Dexmedetomidine in current anaesthesia practice- a review

Guanfacine Use in the ICU for Management of Sedation Weaning

Recent evidence highlights the increasing utilization of guanfacine in the intensive care unit. While dexmedetomidine is a widely used sedative and anti-anxiety agent in the intensive care unit, prolonged use can lead to withdrawal effects when attempting to reduce the dosage. This has generated interest in using guanfacine to manage agitation in patients being weaned off dexmedetomidine. Clonidine has been used for dexmedetomidine weaning, but its use has been associated with adverse cardiovascular events. Some observational studies and case reports have explored the use of guanfacine and have shown its benefits and tolerability for patients taking dexmedetomidine experiencing adverse effects. Guanfacine is increasingly being used in the intensive care unit instead of clonidine and is commonly prescribed for the management of withdrawal effects. While there are limited data from observational studies, it holds promise for future clinical research and broader adoption of guanfacine in the intensive care unit.

Local infiltration anesthesia with high dose ropivacaine and dexmedetomidine in major knee surgery is safe

BACKGROUND

The role of local infiltration anesthesia (LIA) in knee surgery is significant. LIA can be more potent than a nerve block, but without the downsides. A wide range of agents are used for LIA, including some off-label medications such as dexmedetomidine and ropivacaine. Dexmedetomidine has recently received attention for decreasing demand for anesthetic agents and prolonged effect of anesthesia. The purpose of this study was to demonstrate safety of dexmedetomidine and ropivacaine as LIA.

METHODS

This is a retrospective analysis of 200 patients receiving 300 mg of ropivacaine, 100 µg of dexmedetomidine and 10 mL of saline solution as LIA. Both agents are off-label for this use. The LIA applied prior to skin closure as a pertiarticular block. Major knee surgery was defined as ligament reconstruction of at least one ligament, fracture of the femur and the tibia, knee replacement and osteotomy. We evaluated short-term major side-effects of these agents, and evaluated 30-day complications.

RESULTS

Included were 77 arthroplasties, 10 fracture fixations, 19 osteotomies, 55 primary and revision ACL, 10 isolated medial patellar femoral ligament reconstructions, 2 ACLs combined with a partial knee arthroplasty, 4 cartilage transplantations and 23 multiligament knee reconstructions. We observed one transitory discoloration after an ACL reconstruction that disappeared by the 48 h mark. We had no 30-day superficial or deep infections. Cardiac or allergic reactions were not observed.

CONCLUSIONS

LIA in a combination of single high-dose ropivacaine and dexmedetomidine is safe in knee surgery. Further studies evaluating pain relief with this LIA combination are needed.

Effect of perioperative dexmedetomidine on recovery of postoperative gastrointestinal function in patients with general anesthesia: a systematic review and meta-analysis

BACKGROUND

There is controversy surrounding the influence of dexmedetomidine on the recovery of postoperative gastrointestinal dysfunction in patients under general anesthesia. The main purpose of this meta-analysis is to evaluate the effect of dexmedetomidine administration during the perioperative period on the recovery of gastrointestinal function in patients under general anesthesia.

METHODS

A systematic review and meta-analysis with trial sequential analysis was performed to identify randomized controlled trials comparing dexmedetomidine administration with placebo for the recovery of gastrointestinal function. The primary outcomes were gastrointestinal function; first oral feeding time; incidences of postoperative nausea and vomiting, postoperative nausea, and postoperative vomiting; time to first bowel sound; time to first flatus; and time to first defecation. The secondary outcome was the length of hospital stay.

RESULTS

A total of 20 studies comparing 2,470 participants were included in this meta-analysis. Perioperative dexmedetomidine administration did not result in a significant reduction in the time to first oral feeding (MD= -7.91, 95% CI = - 16.45 to 0.62, P = 0.07). However, dexmedetomidine administration was associated with a decreased incidence of postoperative nausea and vomiting (RR = 0.72, 95% CI = 0.58 to 0.88, P = 0.001), time to first flatus (MD= -6.73, 95% CI= -10.31 to -3.15, P = 0.0002), and time to first defecation (MD= -12.01, 95% CI = -22.40 to -1.61, P = 0.02).

CONCLUSIONS

Perioperative dexmedetomidine administration can promote the recovery of gastrointestinal function and reduce the length of hospital stay after abdominal surgery. The optimal dose and timing of dexmedetomidine and the influence on non-abdominal surgery need further investigation.

TRIAL REGISTRATION

The study protocol was registered in the PROSPERO database (registration number: CRD42023443708) on July 9, 2023.

A retrospective study of the safety and efficacy of peritoneal dialysis catheter placement under combined local infiltration anesthesia and monitored anesthesia care

OBJECTIVE

Given the lack of global consensus on anesthesia selection for peritoneal dialysis catheter (PDC) placement via open surgery, this study investigates the safety and efficacy of combining local infiltration anesthesia (LIA) with monitored anesthesia care (MAC) in patients with end-stage renal disease (ESRD).

METHODS

This retrospective analysis of ESRD patients who underwent open surgical placement of PDC in the Department of Nephrology, the First Affiliated Hospital of the Army Medical University from 1 August 2020 to 31 May 2022. Patients were categorized into two groups based on anesthesia method: LIA group and LIA + MA group. MA was defined as preoperative sedation (0.2-0.7 µg/kg/h) with dexmedetomidine injection (Huidrican trade name, DEX), and intraoperative analgesia with dexrazoxane injection (Garonin trade name, DEZ) as appropriate according to the patients' pain scores. We compared the general clinical data of the two groups of patients, the changes in blood pressure and heart rate during the whole operation, the intraoperative and postoperative pain, the total duration of the operation and the immediate postoperative complications.

RESULTS

The study included 123 patients (59 in the LIA + MAC group and 64 in the LIA group). The LIA + MA group exhibited lower pain scores measured by Visual Analogue Scale(VAS) during surgery (skin incision, subcutaneous adipose tissue dissection, anterior fascia, muscle traction, posterior fascia, peritoneum, and catheterization) compared to the LIA group(p<0.05). In terms of surgical incisions, to intraoperative pain scores (VRS), the LIA + MA group showed higher score level I and lower score level II compared to the LIA group (p = 0.002, 0.004, respectively). The LIA + MA group experienced lower postoperative resting pain (NRS) and VAS than the LIA group (p = 0.001,0.003, respectively). The surgical duration for the LIA + MA group was shorter than that of the LIA group (p<0.001). Preoperative systolic and diastolic blood pressures (SBP and DBP) were higher in the LIA + MA group compared to the LIA group (p<0.001,<0.001, respectively). Postoperative heart rate and DBP were lower in the LIA + MA group (p<0.001, 0.004, respectively). The LIA + MA group exhibited greater changes in heart rate, SBP, and DBP during and after surgery compared to the LIA group (p = 0.009, <0.001,<0.001, respectively). In terms of immediate postoperative complications, the proportion of patients requiring analgesics within 24 h post-surgery was significantly lower in the LIA + MA group (p = 0.031).

CONCLUSION

Open surgery for PDC placement under LIA + MAC is both safe and effective.

Dexmedetomidine reduced the severity of emergence delirium and respiratory complications, but increased intraoperative hypotension in children underwent tonsillectomy: a retrospective analysis

BACKGROUND

Intraoperative dexmedetomidine can be useful for its sedative and analgesic sparing effects, and for the prevention of emergence delirium. Conversely, it can cause hypotension and bradycardia. The aim of this study was to assess the safety and efficacy of dexmedetomidine in pediatric anesthesia.

METHODS

This is a retrospective cohort study in children who received intravenous dexmedetomidine (Dex group) or opioids (No-Dex group) during general anesthesia for tonsillectomy, between November 2014 and November 2016. From the medical records, data on the intraoperative phase (hemodynamic adverse events, respiratory failure at the emergence, awakening and extubation times, emergence delirium), recovery room (pain, hemodynamic parameters, and desaturation), and ward stay (pain, and nausea and vomiting) were investigated. Time of hospital discharge was calculated.

RESULTS

Three hundred twenty-eight (Dex group 183; No-Dex group 145) children ranging from 1.5 to 10 years were included. The percentage of intraoperative hypotension was significantly higher in the Dex group (P=0.01). The extubation times were significantly higher in No-Dex group (P=0.0001), although the awakening times were significantly longer with dexmedetomidine (P=0.0001). Desaturation episodes were higher in the Dex group (P=0.0001). The incidence of emergence delirium was similar in the two groups, but of greater intensity in the No-Dex group. While in the immediate postoperative period there was no difference in pain, after 24 hours, the incidence of pain and vomiting was significantly higher (P=0.003; P=0.0001) in the No-Dex group.

CONCLUSIONS

Although several outcome parameters showed important advantages of dexmedetomidine over opioid-based regimens in terms of safety and efficacy, issues such as the increased intraoperative hypotension, indicated that it is not possible to draw any definitive conclusions.

Postoperative recovery of colorectal patients enhanced with dexmedetomidine (PReCEDex): a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Intraoperative administration of dexmedetomidine has shown promise in improving postoperative gastrointestinal function. In the context of colorectal surgery, the results remain inconsistent. This review aims to provide a synthesis of studies assessing the effect of dexmedetomidine on postoperative gastrointestinal function in colorectal surgery patients.

METHODS

CENTRAL, Emcare, Embase, and MEDLINE were searched up to September 2023. Randomized controlled trials involving adult patients (≥ 18 years) undergoing elective colorectal surgery, comparing dexmedetomidine administration to a control group, and reporting on postoperative gastrointestinal function were included. Non-comparative and emergent procedures were excluded. Primary outcome was time to first flatus or bowel movement, and secondary outcomes included length of stay and time to solid oral intake. Risk of bias was assessed using the Cochrane risk of bias tool for randomized studies.

RESULTS

After screening 1194 citations, eight studies were included. Studies comprised of 570 patients in the dexmedetomidine group (mean age: 65.8 years, 43% female, mean BMI: 22.7 kg/m2) and 556 patients in control group (mean age 70.6 years, 40% female, mean BMI 22.5 kg/m2). Dexmedetomidine administration resulted in a shorter time to flatus (MD -4.55 h, 95% CI: 20.14-8.95, p < 0.005, very low certainty of evidence), a shorter time to first bowel movement (MD -11.9 h, 95% CI: 18.74-5.05, p < 0.005, very low certainty of evidence), a shorter time to solid oral intake (MD -4.34 h, 95% CI: 17.43-11.24, p < 0.005, moderate certainty of evidence), and a shorter length of stay (MD -.06 days, 95% CI: 1.99-0.12, p < 0.05, very low certainty of evidence).

CONCLUSION

In adult patients undergoing elective colorectal surgery, intraoperative use of dexmedetomidine results in clinically meaningful improvements in postoperative gastrointestinal function and consequently, shorter length of stay. Therefore, dexmedetomidine may serve as a valuable adjunct in enhancing postoperative recovery of patients following elective colorectal surgery, thereby reducing healthcare utilization, and improving patient outcomes.

A randomised comparative study of erector spinae plane block versus low-dose ketamine-dexmedetomidine intravenous infusion as intraoperative opioid-free analgesia for modified radical mastectomy

Background and Aims

Opioid-sparing analgesia for acute postoperative pain after breast cancer surgery is crucial due to opioid-related side effects. The utilisation of erector spinae plane block and low-dose intravenous ketamine-dexmedetomidine are widely recognised as non-opioid analgesic methodologies. The objective of this study was to conduct a randomised trial to examine the analgesic efficacy of both approaches while minimising the use of opioids.

Methods

Seventy-two female patients scheduled for unilateral modified radical mastectomy were recruited. They were allocated randomly to Group ESPB, which received ipsilateral ultrasound-guided erector spinae plane block by 20 mL bupivacaine 0.5% at the level of T5 after induction of general anaesthesia, and Group Ket-Dex, which received intravenous (IV) bolus 0.25 mg/kg of ketamine and 0.5 µg/kg of dexmedetomidine, followed by an IV infusion of 0.25 mg/kg of ketamine and 0.3 µg/kg of dexmedetomidine per hour. Total postoperative morphine consumption (24 h) was the primary outcome. The secondary outcomes were pain scores over 24 hours during rest, duration of analgesia, isoflurane consumption, time to awakening, postoperative nausea and vomiting (PONV), and postoperative serum cortisol level.

Results

The postoperative morphine consumption over 24-hour in Group ESPB was 3.26 mg (0-6.74) versus 2.35 mg (2.08-4.88) in Group Ket-Dex (P = 0.046). Group Ket-Dex had lower pain scores at rest, longer analgesia duration, longer awakening time, and lower postoperative serum cortisol levels.

Conclusion

Intravenous low-dose ketamine-dexmedetomidine infusion intraoperatively with inhalational-based general anaesthesia provides superior opioid-sparing analgesia to that of ESPB in patients undergoing unilateral non-reconstructive modified radical mastectomy, with less postoperative opioid consumption and stress response.

A Comparative Study of Fixed-Dose Dexmedetomidine and Propofol Infusions on Intraoperative Desflurane Consumption During Bispectral Index-Guided Laparoscopic Surgeries: A Randomized Controlled Study

Background Desflurane is an excellent but expensive volatile anesthetic agent. Dexmedetomidine and propofol may decrease intraoperative desflurane consumption. This study aimed to compare the desflurane-sparing effect of dexmedetomidine and propofol in patients undergoing laparoscopic surgeries under bispectral index (BIS)-guided general anesthesia (GA). Methods Sixty-two adult patients, ASA (American Society of Anesthesiologists) physical status I or II, of either sex, aged between 18 and 60 years, were randomly allocated into group D or group P. Only group D patients received an intravenous (IV) bolus of dexmedetomidine (1 mcg/kg) over 15 minutes before induction. In both groups, GA was induced following the standard protocol with propofol infusion (0.5 mg/kg/min) until the BIS value dropped below 60. For maintenance, group D and group P patients received IV dexmedetomidine infusion (0.5 mcg/kg/h) and propofol infusion (50 mcg/kg/min), respectively. In both groups, desflurane dial concentration was adjusted between 3 and 8% to maintain the BIS within the range of 45-55. An hourly bolus of IV fentanyl (0.5 mcg/kg) and a half-hourly bolus of IV vecuronium (0.02 mg/kg) were administered. The total amount of desflurane consumed, duration of pneumoperitoneum, extra aliquots of propofol used during maintenance, number of boluses of IV atropine, fentanyl, and esmolol, time to attain Ramsay Sedation Score of 2 after extubation, time to first postoperative analgesic request at Numerical Rating Scale (NRS) score ≥ 4, time to reach a Modified Aldrete Score of ≥9, and incidence of any side effects were recorded. All the data were analyzed and compared using appropriate statistical tests, and a p-value of <0.05 was considered significant. Results The final data analysis was performed on 60 patients. The mean desflurane consumption was clinically higher in group P patients than in group D, but the difference was statistically insignificant (p-value > 0.05). The mean induction dose of propofol was significantly less in group D than in group P (p-value < 0.05). After extubation, the difference in time to the first analgesic request (NRS ≥ 4) between the groups was statistically significant (p-value < 0.05). Group D patients had a residual intraoperative analgesic effect. Conclusion The effects of dexmedetomidine and propofol infusions on desflurane consumption in laparoscopic surgeries are comparable, with minimal effects on intraoperative hemodynamics and postoperative recovery profiles.

Dexmedetomidine with different concentrations added to local anesthetics in erector spinae plane block: a meta-analysis of randomized controlled trials

Background

Dexmedetomidine has been used as a perineural local anesthetic (LA) adjuvant to facilitate the potency of erector spinal plane block (ESPB). This quantitative review aimed to evaluate whether perineural dexmedetomidine for ESPB can improve the effects of analgesia compared to LA alone.

Methods

Randomized controlled trials (RCTs) that investigated the addition of dexmedetomidine to LA compared to LA alone in ESPB were included. The pain scores, duration of sensory block, the time to first analgesia requirement, postoperative morphine consumption, rescue analgesia, and dexmedetomidine-related side effects were analyzed and combined using random-effects models.

Results

A total of 823 patients from 13 RCTs were analyzed. Dexmedetomidine was used at the concentration of 0.5 μg/kg in three trials and 1 μg/kg in nine trials, and both in one trial. Both concentrations of dexmedetomidine perineurally administrated significantly reduced the rest VAS scores postoperatively at 12 h (0.5 μg/kg dexmedetomidine: MD = -0.86; 95% CI: -1.59 to -0.12; p = 0.02; 1 μg/kg dexmedetomidine: MD = -0.49; 95% CI: -0.83 to -0.16; p = 0.004), and 24 h (0.5 μg/kg dexmedetomidine: MD = -0.43; 95% CI: -0.74 to -0.13; p = 0.005; 1 μg/kg dexmedetomidine: MD = -0.62; 95% CI: -0.84 to -0.41; p < 0.00001). Both concentrations of dexmedetomidine added in LAs improved the dynamic VAS scores postoperatively at 12 h (0.5 μg/kg dexmedetomidine: MD = -0.55; 95% CI: -0.95 to -0.15; p = 0.007; 1 μg/kg dexmedetomidine: MD = -0.66; 95% CI: -1.05 to -0.28; p = 0.0006) and 24 h (0.5 μg/kg dexmedetomidine: MD = -0.52; 95% CI: -0.94 to -0.10; p = 0.01; 1 μg/kg dexmedetomidine: MD = -0.46; 95% CI: -0.75 to -0.16; p = 0.002). Furthermore, perineural dexmedetomidine prolonged the duration of the sensory block and the time to first analgesia requirement, reduced postoperative morphine consumption, and lowered the incidence of rescue analgesia and chronic pain.

Conclusion

The meta-analysis showed that using perineural dexmedetomidine at either 0.5 μg/kg or 1 μg/kg doses in ESPB can effectively and safely enhance pain relief.

Systematic review registration

PROSPERO (CRD42023424532: https://www.crd.york.ac.uk/PROSPERO/).

Ferroptosis and circular RNAs: new horizons in cancer therapy

Cancer poses intricate challenges to treatment due to its complexity and diversity. Ferroptosis and circular RNAs (circRNAs) are emerging as innovative therapeutic avenues amid the evolving landscape of cancer therapy. Extensive investigations into circRNAs reveal their diverse roles, ranging from molecular regulators to pivotal influencers of ferroptosis in cancer cell lines. The results underscore the significance of circRNAs in modulating molecular pathways that impact crucial aspects of cancer development, including cell survival, proliferation, and metastasis. A detailed analysis delineates these pathways, shedding light on the molecular mechanisms through which circRNAs influence ferroptosis. Building upon recent experimental findings, the study evaluates the therapeutic potential of targeting circRNAs to induce ferroptosis. By identifying specific circRNAs associated with the etiology of cancer, this analysis paves the way for the development of targeted therapeutics that exploit vulnerabilities in cancer cells. This review consolidates the existing understanding of ferroptosis and circRNAs, emphasizing their role in cancer therapy and providing impetus for ongoing research in this dynamic field. See also the graphical abstract(Fig. 1).

The value of local dexmedetomidine as an adjuvant to ultrasound-guided wide awake local anesthesia no tourniquet (WALANT) in flexor tendon repair surgeries: a randomized controlled trial

BACKGROUND

The Wide-Awake Local Anesthesia No Tourniquet (WALANT) technique allows intraoperative motor assessment of tendon repair integrity of the hand compared with general anesthesia or brachial plexus block. No studies have tested the effect of adding dexmedetomidine to lidocaine on the analgesic properties of the WALANT technique, which is the aim of our study.

METHODS

A total of 128 patients aged more than 18 years were scheduled for surgical flexor tendon injury repair using WALANT technique. Patients were divided into two equal groups. Ultrasound-guided subcutaneous injection of lidocaine 1% with dexmedetomidine (1 µg/kg), Group D, or without dexmedetomidine, Group C, was performed at four points: proximal to the wrist joint, the distal forearm, palm region, and proximal phalanges. The primary outcome was total morphine consumption throughout the first postoperative day. Secondary outcomes included number of patients requiring rescue analgesia, time to first analgesic request, and pain score.

RESULTS

Total morphine consumption was significantly (P < 0.001) lower in group D (2.66 ± 0.998) than in group C (3.66 ± 1.144) mg. Number of patients requiring rescue analgesia was significantly (P < 0.001) lower in group D (54.7% (35)) than group C (100.0% (64)). The time for first request for analgesia was significantly (P < 0.001) longer in group D (11.31 ± 6.944) than in group C (5.91 ± 4.839) h. Pain score was significantly higher in group C than D at three (P < 0.001), and six (P = 0.001) hours (P = 0.001) postoperatively.

CONCLUSION

Dexmedetomidine significantly improves the analgesic quality of WALANT when added to lidocaine with less opioid consumption.

TRIAL REGISTRATION

(ID: PACTR202203906027106; Date: 31/07/2023).

Persistent Paradoxical Reaction to Midazolam despite General Anesthesia with Dexmedetomidine

Midazolam is a widely used benzodiazepine due to its rapid onset of action and relatively safe side effect profile. It is used for sedation, anxiolysis, and induction of general anesthesia. However, in <1% of instances, it may cause a paradoxical excitement: agitation, restlessness, myoclonus, stiffening of the limbs, and aggression. We report a case report in which preoperative administration of midazolam caused onset of the aforementioned symptoms that were not attenuated by general anesthesia with dexmedetomidine. This case report aims to create awareness about the rare adverse reactions of midazolam and prepare clinicians to manage these situations.

Premedication with intranasal versus intravenous dexmedetomidine for hypotensive anesthesia during functional endoscopic sinus surgery in adults: A randomized triple-blind trial

Functional Endoscopic Sinus Surgery (FESS) has been performed under controlled hypotension to increase operating field visibility. Intranasal (IN) dexmedetomidine is easy, noninvasive, and possesses lower C max, accompanied by lower pharmacodynamic action, including hypotension, bradycardia, and sedation. This trial aimed to compare IN and intravenous (IV) dexmedetomidine for hypotensive anesthesia during FESS. This randomized, controlled, triple-blinded clinical trial involved sixty cases scheduled for FESS. Patients were divided into two equal groups by random manner. 45-60 min before anesthesia induction, group IN: received 1 μg/kg IN dexmedetomidine diluted in 10 ml of saline 0.9 % intranasally preoperative. Group IV: received 1 μg/kg dexmedetomidine diluted in 10 ml of saline 0.9 % infused over 10 min. The primary outcome was the total amount of administered atropine. The secondary outcomes included hemodynamic, through 1 h before surgery, intraoperatively and postoperatively at different time intervals. The quality of the operative field, sedation, adverse reactions and hemostatic stuffing after FESS were also assessed. The total amount of consumed atropine decreased significantly in group IN compared to group IV. Preoperative Ramsay Sedation scores at T0, T5, T50 and T60 were comparable between the two groups, while at T10, T15, T20, T30, and T40 were lower significantly in the IN group compared with the IV group. Preoperative mean arterial blood pressure at T0, T5 and T60 had comparable differences across both groups while reduced at T10 to T 45 significantly in the IV group than IN group. Both groups had comparable satisfaction, postoperative Ramsey sedation, hemostatic suffering, quality of operative field and complications. In conclusion, IN dexmedetomidine administration is relatively simple and appropriate; moreover, it decreases first-pass metabolism. Onset is prolonged relative to IV dosing; thus, it should be administered nearly 1 h before surgery and recommended in adult patients as they require minor sedation preoperatively.

Regional Anesthesia for Arthroscopic Knee Repair in a Patient With Hypertrophic Obstructive Cardiomyopathy (HOCM) Under Monitored Anesthesia Care With Dexmedetomidine Infusion

Patients with hypertrophic obstructive cardiomyopathy (HOCM) who are scheduled for elective, noncardiac surgery present a distinctive challenge for perioperative healthcare providers. The use of general anesthesia and neuraxial anesthesia carries the risk of unpredictable hemodynamic changes and potential complications. Regional anesthesia (RA) emerges as a prudent and effective option for HOCM patients. RA provides advantages such as minimizing hemodynamic fluctuations, avoiding intubation, reducing pharmacologic side effects, facilitating enhanced recovery after surgery, and contributing to greater patient satisfaction. We share the case of a 15-year-old individual diagnosed with HOCM and exercise intolerance, undergoing arthroscopic repair for right patellar instability. In this instance, the patient received preoperative peripheral nerve blocks for surgical anesthesia and underwent repair utilizing monitored anesthesia care (MAC) with a dexmedetomidine (DEX) infusion.

Music combined with dexmedetomidine relieves preoperative anxiety and promotes postoperative recovery in patients undergoing gynecologic laparoscopic surgery: a randomized clinical trial

OBJECTIVES

To investigate the effects of music combined with dexmedetomidine on perioperative anxiety and postoperative recovery in gynecologic laparoscopic patients.

METHODS

A total of 82 female patients were enrolled in this study. Patients were randomized to the patient-preferred Music+Dexmedetomidine group (M+DEX group, n=41) and the Dexmedetomidine group (DEX group, n=41). Prior to the induction of anesthesia, dexmedetomidine was pumped intravenously at 0.5 µg/kg for 10 minutes in both groups and then maintained at 0.2 µg/kg/hour until 30 minutes before the end of surgery. In contrast to the patients in the DEX group, the patients in the M+DEX group listened to 5 minutes of their favorite music during dexmedetomidine infusion. The primary outcome was the patient's preoperative State Anxiety Inventory (SAI) score. The secondary outcomes included visual analog scale (VAS) pain scores and QoR-15 scores at 24 hours postoperatively.

RESULTS

The clinical data of a total of 82 patients were analyzed. After the music intervention, we found that the preoperative SAI scores were lower in the M+DEX group than in the DEX group (37.9±5.6 vs. 41.5±6.9; P=0.01). The M+DEX group had lower VAS scores at 24 hours postoperatively than the DEX group (1 (1.0, 2.0) vs. 2 (2.0, 3.0), P < 0.01), and the M+DEX group had higher QoR-15 scores at 24 hours after the surgery than the DEX group (127.7±10.0 vs. 122.3±11.2; P=0.03).

CONCLUSION

Patients undergoing gynecologic laparoscopic surgery who listened to their favorite music before the induction of anesthesia had less preoperative anxiety and recovered better 24 hours postoperatively than those who only received dexmedetomidine.

Effects of epidurally administered dexmedetomidine and dexamethasone on postoperative pain, analgesic requirements, inflammation, and oxidative stress in thoracic surgery

The aim of this study was to compare the effects of dexmedetomidine and dexamethasone as adjuvants to preoperative epidural administration of local anesthetic (ropivacaine) in thoracic surgery on the postoperative level of pain, use of analgesics, inflammation, and oxidative stress. The study enrolled 42 patients who underwent elective thoracic surgery in a one-year period at the University Hospital Dubrava (Zagreb, Croatia). Based on a computer-generated randomization list the patients were assigned to the dexmedetomidine (n = 18) or dexamethasone (n = 24) group. Postoperatively, patients of dexmedetomidine group reported lower pain (VAS value 1 h post surgery, 3.4 ± 2.7 vs. 5.4 ± 1.8, dexmedetomidine vs. dexamethasone, p < 0.01) and had lower anal-gesic requirements in comparison with dexamethasone group. Thus, dexmedetomidine in comparison with dexamethasone was more efficient in lowering pain and analgesia requirements 24 h after the surgery. On the contrary, dexamethasone had better anti-inflammatory properties (CRP level 24 h post surgery, 131.9 ± 90.7 vs. 26.0 ± 55.2 mg L-1, dexmedetomidine vs. dexamethasone, p < 0.01). Both dexmedetomidine and dexamethasone exhibited antioxidant effects, however, their antioxidant properties should be further explored. The results of this study improve current knowledge of pain control in thoracic surgery.

Advances in Anesthesia for Shoulder Surgery: A Comprehensive Review of Dexmedetomidine-Enhanced Interscalene Brachial Plexus Block

Surgical procedures on the shoulder pose distinctive challenges in managing pain during the perioperative period, underscoring the importance of exploring innovative anesthesia techniques. This comprehensive review article delves into integrating dexmedetomidine, an alpha-2 adrenergic agonist, within interscalene brachial plexus blocks for shoulder surgery. The review initiates by underscoring the pivotal role of effective anesthesia in shoulder surgery and elucidates the rationale behind investigating dexmedetomidine as an adjunct. It meticulously examines the anatomy and physiology of the brachial plexus, emphasizing its critical significance in shoulder surgery. Furthermore, the article expounds on dexmedetomidine's mechanisms of action and pharmacokinetics, encompassing its safety profile and potential side effects. The conventional interscalene brachial plexus block techniques, along with their limitations and challenges, are discussed, laying the foundation for the integration of dexmedetomidine. The review subsequently delves into exploring the role of dexmedetomidine in regional anesthesia, covering previous studies, mechanisms of action, and the potential advantages of incorporating it into nerve blocks. The review's core concentrates on the practical application of dexmedetomidine-enhanced interscalene brachial plexus blocks. This includes discussions on administration techniques, dosage guidelines, and compelling evidence supporting its utilization. Clinical scenarios where this approach proves most advantageous are thoroughly explored, comparing its effectiveness with traditional techniques in terms of pain control and patient outcomes. A comprehensive examination of relevant clinical trials and case studies highlights the evidence supporting its efficacy. The review also underscores safety considerations associated with dexmedetomidine. It proposes strategies for mitigating risks to ensure patient safety. Insights into future directions and research are provided, encompassing ongoing studies, areas necessitating further investigation, and potential refinements in technique. Finally, the article summarizes key findings, emphasizing the practicality of dexmedetomidine-enhanced interscalene brachial plexus blocks in shoulder surgery and its far-reaching implications for clinical practice and patient care.

Dexmedetomidine in Patients Undergoing Transsphenoidal Resection of Pituitary Adenoma: An Updated Systematic Review and Meta-Analysis of Randomized Placebo-Controlled Trials

Dexmedetomidine has been widely studied in many surgical settings, with possible benefits in lowering anesthetic requirements, improving perioperative hemodynamic stability, and improving postoperative outcomes. This systematic review aims to evaluate the effects of dexmedetomidine in patients undergoing transsphenoidal resection of pituitary adenoma, shedding light on its potential as an adjunctive agent in anesthesia for this specific surgical population. In this review, we searched PubMed, Cochrane Library, Scopus, Web of Science, and Google Scholar from inception to July 20, 2023. A total of six randomized clinical trials (RCTs) investigating the effects of dexmedetomidine versus placebo in patients undergoing transsphenoidal resection of pituitary adenoma were included in this review. The outcomes of interest were extracted from the included studies as mean difference (MD) and standard deviation (SD), then analyzed using the Review Manager (RevMan, RevMan International Inc., New York, USA) software. Our literature search process retrieved 274 records. Of them, six studies were included in the meta-analysis. There was a significant difference between the dexmedetomidine group compared to the placebo group in terms of heart rate at the end of the surgery (MD = -16.5; CI = [-25.36 to -7.64]; P value = 0.0003) and after extubation (MD = -16.81; CI = [-23.18 to -10.43]; P values < 0.00001). Furthermore, dexmedetomidine significantly reduced the mean arterial blood pressure (MAP) at after both intubation and extubation (MD = -9.11 and -21.5; CI = [-13.56 to -4.65] and [-30.93 to -12.06]; P values < 0.00001). This systematic review and meta-analysis demonstrated that dexmedetomidine appears to have several potential benefits in patients undergoing transsphenoidal resection of pituitary adenoma. The use of dexmedetomidine was associated with reductions in heart rate, mean arterial blood pressure, blood loss, and duration of surgery, while showing no significant difference in propofol dose or time to extubation of the trachea.

EEG response of dexmedetomidine during drug induced sleep endoscopy

Introduction

Dexmedetomidine is one of the anesthetics of choice for drug induced sleep endoscopy (DISE), with advantages including limited respiratory depression, analgesia, and decreased incidence of emergence delirium. However, challenges with determining sedation levels and prolonged recovery have limited its usage. An improved understanding of the effect of dexmedetomidine on the level of sedation and the corresponding electroencephalographic (EEG) changes could help overcome these barriers.

Methods

Fifty-one patients received dexmedetomidine sedation with Richmond Agitation-Sedation Scale (RASS) score assessment and continuous EEG monitoring via SedLine for DISE. We constructed a pharmacokinetic model to determine continuous dexmedetomidine blood concentration. From the SedLine, we extracted the patient state index (PSI), and from the EEG we calculated the spectral edge frequency 95% (SEF95) and the correlation dimension (CD), a type of fractal dimension used to assess the complexity of a system. These metrics were subsequently compared against one another and with the dexmedetomidine concentration.

Results

Our pharmacokinetic model yielded a two-compartment model with volumes of 51.8 L and 106.2 L, with clearances of 69.5 and 168.9 L/h, respectively, and a time to effect of 9 min, similar to prior studies. Based on this model, decreasing RASS score, SEF95, CD, and PSI were all significantly associated with increasing dexmedetomidine concentration (p < 0.001, p = 0.006, p < 0.001 respectively). The CD, SEF95, and PSI better captured the effects of increasing dexmedetomidine concentration as compared to the RASS score. Simulating dexmedetomidine concentration based on titration to target levels derived from CD and PSI confirmed commonly used dexmedetomidine infusion dosages.

Conclusion

Dexmedetomidine use for DISE confirmed previous pharmacokinetic models seen with dexmedetomidine. Complex EEG metrics such as PSI and CD, as compared to RASS score and SEF95, better captured changes in brain state from dexmedetomidine and have potential to improve the monitoring of dexmedetomidine sedation.

General Anesthetic Care of Obese Patients Undergoing Surgery: A Review of Current Anesthetic Considerations and Recent Advances

Obesity has long been linked to adverse health effects over time. As the prevalence of obesity continues to rise, it is important to anticipate and minimize the complications that obesity brings in the anesthesia setting during surgery. Anesthetic departments must recognize the innumerable risks when managing patients with obesity undergoing surgery, including anatomical and physiological changes as well as comorbidities such as diabetes, cardiovascular diseases, and malignancies. Therefore, the purpose of this review is to analyze the current literature and evaluate the current and recent advances in anesthetic care of obese patients undergoing surgery, to better understand the specific challenges this patient population faces. A greater understanding of the differences between anesthetic care for obese patients can help to improve patient care and the specificity of treatment. The examination of the literature will focus on differing patient outcomes and safety precautions in obese patients as compared to the general population. Specifically highlighting the differences in pre-operative, intra-operative, and post-operative care, with the aim to identify issues and present possible solutions.

Efficacy of two doses of dexmedetomidine on attenuating cardiovascular response and safety of respiratory tract to extubation

Introduction

Extubation can be associated with an adverse hemodynamic or respiratory response, which may be serious in cardiovascular written or in the elderly. The present study was conducted with the aim of investigating the effect of two different doses of dexmedetomidine in the prevention of extubation complications.

Methods

This randomized clinical trial was conducted in Isfahan in 2020-2021 on 174 patients undergoing elective surgery. Patients were randomly divided into 3 groups receiving dexmedetomidine 1 μg/kg (D1), dexmedetomidine 0.5 μg/kg (D2), and normal saline (S). Hemodynamic variables include heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and peripheral blood oxygen saturation (Spo2) was measured and recorded before removing the endotracheal tube and at 1, 3, 5 and 10 minutes after extubation. Also, airway responses to extubation such as cough, hoarseness, and laryngospasm were investigated.

Results

SBP, MAP, and HR in the D1 group were significantly lower than in other groups. In the D2 group, these measurements were lower than the control group at 3, 5, and 10 minutes after extubation (P<0.05 for all). In placebo group, SBP, MAP, and HR increased significantly after extubation (P=0.01). In group D1, cough (P=0.007) and its intensity (P=0.013), nausea and vomiting (P=0.04) and chills (P=0.001) were less than in other groups.

Conclusion

In the D1 group, attenuation of autonomic response to extubation was more than other groups and side effects were less than D2 group, and in both groups, these side effects were less than the saline group.

[Effect of Ropivacaine Combined with Dexmedetomidine for Serratus Anterior Plane Block Plus Patient-Controlled Intravenous Analgesia on Postoperative Recovery Quality of Patients Undergoing Thoracoscopic Radical Resection of Lung Cancer]

Objective

To study the postoperative analgesic effect of ropivacaine combined with dexmedetomidine for serratus anterior plane block (SAPB) under ultrasound visualization plus patient-controlled intravenous analgesia (PCIA) in patients undergoing thoracoscopic radical resection of lung cancer.

Methods

A total of 129 patients undergoing elective thoracoscopic surgery were enrolled. The patients were randomly assigned to three groups ( n=43 in each group), a normal saline group (control group), a ropivacaine mesylate group (Group R) and a ropivacaine mesylate combined with dexmetomidine hydrochloride group (Group RD). After operation, ultrasound-guided SAPB was performed and patients in the three groups received the injection of 0 mL of 0.9% normal saline, 25 mL of 0.5% ropivacaine, and 25 mL of 0.5% ropivacaine+1 μg/kg dextrometomidine hydrochloride mixture, respectively. In addition, PCIA was used for all the patients. The button on the PCIA pump was pressed when the postoperative pain visual analogue score (VAS)≥4 on coughing, and rescue analgesic of sufentanil was given intravenously at 2.5 μg/bolus. The primary outcome was the VAS scores at rest and on coughing at 10 min (T 1), 6 h (T 2), 12 h (T 3), 24 h (T 4), and 48 h (T 5) after extubation. The secondary outcomes included hemodynamics, the quality of sleep for the first 3 nights after operation, number of times the button on the PCIA pump was pressed, intraoperative and postoperative opioid dosage, time of first postoperative rescue analgesic, duraion of intubation, length of stay at the hospital, adverse reactions, etc.

Results

Compared with those of the control group, the VAS scores of the Group R and Group RD were significantly lower at 10 min, 6 h, and 12 h after extubation ( P<0.05). In comparison with Group R, the number of patients requiring rescue analgesia, the time of first postoperative rescue analgesic, the number of times the button on the PCIA pump was pressed, and the total dose of rescue sufentanil were all significantly lower ( P<0.05) in the Group RD. Patients in the Group RD had better sleep quality in the second and third nights after operation and lower incidence of nausea and vomiting ( P<0.05).

Conclusion

0.5% ropivacaine and 1 μg/kg dexmedetomidine SAPB combined with PCIA can significantly reduce postoperative pain and improve postoperative recovery quality in patients undergoing thoracoscopic radical resection of lung cancer.

A comprehensive evaluation between dexmedetomidine and midazolam for intraoperative sedation in the elderly: protocol for a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The sedative effect of intraoperative sedation in elderly surgery exerts critical influence on the prognosis. Comparison on the safety and efficacy between dexmedetomidine and midazolam in many clinical randomized controlled trials (RCTs) was inconsistent and suspicious. We aim to comprehensively evaluate the safety and efficacy between dexmedetomidine and midazolam for intraoperative sedation in the elderly via meta-analysis and systematic reviews.

METHODS

RCTs regarding to the comparison of sedative effects and safety between dexmedetomidine and midazolam in elderly patients (aged ≥ 60 years) will be comprehensively searched from 2000 October to 2022 May through 4 English databases and 4 Chinese databases. After extraction in duplicate, the systematic review and meta-analysis will be performed on the primary outcomes (hemodynamic changes, sedative effect, cognitive function) and secondary outcomes (analgesic effect, surgical characteristics, complications, or adverse reactions) for assessing the two therapy methods using Review Manager software (Version 5.3). Sensitivity analysis will be conducted to evaluate the heterogeneity of the results; funnel plot and Egger's trial will be performed to analyze publication bias of the included studies, and trial sequential analysis will be applied to assess the robustness and reliability of preliminary meta-analysis results. Finally, rating quality of evidence and strength of recommendations on the meta results will be summarized by Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach.

DISCUSSION

This systematic review and meta-analysis will evaluate the safety and efficacy between dexmedetomidine and midazolam for intraoperative sedation in the elderly; it will give an insight on the application of dexmedetomidine and midazolam and will provide evidence-based reference for clinical decision-making.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021221897.

Effects of Preoperative Sleep Disorders on Anesthesia Recovery and Postoperative Pain in Patients Undergoing Laparoscopic Gynecological Surgery under General Anesthesia

Sleep disorder dramatically affects people's physical and mental health. Here, we investigated the effect of preoperative sleep disorders on anesthesia recovery and postoperative pain in patients undergoing laparoscopic gynecological surgery under general anesthesia. 120 patients who underwent elective laparoscopic gynecological surgery under general anesthesia in Taizhou Central Hospital from November 2021 to March 2022 were included. According to the score of the Pittsburgh sleep quality index (PSQI), the participating patients were divided into four groups: control group (control group), mild sleep disorder group A (group A), moderate sleep disorder group B (group B), and severe sleep disorder group C (group C), with 30 patients in each group. The changes of mean arterial pressure (MAP) and heart rate (HR) at different time points, operation time, anesthesia time, extubation time, the time when Aldrete score reached 10 points, visual analog score (VAS) serum interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-α (TNF-α) were compared among different groups. Our study demonstrated that there were no significant differences in MAP and HR among the four groups at the same time points (all P > 0.05). Significant differences in the time of extubation and Aldrete score reaching 10 points had been found among the four groups (all P < 0.001), indicating more sleep disorder induced longer extubation and recovery time. There were significant differences in VAS scores among the four groups at both different and the same time points (all P < 0.001), suggesting more sleep disorders induced more pain in the sufferers. Serum IL-6 levels were significantly higher in the three sleep disorder groups than the control group at 6 h and 24 h after the operation (all P < 0.05), while group C has the highest IL-6 levels as compared to the other group (P = 0.09 and P < 0.001, respectively). At 6 h after operation, serum levels of TNF-α in group C were significantly higher than in the control group (P = 0.044), but no significant differences were found in the other two groups (all P > 0.05). Positive correlation with preoperative PSQI score has been found with the times of extubation, the time of Aldrete score reaching 10 points, the VAS at 1 h, 6 h, and 24 h after operation, the level of serum IL-6 at 1 day before operation and 6 h and 24 h after operation, and the TNF-α at 6 h and 24 h after operation (all P < 0.001). The present study showed that the degree of preoperative sleep disorders could affect the quality of postoperative awakening and pain of patients undergoing laparoscopic gynecological surgery under general anesthesia, which might be associated with the aggravation of inflammatory reactions in the body.

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.

Usefulness of Continuous Low-Dose Fentanyl in Combination with Dexmedetomidine and Midazolam for Intravenous Sedation: A Randomised Controlled Trial

Intravenous dexmedetomidine (DEX) and midazolam (MZ) are currently used to achieve sedation in dental surgery under local anaesthesia. However, the efficacy of low-dose fentanyl (FEN) in combination with DEX and MZ sedation remains unclear. Therefore, we implemented a prospective randomised controlled trial to investigate the intra- and postoperative analgesic effects, intraoperative respiratory and circulatory dynamics, and frequency of intra- and postoperative adverse events of continuous low-dose fentanyl administration with DEX and MZ sedation. Patients aged 20–64 years scheduled for dental surgery under sedation were randomly assigned to the DEX+MZ (DM) or DEX+MZ+FEN (DMF) group. DEX was administered at 4 μg/kg/h for 10 min and then reduced to 0.7 μg/kg/h until the end of surgery. MZ was administered at 0.04 mg/kg upon the initial administration of DEX and 0.02 mg/kg every hour thereafter. In the DMF group, FEN infusion was administered at 2 μg/kg/h during the initial administration of DEX and then reduced to 1 μg/kg/h after 10 min until the end of surgery. Primary outcomes were intra- and postoperative analgesic efficacies, whereas secondary outcomes were intraoperative respiratory and circulatory dynamics. The total amount of intraoperative local anaesthetic administered and the heart rate were significantly lower in the DMF group than in the DM group (P = 0.044 and P < 0.01, respectively). No significant difference was observed in the frequency of postoperative administration of analgesics and intra- and postoperative adverse events. These findings demonstrated that low-dose FEN infusion in combination with DEX and MZ sedation in dental surgery provides intraoperative analgesia and suppresses tachycardia with little effect on blood pressure and respiratory dynamics and without effect on postoperative analgesia.

Dexmedetomidine versus propofol sedation in flexible bronchoscopy: a randomized controlled trial

Background

Dexmedetomidine (DEX), is a highly selective alpha2 adrenoceptor (α2-AR) agonist, successfully used in various procedures including flexible bronchoscopy. Randomized controlled trials (RCTs) evaluating DEX sedation during bronchoscopy report equivocal results regarding respiratory and hemodynamic outcomes.

Methods

We conducted an RCT to evaluate the efficacy and safety of dexmedetomidine compared to propofol for sedation during bronchoscopy. The primary outcome was the number of desaturation events, secondary outcomes were transcutaneous Pco2 level, hemodynamic adverse events and physician and patient satisfaction.

Results

Overall, 63 patients were included, 30 and 33 in the DEX and propofol groups, respectively. The number of desaturation events was similar between groups, median (IQR) 1 (0–1) and 1 (0–2) in the DEX and control groups, respectively (P = 0.29). Median desaturation time was 1 (0–2) and 1 (0–3) minutes in the DEX and control groups, respectively (P = 0.48). Adverse events included hypotension, 33% vs 21.1% in intervention and control groups, respectively (P = 0.04), bradycardia, cough, and delayed recovery from sedation. Total adverse events were 22 and 7 in DEX and propofol groups, respectively (P = 0.009).

Conclusion

Dexmedetomidine sedation during bronchoscopy did not show differences in oxygen saturation and transcutaneous CO2 level in comparison to propofol. Moreover, DEX sedation required a significantly higher number of rescue boluses, due to inadequate sedation and was associated with a higher rate of adverse events.

Trial registration NCT04211298, registration date: 26.12.2019.

Implications of Electronic Cigarettes on the Safe Administration of Sedation and General Anesthesia in the Outpatient Dental Setting

Today the number of electronic cigarette users continues to rise as electronic cigarettes slowly, yet steadily overtake conventional cigarettes in popularity. This shift is often attributed to the misconception that electronic cigarettes are "safer" or "less dangerous" than conventional cigarettes. Recent studies have shown that electronic cigarettes are far from safe and that the inhaled agents and byproducts within vaping aerosols can have adverse effects on systemic and oral health like combustible tobacco products. The first electronic cigarettes were originally introduced as a tool for smoking cessation. However, newer iterations of electronic cigarette devices have been modified to allow the user to consume tetrahydrocannabinol (THC), the psychoactive component of cannabis, in addition to nicotine. As the popularity of these devices continues to rise, the number of patients seeking dental treatment who also consume electronic cigarettes will too. This article aims to shed light on the deleterious effects electronic cigarettes can have on systemic and oral health, as well as the special considerations for sedation and anesthesia providers treating patients who use electronic cigarettes.

Nonopioid analgesics for analgesia in critically ill patients: Friends, enemies, or collaborators

Patients in intensive care units (ICUs) experience pain, which they describe as a significant cause of stress during treatment. It can progress to chronic pain and significantly affect the quality of life. Opioids have long been the backbone of ICU pain therapy. The consequences of their long-term use are known today, such as prolonged ICU stay and mechanical ventilation, resulting in increased treatment costs. Additionally, abstinence syndrome is a consequence of abrupt opioid withdrawal. Also, there is a risk of tolerance and hyperalgesia after prolonged opioid use. Globally, opioid dependence after hospital opioid treatment is alarming, although there is still a lack of data on its incidence after ICU. Multimodal analgesia enables comfort to the patient, opioid-sparing, and avoidance of side effects of non-opioid analgesics. Nonsteroidal anti-inflammatory drugs (NSAIDs) are a broad group of drugs recommended with paracetamol to treat mild to moderate acute postoperative pain. Although often prescribed by intensivists, their use in treating painful conditions in ICU is controversial due to the possible consequences on the organs of critically ill patients. Due to the inhibition of cyclooxygenases, NSAIDs indirectly cause vasoconstriction of the renal arteries and arterioles, leading to kidney damage. NSAIDs inhibit platelet aggregation and may predispose to bleeding. Analgesia of a critically ill patient is a important part of their treatment, however it can be challenging in certain patients. Numerous combinations of pharmacological and non-pharmacological approaches can be adapted to the patient's current characteristics.

Practical Considerations for Dexmedetomidine Sedation in Adult Cataract Surgery Under Local/Regional Anesthesia: A Narrative Review

Cataract surgery is predominantly performed under local/regional anesthesia, with or without sedation. The practice pattern of sedation is unknown and seems to vary significantly among institutions and countries, routinely administered in some parts of the world to the other extreme of none at all. The selection of sedative agents and techniques varies widely. Currently, there is no ideal sedative agent. Dexmedetomidine has gained recent attention for sedation in ophthalmic local/regional anesthesia due to its alleged advantages of effective sedation with minimal respiratory depression, decreased intraocular pressure, and reduced pain during the local anesthetic injection; however, they are subject to differing interpretations. Published literature also suggests that although dexmedetomidine sedation for cataract surgery under local/regional anesthesia is potentially useful, its role may be limited due to logistical difficulties in administering the recommended dose.

Effects of dexmedetomidine on blood coagulation: an in vitro study using rotational thromboelastometry

PURPOSE

To assess the effects of various concentrations of dexmedetomidine on the human blood coagulation profile using rotational thromboelastometry (ROTEM).

METHODS

Venous blood samples were collected from 11 healthy volunteers and divided into four specimen bottles; dexmedetomidine was added to attain final sample concentrations of 0, 0.5, 1.0, and 1.5 ng/mL. ROTEM was performed on each study sample.

RESULTS

The concentration of dexmedetomidine increased, and the ROTEM values showed a hypercoagulable state. The change in clotting time (CT) for INTEM was larger in samples with a dexmedetomidine concentration of 1.5 ng/mL (- 34%) than in the 0.5 ng/mL samples (- 16%) (P = 0.010). The change in clot formation time (CFT) for INTEM was greater in 1.5 ng/mL samples (- 16%) than in 0.5 ng/mL samples (- 4%) (P = 0.004). A greater decrease in CT for EXTEM was identified in the 1.0 ng/mL and 1.5 ng/mL samples (- 36% and - 37%, respectively) than in the 0.5 ng/mL samples (- 12%) (P = 0.003 for both categories). The change in CFT for EXTEM was greater in the 1.0 ng/mL and 1.5 ng/mL samples (- 11% and - 13%, respectively) than in the 0.5 ng/mL samples (- 4%) (P = 0.006 and P = 0.001, respectively). A bigger change in maximum clot firmness (MCF) for EXTEM was observed in the 1.5 ng/mL samples (4%) than in the 0.5 ng/mL samples (0%) (P = 0.002). The change in MCF for FIBTEM was greater in the 1.5 ng/mL samples (19%) than in the 0.5 ng/mL samples (5%) (P = 0.001).

CONCLUSIONS

All coagulation pathways showed a hypercoagulable state as the concentration of dexmedetomidine increased. Nevertheless, most of the values of ROTEM were maintained within the reference ranges. Clinical Trial NCT04269278.

Evaluating sedative effects of dexmedetomidine and morphine in the patients with opioid use disorder undergoing cataract surgery

BACKGROUND

Considering that patients with opioid dependence are at higher risk of inadequate sedation during operations, and the rescue analgesia in these patients are usually greater than the general population; the aim of this study was comparison of sedation quality of dexmedetomidine and morphine in patients with opioid use disorder undergoing cataract surgery.

METHODS

This clinical trial was conducted on 60 patients with opioid use disorder underwent cataract surgery that were referred to Feiz Hospital, Isfahan, Iran in 2018. Patients were randomly divided into two groups as the dexmedetomidine group started 1 μg/kg dexmedetomidine in 10 minutes before surgery and then continued with 0.5 μg/kg/h while the morphine group received 0.1 mg/kg of morphine before surgery. Sedation score, pain intensity, hemodynamic parameters, analgesic request and side effects were compared in the two groups.

RESULTS

There was no significant differences between groups based on Ramsay score before, during and after surgery (P > 0.05), the pain intensity in the morphine group was significantly lower during the recovery period than dexmedetomidine group, the duration of recovery and sedation in the morphine group was significantly more than the dexmedetomidine group, and nausea and vomiting and eye pain in the morphine group were significantly higher than dexmedetomidine (P < 0.05).

CONCLUSION

Morphine usage was more effective in pain relief than dexmedetomidine in patients with opioid use disorder undergoing cataract surgery, but the complications and recovery time were higher in morphine usage. Also the sedation was similar in both groups.

Propofol but not dexmedetomidine produce locomotor sensitization via nitric oxide in rats

RATIONALE

The abused potential of some anesthetics has been debated. Measurement of locomotor sensitization is a better way to detect the neurobehavioral plasticity of addiction.

OBJECTIVES

The present study aims to explore whether propofol and dexmedetomidine are capable of inducing locomotor sensitization.

METHODS

Male Wistar rats (250-300 g) were the subjects (n = 8 for each group). Propofol (20 and 40 mg/kg) and dexmedetomidine (2.5-20 μg/kg) or saline were injected to rats intraperitoneally (IP), and their locomotor activities were recorded for 15 min. Consequently, L-NAME (30 and 60 mg/kg)-a nitric oxide (NO) inhibitory agent-was injected to rats 30 min before propofol (40 mg/kg) or saline injections, and the locomotor activity was recorded. The process was carried out for 13 days, with 7 sessions applied every other day.

RESULTS

Dexmedetomidine did not produce any significant locomotor sensitization. While propofol (20 mg/kg) produced a significant locomotor sensitization in the last treatment session (day 13), at the higher dose, it prompted a significant locomotor sensitization from the 3rd treatment session. L-NAME blocked propofol-induced locomotor hyperactivity and sensitization significantly without producing any noteworthy changes on the locomotor activity during the testing period of 13 days when administered alone.

CONCLUSIONS

Our results suggest that propofol but not dexmedetomidine produced a significant locomotor sensitization via central nitrergic system. Dexmedetomidine may have a lesser psychostimulant type addictive potential than propofol. Sensitization development by propofol implies that this drug might be effective on the neuroadaptive processes associated with a stimulant type of dependence.

Understanding the Effects of Anesthesia on Cortical Electrophysiological Recordings: A Scoping Review

General anesthesia in animal experiments is an ethical must and is required for all the procedures that are likely to cause more than slight or momentary pain. As anesthetics are known to deeply affect experimental findings, including electrophysiological recordings of brain activity, understanding their mechanism of action is of paramount importance. It is widely recognized that the depth and type of anesthesia introduce significant bias in electrophysiological measurements by affecting the shape of both spontaneous and evoked signals, e.g., modifying their latency and relative amplitude. Therefore, for a given experimental protocol, it is relevant to identify the appropriate anesthetic, to minimize the impact on neuronal circuits and related signals under investigation. This review focuses on the effect of different anesthetics on cortical electrical recordings, examining their molecular mechanisms of action, their influence on neuronal microcircuits and, consequently, their impact on cortical measurements.

Injection of Lidocaine Alone versus Lidocaine plus Dexmedetomidine in Impacted Third Molar Extraction Surgery, a Double-Blind Randomized Control Trial for Postoperative Pain Evaluation

Objectives

Administration of medications such as dexmedetomidine as a topical anesthetic has been suggested in the pain control in dentistry. This double-blind randomized control trial study evaluated postoperative pain and associated factors following impacted third molar extraction surgery. Lidocaine alone was taken as the control and lidocaine plus dexmedetomidine as the intervention.

Materials and Methods

Forty patients undergoing mandibular third molar extraction entered the study and were randomly allocated to the control and interventional groups. 0.15 ml of dexmedetomidine was added to each lidocaine cartridge and the drug concentration was adjusted to 15 μg for the intervention group while only lidocaine was used in the control group. A visual analog scale was used to measure and record pain levels at the end of the surgery and 6, 12, and 24 hours after the surgery and number of painkillers taken by the patients after the surgery was also recorded.

Results

Pain scores of the intervention group decreased significantly during the surgery and also 6, 12, and 24 hours after the surgery compared to the control group. The pain score was correlated significantly with our intervention during the surgery and also 6 and 12 hours after that (all P value < 0.05). There was a nonsignificant reduction in the number of painkillers taken by the patients at 6, 12, and 24 hours after surgery (all P value > 0.05).

Conclusion

In patients undergoing molar surgery, administration of a combination of dexmedetomidine and lidocaine is beneficial for the pain control. Clinical Relevance. Compared to the injection of lidocaine alone, combination of dexmedetomidine and lidocaine can be used for a better pain control in molar surgeries.

Molecular Diversity of Anesthetic Actions Is Evident in Electroencephalogram Effects in Humans and Animals

Anesthetic agents cause unique electroencephalogram (EEG) activity resulting from actions on their diverse molecular targets. Typically to produce balanced anesthesia in the clinical setting, several anesthetic and adjuvant agents are combined. This creates challenges for the clinical use of intraoperative EEG monitoring, because computational approaches are mostly limited to spectral analyses and different agents and combinations produce different EEG responses. Thus, testing of many combinations of agents is needed to generate accurate, protocol independent analyses. Additionally, most studies to develop new computational approaches take place in young, healthy adults and electrophysiological responses to anesthetics vary widely at the extremes of age, due to physiological brain differences. Below, we discuss the challenges associated with EEG biomarker identification for anesthetic depth based on the diversity of molecular targets. We suggest that by focusing on the generalized effects of anesthetic agents on network activity, we can create paths for improved universal analyses.

Dexmedetomidine-Associated Hyperpyrexia in Three Critically Ill Patients With Coronavirus Disease 2019

Objectives:

To present three patients with severe coronavirus disease 2019 infection who developed life-threatening hyperpyrexia while being treated with dexmedetomidine for sedation.

Data Sources:

Clinical records.

Study Selection:

Case report.

Data Extraction:

Relevant clinical information.

Data Synthesis:

We describe three patients, a 60-year-old female, 43-year-old female, and 46-year-old male, who were hospitalized in surge ICUs during the coronavirus disease 2019 pandemic in the early spring of 2020. All developed hyperpyrexia, defined as a temperature above 41.1°C, following an increase in dexmedetomidine dosing to above 1.5 µg/kg/hr. Fevers resolved following discontinuation of dexmedetomidine.

Conclusions:

While the exact mechanism of hyperpyrexia remains unclear, findings in this study suggest that high doses of dexmedetomidine infusion are associated with hyperpyrexia in a seemingly dose-dependent fashion in critically ill patients with coronavirus disease 2019. Coronavirus disease 2019 infection causes a hyperinflammatory state characterized by pro-inflammatory cytokine dysregulation. Dexmedetomidine, a centrally acting alpha-2 agonist, may alter hypothalamic temperature regulation through disturbances in neurotransmitter expression and metabolism. We postulate that the use of high-dose dexmedetomidine in a hyperinflammatory state may increase the risk of developing hyperpyrexia in this severe disease state.

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.

Dexmedetomidine or midazolam in combination with propofol for sedation in endoscopic retrograde cholangiopancreatography: a randomized double blind prospective study

Introduction

Interventional endoscopic procedures, such as endoscopic retrograde cholangiopancreatography (ERCP), often require sedation during the procedure. The most commonly used drugs for this purpose are midazolam and propofol, which are used as sedative and hypnotic agents with minimal analgesic potential.

Aim

To compare the analgesic sedative effects of midazolam-propofol and dexmedetomidine-propofol combinations and their influence on hemodynamic and respiratory variables in patients undergoing ERCP.

Material and methods

Forty adult patients aged 20-78 and undergoing ERCP were randomized to two groups. Patients were premedicated with midazolam (0.05 mg/kg 10 min before the procedure) in group M and with dexmedetomidine (1 μg/kg for 10 min) in group D. Propofol was used for maintenance. The sedation level was monitored using the bispectral index (BIS) to maintain a score between 70 and 80. Hemodynamic and respiratory variables, recovery time and adverse events were recorded.

Results

The hemodynamic and respiratory variables were similar in both groups. Total propofol consumption was significantly lower in the dexmedetomidine group (208.5 ±80.0 vs. 154.5 ±66.7 mg; p = 0.011). The recovery period was shorter in group D (time to achieve the Aldrete score 9 was 9.4 ±2.1 vs. 6.6 ±1.1 min; p < 0.001). Changes in hemodynamic and respiratory variables and adverse events were not different between the two groups.

Conclusions

We found a shorter recovery time and comparable sedative and adverse effects with the dexmedetomidine-propofol combination compared with the midazolam-propofol combination. Dexmedetomidine in combination with propofol may be a safe and useful alternative for sedation for ERCP patients.

A randomised controlled trial to evaluate the peri-operative role of intraoperative dexmedetomidine infusion in robotic-assisted laparoscopic oncosurgeries

Background:

Robotic and minimal invasive surgeries pose challenges to the anaesthesiologists. Dexmedetomidine (dexmed), with distinct properties of sedation and analgesia has emerged as a promising drug. Our primary aim, in this double-blinded study, was to evaluate reduction in the intraoperative opioid requirement with the use of intravenous dexmed infusion. Secondary objectives included effect on intraoperative anaesthetic and postoperative analgesic requirement.

Methodology:

After approval from Ethics board and registration of the trial, 46 eligible patients planned for robotic oncosurgeries (abdomen) were included. As per computer generated randomisation chart, patients were randomised into either dexmed or saline group. Five minutes after insufflation of the abdomen, the study drug bolus—saline or dexmed (1 μg/kg) was given over 10 min and was followed by maintenance infusion (0.2 μg/kg/h) until release of pneumoperitoneum. Study drug titration, fentanyl boluses, and changes in minimum alveolar concentration (MAC) of inhalational agent were protocolised.

Results:

The mean intraoperative fentanyl requirement was significantly lower in the dexmed group 192.6 μg (±66.4) versus the saline group 260.7 μg (±88.6), P = 0.013. The MAC requirement of inhalational agent was significantly lower in the dexmed group. Intraoperative episodes of hypotension and bradycardia were similar in both groups. First analgesic request, 24 h postoperative pain scores and side effects profile were comparable in both groups.

Conclusion:

Intraoperative dexmed (bolus of 1 μg/kg followed by 0.2 μg/kg/h infusion) has an opioid and inhalational anaesthetic sparing role during robotic oncosurgeries. However, no benefit of the infusion is seen in the postoperative period.

Intraperitoneal Alfaxalone and Alfaxalone-Dexmedetomidine Anesthesia in Sprague-Dawley Rats (Rattus norvegicus)

Due to their unpredictability and variable effects, injectable anesthetic regimens in laboratory rodent species warrant refinement. In our study we sought to evaluate alfaxalone, which has gained recent popularity in veterinary medicine, alone and in combination with dexmedetomidine to evaluate their anesthetic ability in Sprague-Dawley rats when administered intraperitoneally. Three doses of alfaxalone only and 4 dose combinations of alfaxalone-dexmedetomidine were tested in males and female rats. The time to induction, anesthetic duration, pulse rate, respiratory rate, temperature, and time to recovery were recorded by a blind observer. The level of anesthesia induced by the various anesthetic protocols was assessed by using pedal withdrawal reflex to a noxious stimulus and scored according to the response. Dependent on the treatment group, atipamezole or saline was administered intraperitoneally once animals reached 60 min of anesthesia. Regardless of the dose, alfaxalone alone achieved only a sedative level of anesthesia, whereas all alfaxalone-dexmedetomidine combinations led to a surgical level of anesthesia in all animals. Anesthesia regimens using alfaxalone alone and in combination with dexmedetomidine demonstrated sex-associated differences, with female rats maintaining longer durations of sedation or anesthesia than their male counterparts. Both male and female rats displayed decreases in physiologic parameters consistent with the effects of dexmedetomidine. Given the results described herein, we recommend 20 mg/kg alfaxalone for sedation and 30 mg/kg alfaxalone combined with 0.05 mg/kg dexmedetomidine for surgical anesthesia in female rats. Appropriate doses of alfaxalone only and alfaxalone-dexmedetomidine for male rats were not determined in this study and need further evaluation.

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.

Comparison of Intranasal Dexmedetomidine Versus Intranasal Ketamine as Premedication for Level of Sedation in Children Undergoing Radiation Therapy: A Prospective, Randomised, Double-Blind Study

OBJECTIVE

Radiation therapy is indicated in many solid tumours in children. Absolute immobility is required to precisely position children for optimal delivery of radiation energy to the target tissues, improve success rate and reduce the damage to nearby normal tissues. Intranasal (IN) administration of drugs is well tolerated, effective and fast acting. The primary aim of the present study was to evaluate the effectiveness of IN ketamine and dexmedetomidine for providing sedation in children before shifting to the radiotherapy suite. The secondary objective was to assess the requirement of propofol dosage in these patients.

METHODS

A total of 243 children aged between 1 and 5 years scheduled to undergo external beam radiotherapy were randomised to receive 5 mg kg-1 ketamine (group K, n=80), 2.5 μg kg-1 dexmedetomidine (group D, n=85) or 0.5 ml of saline (group S, n=78) in each nostril. After 45 min, sedation score was measured according to the modified Ramsay score (MRS) at the time of shifting for radiation. Time to awakening and time to discharge after the procedure were also noted.

RESULTS

A significantly higher proportion of children in group D (84.7%) achieved an MRS score ≥3 as compared to group K (36.2%) and group S (3.84%). The total propofol dose (mg kg-1) required was significantly less in group D (p<0.01). The patients in group D required more time to awakening, but this difference was not clinically significant.

CONCLUSION

The present study demonstrated that IN dexmedetomidine is superior to IN ketamine to provide procedural sedation for radiotherapy in children.

Perioperative Dexmedetomidine for outpatient cataract surgery: a systematic review

Background

Cataract surgery is one of the most common procedures performed worldwide in the elderly. Various medications can provide effective anesthesia and analgesia for cataract surgery, but undesirable side effects limit the utility of each medication or combination of medications. Dexmedetomidine may serve as an anesthesia adjunct for outpatient cataract surgery in the elderly.

Methods

Searches were conducted in Cochrane, Embase, and PubMed for randomized clinical trials investigating the use of dexmedetomidine in adult patients undergoing outpatient, or ambulatory, cataract surgery with sedation and topical or peribulbar block. Ninety-nine publications were identified, of which 15 trials satisfied the inclusion criteria. A total of 914 patients were included in this review. The following data were collected: American Society of Anesthesiologists’ (ASA) physical status and age of study patients; method of blinding and randomization; medication doses and routes of administration; and intraoperative levels of sedation. We also recorded statistically significant differences between dexmedetomidine and other study medications or placebo with respect to the following outcomes: hemodynamic and respiratory parameters; pain; sedation; post-operative nausea and vomiting (PONV); discharge from post-anesthesia care unit (PACU) or recovery times; patient satisfaction; surgeon satisfaction; and effects on intraocular pressure (IOP).

Results

Hypotension with or without bradycardia was reported following bolus doses of dexmedetomidine ranging from 0.5–1.0 mcg/kg with or without a continuous dexmedetomidine infusion. Delayed PACU discharge times were associated with the use of dexmedetomidine, but no clear association was identified between delayed recovery and higher levels of intraoperative sedation. Better analgesia and higher patient satisfaction were commonly reported with dexmedetomidine as well as reductions in IOP.

Conclusions

Overall, this review demonstrates better analgesia, higher patient satisfaction, and reduced IOP with dexmedetomidine for outpatient cataract surgery when compared to traditional sedatives, hypnotics, and opioids. These benefits of dexmedetomidine, however, must be weighed against relative cardiovascular depression and delayed PACU discharge or recovery times. Therefore, the utility of dexmedetomidine for outpatient cataract surgery should be considered on a patient-by-patient basis.

A prospective randomized double-blinded study of dexmedetomidine versus propofol infusion for orbital surgeries

PURPOSE

Orbital surgeries are traditionally taken up under general anesthesia. Local anesthesia combined with moderate sedation can also be considered as an alternative option. This study was performed to compare the safety and efficacy of dexmedetomidine and propofol infusion for orbital surgeries under local anesthesia.

METHODS

Twenty patients undergoing orbital surgery by a single surgeon were enrolled in this prospective randomized study. Selected patients were randomly administered dexmedetomidine (Group D) or propofol (Group P). Hemodynamic and respiratory effects, sedation levels, recovery profile, analgesic properties, and satisfaction levels of the patients and the surgeon were assessed.

RESULTS

There was a significant decrease in mean arterial pressures following drug administration compared to initial measurements in both the groups. However, a statistically significant decrease in heart rate was observed only in Group P. The sedation score at the end of loading dose was 3.3 ± 0.82 in Group D and 2.5 ± 0.52 in Group P and this difference was also statistically significant (P value-0.027). The surgeon's satisfaction score was 6.5 ± 0.71 in Group D and 5.6 ± 1.07 in Group P (P value - 0.045). There were no statistically significant differences observed in patients' satisfaction, pain, and anxiety scores in either group. No major hemodynamic changes or complications were noted in either of the groups.

CONCLUSION

Dexmedetomidine, in comparison to propofol, provides better sedation levels with good hemodynamic stability. It also offers better surgeon satisfaction, thus providing a useful alternative for general anesthesia in selective patients undergoing orbital surgery.

Comparison of the efficacy of two doses of dexmedetomidine in attenuating the hemodynamic response to intubation in patients undergoing elective cardiac surgery: A randomized double-blinded study

Background and Aims:

Transient tachycardia and hypertension associated with laryngoscopy and intubation may be hazardous to patients presenting for cardiac surgery. The α 2 agonist dexmedetomidine may blunt this stress response, but the optimal dose which will accomplish this without causing hypotension and bradycardia is not well established. The primary objective of this study was to compare the efficacy of two doses of dexmedetomidine (0.5 and 1 μg/kg) as a 15 min infusion in attenuating the hemodynamic stress response to laryngoscopy and endotracheal intubation in elective cardiac surgery.

Material and Methods:

Seventy six patients scheduled for elective cardiac surgery received a single preoperative dose of dexmedetomidine of either 0.5 μg/kg (low dose) or 1 μg/kg (high dose) as a 15-min infusion prior to induction. The hemodynamic response to laryngoscopy and endotracheal intubation (heart rate, systolic blood pressure, mean arterial pressure, and diastolic blood pressure) were recorded at different times. Independent sample t-test, Chi-square test of association, and repeated measures analysis of variance were used to analyze the collected data.

Results:

The incidence of hypertension following intubation was significantly more in the low-dose group. Administration of 1 μg/kg dexmedetomidine was not accompanied by hypotension or bradycardia.

Conclusion:

Dexmedetomidine in a dose of 1 μg/kg is more effective than 0.5 μg/kg for attenuation of hemodynamic stress response to intubation in cardiac surgery. A more graded increase in the dose of dexmedetomidine may lead to an optimum dose in attenuating the hemodynamic response to intubation.

Dexmedetomidine reduces inflammation in traumatic brain injury by regulating the inflammatory responses of macrophages and splenocytes

Traumatic brain injury (TBI) affects people in all demographics, since it is associated with a variety of chronic degenerative diseases, such as Alzheimer's and Parkinson's disease. In TBI, the central nervous system elicits an immune response involving various immune cells that is necessary for healing and defending the body against pathogens, but can also cause secondary damage to the brain if the response is prolonged. In our clinical practice, it has been identified that administration of dexmedetomidine was associated with reduced production of inflammatory cytokines in patients with TBI, which led to the hypothesis that dexmedetomidine may regulate certain inflammatory responses. To test this hypothesis, the roles of dexmedetomidine in the immune system of mice were investigated. Different biological assays were used to assess the influence of dexmedetomidine on the production of inflammatory cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-8 and IL-1β. To understand how dexmedetomidine affects different types of immune cells, the influence of dexmedetomidine on splenocytes was also investigated. Finally, the effects of dexmedetomidine on macrophage activation and inflammatory functions were studied. In the present study, clinical observations and in vivo results using a mouse model of TBI revealed the regulatory functions of dexmedetomidine in TBI-associated immune response.

Fentanyl vs fentanyl-dexmedetomidine in lumbar foraminotomy surgery

Aim

Lumbar foraminotomy surgery requires a potent opioid with short duration and rapid onset of action. In the present study we intended to compare the efficacy of fentanyl alone vs the combination of dexmedetomidine and fentanyl during lumbar foraminotomy surgery.

Methods

The duration and requirements for first postoperative analgesics, hemodynamic stability, and respective side effects were studied. A prospective, randomized, double blind study of 40 patients (fentanyl group [Fen group] and fentanyl-dexmedetomidine group [Fen-Dex group], n=20 each) scheduled for lumbar foraminotomy surgery under pharmaceutical care intervention was carried out. Patients were classified as class I or II, according to the American Society of Anesthesiologists physical status classification. Patients received intraoperative propofol, sevoflurane, atracurium, and either fentanyl loading dose of 1.0 μg/kg and maintenance infusion dose of 0.2 μg/kg/h in both groups. The patients of the Fen group received normal saline (0.9%) placebo, while the patients of the Fen-Dex group received dexmedetomidine infusion (0.5 μg/kg/h) along with the fentanyl infusion. Postoperative morphine doses were given. Hemodynamic stability, pain, postoperative analgesia requirement, side effects of drugs, and other effects were monitored.

Results

In the Fen-Dex group, the pain score was significantly less than in the Fen group (p<0.05). The time to first postoperative analgesia request was prolonged in the Fen-Dex group compared to the Fen group. On the other hand, requirement of morphine, and postoperative symptoms and episodes of nausea and vomiting were significantly greater in the Fen group than in the Fen-Dex group (p<0.05).

Conclusion

The present study suggests the addition of dexmedetomidine during lumbar foraminotomy surgery at different levels would be beneficial to reduce morphine consumption and any adverse drug reaction.