Dexmedetomidine Dose Dependently Enhances the Local Anesthetic Action of Lidocaine in Inferior Alveolar Nerve Block: A Randomized Double-Blind Study

Synergistic interaction of guanfacine or dexmedetomidine coadministered with lidocaine for cutaneous analgesia in rats

BACKGROUND

This study examined the cutaneous analgesic effects of lidocaine co-injected with guanfacine and its comparison with dexmedetomidine.

METHODS

Cutaneous analgesic effects are quantified through the blocking effects of the cutaneous trunci muscle reflex against skin pinpricks in rats. The dose-response curves of guanfacine, dexmedetomidine, and lidocaine were constructed and drug-drug interactions were analyzed by the ED50 isobologram.

RESULTS

Subcutaneous injections of guanfacine, dexmedetomidine, and lidocaine produced dose-dependently nociceptive/sensory blockade. On the ED50 (50% effective dose) basis, the potency rankings of the drug are dexmedetomidine (0.09 [0.08-0.11] μmol/kg) > guanfacine (3.98 [2.96-5.34] μmol/kg) > lidocaine (25.40 [23.51-27.44] μmol/kg) (p < 0.01). On their equipotent doses (ED25, ED50, and ED75), the duration of sensory blockade induced by guanfacine or dexmedetomidine was longer than lidocaine's (p < 0.01). Both guanfacine and dexmedetomidine showed synergistic effects with lidocaine.

CONCLUSIONS

We showed that guanfacine elicits dose-dependent cutaneous analgesia when administered subcutaneously. Lidocaine is less potent than guanfacine or dexmedetomidine. Both guanfacine and dexmedetomidine enhance the potency and duration of lidocaine. Better synergistic responses we are getting with guanfacine plus lidocaine.

Clinical Use of Adrenergic Receptor Ligands in Acute Care Settings

In this chapter, we review how ligands, both agonists and antagonists, for the major classes of adrenoreceptors, are utilized in acute care clinical settings. Adrenergic ligands exert their effects by interacting with the three major classes of adrenoceptors. Adrenoceptor agonists and antagonists have important applications, ranging from treatment of hypotension to asthma, and have proven to be extremely useful in a variety of clinical settings of acute care from the operating room to the critical care environment. Continued research interpreting the mechanisms of adrenoreceptors may help the discovery of new drugs with more desirable clinical profiles.

Pelvic limb anesthesia and analgesia in dogs undergoing tibial plateau leveling osteotomy (TPLO): A survey of board-certified anesthesiologists

OBJECTIVE

To report the locoregional anesthesia and analgesia preferences of veterinary anesthesiologists for use in dogs undergoing a TPLO and determine any association with specialty college, time from board-certification, or employment sector.

STUDY DESIGN

Cross sectional study.

SAMPLE POPULATION

Diplomates of the American (ACVAA) and European (ECVAA) Colleges of Veterinary Anesthesia and Analgesia.

METHODS

An electronic survey was distributed to diplomates and responses were used to determine associations between preferred methods.

RESULTS

The survey response rate was 28% (141/500) with 69% (97/141) of ACVAA diplomates and 31% of diplomates with ECVAA (44/141) certification. Peripheral nerve block (PNB) was preferred by 79% (111/141) of all diplomates, lumbosacral epidural (LE) by 21% (29/141), and peri-incisional infiltration (PI) by <1% (1/141). There was no association (p = .283) with specialty college. There was an association (p < .001) with time from board-certification with increased preference for LE when >10-years from certification and PI preferred by only those board-certified >20-years ago. There was an association with employment sector (p = .003) with more academic diplomates preferring LE. Anesthesiologists reported that treatment decisions were affected by various factors including time pressure and surgeon influence.

CONCLUSION

Diplomates of ACVAA and ECVAA prefer PNB as the locoregional method of pelvic limb anesthesia in dogs undergoing TPLO. A greater percentage of newer and private practice diplomates prefer PNB while a larger percentage of senior and academic diplomates prefer LE. Decision making is multifactorial and includes perceived time pressure and surgeon influence.

CLINICAL SIGNIFICANCE

Veterinary anesthesiologists prefer and frequently use PNB in dogs undergoing TPLO and surgeon influence may affect their chosen treatment.

Sublingual dexmedetomidine (BXCL501) reduces opioid withdrawal symptoms: findings from a multi-site, phase 1b/2, randomized, double-blind, placebo-controlled trial

Background: Like other alpha-2-adrenergic receptor agonists, dexmedetomidine may reduce the severity of opioid withdrawal but with fewer adverse cardiovascular effects.Objective: This study assessed the safety of sublingual dexmedetomidine (BXCL501) and its preliminary efficacy in treating opioid withdrawal (ClinicalTrials.gov: NCT04470050).Methods: Withdrawal was induced among individuals with physiological dependence on opioids via discontinuation of oral morphine (Days 1-5). Participants were randomized to receive placebo or active BXCL501: 30, 60, 90, 120, 180, and 240 μg twice daily (Days 6-12). Treatment-emergent adverse events (TEAEs) were the primary outcome measure. Secondary outcomes included the Clinical and Subjective Opiate Withdrawal Scales (COWS and SOWS-Gossop, respectively), and the Agitation and Calmness Evaluation Scale (ACES).Results: Of 225 participants enrolled, 90 discontinued during morphine stabilization. Post-BXCL501 randomization (Day 6) data were available from 135 participants (73% male), with 33% completing thru Day 12. In total, 36 subjects reported 1 or more TEAE. Higher doses of BXCL501 (i.e. 180 and 240 µg, twice daily) increased the frequency of: hypotension, orthostatic hypotension, and somnolence. TEAEs related to BXCL501 were mild or moderate in severity, except for one participant in the 120 µg condition whose orthostatic hypotension and bradycardia were classified as severe. Higher BXCL501 dose conditions (120, 180, and 240 µg) resulted in statistically significant reductions in COWS & SOWS scores. Mean ratings on the ACES were between 3 (mild), 4 (normal), and 5 (mild calmness), with few significant differences as a function of dose.Conclusions: These findings support the continued development of BXCL501 for the management of opioid withdrawal.

Effect of Dexmedetomidine Added to Lidocaine Cartridge on the Level of Patient Sedation, Cooperation, and Patient and Surgeon Satisfaction during Mandibular Third-Molar Extraction Surgery: A Randomized Double-Blind Controlled Trial

Background. Various methods have been introduced for anxiety control during third-molar extraction surgery. Dexmedetomidine (DEX) is known to have analgesic, anxiolytic, and sympatholytic properties with minimal adverse effects. This study aimed to evaluate the impact of the local injection of the combination of DEX and Lidocaine on patients’ anxiety and the surgeon’s satisfaction during third-molar extraction surgery. Methods. A total number of 26 healthy volunteers with symmetrical bilateral impacted mandibular third-molar teeth indicated for surgical removal were included in this double-blind randomized controlled trial. A single experienced surgeon performed two surgical extraction procedures within at least four-week time intervals using anesthetic cartridges containing “DEX + LIDO” or “LIDO alone” used randomly on each side for each patient. The Visual Analog Scale and the SDFQ index were used to evaluate patients’ anxiety and surgeon satisfaction during the procedure. Results. SDFQ reports showed that patients in the “DEX” group were 1.5 times more relaxed than those in the “LIDO alone” group. As a result, the level of sedation was considered statistically significant between the two groups (Wilcoxon test, $P$ value <0.019). Wilcoxon test results also showed significant differences between the two groups regarding patients’ overall cooperation in terms of interfering movement and verbal presentation of discomfort ( $P$ value <0.05); however, this difference was not considered significant regarding nonverbal signs of discomfort ( $P$ value >0.05). Moreover, both the surgeon and the patients reported a significantly higher satisfaction rate in the DEX group (paired T-test, df = 25, $P$ value <0.05). Conclusions. It was inferred from the outcomes of the present study that the application of DEX added to the LIDO local anesthesia cartridge could significantly benefit anxious patients with previous unpleasant dental treatment experiences. Trial Registration. This trial is registered with the clinical trial registration number: IRCT20200406046966N.

Efficacy of adding dexmedetomidine to lidocaine to enhance inferior alveolar nerve block in patients with asymptomatic irreversible pulpitis: double-blind randomized clinical trial

OBJECTIVES

This randomized, double-blind study was to determine whether dexmedetomidine (DEX) helped to improve the inferior alveolar nerve block's (IANB) success in patients with asymptomatic irreversible pulpitis (AIP). We hypothesized that adding DEX to lidocaine enhances the anesthetic effect of lidocaine to a satisfactory level by localizing anesthesia in a safer way.

MATERIALS AND METHODS

Fifty adult volunteers with AIP in a first or second mandibular molar were randomly assigned to two groups to either receive 1.4 ml 2% plain lidocaine or 1.4 ml 2% lidocaine + 0.4 ml (40 μg) DEX, for standard IANB injection. Access cavity preparation initiated 10-15 min postinjection when the patient reported lower lip numbness and had two negative electric pulp tests (EPTs) with 5-min intervals. Heft-Parker visual analog scale (VAS) was used to report pain in three steps: during caries and dentin removal, access cavity preparation, and canal working-length determinations; EPT and VAS were analyzed by Friedman test; and success rates were analyzed by Mann-Whitney and Fisher's exact test using SPSS software version 20.

RESULTS

Successful anesthesia (defined as no or mild pain during any of steps and no need for additional injection) is obtained in 12% of patients in the lidocaine group, while DEX-lidocaine group increased the success rate of IANB to 72% (p-value = 0.0001).

CONCLUSIONS

DEX significantly increases the anesthetic effect of lidocaine in IANB injection in patients with AIP.

CLINICAL RELEVANCE

DEX would be a safe adjunct to lidocaine to increase the success rate in IANB and could be a suitable alternative for conventional vasoconstrictors in sensitive groups.

Does dexmedetomidine combined with levobupivacaine in inferior alveolar nerve blocks among patients undergoing impacted third molar surgery control postoperative morbidity?

Background

Postoperative analgesia (POA) is an important determinant of successful treatment. Dexmedetomidine (DEX) has recently gained attention as a promising adjuvant to local anesthetics (LA). The present study aimed to evaluate the efficacy and safety of levobupivacaine (LB) as an adjuvant during inferior alveolar nerve block (IANB) in the extraction of lower impacted third molars (LITM).

Methods

A prospective, randomized, placebo-controlled, triple-blind, parallel-arm, and clinical study was performed on 50 systemically healthy participants who required removal of an asymptomatic LITM. Using a 1:1 distribution, the participants were randomized into two groups (n = 25). Group L (control group) received 1.8 mL of 0.5% LB and 0.2 mL normal saline (placebo) and Group D (study group) received a blend of 1.8 mL of 0.5% LB and 0.2 mL (20 µg) DEX. The primary outcome variable was the duration of POA and hemodynamic stability, and the secondary variable was the total number of analgesics required postoperatively for up to 72 h. The participants were requested to record the time of rescue analgesic use and the total number of rescue analgesics taken. The area under the curve was plotted for the total number of analgesics administered. The pain was evaluated using the visual analog scale. Data analysis was performed using paired students and unpaired t-test, Mann–Whitney U test, Chi-square test, and receiver operating characteristic analysis. Statistical significance was set at P < 0.05.

Results

The latency, profoundness of anesthesia, and duration of POA were statistically significant (P < 0.05). The differences between mean pain scores at 6, 12, 24, 48, and 72 h were found to be significant (each P = 0.0001). Fewer analgesics were required by participants in group D (2.12 ± 0.33) than in L (4.04 ± 0.67), with a significant difference (P = 0.0001).

Conclusion

Perineurally administered LA with DEX is a safe, effective, and therapeutic approach for improving latency, providing profound POA, and reducing the need for postoperative analgesia.

Levobupivacaine versus levobupivacaine plus dexmedetomidine in transversus abdominis plane block in patients undergoing abdominal aortic surgery

Background:

Severe postoperative pain is a major dilemma for patients undergoing abdominal aortic surgery. Transversus abdominis plane (TAP) block has been described a successful pain management technique after major abdominal surgery. Dexmedetomidine was proved to enhance the analgesic action of local anesthetics.

Aim:

This study was aimed to assess the impact of adding dexmedetomidine to levobupivacaine during TAP block in patients undergoing abdominal aortic operations.

Patients and Methods:

We included 114 patients in this prospective trial, and they were enrolled into two groups; the L group received levobupivacaine only, and the LD group received levobupivacaine plus dexmedetomidine. The block was performed before anesthetic induction. Postoperative pain score was our main outcome.

Statistical Analysis:

The collected data were tabulated and analyzed through the SPSS software program IBM's Statistical Package for the Social Sciences (SPSS) statistics for Windows (version 25, 2017) (IBM Corporation, Armonk, NY, USA). The categorical data were expressed as numbers and percentages and then compared using the Chi-square test. The continuous data were expressed as mean and standard deviation if normally distributed, or median and range if abnormally distributed. The former data were compared through the one-way ANOVA, while the latter were compared through the Kruskal–Wallis test. Any P < 0.05 was considered statistically significant.

Results:

Group LD showed significantly earlier sensory blocks compared to the other group. Postoperative pain scores were comparable between the two groups for the initial 4 h following the surgery. Adjuvant dexmedetomidine was associated with better pain scores for the subsequent 12 h compared to Group L. The duration till the first analgesic request showed a significant increase in the LD group (13.3 vs. 11.09 h in Group L). In addition, the same group showed a significant decline in their opioid consumption after the operation (48.95 μg vs. 72.63 μg in the other group). Postoperative nausea and vomiting were significantly increased in Group L.

Conclusion:

Adjuvant dexmedetomidine has a significant beneficial impact on postoperative analgesic profile. Its use as an adjuvant to peripheral and neuraxial nerve blocks should be recommended in pain management practice.

Intranasal Dexmedetomidine in Elderly Patients (Aged > 65 Years) During Maxillofacial Surgery: Sedative Properties and Safety Analysis

PURPOSE

Light sedation rather than intravenous sedation is preferred when patients have a low heart rate and blood pressure during maxillofacial surgery. Intranasal administration of dexmedetomidine is reported to be efficacious and safe in adults. However, dexmedetomidine could be unsuitable for routine clinical use in elderly patients because many of these patients take β-blockers, which increase the cardiovascular effects of dexmedetomidine. The objectives of the study were to evaluate the sedative properties and safety of intranasal dexmedetomidine, regardless of concurrent β-blocker treatment, in elderly patients who underwent maxillofacial surgery.

METHODS

This study was a retrospective analysis of 535 patients aged > 65 years (American Society of Anesthesiologists physical status I or II) who were undergoing maxillofacial surgery. Very anxious patients and those with hypertension received intranasal 1 µg/kg dexmedetomidine through an intranasal mucosal atomization device before anesthesia (local ropivacaine).

RESULTS

Intranasal administration of dexmedetomidine decreased the requirement for midazolam before surgery (18 of 252 vs 63 of 283, P < .0001), but increased the requirement for norepinephrine (102 of 252 vs 8 of 283, P < .0001) during or after the surgery. A combination of a β-blocker and intranasal administration of dexmedetomidine reduced the hemodynamic parameters for an extended period. Intranasal administration of dexmedetomidine resulted in bradycardia and hypotension, regardless of concurrent β-blocker treatment.

CONCLUSIONS

Intranasal 1 µg/kg dexmedetomidine was associated with a high sedation score during the operation, but also with bradycardia and hypotension.

Clinical efficacy of dexmedetomidine combined with lidocaine for femoral and sciatic nerve blocks in dogs undergoing stifle surgery

OBJECTIVE

To evaluate the effects of dexmedetomidine administered perineurally or intramuscularly (IM) on sensory, motor function and postoperative analgesia produced by lidocaine for sciatic and femoral nerve blocks in dogs undergoing unilateral tibial tuberosity advancement surgery.

STUDY DESIGN

Prospective, blinded, clinical study.

ANIMALS

A group of 30 dogs.

METHODS

Dogs were anaesthetized with acepromazine, propofol and isoflurane in oxygen/air. Electrolocation-guided femoral and sciatic nerve blocks were performed: group L, 0.15 mL kg^-1 2% lidocaine (n = 10); group LD_loc, lidocaine and 0.15 μg kg^-1 dexmedetomidine perineurally (n = 10); group LD_sys, lidocaine and 0.3 μg kg^-1 dexmedetomidine IM (n = 10). After anaesthesia, sensory blockade was evaluated by response to forceps pinch on skin innervated by the saphenous/femoral, common fibular and tibial nerves. Motor blockade was evaluated by observing the ability to walk and proprioception. Analgesia was monitored with Short Form of Glasgow Composite Pain Scale for up to 4 hours after extubation. Methadone IM was administered as rescue analgesia. Data were analysed by linear mixed effect models and Kaplan-Meier test (p < 0.05).

RESULTS

Median duration of the sensory blockade for all nerves was longer (p < 0.001) for group LD_loc than for groups L and LD_sys and was longer (p = 0.0011) for group LD_sys than for group L. Proprioception returned later (p < 0.001) for group LD_loc [285 (221-328) minutes] compared with group L [160 (134-179) minutes] or LD_sys [195 (162-257) minutes]. Return of the ability to walk was similar among all groups. Dogs in group LD_loc required postoperative rescue analgesia later (p = 0.001) than dogs in groups LD_sys and L.

CONCLUSIONS AND CLINICAL RELEVANCE

Dexmedetomidine administered perineurally with lidocaine prolonged sensory blockade and analgesia during the immediate postoperative period. Systemic dexmedetomidine also prolonged the sensory blockade of perineural lidocaine.

Dexmedetomidine 2 ppm Is Appropriate for the Enhancement Effect of Local Anesthetic Action of Lidocaine in Inferior Alveolar Nerve Block: A Preliminary, Randomized Cross-over Study

OBJECTIVE

Local anesthesia is essential for pain management in dentistry. The duration of anesthetic action of the addition of 5.0 and 7.5 ppm of dexmedetomidine (DEX) was significantly longer than the addition of adrenaline, and the mean duration of anesthetic action of the addition of 2.5 ppm DEX was also longer than the addition of adrenaline. We hypothesized that it is possible to safely achieve an equal local anesthesia effect as with 1:80,000 adrenaline, without using adrenaline or felypressin, by the addition of <2.5 ppm DEX to the local anesthetic solution.

MATERIALS AND METHODS

Nineteen healthy volunteers were randomly assigned by a computer to receive 1.8 mL of 1 of 3 drug combinations (1.8% lidocaine with 1.0 ppm [1.8 μg] DEX, lidocaine with 2.0 ppm [3.6 μg] DEX or lidocaine with 1:80,000 [22.5 μg] adrenaline), to produce inferior alveolar nerve block. Pulp latency and lower lip numbness (for assessing onset and duration of anesthesia) were tested, and sedation level, blood pressure, and heart rate were recorded every 2 minutes for 10 minutes, every 5 minutes from 10 to 20 minutes, and every 10 minutes from 20 to 60 minutes.

RESULTS

Pulp latency increased compared with the baseline, from 4 minutes until 60 minutes; there were no significant intergroup differences at any timepoint. Anesthesia onset did not differ between groups. Anesthesia duration did not differ between groups. Blood pressure and heart rate did not change in any group. Sedation score did not indicate deep sedation in any of the groups.

DISCUSSION

DEX at a concentration of 1.0 to 2.0 ppm enhances the local anesthetic action of lidocaine. DEX at 2.0 ppm produces similar enhancement of local anesthesia effect as the addition of 1:80,000 adrenaline.

Calcium channel blockers, angiotensin II receptor antagonists and alpha-blockers accentuate blood pressure reducing caused by dental local anesthesia

OBJECTIVE

The primary aim of this study was to investigate the effect associated with patients' factor such as systemic disease on the blood pressure of patients in dental procedure. The secondary aim of this study was to investigate the effect associated with systemic disease and antihypertensive on the blood pressure changes with local anesthesia.

METHODS

The blood pressure was measured before and after local anesthesia injection for dental treatment. The effect associated with patients' factor such as systemic disease on the blood pressure and the effect on blood pressure changes of the type of antihypertensive drugs and the systemic disease were analyzed using a multivariate analysis of variance test.

RESULTS

We analyzed 1306 patients scheduled for the dental procedure. Age and some systemic diseases such as hypertension and angina pectoris affected blood pressure before local anesthesia. On the other hand, age and systemic diseases did not affect blood pressure changes. And, some antihypertensive affected systolic blood pressure changes.

CONCLUSIONS

The blood pressure change with local anesthesia was not associated with systemic diseases and age but was associated with antihypertensive agents. In particular, calcium channel blockers, angiotensin II receptor antagonists and alpha-blockers accentuate blood pressure reducing caused by local anesthesia.

CLINICAL RELEVANCE

The blood pressure change with local anesthesia was associated with antihypertensive agents. This study was registered with the University Hospital Medical Information Network Clinical Trials Registry (number UMIN000030695).

Effects of adding a combined femoral and sciatic nerve block with levobupivacaine and clonidine to general anaesthesia in femoropopliteal bypass surgery: A randomised, double-blind, controlled trial

BACKGROUND

Adding a regional block to general anaesthesia can prevent postoperative pain and improve peripheral circulation.

OBJECTIVE

To seek improved postoperative analgesia and care due to a long-acting combined femoral and sciatic nerve block in patients undergoing femoropopliteal bypass surgery.

DESIGN

A randomised, double-blind, controlled trial.

SETTING

Vascular surgery unit of a French university hospital.

PATIENTS

Forty-four adults scheduled for bypass surgery under general anaesthesia.

INTERVENTION

Patients were allocated to receive either an active nerve block with 20 ml of 0.375% levobupivacaine and clonidine 0.5 μg kg, or a simulated (sham) block only, but with local anaesthesia of the skin, before general anaesthesia. General anaesthesia was standardised with propofol, then sevoflurane and sufentanil adjusted according to clinical need. Postoperative analgesia was standardised with paracetamol 1 g every 6 h, and intravenous morphine, initially titrated in the postanaesthesia care unit and then patient-controlled. Oral analgesics were repeated up to day 3.

MAIN OUTCOME MEASURES

The primary outcome was morphine consumption during the first 24 postoperative hours. In a subgroup of postoperative patients distal tissue oxygen saturation was recorded at the lateral side of the blocked calf.

RESULTS

Patients in the active group received less intra-operative sufentanil (median dose 25 vs. 41 μg), needed less morphine during the first 24 h (15 vs. 27 mg) and 72 (20 vs. 35 mg) postoperative hours, than in the control group. They also had less pain on movement, but pain at rest, the tissue oxygen saturation and other rehabilitation outcomes were unaffected by the treatment. Tolerance outcomes were also similar between groups.

CONCLUSION

Combining the two regional blocks improves the quality of postoperative care in this frail population, probably by reducing the amount of peri-operative opioid.

TRIAL REGISTRATION

ClinicalTrials.gov (ref. NCT01785693).

Nebulized dexmedetomidine-lidocaine inhalation as a premedication for flexible bronchoscopy: a randomized trial

Background

Dexmedetomidine plus opioid infusion after topical anaesthesia with nebulized lidocaine for cough suppression is a commonly used method for flexible bronchoscopy. Recently, the use of dexmedetomidine as an additive to local anaesthetics has been reported to have several advantages over conventional intravenous administration. However, there are no data regarding the use of nebulized dexmedetomidine-lidocaine for topical anaesthesia as a premedication for flexible bronchoscopy. Therefore, this study compared the tolerability and safety of nebulized dexmedetomidine with that of conventional intravenous administration in patients undergoing bronchoscopy with moderate sedation.

Methods

Sixty patients requiring flexible bronchoscopy were randomly assigned to three groups: (I) nebulized dexmedetomidine + lidocaine, n=20; (II) intravenous dexmedetomidine + nebulized lidocaine, n=20; and (III) nebulized lidocaine alone (no dexmedetomidine), n=20. The patients' coughing scores were assessed and graded. Our primary hypothesis was that nebulized dexmedetomidine-lidocaine could reduce the incidence of moderate to severe coughing. The secondary endpoints were the rates of glottis closure, complete jaw relaxation and limb movement during the procedure; the elapsed time until recovery; and the dosages of vasoconstrictors and atropine.

Results

The incidence of moderate to severe coughing was 15% in the nebulized dexmedetomidine group, 50% in the intravenous dexmedetomidine group and 55% in the no dexmedetomidine group. The nebulized dexmedetomidine group had the lowest incidence of moderate to severe coughing (P=0.019). Nebulized dexmedetomidine showed a protective effect for reducing coughing compared with intravenous dexmedetomidine [P=0.008, odds ratio (OR): 0.273, 95% confidence interval (CI): 0.089-0.833]. No differences in the rates of complete jaw relaxation and limb movement during the procedure were observed among the three groups (all P>0.05). The rates of glottis closure were similar (20%, 25%, and 35%; P>0.05). The elapsed time until recovery in the nebulized dexmedetomidine group was significantly shorter than that in the intravenous dexmedetomidine group (10.60±1.39 vs. 15.10±1.45, P<0.001). The vasoconstrictor dosages were significantly lower in the nebulized dexmedetomidine group than in the intravenous dexmedetomidine group (P<0.001).

Conclusions

Nebulized dexmedetomidine-lidocaine inhalation as a premedication for flexible bronchoscopy was well tolerated during bronchoscopies performed under moderate sedation and was associated with a reduced incidence of moderate to severe coughing, a shorter recovery time and reduced vasoconstrictor consumption.

The impact of dexmedetomidine added to ropivicaine for transversus abdominis plane block on stress response in laparoscopic surgery: a randomized controlled trial

BACKGROUND

Intravenous dexmedetomidine is known to attenuate stress response in patients undergoing laparoscopic surgery. We investigated whether the addition of the highly selective alpha-2 adrenergic agonist dexmedetomidine into ropivacaine for ultrasound-guided transversus abdominis plane block could inhibit stress response during laparoscopic surgery, and determined the optimal dose of dexmedetomidine in it.

METHODS

One hundred and twenty-five patients undergoing laparoscopic gynecological surgery were included in this prospective and randomized double-blind study. Patients received general anesthesia with or without a total of 60 ml of 0.2% ropivacaine in combination with low (0.25 μg/kg), medium (0.50 μg/kg) or high dose (1.0 μg/kg) of dexmedetomidine for the four-quadrant transversus abdominis plane block (n = 25). The primary outcomes were stress marker levels during the operation.

RESULTS

One hundred and twenty patients completed the study protocol. Dexmedetomidine added to ropivacaine for transversus abdominis plane block significantly reduced serum levels of cortisol, norepinephrine, epinephrine, interleukin-6, blood glucose, mean arterial pressure and heart rate in a dose-dependent manner (P < 0.05), accompanied with decreased anesthetic and opioid consumption during the operation (P < 0.05), but the high dose of dexmedetomidine induced higher incidences of bradycardia than low or medium dose of dexmedetomidine (P < 0.05).

CONCLUSION

The addition of dexmedetomidine at the dose of 0.5 μg/kg into ropivacaine for ultrasound-guided transversus abdominis plane block is the optimal dose to inhibit stress response with limited impact on blood pressure and heart rate in patients undergoing laparoscopy gynecological surgery.

TRIAL REGISTRATION

This study was registered at www.chictr.org.cn on November 6th, 2016 (ChiCTR-IOR-16009753).

Risk Factors and Prevention Strategies for Postoperative Opioid Abuse

Worldwide, 80% of patients who undergo surgery receive opioid analgesics as the fundamental agent for pain relief. However, the irrational use of opioids leads to excessive drug dependence and drug abuse, resulting in an increased mortality rate and huge economic loss. The crisis of opioid overuse remains a great challenge. In this review, we summarize several key factors in opioid abuse, including race, region, income, genetic factors, age and gender, smoking and alcohol abuse, history of chronic pain and analgesic drug abuse, surgery, neuropsychiatric illness, depression and antidepressant use, human factors, national policies, hospital regulations, and health insurance under treatment of pain. Furthermore, we present several prevention strategies, such as perioperative measures, opioid substitutes, treatment of the primary illness, emotional regulation, use of opioid antagonists, efforts of the state, hospitals, doctors and pharmacy benefit managers, gene therapy, and vaccines. Greater understanding and better assessment are required of the risks associated with opioid abuse to ensure the safety and analgesic effects of pain treatment after surgery.

Safety and sedative effect of intranasal dexmedetomidine in mandibular third molar surgery: a systematic review and meta-analysis

Objective

The focus of this meta-analysis was to assess the sedative effect and safety of intranasal dexmedetomidine (Dex) in mandibular third molar surgery.

Methods

The PubMed/Medline, Web of Science, Cochrane Library, and China National Knowledge Infrastructure databases were searched for studies published until May 1, 2018. Eligible studies were restricted to randomized controlled trials (RCTs) and controlled clinical trials. The evaluation indicators mainly included the bispectral index, observer assessment of alertness/sedation scale, systolic blood pressure, and heart rate. Data for each period in the Dex and control groups were pooled to evaluate its sedative effect and safety.

Results

Five RCTs met the inclusion criteria. This study included 363 patients: 158 patients received intranasal inhalation of Dex before surgery, and 158 patients were negative controls. The pooled results showed a good sedative effect during tooth extraction when intranasal inhalation of Dex was performed 30 minutes before third molar extraction (assessment of alertness/sedation, Dex vs control SMD −1.20, 95% CI −1.73 to −0.67, I²=0, P=0.95; bispectral index, Dex vs control SMD −11.68, 95% CI −19.49 to −3.87, I²=89%; P=0.0001), and parameters returned to normal within 90 minutes after inhalation. During the operation, blood pressure and heart rate decreased to some extent, but the decreases did not exceed 20% of the baseline, and all patients returned to normal conditions within 90 minutes after inhalation.

Conclusion

Intranasal inhalation of Dex 30 minutes before third molar extraction can provide a good sedative effect, and large-sample multicenter RCTs are needed to evaluate the analgesic effect of Dex.

Risks and benefits of pre-operative dexmedetomidine in oral and maxillofacial surgeries: a systematic review

INTRODUCTION

Oral and maxillofacial surgeries might induce anxiety and pain to the patients. Sedative agents are one of the best ways for eliminating such consequences. Dexmedetomidine (DEX) is a recent sedative agent which presents higher sedative quality with greater specificity than other drugs. The aim of present paper is to evaluate the risks and benefits of administrating DEX during oral and maxillofacial surgeries by reviewing high quality released articles. Areas covered: Searches on PubMed, Scopus and Web of Science databases were completed with focus on randomized controlled trials (RCT). Related articles, from 2000 to 2015, were selected based on inclusion criteria and quality assessments factors. Full texts of the selected articles were screened and their significant information were gathered for judgments. Expert opinion: 17 RCTs on a total of 765 patients were screened. Some of the difficulties during reviewing the articles were: different pharmacokinetic and pharmacodynamics of drugs when combined with DEX, different time spots and method of monitoring, including studies on both minor and major surgeries for better data collection. Recent researches are going to focus on application of DEX for in-office procedures because of its desirable properties. Nevertheless, the analgesic and amnesic features of DEX are still questionable.