Dexmedetomidine: New avenues

Electroencephalogram monitoring during anesthesia and critical care: a guide for the clinician

Perioperative anesthetic, surgical and critical careinterventions can affect brain physiology and overall brain health. The clinical utility of electroencephalogram (EEG) monitoring in anesthesia and intensive care settings is multifaceted, offering critical insights into the level of consciousness and depth of anesthesia, facilitating the titration of anesthetic doses, and enabling the detection of ischemic events and epileptic activity. Additionally, EEG monitoring can aid in predicting perioperative neurocognitive disorders, assessing the impact of systemic insults on cerebral function, and informing neuroprognostication. This review provides a comprehensive overview of the fundamental principles of electroencephalography, including the foundations of processed and quantitative electroencephalography. It further explores the characteristic EEG signatures associated wtih anesthetic drugs, the interpretation of the EEG data during anesthesia, and the broader clinical benefits and applications of EEG monitoring in both anesthetic practice and intensive care environments.

Effects of Intranasal and Intravenous Dexmedetomidine on Hemodynamic Responses to Tracheal Intubation and Skull Pin Holder Fixation: A Double-Blinded, Randomized Controlled Trial

Background Laryngoscopy and tracheal intubation (L&I) and the fixation of skull-pin head-holders are associated with various sympathetic stimuli leading to hemodynamic changes. These changes may lead to myocardial ischemia, brain edema, an increase in intracranial pressure, or intracranial hemorrhage. Many drugs have been used in different combinations to attenuate the sympathetic responses to L&I and skull-pin insertion. The aim of this study was to compare the efficacy of intranasal (IN) dexmedetomidine with intravenous (IV) dexmedetomidine (IV) in attenuating the hemodynamic responses to L&I and the fixation of skull-pin holders in patients undergoing craniotomy. Material and methods This randomized-controlled, double-blind study was conducted on 120 patients with American Society of Anesthesiology (ASA) physical status I and II, aged 18 to 70 years, undergoing elective craniotomy and requiring skull-pin insertion. Patients were randomly divided into two equal groups. Group DIV: IV dexmedetomidine 0.50 µg/kg given over 40 minutes before induction. Group DIN: Undiluted dexmedetomidine 1µg/kg given as IN drops 40 minutes before induction. Heart rate (HR), mean arterial pressure (MAP), systolic (SBP), and diastolic blood pressure (DBP) were noted at baseline and at predetermined intervals after L&I and skull-pin fixation. Sedation scores were assessed preoperatively at baseline and at 10, 20, 30, and 40 minutes after study drug administration. Data were analyzed using IBM SPSS Statistics for Windows, version 25.0. Results Both IN and IV dexmedetomidine successfully attenuated the stress responses to L&I and skull-pin fixation without significant hypertension or tachycardia. All hemodynamic parameters (MAP, SBP, DBP, HR) were maintained within normal limits (±20% of baseline) before and during L&I and after skull-pin fixation in both groups. However, the preoperative Ramsay sedation scale score was significantly higher in the IV than in the IN group at 10, 20, and 30 minutes of drug administration (p<0.05). The incidence of hypoxia and bradycardia was also higher in the IV than in the IN group. Nausea, vomiting, or respiratory depression were not observed in any patient. Conclusion Both IN and IV dexmedetomidine are effective in blunting the hemodynamic responses to L&I and skull-pin fixation. However, IN dexmedetomidine is a better alternative to IV dexmedetomidine as it causes less sedation and fewer side effects.

Comparative efficacy of intravenous treatments for perioperative shivering in patients undergoing caesarean delivery under neuraxial anaesthesia: A systematic review and Bayesian network meta-analysis of randomised-controlled trials

INTRODUCTION

Shivering affects 52 % of patients undergoing caesarean delivery under neuraxial anaesthesia. Despite extensive research focused on its prevention, there is still no consensus regarding optimal pharmacological treatment. This systematic review and network meta-analysis aims to compare available intravenous treatments of perioperative shivering in patients undergoing caesarean delivery under neuraxial anaesthesia.

METHODS

We searched seven databases (PubMed MEDLINE, Scopus, Web of Science, Embase, LILACS, Cochrane CRCT and clinicaltrials.gov) for randomised controlled trials comparing intravenous treatments of perioperative shivering during caesarean delivery and performed a Bayesian model network meta-analysis. We assessed study quality using the Cochrane risk of bias assessment tool. The primary outcome evaluated in this meta-analysis was shivering control (cessation or significant reduction in intensity), and secondary outcomes included time to shivering control, shivering recurrence, and incidence of maternal nausea.

RESULTS

Twenty randomised controlled trials, with a total of 1983 patients, were included in this analysis. Network estimates of odds ratios (OR [95 % Credible Interval]) of effective treatment of shivering compared with saline were: dexmedetomidine (38.1 [14.2 to 111.5]), tramadol (33.6 [15.1 to 81.8]), nalbuphine (26.2 [10.8 to 80.2]), meperidine (20.9 [6.2 to 73.1]), ondansetron (6.6 [2.2 to 23.2]), and clonidine (3.2 [0.6 to 14.9]). The rank order of interventions by surface area under the cumulative ranking curve scores (in parenthesis) for shivering control was dexmedetomidine (0.87) > tramadol (0.85) > nalbuphine (0.74) > meperidine (0.66) > ondansetron (0.41) > clonidine (0.3) > amitriptyline (0.03). Dexmedetomidine was also the top-ranked intervention for time to shivering control, shivering recurrence and maternal nausea. We judged the certainty in the evidence to be moderate for dexmedetomidine and nalbuphine, and low for all other interventions.

CONCLUSION

This network meta-analysis identified four effective intravenous treatments for shivering in patients undergoing caesarean delivery under neuraxial anaesthesia: dexmedetomidine, tramadol, nalbuphine and meperidine. Dexmedetomidine was the top-ranked intervention for all outcomes.

Comparing the efficacy of adrenaline, clonidine, and dexmedetomidine in enhancing local anesthesia for impacted third molar extraction: a randomized controlled trial

Background

In human dentition, the most commonly impacted teeth are the mandibular third molars (M3M). The removal or extraction of these teeth often causes anxiety in patients due to the perceived pain involved in the process. Therefore, pain must be effectively managed using anesthesia. The use of newer local anesthetic drugs can help minimize side effects and drug interactions. Traditionally, adrenaline is used as a vasoconstrictor along with lignocaine. When combined with lignocaine, the alpha agonists dexmedetomidine and clonidine can extend the duration of anesthesia, thereby reducing the need for additional pain-relieving medications.

Methods

This study used a randomized, triple-blind, parallel-arm design. Sixty patients were screened, and 45 systemically healthy patients requiring unilateral surgical removal of impacted mandibular third molars with similar difficulty (moderate-to-difficult according to the Modified Pederson's Index) were included in the study. Patients were allocated into three groups as follows: Group A: 2% Lignocaine Hydrochloride with 1:100,000 Adrenaline, Group C: 2% Lignocaine Hydrochloride with 15 µg/mL Clonidine, and Group D: 2% Lignocaine Hydrochloride with 1 µg/mL Dexmedetomidine. The evaluated parameters were the time of onset of anesthesia, depth of anesthesia, hemodynamic parameters, and duration of postoperative analgesia.

Results

Group D had a faster onset of action and prolonged duration of postoperative analgesia compared with Groups A and C. No statistically significant differences were observed between the three groups in terms of the depth of anesthesia and hemodynamic parameters.

Conclusion

Group D exhibited a significantly more rapid onset of anesthesia than Groups A and C, and the postoperative analgesic effect in Group D was significantly prolonged (7.22 hours) compared with that in Groups A (4.54 hours) and C (2.1 hours). Patients receiving the Group D solution experienced an extended period of comfort without the need for analgesics for up to 7.22 hours post-procedure.

Effect of different doses of dexmedetomidine as an adjuvant to lignocaine nebulization: A comparative study during awake flexible fiberoptic bronchoscopy

Background and Aims

Mild to moderate sedation during bronchoscopy is essential for patient safety, comfort during and after the procedure, and to facilitate the performance of the bronchoscopist. Dexmedetomidine is a highly selective, centrally acting α-2 agonist used to provide conscious sedation during various procedures. The aim of this study was to compare the efficacy of three different doses of dexmedetomidine nebulization as an adjuvant to lignocaine during bronchoscopy.

Material and Methods

Ninety American Society of Anesthesiologists physical status I/II patients, aged from 18 to 60 years, scheduled for an elective bronchoscopy, were recruited. They were divided into three groups: 30 patients in each group. Group I: The patient was nebulized with a mixture of 4 ml of 4% lignocaine and dexmedetomidine 0.5 μg/kg. Group II: The patient was nebulized with a mixture of 4% lignocaine, 4 ml, and dexmedetomidine, 1 μg/kg. Group III: The patient was nebulized with 4% lignocaine 4 ml and dexmedetomidine 1.5 μg/kg.

Results

The mean cough score was (1.17 ± 0.37), (1.40 ± 0.49), and (1.70 ± 0.75) in group III, group II, and group I, respectively. A significant difference was found between the groups. Patients were more comfortable with a statistically significant difference in the comfort score in group III as compared to group II and group I.

Conclusion

Dexmedetomidine nebulization in a dose of 1.5 μg/kg (compared to 1 μg/kg or 0.5 μg/kg) as an adjuvant to lignocaine, provides better bronchoscopy conditions and patient satisfaction.

Efficacy of IM dexmedetomidine in alleviating catheter related bladder discomfort and postoperative inflammatory response following percutaneous nephrolithotomy. A prospective randomized controlled study

Background and Aims

Catheter-related bladder discomfort (CRBD) causes significant distress to the patient and requires great attention to analgesia and increases morbidity in the postoperative period. This study evaluated the efficacy of intramuscular dexmedetomidine in alleviating CRBD following percutaneous nephrolithotomy (PCNL) and postoperative inflammatory response.

Material and Methods

A prospective randomized double-blind study was conducted in a tertiary care hospital from December 2019- March 2020. Sixty seven of ASA I and II patients scheduled for elective PCNL were randomized and group I received 1 μg/kg dexmedetomidine intramuscularly and group II normal saline as control 30 minutes before induction of anesthesia. Standard anesthesia protocol was followed and patients were catheterized with 16 Fr Foleys after induction of anesthesia. Rescue analgesia was paracetamol if the score was moderate. Postoperatively CRBD score and inflammatory markers; total white cell count, erythrocyte sedimentation rate and temperature were noted for 3 days.

Results

There was a significant low CRBD score in group I. Ramsay sedation score was 2 in group I with p 0.00 and rescue analgesia required was very low with p 0.00. Statistical Package for social Sciences software version 20 was used for analysis. Student ttest, analysis of variance, and Chisquare test were applied for quantitative and qualitative analysis respectively.

Conclusion

Single dose intramuscular dexmedetomidine is effective, simple and safe in preventing the CRBD and the inflammatory response remained uninfluenced except ESR, the reason remains largely unknown.

Comparison of single-shot nebuliser protocol between dexmedetomidine and ketamine in children undergoing magnetic resonance imaging

BACKGROUND

Sedation for magnetic resonance imaging mandates deep sedation to ensure patient immobility. The nebulised route of drug delivery carries the advantage of good bioavailability and safety profile. We aimed to compare the efficacy and safety of nebulised dexmedetomidine and ketamine for sedation in children undergoing magnetic resonance imaging.

METHODS

A total of 71 children, aged two to eight years scheduled for outpatient magnetic resonance imaging were randomly allocated to receive nebulised dexmedetomidine 2 μg/kg (group D) or nebulised ketamine 2 mg/kg (group K) 30min before magnetic resonance imaging.

RESULTS

Nebulised dexmedetomidine (2 μg/kg) resulted in faster onset and significantly better sedation scores with rapid clear-headed recovery. Ketamine resulted in better venepuncture scores but was associated with more neuropsychological events at recovery.

CONCLUSION

Nebulised dexmedetomidine at 2 μg/kg provides rapid onset of satisfactory sedation, with good parental separation and a quicker and more clear-headed recovery, allowing for a smooth magnetic resonance imaging experience.

Dexmedetomidine in Prevention of Postoperative Delirium: A Systematic Review

Delirium is defined by the DSM-5 as a fluctuating course of disturbance in attention, cognition, and awareness that develops over a short period without any pre-existing neurocognitive disorder. As people age, there is an increased risk of complications that may occur following a surgical procedure and one such acute complication is delirium. Studies are emerging to reduce the incidence of postoperative delirium, and one such preventive measures implemented in recent years include the administration of dexmedetomidine, a high selectivity α-2 adrenoceptor agonist. This study aims to review the efficacy of Dexmedetomidine in the prevention of postoperative delirium in randomized controlled trials in patients older than 18 years of age. The literature was explored in three online databases, namely, PubMed, Science Direct, and Scopus. Appropriate keywords and MesH terms were employed to scrutinize relevant articles that demonstrated the effects of dexmedetomidine in the prevention of postoperative delirium. The data was restricted to randomized controlled trials and clinical trials published from 2017 to 2021 in human patients older than >18 years of age undergoing non-cardiac-related procedures. The randomized clinical trials were critically assessed with the Cochrane risk of bias tool. We proceeded to screen 428 records with the assessment of the PRISMA chart and filtered out 420 papers to obtain a total of eight studies where we identified data such as sample size, types of surgeries in which the patients were involved, the delirium assessment tool, the plan of the administration of dexmedetomidine and the outcomes evaluated in each study. The Confusion Assessment Method (CAM) was the prevailing assessment tool used with the sole purpose to evaluate the incidence of postoperative delirium as the primary outcome, and assessment of inflammatory cytokines, sleep quality, and pain scales were considered as secondary outcomes. The dosage of dexmedetomidine varied among studies, and it displayed varying impacts on postoperative delirium and the secondary outcomes as well. Limitations include varying ages and ethnicities of the population. It was concluded that dexmedetomidine prevents the development of postoperative delirium in elderly patients undergoing non-cardiac surgical interventions by modulating important predisposing factors such as neuroinflammation, pain, and sleep quality. No funding was made for this study.

Role of nebulised dexmedetomidine, midazolam or ketamine as premedication in preschool children undergoing general anaesthesia-A prospective, double-blind, randomised study

Background and Aims

Preschool age children are psycho-biologically vulnerable to all surgical procedures. In this study, we investigated the effect of nebulised dexmedetomidine, midazolam and ketamine as sedative premedication for alleviating parental separation anxiety, facilitating face mask acceptance and reducing emergence agitation in paediatric patients undergoing general anaesthesia.

Methods

A prospective, randomised, double-blind study was done involving 96 children of age 3-7 years, randomly allocated into three equal groups and pre-medicated with either nebulised dexmedetomidine 2 mg/kg (GroupD), midazolam 0.2 mg/kg (GroupM) or ketamine 2 mg/kg (Group K). The scores of sedation scale, parental separation anxiety scale, mask acceptance scale and emergence agitation scale were recorded along with haemodynamic parameters. Two-way repeated measures analysis of variance (ANOVA), post hoc test and Kruskal-Wallis test were used for statistical analysis.

Results

A statistically significant difference in sedation score was seen between the different study groups, χ²(2) = 8.561, P = 0.014 with mean rank sedation score of 56.50 for Group D, 38.92 for Group M and 43.84 for Group K. Parental separation anxiety scale score and Mask acceptance scale score also showed statistically significant difference between the different study groups, χ²(2) = 9.369, P = 0.009 and χ²(2) = 11.97, P = 0.003, respectively.

Conclusion

Nebulisation with dexmedetomidine produced easy parental separation, more satisfactory sedation and face mask acceptance with less postoperative agitation than nebulisation with midazolam or ketamine.

Evaluation of Nebulised Dexmedetomidine Given Pre-operatively to Attenuate Hemodynamic Response to Laryngoscopy and Endotracheal Intubation: A Randomised Control Trial

Background and aim

A variety of medications have been studied to reduce the hemodynamic response to laryngoscopy and intubation. Dexmedetomidine has been used intravenously in many studies to reduce the hemodynamic response to laryngoscopy and intubation. In high-risk patients, this pressor response can increase morbidity and mortality. As dexmedetomidine has a good bioavailability via the nebulisation route, we formulated this study to evaluate the effect of nebulised dexmedetomidine on the hemodynamic response to laryngoscopy and endotracheal intubation.

Methods

This is a prospective, randomised controlled trial conducted on 100 patients with the American Society of Anesthesiologists grade I and II. The primary objective of the study was to see if nebulised dexmedetomidine at a dose of 1 microgram/kg could reduce the stress reaction to laryngoscopy and intubation. The secondary objective was to study the dose sparing effect of nebulised dexmedetomidine on the amount of propofol used during induction of general anaesthesia. The study population was randomly divided into two groups: group A (n = 50) included patients nebulised with dexmedetomidine 1 microgram/kg and group B (n = 50) included patients nebulised with 5 ml saline 30 minutes before induction of anaesthesia in a sitting position.

Results

The demographics were similar in both groups. Following laryngoscopy and intubation, the systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate showed a significant increase in the control group B as compared to the treatment group A. In group A, there was attenuation in SBP (one minute = 113.2 ± 14.503, P < 0.001; five minutes = 109.86 ± 8.342, P < 0.001; 10 minutes = 114.24 ± 7.797, P = 0.010), DBP (one minute = 73.72 ± 10.986, P = 0.011; five minutes = 71.62 ± 9.934, P = 0.005; 10 minutes = 76.1 ± 8.006, P = 0.009), MAP (one minute = 86.80 ± 11.86, P = 0.001; five minutes = 84.44 ± 8.97, P = 0.006; 10 minutes = 88.72 ± 7.44, P = 0.018), and heart rate (one minute = 83.34 ± 12.325, P = 0.001; five minutes = 81.56 ± 13.33, P = 0.003; 10 minutes = 80.16 ± 14.086, P = 0.013) following laryngoscopy and intubation. Induction dose of propofol was significantly lower in the dexmedetomidine group (73 ± 19.509, P < 0.001).

Conclusion

Nebulised dexmedetomidine effectively blunts the hemodynamic response to laryngoscopy and intubation and also has a dose sparing effect on the induction dose of propofol.

A Multimodal Analgesic Protocol with Gabapentin-dexmedetomidine for Post-operative Pain Management after Modified Radical Mastectomy Surgery: A Randomized Placebo-Controlled Study

Background and Aim: Modified radical mastectomy (MRM) is accompanied by severe acute postoperative pain. This study evaluated the safety and efficacy of oral gabapentin plus dexmedetomidine infusion as an analgesic multimodal protocol in patients undergoing MRM. Methods: This prospective randomized, double-blind placebo-controlled study included 30 females scheduled for MRM from June 2021 to December 2021. They were randomly divided into two groups. GD Group (n=15) received oral gabapentin 400 mg and IV infusion of Dexmedetomidine 0.4 µg/kg/h over 10 min after a bolus of 0.5 µg/kg before induction of general anesthesia. Placebo Group (n=15) received a placebo capsule and saline infusion identical to the GD Group. The primary outcome measure was total morphine consumption, and secondary outcomes were pain and sedation scores and intraoperative fentanyl consumption. Results: Pain score was significantly lower in the GD Group than the Placebo group, starting immediately postoperative up to 24 hours except after 18 hours. The total intraoperative fentanyl consumption and postoperative morphine consumption were significantly lower in the GD Group. The sedation score was significantly higher in the GD Group compared to the Placebo group immediately postoperative and after 2 hours. The heart rate and mean arterial pressure were within the clinically accepted ranges intra- and postoperatively in the two groups. Conclusion: Preemptive oral gabapentin plus dexmedetomidine IV infusion is a safe and effective analgesic alternative for patients undergoing MRM.

Effect of intratracheal dexmedetomidine combined with ropivacaine on postoperative sore throat: a prospective randomised double-blinded controlled trial

Background

The present study aimed to investigate whether intratracheal dexmedetomidine combined with ropivacaine reduces the severity and incidence of postoperative sore throat after tracheal intubation under general anaesthesia.

Methods

Two hundred patients with American Society of Anaesthesiologists physical status I-II who were subjected to general anaesthesia were randomly divided into four groups, namely, Group D, Group R, Group DR and Group S; these groups received intratracheal dexmedetomidine (1 µg/kg), 0.8% ropivacaine (40 mg), dexmedetomidine (1 µg/kg) combined with 0.8% ropivacaine (40 mg) and normal saline before endotracheal intubation, respectively. The primary outcomes were the incidence and grade of sore throat and hoarseness at 2 h and 24 h after surgery. Moreover, the modified Observer's Assessment of Alertness/Sedation Scale results were recorded at each time point. The secondary outcomes were intraoperative haemodynamic fluctuations, intraoperative anaesthetic drug requirements, and adverse reactions during and after surgery. The patients’ vital signs before induction, before superficial anaesthesia, after superficial anaesthesia, before intubation, after intubation, and 1 min after intubation were recorded. The use of anaesthetic drugs and occurrence of adverse effects were also recorded.

Results

The incidence and severity of sore throat were significantly lower in Group DR than in the other three groups 2 h after the operation, but they were only significantly lower in Group DR than in the control group 24 h after the operation. Moreover, compared with Group S and Group D, Group DR exhibited more stable haemodynamics during intubation. The doses of remifentanil and propofol were significantly lower in Group DR than in the other groups.

Conclusion

The combined use of dexmedetomidine and ropivacaine for surface anaesthesia before intubation significantly reduced the incidence and severity of postoperative sore throat. This treatment also decreased anaesthetic drug requirements and intraoperative haemodynamic fluctuations and caused no adverse effects.

Trial registration

This clinical research was registered at the Chinese Clinical Trial Registry (ChiCTR1900022907, Registration date 30/04/2019).

Different modalities of analgesia in open heart surgeries in Mansoura University

Background: Opioid usage in cardiac surgery is considered to be the corner stone in management. Inadequate pain control after cardiac surgery complicates patient recovery and increases the load on healthcare services. Multimodal analgesia can be used to achieve better analgesic effect and improves patient outcome.  Material and methods: A total of 90 patients undergoing cardiac surgery with median sternotomy were randomly allocated equally into three groups intraoperatively where first group received continuous infusion of high dose opioids, second group received boluses of low dose opioids and third group received multimodal non opioid analgesics including dexmedetomidine, ketamine and magnesium sulphate. All patients received the same post-operative analgesic regimen consists of morphine patient controlled analgesia (PCA). Results: Patients in multimodal non opioid group had more stable hemodynamics intra and postoperatively. Also, patients in multimodal group had lower pain scores extubation, earlier extubation, shorter ICU stay, earlier mobilization and earlier return of bowel movements compared to patients of both groups received intraoperative higher opioid doses.

Spinal or Intravenous Dexmedetomidine for Spinal Anesthesia with Chloroprocaine in Ambulatory Knee Arthroscopies: A Double-Blind Randomized Trial

Purpose

Chloroprocaine provides spinal anesthesia for day-case surgery lasting up to 40 minutes. Intravenous and spinal dexmedetomidine can prolong spinal anesthesia, but no data are available for the combination with chloroprocaine. This double-blind randomized controlled trial compares chloroprocaine with spinal or intravenous dexmedetomidine regarding block characteristics, micturition, and discharge times.

Patients and Methods

After ethical approval and informed consent, 135 patients scheduled for knee arthroscopy were randomized to receive either 40mg spinal chloroprocaine (Chloro-group), 40mg chloroprocaine with 5 mcg spinal dexmedetomidine (Spinal Dex-group) or 40mg chloroprocaine with 0.5 mcg/kg IV dexmedetomidine (IV DEXgroup). Block characteristics, hemodynamic variables and the use of analgesics were registered. Voiding and discharge times were noted. A scoring system was used for micturition problems and sedation. Transient neurological symptoms (TNS) and other late side effects were evaluated after one week.

Results

Demographic data were similar between groups. Block onset times and intensity of motor block were comparable between groups. The time to L2 and Bromage 1 regression was prolonged in the SpinalDEx-group by approximately 30 minutes compared to the other groups (p < 0.01). First voiding as well as discharge from the hospital was prolonged in the Spinal Dex-group by approximately 40 minutes p < 0.01. There was no significant difference between groups regarding treatment of hypotension, sedation, micturition problems or the use of postoperative analgesics (P > 0.8). One patient experienced TNS.

Conclusion

Intrathecal but not intravenous (0.5 mcg/kg) dexmedetomidine can prolong chloroprocaine (40mg) spinal anesthesia when surgery is expected to last over 40 minutes. Despite a similar incidence of adverse effects, this also led to a postponed hospital discharge time.

Monitored Anesthesia Care with Dexmedetomidine Supplemented by Midazolam/Fentanyl versus Midazolam/Fentanyl Alone in Patients Undergoing Pleuroscopy: Effect on Oxygenation and Respiratory Function

Although pleuroscopy is considered a safe and well tolerated procedure with a low complication rate, it requires the administration of procedural sedation and analgesia. The purpose of this study was to assess the effects of dexmedetomidine administration on oxygenation and respiratory function in patients undergoing diagnostic or therapeutic pleuroscopy. Through a prospective, single center, cohort study, we studied 55 patients receiving either a dexmedetomidine intravenous infusion supplemented by midazolam/fentanyl (Group DEX + MZ/F) or a conventional sedation protocol with midazolam/fentanyl (Group MZ/F). Our primary outcome was the changes in lung gas exchange (PaO₂/FiO₂ ratio) obtained at baseline and at predetermined end points, while changes in respiratory mechanics (FEV1, FVC and the ratio FEV1/FVC) and PaCO₂ levels, drug consumption, time to recover from sedation and adverse events were our secondary endpoints (NCT03597828). We found a lower postoperative decrease in FEV1 volumes in Group DEX + MZ/F compared to Group MZ/F (p = 0.039), while FVC, FEV1/FVC and gas exchange values did not differ between groups. We also found a significant reduction in midazolam (p < 0.001) and fentanyl consumption (p < 0.001), along with a more rapid recovery of alertness postprocedure in Group DEX + MZ/F compared to Group MZ/F (p = 0.003), while pain scores during the postoperative period, favored the Group DEX + MZ/F (p = 0.020). In conclusion, the use of intravenous dexmedetomidine during pleuroscopy is associated with a smaller decrease in FEV1, reduction of the consumption of supplementary sedatives and analgesics and quicker awakening of patients postoperatively, when compared to midazolam/fentanyl. Therefore, dexmedetomidine administration may provide clinically significant benefits in terms of lung mechanics and faster recovery of patients undergoing pleuroscopy.

A Comparative Study of Periarticular Infiltration with Dexmedetomidine versus Ketorolac as an Additive to Ropivacaine after Total Knee Arthroplasty: A Prospective, Randomized Double-Blind Study

Background:

Periarticular infiltration (PAI) analgesia has been found to be an effective analgesia modality after total knee arthroplasty (TKA). Dexmedetomidine has many beneficial effects on postoperative analgesia by different routes, but studies on PAI are lagging.

Aims and Objectives:

In this study, we compared postoperative analgesia after PAI with dexmedetomidine versus ketorolac as an additive to ropivacaine after TKA.

Setting and Design:

This is a prospective, randomized, double-blind study conducted on 75 patients belonging to American Society of Anesthesiologists I to III, undergoing total knee arthroplasty, of either gender, belonging to American Society of Anesthesiologists I to III.

Materials and Methods:

After institutional ethics committee approval and written informed consent, patients were randomly allocated into three groups. Group C (n = 25) received cocktail of 60 mL ropivacaine (0.25%) infiltration with adrenaline 5 mL (0.1 mg.mL⁻¹), Group D (n = 25) received additive dexmedetomidine 1 ug.kg⁻¹ to above cocktail, and Group K (n = 25) received ketorolac 30 mg. Postoperatively pain by Visual Analog Scale, vitals, total duration of analgesia, need for rescue analgesia, sedation, patient satisfaction, mobilization time, and complications were recorded.

Statistical Analysis:

The Statistical Package for the Social Sciences version 20 was used for statistical analysis. Analysis of variance has been used to find the significance of study parameters between the three groups of patients. P < 0.05 was considered statistically significant.

Results:

Postoperative pain score was lesser in the ketorolac group (1.52 ± 0.71, P = 0.001) than the other two groups. Duration of analgesia was more with ketorolac (343.00 ± 144.45, P < 0.001) compared with the other two groups, and epidural activation timings (462 ± 235.84) were significantly delayed in Group K compared to Group C and Group D. There was no significant difference in mobilization time, patient satisfaction, and complications between the three groups.

Conclusion:

Ketorolac was a better additive to ropivacaine than dexmedetomidine for postoperative analgesia after TKA.

Intraoperative multimodal analgesic bundle containing dexmedetomidine and ketorolac may improve analgesia after robot-assisted prostatectomy in patients receiving rectus sheath blocks

BACKGROUND

Minimally invasive robot-assisted laparoscopic radical prostatectomy (RALP) has replaced open prostatectomy. However, RALP does not reduce postoperative pain compared to the open approach. We explored whether bundled intraoperative intravenous infusion of dexmedetomidine and ketorolac reduced opioid requirements during the 24 h after RALP.

METHODS

Eighty patients (two parallel groups) were enrolled in this prospective non-randomized study from September 2020 to November 2020. All received preoperative rectus sheath blocks for analgesia after RALP. A multimodal analgesic bundle (dexmedetomidine and ketorolac) was administered intraoperatively in the study group (n = 39) but not in the control group (n = 40). The total postoperative opioid requirements (expressed in milligrams of intravenous morphine) and pain scores (derived using a visual analog scale) were compared between the two groups up to 24 h after surgery.

RESULTS

The two groups were demographically similar. During surgery, patients in the study group received less remifentanil and more ephedrine than controls. The study group required significantly less opioids during the 24 h after surgery (28.3 vs. 40.0 mg, p = 0.006). The between-group pain scores differed significantly at 1 and 6 h after surgery. All other postoperative characteristics were comparable between the two groups.

CONCLUSIONS

The intraoperative multimodal analgesic bundle (intravenous dexmedetomidine and ketorolac) improved postoperative analgesia after RALP in patients with rectus sheath blocks, as evidenced by the opioid-sparing effect after surgery.

The Current Role of Dexmedetomidine as Neuroprotective Agent: An Updated Review

Dexmedetomidine, selective α2-adrenergic agonist dexmedetomidine, has been widely used clinically for sedation and anesthesia. The role of dexmedetomidine has been an interesting topic of neonatological and anesthetic research since a series of advantages of dexmedetomidine, such as enhancing recovery from surgery, reducing opioid prescription, decreasing sympathetic tone, inhibiting inflammatory reactions, and protecting organs, were reported. Particularly, an increasing number of animal studies have demonstrated that dexmedetomidine ameliorates the neurological outcomes associated with various brain and spinal cord injuries. In addition, a growing number of clinical trials have reported the efficacy of dexmedetomidine for decreasing the rates of postoperative neurological dysfunction, such as delirium and stroke, which strongly highlights the possibility of dexmedetomidine functioning as a neuroprotective agent for future clinical use. Mechanism studies have linked dexmedetomidine’s neuroprotective properties with its modulation of neuroinflammation, apoptosis, oxidative stress, and synaptic plasticity via the α2-adrenergic receptor, dependently or independently. By reviewing recent advances and preclinical and clinical evidence on the neuroprotective effects of dexmedetomidine, we hope to provide a complete understanding of the above mechanism and provide insights into the potential efficacy of this agent in clinical use for patients.

Effects of Dexmedetomidine as an Analgesic Adjuvant for Surgery of Femur Fracture: A Systematic Review and Meta-Analysis

Patients who undergo surgery of femur fracture suffer the excruciating pain. Dexmedetomidine (DEX) is a unique α2-adrenergic receptor agonist with sedative and analgesic properties, whose efficacy and safety are still unclear for surgery of femur fracture. Randomized controlled trials comparing the effects of addition of DEX to general or local anesthesia in surgery of femur fracture were searched from MEDLINE, EMBASE, and the Cochrane Library database. Patients who received DEX infusion had a significant longer time to rescue analgesia compared with those without DEX coadministration. DEX treatment seemed to reduce the visual analog score; however, the significance did not reach any statistical difference. DEX as an analgesic adjuvant did not reduce the onset of sensory block time, shorten the time to achieve maximum sensory block level, and provide a longer duration of sensory block. The difference in mean sedation scores between 2 groups was not statistically significant. As for adverse effects, DEX therapy significantly increased the rate of hypotension. In conclusion, dexmedetomidine as a local anesthetic adjuvant in femur fracture surgery had a longer duration of rescue analgesia. However, the incidence of hypotension was markedly increased in these patients. It was worth noting that the evidence was of low to moderate quality.

Is Spinal Dexmedetomidine Aggravating Hypotension after Tourniquet Deflation?

Background and Aims:

The addition of dexmedetomidine to spinal anesthesia decreases the incidence of tourniquet pain but may aggravate hypotension after tourniquet deflation.

Methods:

Fifty patients were included in this prospective, double-blinded, randomized study, randomly divided into two equal groups of 25 patients each. Spinal anesthesia was performed using 2.5 mL of 0.5% hyperbaric bupivacaine plus 0.5 mL of normal saline in control group (Group C) or 2.5 mL of 0.5% hyperbaric bupivacaine plus 0.5 mL (5 μg) of dexmedetomidine in (Group D). Tourniquet pain was treated by 50 mg of meperidine and repeated in a dose of 20 mg, and the total meperidine consumption was calculated. After tourniquet deflation, heart rate and mean blood pressure were measured for 15 min in the operating room and at these times: before induction of anesthesia (baseline), after inflating tourniquet (inflation), 1 min before deflating tourniquet (predeflation), after tourniquet deflation (10 min postdeflation), and maximum blood pressure and heart rate changes. Duration of time that started before the minimum blood pressure and maximum heart rate was changed until recovery was recorded.

Results:

Pain after torniquet inflation was significantly higher in the Group C compared to the Group D. The maximal change of blood pressure was lower in the dexmedetomidine than in the control group. The mean time between the maximal change in blood pressure reached and started to recover was 135 ± 14 s in the dexmedetomidine group and 80 ± 31 s in the control group (P < 0.01) and maximal heart rate change was lower in dexmedetomidine group than the control group. The time between the maximal heart rate changes until recovery was 113.2 ± 19 s in the dexmedetomidine group and 53.2 ± 11 s in the control group P < 0.01.

Conclusion:

Adding dexmedetomidine to spinal anesthesia decreases the incidence of tourniquet pain but aggravates the hemodynamic effect of tourniquet deflation.

Dexmedetomidine as an Analgesic Agent with Neuroprotective Properties: Experimental and Clinical Aspects

Dexmedetomidine (Dexdor or Precedex®) is considered as a sedative agent which is widely used as an adjuvant in general anesthesia and critical care practice. There is extensive evidence indicating its neuroprotective properties especially in various ischemic and hemorrhagic brain injury models of animals. Clinical trials have shown that dexmedetomidine (DEX) can improve the outcome of intensive care unit (ICU) patients. Also, DEX is appropriate as a non-opioid analgesic therapy whenever minimizing opioid-related side effects is necessary. The present article reviews the recent advances in the use of DEX as a neuroprotective agent in both animal and human studies including newest findings about the mechanism of the drug as well as analgesic efficacy of this drug at all perioperative stages. In spite of the beneficial effects of the drug on the nervous system, there are potential adverse effects, such as hypotension and bradycardia, which can be treated pharmacologically and must be taken into consideration by clinicians.

Effectiveness of nebulized dexmedetomidine for treatment of post-dural puncture headache in parturients undergoing elective cesarean section under spinal anesthesia: a randomized controlled study

PURPOSE

The need for effective treatment for post-dural puncture headache (PDPH) is a growing research entity. This study aimed to test the effectiveness of additional dexmedetomidine (DEX) to PDPH conservative management and evaluate its cerebral hemodynamic effects trans-cranial Doppler.

METHODS

This prospective randomized double-blind controlled trial was conducted on 43 post-partum females suffering from PDPH with visual analog score (VAS) ≥ 4 and Lybecker score ≥ 2. The study subjects were allocated into control group [n = 22] received nebulization of 4 mL 0.9% saline and DEX group [n = 21] received nebulization of 1 µg/kg DEX diluted in 4 mL 0.9% saline twice daily that was continued until achieving VAS score ≤ 3 and Lybecker score < 2 and/or for a maximum of 72 h. Both groups received routine conservative management. The primary outcome was the VAS and Lybecker scores and the secondary results were the DEX effects on cerebral vessels and the occurrence of any adverse effects.

RESULTS

VAS and Lybecker scores were significantly lower in DEX group. The middle cerebral artery mean flow velocity was significantly lower, and the pulsatility index was considerably higher after DEX nebulization compared to placebo. Two patients in the control group were indicated for epidural blood patch.

CONCLUSION

The addition of DEX nebulization (1 µg/kg twice daily) to the PDPH conservative care effectively relieved the symptoms and lowered pain scores which could be due to its analgesic and cerebral vasoconstrictive effects.

TRIAL REGISTRATION

This study was approved by the research ethical committee of Faculty of Medicine, Zagazig University with the reference number (ZU-IRB#: 6075/26-4-2020) and it was registered under clinicaltrials.gov (NCT04327726).

Cardioprotective effects of propofol-dexmedetomidine in open-heart surgery: A prospective double-blind study

Background:

Myocardial protection in cardiac surgeries is a must and requires multimodal approaches in perioperative period to decrease and prevent the increase of myocardial oxygen demand and consumption that lead to postoperative cardiac complications including myocardial ischemia, dysfunction, and heart failure.

Study Design:

Prospective, controlled, randomized, double-blinded study.

Aims:

This study aims to study the effect of propofol-dexmedetomidine continuous infusion cardioprotection during open-heart surgery in adult patients.

Materials and Methods:

Sixty adult patients of both sexes aged from 30 to 60 years old belonging to the American Society of Anesthesiologists III or IV undergoing open-heart surgery were randomly divided into two equal groups: Group P (control group) received continuous infusion of propofol at a rate of 2 mg/kg/h and 50 cc 0.9% sodium chloride solution infused at a rate of 0.4 μg/kg/h (used as a placebo) and Group PD received continuous infusion of propofol at a rate of 2 mg/kg/h and dexmedetomidine 200 μg diluted in 50 cc 0.9% sodium chloride solution infused at a rate of 0.4 μg/kg/h. Infusion for all patients started immediately preoperative till skin closure. Hemodynamic measurements of heart rate (HR), invasive mean arterial pressure, and oxygen saturation were recorded at baseline before induction of anesthesia, immediately after intubation, at skin incision, at sternotomy and every 15 min in the 1^st h then every 30 min during the prebypass period then every 15 min in the 1^st h then every 30 min after weaning from CPB till the end of the surgery. Serum biomarkers; cardiac troponin (cTnI) and creatine kinase-myocardial bound (CK-MB) samples were measured basally (T1), 15 min after unclamping of the aorta (T2), immediate postoperative (T3), and 24 h postoperative (T4). Intraoperative data were also recorded including the number of coronary grafts, aortic cross-clamping duration, duration of cardiopulmonary bypass (CPB), duration of surgery, and rhythm of reperfusion. Fentanyl requirement, extubation time, and length of intensive care unit (ICU) stay were also recorded for every case.

Results:

There was no statistically significant differences as regard to demographic data between the studied two groups. HR and blood pressure recorded was lower in the PD group than the control group, and this difference was noted to be statistically significant. Furthermore, the PD group showed lower levels of myocardial enzymes (cTnI and CK-MB), decreased total fentanyl requirement, earlier postoperative extubation, and shorter ICU stay than the P (control) group.

Conclusion:

The use of propofol-dexmedetomidine in CPB surgeries offers more cardioprotective effects than the use of propofol alone.

Pharmacokinetics and Pharmacodynamics of 3 Doses of Oral-Mucosal Dexmedetomidine Gel for Sedative Premedication in Women Undergoing Modified Radical Mastectomy for Breast Cancer

BACKGROUND

Buccal dexmedetomidine (DEX) produces adequate preoperative sedation and anxiolysis when used as a premedication. Formulating the drug as a gel decreases oral losses and improves the absorption of buccal DEX. We compared pharmacokinetic and pharmacodynamic properties of 3 doses of buccal DEX gel formulated in our pharmaceutical laboratory for sedative premedication in women undergoing modified radical mastectomy for breast cancer.

METHODS

Thirty-six patients enrolled in 3 groups (n = 12) to receive buccal DEX gel 30 minutes before surgery at 0.5 µg/kg (DEX 0.5 group), 0.75 µg/kg (DEX 0.75 group), or 1 µg/kg (DEX 1 group). Assessments included plasma concentrations of DEX, and pharmacokinetic variables calculated with noncompartmental methods, sedative, hemodynamic and analgesic effects, and adverse effects.

RESULTS

The median time to reach peak serum concentration of DEX (Tmax) was significantly shorter in patients who received 1 µg/kg (60 minutes) compared with those who received 0.5 µg/kg (120 minutes; P = .003) and 0.75 µg/kg (120 minutes; P = .004). The median (first quartile-third quartile) peak concentration of DEX (maximum plasma concentration [Cmax]) in plasma was 0.35 ng/mL (0.31-0.49), 0.37 ng/mL (0.34-0.40), and 0.54 ng/mL (0.45-0.61) in DEX 0.5, DEX 0.75, and DEX 1 groups (P = .082). The 3 doses did not produce preoperative sedation. The 1 µg/kg buccal DEX gel produced early postoperative sedation and lower intraoperative and postoperative heart rate values. Postoperative analgesia was evident in the 3 doses in a dose-dependent manner with no adverse effects.

CONCLUSIONS

Provided that it is administered 60-120 minutes before surgery, sublingual administration of DEX formulated as an oral-mucosal gel may provide a safe and practical means of sedative premedication in adults.

The Effectiveness of Caudal Block with Low Doses of Dexmedetomidine and Pethidine in Transrectal Prostate Biopsy: Preliminary Results

PURPOSE

To evaluate the effectiveness of caudal block (CB) using dexmedetomidine and pethidine instead of local anesthesia (LA) for prostate needle biopsy and the effect of CB on urinary retention.

MATERIAL AND METHODS

A transrectal ultrasound-guided prostate needle biopsy (TRUS-Bx) was performed on 68 patients with a mean age of 65 ± 2.18 years. CB with a combination of dexmedetomidine and pethidine without LA was administered to the patients. The pain levels of the patients were determined using numeric rating scale (NRS) scores to evaluate the effectiveness of CB. Preoperative and postoperative postvoid residual urine volumes (PRUV) were also calculated.

RESULTS

The CB success rate was 93.15%. The NRS scores were 0.79 ± 0.19 and 0.89 ± 0.22 during probe entry and manipulation and biopsy, respectively, without any significant differences between them (p = 0.382). The mean PRUVs before and after biopsy did not differ significantly (41 ± 15.6 vs. 71.93 ± 22.3, p = 0.379). The degree of sedation, as assessed using the Ramsay scale, was 2 or 3 in all patients.

CONCLUSION

The combination of dexmedetomidine and pethidine for CB in TRUS-Bx provided quality analgesia for the patient and prevented the development of postoperative urinary retention.

Dexmedetomidine versus clonidine adjuvants to levobupivacaine for ultrasound-guided transversus abdominis plane block in paediatric laparoscopic orchiopexy: Randomized, double-blind study

BACKGROUND

Laparoscopic surgeries are associated with less postoperative pain and adverse events compared to open procedures. But, it still reduces the quality of life in children. Transversus abdominis plane (TAP) block is used to reduce pain. We hypothesized that dexmedetomidine or clonidine could improve the analgesic profile of levobupivacaine to the same extent during TAP block in children.

METHODS

Ninety children were randomly allocated in a randomized double-blind trial to receive bilateral TAP block with levobupivacaine plus normal saline (group B, n = 30), or dexmedetomidine (group D, n = 30) or clonidine (group C, n = 30). Primary outcome was the modified Children's Hospital of Eastern Ontario Pain Scale score. Secondary outcomes included time to initial analgesic request, number of analgesic claims, total analgesic consumption, parents' satisfaction, sedation score and complications.

RESULTS

Children of group D showed reduced pain scores compared to other groups. They represented the longest period of analgesia (565.00 ± 71.5 min) with p < 0.001, and fewer patients required two doses of analgesia during the first postoperative day. The cumulative amount of backup analgesia was significantly different between these groups (p = 0.026). Higher parents' satisfaction scores were recorded in groups D and C compared to group B. Sedation among the study groups revealed significant differences (p = 0.035), but no severe complications were recorded.

CONCLUSIONS

Adding dexmedetomidine to levobupivacaine can extend the time of analgesia and reduce the use of postoperative backup analgesics with minimal sedation effects when used in TAP block in paediatrics undergoing laparoscopic orchiopexy. Clonidine can be used as an alternative adjuvant to local anaesthetics with good postoperative analgesic profiles.

SIGNIFICANCE

Clonidine can alternate dexmedetomidine during TAP block with local anesthetics for pediatrics laparoscopies. Both can lead to better postoperative analgesic profiles. Clonidine may be preferred, especially in our developing regions, because of its easy availability and lower cost than that of dexmedetomidine.

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 intrathecal dexmedetomidine versus intravenous dexmedetomidine on subarachnoid anesthesia with hyperbaric bupivacaine

Background and Aim:

Alpha-2 agonists such as dexmedetomidine when given intravenously or intrathecally as an adjuvant potentiate subarachnoid anesthesia. We studied the difference in subarachnoid anesthesia when supplemented with either intrathecal or intravenous dexmedetomidine.

Material and Methods:

Seventy-five patients posted for lower limb and infraumbilical procedures were enrolled for a prospective, randomized, double-blind, placebo-controlled study and divided into three groups: Group B (n = 25) received intravenous 20 mL 0.9%N aCl over 10 min followed by intrathecal 2.4 mL 0.5%bupivacaine + 0.2 mL sterile water; Group B_DexIT (n = 25) received intravenous 20 mL 0.9%N aCl over 10 min followed by intrathecal 2.4 mL 0.5%b upivacaine + 0.2 mL (5 μg) dexmedetomidine; Group B_DexIV (n = 25) received intravenous dexmedetomidine 1 μg/kg in 20 mL 0.9%N aCl over 10 min followed by intrathecal 2.4 mL 0.5%b upivacaine + 0.2 mL sterile water. Onset and recovery from motor and sensory blockade, and sedation score were recorded. Onset of sensory and motor blockade was assessed using Kruskal–Wallis test, whereas 2-segment regression and recovery was analyzed using ANOVA and post hoc Tukey's test to determine difference between the three groups. P value <0.05 was considered statistically significant.

Results:

Although onset of sensory and motor block was similar in the three groups, motor recovery (modified Bromage scale 1) and two-segment sensory regression was prolonged in Group B_DexIT > Group B_DexIV > Group B (P < 0.001). Patients in Group B_DexIT and Group B_DexIV were sedated but easily arousable.

Conclusion:

Intrathecal dexmedetomidine prolongs the effect of subarachnoid anesthesia with arousable sedation when compared with intravenous dexmedetomidine.

Postoperative Analgesic Effect of Bupivacaine alone and with Dexmedetomidine in Wound Instillation for Lumbar Laminectomy: A Randomized Control Trial

Background:

Dexmedetomidine has been used as an effective adjuvant to local anesthetics in peripheral nerve blocks and at the incision site.

Aims:

We compared the postoperative analgesic effect of bupivacaine alone and in addition of dexmedetomidine to bupivacaine in wound instillation during lumbar laminectomy.

Setting and Design:

This was a prospective, double-blind, randomized control trial.

Subjects and Methods:

Sixty adults of the American Society of Anesthesiologists Grade I–II scheduled for elective lumbar laminectomy under general anesthesia were randomly allocated into two groups. Group B (control group) patients received wound instillation with 20 mL of 0.25% bupivacaine at the end of surgery and Group D patients received 2 μg.kg⁻¹ dexmedetomidine diluted in 20 mL 0.25% bupivacaine as instillation over the incision site. If the NRS exceeded “4” at any point of time, rescue analgesia with injection diclofenac 75 mg deep intramuscular was administered. Postoperative pain score, duration of analgesia, total rescue analgesic required in the first 24 h, and side effects were compared between the groups.

Results:

Demographic data were comparable in both the groups. Duration of analgesia (19.93 ± 3.2 in Group D vs. 12.13 ± 1.8 in Group B) was significantly more in Group D, number of analgesic demands were less in group D as compared to Group B, and total rescue analgesic required (62.51 ± 39.13 vs. 95.68 ± 33.5) was significantly less in Group D as compared to Group B.

Conclusions:

We conclude that dexmedetomidine 2 μg.kg⁻¹ is an effective adjuvant to bupivacaine for wound instillation in terms of quality and duration of postoperative analgesia following lumbar laminectomy.

Intravenous dexmedetomidine versus tramadol for treatment of shivering after spinal anesthesia: a meta-analysis of randomized controlled trials

Background

Shivering is a frequent complication after spinal anesthesia. Increasing studies have compared the effect of intravenous dexmedetomidine and intravenous tramadol on shivering after spinal anesthesia, hence we performed a meta-analysis of randomized controlled trials to compare dexmedetomidine with tramadol on the treatment of post-spinal anesthesia shivering.

Methods

PubMed, Embase, Cochrane library, Web of Science and Google Scholar were searched to find the eligible studies comparing the effect of dexmedetomidine and tramadol on the treatment of shivering after spinal anesthesia. Mean difference (MD) or risk ratio (RR) along with 95% confidence interval (CI) was used to analyze the outcomes. I² test was conducted to assess the heterogeneity of the included trials. We utilized Review Manager 5.3 to perform statistical analyses.

Results

Thirteen randomized controlled trials including 864 subjects were included. Dexmedetomidine had higher effective rate of shivering control (RR =1.03; 95%CI [1.01, 1.06], P = 0.01, I² = 14%), shorter time to cease shivering (MD = -2.14; 95%CI [− 2.79, − 1.49], P < 0.00001, I² = 98%), lower recurrent rate of shivering (RR = 0.45; 95%CI [0.27, 0.73], P = 0.001, I² = 0%), lower incidences of nausea (RR = 0.10; 95%CI [0.05, 0.19], P < 0.00001, I² = 48%), and vomiting (RR = 0.13; 95%CI [0.06, 0.30], P < 0.00001, I² = 0%), higher incidence of sedation (RR = 2.48; 95%CI [1.32, 4.65], P = 0.005, I² = 82%), hypotension (RR = 2.50; 95%CI [1.24, 5.03], P = 0.01, I² = 0%) and bradycardia (RR = 4.78; 95%CI [1.76, 13.00], P = 0.002, I² = 0%), compared with tramadol.

Conclusions

Dexmedetomidine is superior to tramadol for shivering treatment, due to higher effective rate of shivering control, earlier onset of action and lesser recurrence of shivering with higher incidence of sedation and lower incidences of nausea and vomiting. However, dexmedetomidine is also associated with higher incidences of hypotension and bradycardia than tramadol.

Dexmedetomidine and Bupivacaine Association in Caudal Epidural Injection in Mares

The objective of the study was to compare the effects of caudal epidural bupivacaine and dexmedetomidine (DEX) combination, with bupivacaine or DEX plain for perineal analgesia in mares. Six healthy saddle mares weighing 330-370 kg and aged 10-15 years were used in this study. Each mare was assigned to receive three treatments: 0.04 mg/kg 0.25% bupivacaine (BP), 2 μg/kg DEX (DX), or 0.02 mg/kg bupivacaine and 1 μg/kg DEX (BPDX). The order of treatments was randomized. All drugs were injected into the caudal epidural space (Co1-Co2) through a 16-G Tuohy epidural needle. After the epidural injections, heart rate, respiratory rate, arterial blood pressures (systolic, diastolic, and mean), and rectal temperature were measured at 5, 10, 15, 30, 60, 90, and 120 minutes, and after this time, every 60 minutes until the end of the experiments. A subjective score system was used to assess analgesia, behavioral and motor blockade at the same time points. The BPDX treatment produced analgesic action with twice the duration (200 minutes) of the BP treatment (97 minutes), but with an analgesic duration shorter than the DX treatment (240 minutes) in the regions of the tail, perineum, and upper hind limbs in mares. All treatments showed mild motor blockade. No behavioral changes were observed in any of the animals. There was hemodynamic stability without significant changes in respiratory rate for all treatments. Epidural analgesia using DEX alone or the combination of DEX and bupivacaine may be an option for painful obstetric and gynecological procedures in mares.

Dexmedetomidine in Enhanced Recovery After Surgery (ERAS) Protocols for Postoperative Pain

PURPOSE OF REVIEW

Effective acute pain management has evolved considerably in recent years and is a primary area of focus in attempts to defend against the opioid epidemic. Persistent postsurgical pain (PPP) has an incidence of up to 30-50% and has negative outcome of quality of life and negative burden on individuals, family, and society. The 2016 American Society of Anesthesiologists (ASA) guidelines states that enhanced recovery after surgery (ERAS) forms an integral part of Perioperative Surgical Home (PSH) and is now recommended to use a multimodal opioid-sparing approach for management of postoperative pain. As such, dexmedetomidine is now being used as part of ERAS protocols along with regional nerve blocks and other medications, to create a satisfactory postoperative outcome with reduced opioid consumption in the Post anesthesia care unit (PACU).

RECENT FINDINGS

Dexmedetomidine, a selective alpha2 agonist, possesses analgesic effects and has a different mechanism of action when compared with opioids. When dexmedetomidine is initiated at the end of a procedure, it has a better hemodynamic stability and pain response than ropivacaine. Dexmedetomidine can be used as an adjuvant in epidurals with local anesthetic sparing effects. Its use during nerve blocks results in reduced postoperative pain. Also, local infiltration of IV dexmedetomidine is associated with earlier discharge from PACU. Perioperative use of dexmedetomidine has significantly improved postoperative outcomes when used as part of ERAS protocols. An in-depth review of the use of dexmedetomidine in ERAS protocols is presented for clinical anesthesiologists.

Emergence agitation: current knowledge and unresolved questions

Emergence agitation (EA), also referred to as emergence delirium, can have clinically significant consequences. The mechanism of EA remains unclear. The proposed risk factors of EA include age, male sex, type of surgery, emergency operation, use of inhalational anesthetics with low blood-gas partition coefficients, long duration of surgery, anticholinergics, premedication with benzodiazepines, voiding urgency, postoperative pain, and the presence of invasive devices. If preoperative or intraoperative objective monitoring could predict the occurrence of agitation during emergence, this would help to reduce its adverse consequences. Several tools are available for assessing EA. However, there are no standardized clinical research practice guidelines and its incidence varies considerably with the assessment tool or definition used. Total intravenous anesthesia, propofol, μ-opioid agonists, N-methyl-D-aspartate receptor antagonists, nefopam, α2-adrenoreceptor agonists, regional analgesia, multimodal analgesia, parent-present induction, and preoperative education for surgery may help in preventing of EA. However, it is difficult to identify patients at high risk and apply preventive measures in various clinical situations. The risk factors and outcomes of preventive strategies vary with the methodologies of studies and patients assessed.This review discusses important outcomes of research on EA and directions for future research.

Comparison of midazolam and low-dose dexmedetomidine in flexible bronchoscopy: A prospective, randomized, double-blinded study

BACKGROUND

Dexmedetomidine is a clinically useful drug for providing sedation, but concern regarding its cardiovascular side effect profile can limit its widespread use during routine diagnostic flexible bronchoscopy (FB).

MATERIALS AND METHODS

Patients between 18 and 65 years of age, who required diagnostic FB, were screened. Eligible patients were randomized to either receive 0.5 μg/kg intravenous dexmedetomidine over 10 min or intravenous midazolam 0.035 mg/kg over 1 min. If required, rescue medication (intravenous midazolam 0.5 mg bolus) was administered. The primary outcome measure was the composite score. Other parameters observed were numerical rating scale, hemodynamic variables, oxygen saturation, number of doses of rescue medication, visual analog scale score for cough, ease of bronchoscopy, Ramsay Sedation Score, and postprocedure patient response after 24 h of bronchoscopy.

RESULTS

A total of 54 patients were enrolled, 27 in each group. Total composite score (mean ± standard deviation) in dexmedetomidine and midazolam group at nasopharynx was 7.04 ± 2.19 and 6.59 ± 1.55 (P = 0.387), respectively. The corresponding values at the level of trachea were 9.22 ± 3.69 and 8.63 ± 2.13 (P = 0.475). In the dexmedetomidine group, patient response after 24 h of bronchoscopy showed the quality of sedation to be excellent in three patients, good in 10, fair in 11, and poor in 3 and discomfort to be nil in 14, mild 7, moderate in 3, and severe in 3. The corresponding values in the midazolam group for the quality of sedation were 0, 9, 18, 0 and for discomfort 10, 16, 1, 0. Other parameters did not reveal any statistically significant difference.

CONCLUSION

Dexmedetomidine at a dose of 0.5 μg/kg may provide clinically useful conscious sedation, comparable to midazolam.

Intravenous sedation in dental implant surgeries: A systematic review of hemodynamic effects

BACKGROUND

The main objective of thissystematic review wasto identify the hemodynamic effects of intravenous sedatives used in dental implant surgeries.

METHODS

Embase, PubMed, ProQuest, Scopus, Ovid, and Cochrane databases were searched with no limitations. Of 59 studies obtained, 50 studies were excluded due to incompatibility with the subject. The remaining studies were reviewed in full text and assessed for the risk of bias individually. The included studies were reviewed by the research team, and the necessary data were extracted.

RESULTS

Four studies were finally included. Two of the studies compared local anesthesia and intravenous sedation, while the other two compared the consequences of different types of intravenous sedation. By comparing the hemodynamic effects, the systolic and diastolic blood pressure and the heart rate data were collated. Midazolam was the most frequently used intravenous sedative, and Dexmedetomidine affected hemodynamics the most.

CONCLUSION

Intravenous sedation leads to decreased heart rate and blood pressure. Better hemodynamic outcomes improve the patients' cooperation by decreasing stress and anxiety. Dexmedetomidine seems to be the first choice for intravenous sedation.

Intravenous infusion of dexmedetomidine amplifies thoracic epidural analgesic effect after open thoracotomy: A prospective, double-blind, randomized controlled trial

BACKGROUND

The anesthetic-sparing effect of dexmedetomidine has led to its use as a general adjuvant. The present study aimed to determine intravenous infusion of dexmedetomidine to epidural analgesia after open thoracotomy.

METHODS

Forty-four patients scheduled for admission to the intensive care unit after open thoracotomy were divided into 2 groups. An epidural catheter was placed at T4 to T7. Thirty minutes before the end of thoracotomy, group D was injected with 0.3 μg/kg/h of dexmedetomidine and group C received an equal dose of normal saline. For patient-controlled epidural analgesia (PCEA), 150 mL of levobupivacaine 300 mg was infused at a rate of 1 mL/h, plus a bolus dose of 3 mL with a lockout time of 30 minutes. The primary outcome evaluated was analgesic efficacy using a visual analog scale (VAS) 48 hours postoperatively. Other outcomes included additional analgesic use, total consumed local analgesia via PCEA, sedation score, blood pressure, heart rate, arterial blood gases, patient satisfaction, and adverse effects.

RESULTS

The VAS scores in group D were significantly lower than that in group C immediately, 1, 4, 12, 36, and 48 hours after admission to the intensive care unit (P = .016, .009, .015, .002, .001, and .042, respectively). The total dose of additional analgesic was also significantly lower in group D (P = .011). Patient satisfaction was higher in group D (P < .05). There were no significant differences in the other outcomes between groups.

CONCLUSION

Intravenous infusion of dexmedetomidine amplifies thoracic epidural analgesic effect after open thoracotomy.

Intra-Articular Morphine versus Dexmedetomedine for Knee Arthroscopy under Local Anesthesia

Background:

Knee arthroscopy has both diagnostic and therapeutic applications which can be performed under general, regional, or local anesthesia. Morphine is used as an additive to local anesthetics. Dexmedetomedine, the highly selective alpha-2 (α2)-adrenoceptor agonist with the sedative and analgesic effect can be used also to augment local anesthetic effect.

Patients and Methods:

Sixty patients submitted for elective knee arthroscopy whose age between 25 and 45 years, of either sex, the American society of anethesiologists physical status Classes I and II at a university hospital were enrolled in this study. Patients were classified into two groups. Morphine Group (M) (n = 30): Patients received 20 ml of 0.5% bupivacaine plus 5 ml of 0.2% lidocaine with epinephrine 1:200,000 plus 1 mg morphine. Dexmedetomedine Group (D) (n = 30): Patients received 20 ml of 0.5% bupivacaine plus 5 ml of 0.2% lidocaine with epinephrine 1:200,000 plus 1 μg/kg dexmedetomedine.

Results:

Demographic data of patients showed no significant difference among the studied groups. Heart rate (HR) was significantly lower in (D) Group compared to that of (M) Group 5 min from the start of procedure to immediately postoperatively. Moreover, (D) Group showed a significant decrease in HR 10 min up to 35 min intraoperatively compared to the basal value. Furthermore, mean arterial blood pressure (MBP) was significantly lower in (D) Group compared to that of (M) Group 15 min from the start of surgery up to 1 h postoperatively. Furthermore, (D) Group showed a significant decrease in MBP 15 min intraoperative up to 2 h postoperatively compared to the basal value. While there was no significant difference in (visual analogue score [VAS], onset and total consumption of ketorolac, surgeon and patients’ satisfaction, side effects in (D) Group compared to (M) Group, respectively.

Conclusion:

Addition of either morphine or dexmedetomidine to bupivacaine intraarticularly improved both intraoperative anesthesia and postoperative analgesia with minimal side effects or complications in knee arthroscopy, with superiority of dexmedetomidine compared to morphine on hemodynamic stability.

Efficacy of Adding Low-Dose Ketamine to Dexmedetomidine Versus Low-Dose Ketamine and Propofol for Conscious Sedation in Patients Undergoing Awake Fiber-optic Intubation

Background and Aims:

Conscious sedation is the key for successful AFOI. This trial was conducted to compare the effectiveness of dexmedetomidine and low dose of ketamine against propofol and low dose ketamine.

Materials and Methods:

Sixty patients subjected for general anesthesia were invited to participate in the study and randomly allocated into two equal groups: D-K (n = 30) had been received a bolus dose of both ketamine 0.5mg /kg and dexmedetomidine 1ug/kg over 10 min. Then continuous infusion of ketamine 0.5mg /kg and dexmedetomidine 1ug/kg. The second group (P-K group) (n = 30): had been received a bolus dose of both ketamine 0.5mg/kg and propofol 1mg/kg over 10 min. Then continuous infusion of ketamine 0. 5mg/kg and propofol 1mg/kg.

Results:

The intubation time was statistically significant shorter within the D-K group (58.9 ± 6.1) versus P-K group (63.4 ± 5.3) with p-value 0.02. The shorter time needed to achieve the OAA/S score = 2 was in the D-K group (2.25 ± 0.75) versus (2.9 ± 0.79) in P-K group with (P-value 0.004). The intubation scores were insignificant different between both groups except vocal cord opening which was statistical better among D-K group with P-value 0.03. The significant hypotensive recorded data were among P-K group while the decreased heart rate were recorded in D-K group. Eighty percentages of patients had excellent score of satisfaction within the D-K gp against 47% among the patients within P-K gp with P-value 0.01.

Conclusion:

The concomitant administration of low dose of ketamine with dexmedetomidine had better intubation time and sedation scores with higher patient satisfaction scores than the combination of propofol and low dose of ketamine.

Postoperative analgesia with ropivacaine and dexmedetomidine for ultrasound-guided fascia iliaca compartment block after arthroscopic knee surgery

Objective

The objective of this study is to evaluate the postoperative analgesic effect of a combination of ropivacaine and dexmedetomidine for ultrasound-guided fascia iliaca compartment block (FICB) after knee arthroscopy.

Materials and Methods

Forty patients scheduled for knee arthroscopy were randomized to receive either 30 ml of 0.25% ropivacaine alone (Group A, n = 20) or combined with dexmedetomidine 1 μg/kg (Group B, n = 20). Pain intensity was evaluated using the visual analogue scale (VAS), at rest and during activity at 4, 6, 8, 12, and 24 h after surgery. Level of consciousness was evaluated using the Ramsay sedation score. Time to first analgesic request after surgery, the dose of analgesic used in the first 24 h after surgery, variation of heart rate, and adverse reactions were also recorded.

Results

VAS scores at 6 and 12 h after surgery were significantly lower in Group B compared to Group A (P < 0.05). No significant difference was observed in the Ramsay sedation score or time to first analgesic request after surgery (P > 0.05). The total dose of analgesic used in the first 24 h after surgery was higher in Group A than in Group B. The incidence of bradycardia was higher in Group B compared to Group A. No adverse reactions were observed in either group.

Conclusion

FICB with a combination of ropivacaine and dexmedetomidine resulted in significant reduction of VAS scores with lower postoperative analgesic requirement after arthroscopic knee surgery. No adverse reactions or complications were noted except for lower heart rate in Group B patients.

Comparison of dexmedetomidine and sufentanil as adjuvants to local anesthetic for epidural labor analgesia: a randomized controlled trial

Background

The epidural dexmedetomidine combined with ropivacaine has been successfully used for labor analgesia. We compared the effects of dexmedetomidine and sufentanil as adjuvants to local anesthetic for epidural labor analgesia.

Methods

Eighty nulliparous women were enrolled in the double-blind study and randomly divided into two groups. Group D received 0.5 µg/mL dexmedetomidine with 0.1% ropivacaine for epidural labor analgesia, and group S (control group) received 0.5 µg/mL sufentanil with 0.1% ropivacaine for labor analgesia. Hemodynamic parameters were monitored. Pain was assessed using a visual analog scale. The onset of epidural analgesia, duration of stages of labor, Ramsay Sedation Scale, blood loss, neonatal Apgar scores, umbilical artery blood pH and adverse effects, such as respiratory depression, nausea, vomiting, pruritus, and bradycardia, were recorded.

Results

Compared with the control group, visual analog scale values after cervical dilation >3 cm were lower in group D (P<0.05) and first-stage labor duration was shorter in group D (378.5±52.6 vs 406.5±58.2, P<0.05). Ramsay Sedation Scale values were higher in group D compared to the control group (2.8±0.6 vs 2.4±0.5, P<0.05). No significant differences in side effects were observed between the groups.

Conclusion

Dexmedetomidine is superior to sufentanil in analgesic effect and duration in first-stage labor during epidural analgesia when combined with 0.1% ropivacaine (www.chictr.org.cn, registration ChiCTR-OPC-16008548).

Comparison of the Analgesic Efficacy of a Single Dose of Epidural Dexmedetomidine versus Fentanyl as an Adjuvant to Bupivacaine in Abdominal Surgery

Background:

Fentanyl as an epidural additive act on spinal opioid receptors, while dexmedetomidine has selective alpha-2 receptor agonist action enhancing analgesic effects.

Aims:

We aimed to compare the postoperative analgesic efficacy of single doses of dexmedetomidine against fentanyl as epidural adjuvant to 0.125% bupivacaine.

Settings and Design:

A prospective, randomized, controlled, double-blind trial was conducted in a tertiary care teaching institute.

Patients and Methods:

Forty-six patients undergoing abdominal surgery under general anesthesia with epidural analgesia were allocated into two groups to receive postoperative analgesia with single doses of 10 mL 0.125% bupivacaine with the addition of dexmedetomidine 0.5 μg.kg-1 (Group D) or fentanyl 0.5 μg.kg-1 (Group F). The primary outcome was the duration of postoperative analgesia between the two groups. The secondary outcomes were hemodynamic variations, vasopressor need, and motor blockade.

Statistical Analysis:

Chi-square test for static parameters and Student's t-test or Mann–Whitney test for continuous variables were used for analysis.

Results:

The duration of analgesia was longer in Group D (5.0 ± 2.0 h) versus Group F (2.9 ± 1.4 h), Sixteen patients in Group D versus seven patients in Group F needed vasopressors after the bolus to maintain the blood pressure (BP) within 20% of prebolus value (P = 0.018). Heart rate and mean and systolic BP were lower in Group D at various time points following bolus administration.

Conclusion:

A single dose of dexmedetomidine as an additive to epidural local anesthetic postoperatively prolongs the duration of analgesia in comparison to fentanyl but is associated with changes in hemodynamics, including the need for the administration of vasoactive drugs.

Comparison of Prolongation of Spinal Anesthesia Produced by Intravenous Dexmedetomidine and Midazolam: A Randomized Control Trial

Context:

Various intravenous (i.v.) adjuvants have been used along with spinal anesthesia to delay the onset of postoperative pain.

Aims:

To compare effects of i.v. dexmedetomidine with midazolam on duration of spinal anesthesia.

Settings and Design:

This prospective randomized control trial was conducted in a tertiary care institution.

Subjects and Methods:

Forty-three patients presenting for elective infraumbilical surgery under spinal anesthesia were randomly allocated into two groups. Group A received a loading dose of 0.5 μg/kg followed by 0.5 μg/kg/h of i.v. dexmedetomidine. Group B received a loading dose of 0.03 mg/kg followed by 0.03 mg/kg/h of i.v. midazolam. Two dermatomal regressions, regression to S₁ level, and sedation score were noted.

Statistical Analysis Used:

To test the statistical significance of duration of sensory blockade, Mann–Whitney U-test was applied. The incidence of bradycardia and hypotension was analyzed using Pearson's correlation coefficient test.

Results:

The mean time for two dermatomal regressions was significantly prolonged in Group A (2.3 ± 0.4 h) than Group B (1.6 ± 0.5 h, P = 0.001). Mean time for sensory regression to S₁ dermatome was also prolonged in Group A (5.2 ± 0.83 h) than in Group B (4.4 ± 0.87 h, P = 0.01). Glycopyrrolate was administered in 45% of patients in Group A and 21% in Group B, which was statistically significant (P = 0.039).

Conclusion:

Conscious sedation with i.v. dexmedetomidine at a loading dose of 0.5 μg/kg followed by 0.5 μg/kg/h prolongs duration of spinal anesthesia than i.v. midazolam at a loading dose of 0.03 mg/kg followed by 0.03 mg/kg/h in patients undergoing infraumbilical surgeries. However, dexmedetomidine is associated with higher incidence of hemodynamic instability.