexmdetomidine and fentanyl in attenuation of pressor responses to laryngoscopy, intubation, and PNP in laparoscopic cholecystectomy (LC).

Materials and Methods:

A total of 60 patients of 18–65 years, American Society of Anaesthesiologists Class I/II of either sex for elective LC, were included. The patients were divided into two groups of 30 patients each. Group I received dexmedetomidine and Group II Fentanyl loading 1 μg/kg over 15 min followed by maintenance 0.2 μg/kg/h throughout the PNP.

Measurements:

Heart rate (HR), systolic blood pressure, diastolic blood pressure, and mean arterial blood pressure (MAP) were recorded preoperatively, 15 min after infusion of study drug, 1 min after induction, 1 min after intubation, throughout the PNP, end of surgery, and until 60 min in postoperative period. Sedation score, visual analog scale score along with modified Alderete score applied in postanesthesia care unit.

Results:

Control of HR and MAP in Group I was better than in Group II during laryngoscopy, intubation and PNP. There was also smooth extubation, less sedation and better control of pain in Group I than in Group II.

Conclusion:

The present study demonstrates the benefits of dexmedetomidine over fentanyl in hemodynamic stability and analgesic quality in LC. Thus, it is establishing its utility over for attenuation of pressor response.

Comparative Evaluation of Bolus Administration of Dexmedetomidine and Fentanyl for Stress Attenuation During Laryngoscopy and Endotracheal Intubation

BACKGROUND

Laryngoscopy and endotracheal intubation can cause hypertension and tachycardia which can result in myocardial ischemia or stroke in vulnerable people. The objective of our study was to compare the efficacy of bolus dose of dexmedetomidine and fentanyl in attenuating haemodynamic stress responses following laryngoscopy and intubation.

MATERIALS AND METHODS

Sixty patients who were fixed to undergo elective surgeries under general anaesthesia were randomly divided into 2 groups. Group 1 received 1 mcg/kg of dexmedetomidine over 10 minutes and group 2 received fentanyl 2mcg/kg before induction. Anaesthesia was standardized in both the groups and vital parameters were recorded for up to 10 minutes after intubation.

RESULTS

Dexmedetomidine in a dose of 1mcg/kg prevented an increase in heart rate following laryngoscopy when compared to fentanyl group. This effect lasted for 10 minutes after intubation is performed. Though dexmedetomidine prevented an increase in blood pressure, this effect was statistically significant only for 2 minutes after intubation when compared to fentanyl group.

CONCLUSION

Attenuation of rise in heart rate and blood pressure following laryngoscopy and endotracheal intubation was better with 1mcg/kg of dexmedetomidine when compared to fentanyl.

Endocrinopathies: The current and changing perspectives in anesthesia practice

The gateways to advancements in medical fields have always been accessed through the coalition between various specialties. It is almost impossible for any specialty to make rapid strides of its own. However, the understanding of deeper perspectives of each specialty or super specialty is essential to take initiatives for the progress of the other specialty. Endocrinology and anesthesiology are two such examples which have made rapid progress in the last three decades. Somehow the interaction and relationship among these medical streams have been only scarcely studied. Diabetes and thyroid pathophysiologies have been the most researched endocrine disorders so far in anesthesia practice but even their management strategies have undergone significant metamorphosis over the last three decades. As such, anesthesia practice has been influenced vastly by these advancements in endocrinology. However, a comprehensive understanding of the relationship between these two partially related specialties is considered to be an essential cornerstone for further progress in anesthesia and surgical sciences. The current review is an attempt to imbibe the current and the changing perspectives so as to make the understanding of the relationship between these two medical streams a little simple and clearer.

Comparative evaluation of esmolol and dexmedetomidine for attenuation of sympathomimetic response to laryngoscopy and intubation in neurosurgical patients

Background and Aims:

The present study compared the efficacy of esmolol and dexmedetomidine for attenuation of the sympathomimetic response to laryngoscopy and intubation in elective neurosurgical patients.

Material and Methods:

A total of 90 patients aged 20-60 years, American Society of Anesthesiologists physical status I or II, either sex, scheduled for elective neurosurgical procedures were included in this study. Patients were randomly allocated to three equal groups of 30 each comprising of Control group (group C) 20 ml 0.9% saline intravenous (IV), group dexmedetomidine (group D) 1 μg/kg diluted with 0.9% saline to 20 ml IV and group esmolol (group E) 1.5 mg/kg diluted with 0.9% saline to 20 ml IV. All the drugs were infused over a period of 10 min and after 2 min induction of anesthesia done. Heart rate (HR), systolic blood pressure, diastolic blood pressure, and mean arterial pressure were recorded baseline, after study drug administration, after induction and 1, 2, 3, 5, 10, and 15 min after orotracheal intubation.

Results:

In group D, there was no statistically significant increase in HR and blood pressure after intubation at any time intervals, whereas in group E, there was a statistical significant increase in blood pressure after intubation at 1, 2, and 3 min only and HR up to 5 min.

Conclusion:

Dexmedetomidine 1 μg/kg is more effective than esmolol for attenuating the hemodynamic response to laryngoscopy and intubation in elective neurosurgical patients.

Anaesthetic challenges and management during pregnancy: Strategies revisited

During pregnancy, an obstetrician can encounter various complications and sometimes require surgery or operative intervention for delivery. However, the role of anaesthesiologists during such clinical scenario is grossly under-estimated. Without any close coordination and team work among obstetricians, neonatologists and an anaesthesiologist, morbidity and mortality can increase during these surgical interventions. The clinical scenario can become more challenging if the parturient suffers from any comorbid diseases. The present article reviews some of the common challenging scenarios during pregnancy that an anaesthesiologist frequently encounters during routine practice. Anaesthetic management has been discussed briefly and separately for each trimester and post-partum period. The article also aims at gaining in-depth knowledge of these obstetrical and surgical emergencies so as to ensure close-knit team work among obstetricians, anaesthesiologists, intensivists and a neonatologist.

Pregnancy with co-morbidities: Anesthetic aspects during operative intervention

The presence of co-morbidities during pregnancy can pose numerous challenges to the attending anesthesiologists during operative deliveries or during the provision of labor analgesia services. The presence of cardiac diseases, endocrinological disorders, respiratory diseases, renal pathologies, hepatic dysfunction, anemia, neurological and musculoskeletal disorders, connective tissue diseases and many others not only influence the obstetric outcome, but can significantly impact the anesthetic technique. The choice of anesthesia during the pregnancy depends upon the type of surgery, the period of gestation, the site of surgery, general condition of patient and so on. Whatever, the anesthetic technique is chosen the methodology should be based on evidentially supported literature and the clinical judgment of the attending anesthesiologist. The list of co-morbid diseases is unending. However, the present review describes the common co-morbidities encountered during pregnancy and their anesthetic management during operative deliveries.

Clinical conundrums and challenges during geriatric orthopedic emergency surgeries

Despite so many advancements and innovations in anesthetic techniques, expectations and challenges have also grown in plenty. Cardiac, pediatric, obstetric and neuro-anesthesia have perfectly developed to fulfill the desired needs of respective patient population. However, geriatric anesthesia has been shown a lesser interest in teaching and clinical practices over the years as compared with other anesthetic sub-specialties. The large growing geriatric population globally is also associated with an increase number of elderly patients presenting for orthopedic emergency surgeries. Orthopedic emergency surgery in geriatric population is not only a daunting clinical challenge but also has numerous socio-behavioral and economic ramifications. Decision making in anesthesia is largely influenced by the presence of co-morbidities, neuro-cognitive functions and the current socio-behavioral status. Pre-anesthetic evaluation and optimization are extremely important for a better surgical outcome but is limited by time constraints during emergency surgery. The current review aims to highlight comprehensively the various clinical, social, behavioral and psychological aspects during pre-anesthetic evaluation associated with emergency orthopedic surgery in geriatric population.

Comparison of two different doses of dexmedetomidine in attenuating cardiovascular responses during laryngoscopy and endotracheal intubation: A double blind, randomized, clinical trial study

Introduction. Secure airway for proper ventilation during anesthesia is one important component of a successful surgery. Endotracheal intubation is one of the most important methods in this context. Intubation method and used medication are considerably important in attenuating complications. This research aimed to investigate the impact of two different doses of dexmedetomidine in mitigating cardiovascular responses to endotracheal intubation in candidate cases supporting voluntary operation. Methods. The current research contained 90 cases in the range of 18 and 50 old, with ASA I,II supporting voluntary operation, who were randomly classified into three teams, each group consisting of 30 cases. The first set (A) got 0.5 μg/ kg dexmedetomidine, the second set (B) got 1 μg/ kg dexmedetomidine and the third set (C) got an equal volume of saline as placebo, 600 seconds earlier the initiation of anesthesia. Hemodynamic parameters were recorded at baseline (T0), then after the injection and the earlier initiation of anesthesia (T1), after the induction of anesthesia and before the endotracheal intubation (T2), promptly after tracheal intubation, 180, and 300 after endotracheal intubation (T4, T5). Data was analyzed and p < 0.05 was supposed notable. Findings. In this research, 3 teams were similar regarding weight, age, height, sex and duration of laryngoscopy. The diastolic mean arterial pressure, heart rate, and systolic arterial pressure were significantly lower in dexmedetomidine teams (A,B) at all times after the endotracheal intubation compared to group C. There were no significant differences in hemodynamic factors among group A, B. Conclusion. Dexmedetomidine effectively and significantly attenuates cardiovascular and hemodynamic responses during endotracheal intubation. In addition, different doses of dexmedetomidine did not cause any significant distinct result in mitigating cardiovascular responses.

Comparison of dexmedetomidine, propofol and midazolam for short-term sedation in postoperatively mechanically ventilated neurosurgical patients

BACKGROUND

Effective management of analgesia and sedation in the intensive care unit depends on the needs of the patient, subjective and/or objective measurement and drug titration to achieve specific endpoints.

AIM

The present study compared the efficacy of dexmedetomidine, propofol and midazolam for sedation in neurosurgical patients for postoperative mechanical ventilation.

MATERIALS AND METHODS

Ninety patients aged 20-65 years, ASA physical status I to III, undergoing neurosurgery and requiring postoperative ventilation were included. The patients were randomly divided into three groups of 30 each. Group D received dexmedetomidine 1 mcg/kg over 15 minutes as a loading dose, followed by 0.4-0.7 mcg/kg/h. Group P received propofol 1 mg/kg over 15 minutes as a loading dose, followed by 1-3 mg/kg/h. Group M received midazolam 0.04 mg/kg over 15 minutes as a loading dose, followed by 0.08 mg/kg/h.

MEASUREMENTS

Heart rate, mean arterial pressure, sedation level, fentanyl requirement, ventilation and extubation time were recorded.

RESULTS

Adequate sedation level was achieved with all three agents. Dexmedetomidine group required less fentanyl for postoperative analgesia. In group D there was a decrease in HR after dexmedetomidine infusion (p<0.05), but there was no significant difference in HR between group P and group M. After administration of study drug there was a significant decrease in MAP comparison to baseline value in all groups at all time intervals (p<0.05), except postextubation period (p>0.05). Extubation time was lowest in group P (p<0.05).

CONCLUSION

Dexmedetomidine is safer and equally effective agent compared to propofol and midazolam for sedation of neurosurgical mechanically ventilated patients with good hemodynamic stability and extubation time as rapid as propofol. Dexmedetomidine also reduced postoperative fentanyl requirements.

A comparative evaluation of epidural and general anaesthetic technique for renal surgeries: A randomised prospective study

Background and Aims:

Neuraxial anaesthesia has become popular for the renal surgeries during the last few years. This study was aimed at comparing general anaesthesia (GA) with epidural anaesthesia in patients undergoing renal surgeries.

Methods:

One hundred American Society of Anaesthesiologists (ASA) physical status-I and II adult consenting patients of both gender in the age group of 25-55 years undergoing renal surgeries were randomly assigned to two groups of 50 patients each: Group G and Group E. Group G patients were administered conventional GA while Group E received epidural anaesthesia (EA) with 3 mg/kg of ropivacaine and 1 μg/kg of dexmedetomidine. Besides cardio-respiratory parameters, surgeon's satisfaction, patient's satisfaction and side effects were observed. Parametric data were analysed by ANOVA while non-parametric data were compared with Mann–Whitney U-test and Wilcoxon test. Value of P < 0.05 was considered statistically significant.

Results:

The demographic profile, total anaesthesia time, surgical time and haemodynamic parameters and surgeon's satisfaction scores were comparable in both groups. Patient's satisfaction scores were better in Group E during the post-operative period. Incidence of side-effects such as nausea and vomiting and shivering were higher in Group G (P < 0.001) while the incidence of dry mouth was higher in Group E (P < 0.001).

Conclusion:

Epidural anaesthesia with ropivacaine and dexmedetomidine can be safely and effectively used in patients undergoing renal surgeries.