Dexmedetomidine: A potential agent for use in procedural dental sedation

The EC50 of propofol with different doses of dexmedetomidine during gastrointestinal endoscopy: A double-blind, placebo-controlled trial

PURPOSE

The goal of this study was to evaluate the dose-response relationship between dexmedetomidine and propofol in sedating patients and to determine the optimal dosage of dexmedetomidine during gastrointestinal endoscopy.

METHODS

One hundred fifty patients were divided into 5 groups, each receiving a loading dose of dexmedetomidine (0.4, 0.6, 0.8, 1.0 µg/kg) or saline, with propofol for sedation. The median effective concentration (EC50) of propofol was calculated using the modified Dixon up-and-down approach. Adverse effects, vital signs, procedure, and recovery times were recorded.

RESULTS

The EC50 of propofol in groups NS, D0.4, D0.6, D0.8, and D1.0 were 3.02, 2.44, 1.97, 1.85, and 1.83 µg/mL, respectively. Heart rate in the dexmedetomidine groups decreased more than the NS group (P < .001). The mean arterial pressure (MAP) in the NS group experienced a decline compared to groups D0.8 and D1.0 when the plasma concentration and effect-site concentration reached equilibrium. Additionally, the respiratory rate was found to be lower in groups NS, D0.4, D0.6, and D0.8 (P < .05). Recovery time in groups D0.8 and D1.0 was longer than the NS group (P < .05). Bruggemann comfort scales score was higher in group D1.0 (P < .05). No significant difference was found in the incidences of hypotension and bradycardia, and the dose of ephedrine and atropine. Respiratory depression was significantly reduced in groups D0.8 and D1.0 compared to the NS group.

CONCLUSION

A single dose of 0.6 to 0.8 µg/kg of dexmedetomidine should be recommended in combination with propofol for gastrointestinal endoscopy. And the EC50 of propofol is 1.97 to 1.85 µg/mL.

Evaluation of lignocaine, dexmedetomidine, lignocaine-dexmedetomidine infusion on pain and quality of recovery for robotic abdominal hysterectomy: a prospective randomized controlled trial

Background: Acute postoperative pain is associated with poor quality of recovery after surgery. Perioperative use of intravenous lignocaine or dexmedetomidine have demonstrated better pain control, early return of bowel function, and effects on quality of recovery.

Methods: Ninety-six women planned for elective robotic abdominal hysterectomy were randomized into four groups. Groups received lignocaine infusion (1.5 mg.kg⁻¹ loading, 2 mg.kg⁻¹.h⁻¹ infusion) (Group I), dexmedetomidine infusion (1 µg.kg⁻¹ loading, 0.6 µg.kg⁻¹.h⁻¹ infusion) (Group 2), lidocaine (1.5 mg.kg⁻¹ loading, 2 mg.kg⁻¹.h⁻¹ infusion), and dexmedetomidine infusions (1 µg.kg⁻¹ loading, 0.5 µg.kg⁻¹.h⁻¹ infusion) (Group 3), and normal saline 10 mL loading, 1 mL.kg⁻¹.h⁻¹ infusion) (Group 4). Primary outcome was visual analogue pain scores at 1, 2, 4, 12, and 24 hours after surgery. Secondary outcomes included postoperative fentanyl requirement, time of return of bowel sounds and flatus, QoR15 score on day 1, 2, and discharge.

Results: The VAS was significantly lower in Groups 2 and 3 compared to Groups 1 and 4. Total postoperative fentanyl consumption in the first 24 hours was 256.25 ± 16.36 mcg (Group 1), 177.71 ± 16.81 mcg (Group 2), 114.17 ± 16.19 mcg (Group 3), and 304.42 ± 31.26 mcg (Group 4), respectively. Time to return of bowel sounds and passage of flatus was significantly shorter in Groups 2 and 3 (p < 0.01). QoR15 scores after surgery were higher in Group 3 compared to Groups 1, 2, and 4, (p < 0.01) respectively.

Conclusion: Combined infusion of lignocaine and dexmedetomidine significantly decreased postoperative pain, fentanyl consumption, and improved quality of recovery score after surgery in patients undergoing Robotic abdominal hysterectomy.

Role of dexmedetomidine in pediatric dental sedation

Dexmedetomidine is a highly selective α2-adrenoceptor agonist with a vast array of properties, making it suitable for sedation in numerous clinical scenarios. Its use was previously restricted to the sedation of intensive care unit patients. However, its use in pediatric dental sedation has been gaining momentum, owing to its high suitability when compared with conventional pediatric sedatives. Its properties range from sedation to anxiolysis to analgesia, due to its sympatholytic properties and minimal respiratory depression ability. Because dexmedetomidine is an efficacious and safe drug, it is gaining importance in pediatric sedation. Thus, the aim of this review is to highlight the properties of dexmedetomidine, its administration routes, its advantages over the commonly used pediatric sedatives, and especially its role as an alternative pediatric sedative.

Recovery time after oral and maxillofacial ambulatory surgery with dexmedetomidine: an observational study

OBJECTIVES

To evaluate the relationship between pharmacokinetic descriptors of dexmedetomidine (predicted area under the curve during the procedure, predicted plasma level at the end of the procedure, and duration of procedure) and sedation depth (proportion of time with bispectral index < 85 during the procedure) with recovery time after ambulatory procedures.

MATERIALS AND METHODS

Clinical observational study of patients undergoing oral and maxillofacial ambulatory surgery with dexmedetomidine as sole sedative agent. Patients received a loading dose of dexmedetomidine (0.25-1 μg kg^-1) followed by a maintenance infusion (0.2-1.4 μg kg^-1 h^-1) to keep a bispectral index < 85 until 5 min before the end of the procedure, and were transferred to a post-anesthesia care unit until criteria for discharge were met.

RESULTS

Data from 75 patients was analyzed. Sedation depth was directly associated with recovery time (Pearson correlation coefficient [r] = 0.26; p = 0.024). Around 7% of the variation in recovery time was explained by the proportion of time with bispectral index < 85. No association with procedure duration (r = 0.01; p = 0.9), predicted area under the curve (r = 0.1; p = 0.4), or predicted plasma level of dexmedetomidine at the end of the procedure (r = 0.12; p = 0.3) with recovery time was observed.

CONCLUSIONS

Sedation depth with dexmedetomidine could play a role in increasing recovery time after oral and maxillofacial ambulatory surgery. In our study, the pharmacokinetic descriptors of dexmedetomidine did not seem to influence recovery time.

CLINICAL RELEVANCE

Sedation depth with dexmedetomidine could play a role in increasing recovery time after ambulatory procedures.

Loading dose of Dexdor® and optimal sedation during oral and maxillofacial ambulatory surgery procedures: An observational study

INTRODUCTION

Dexdor^® do not include the possibility of loading dose, which could increase time to achieve adequate sedation for ambulatory procedures. The objective of this study was to evaluate the effect of several loading dose of dexmedetomidine in the time to achieve and maintain an optimal level of sedation and its clinical hemodynamic repercussion.

MATERIAL AND METHODS

The IRB approved this observational study for patients that underwent oral and maxillofacial ambulatory surgery under dexmedetomidine at the University of Navarra Clinic from February 2013 to November 2014. According to the loading dose the patients were grouped into 3 categories:<0.5, 0.5, and>0.5μg/kg. Optimal level of sedation was defined as bispectral index<85. Data were analyzed using survival analysis techniques. Vasoactive drugs requirements was evaluated using exact logistic regression.

RESULTS

Eighty-one patients were evaluated. Hazard ratios for patients in 0.5 and >0.5μg/kg loading dose categories for achieving a bispectral index<85 were 1.5 (95% CI 0.9, 2.6) and 1.8 (95% CI 0.8, 3.9), respectively, compared with the lowest category. Five patients (6.2%) required atropine for bradycardia. Patients in the group>0.5μg/kg showed greater risk of requiring atropine compared with the group<0.5μg/kg (odds ratio 2.2; 95% CI 0.03, 183).

CONCLUSION

Loading dose of dexmedetomidine>0.5μg/kg appears minimize the time to achieve and maintain an optimal level of sedation during the first 60min of procedure. Further investigation to elucidate the association between loading dose of dexmedetomidine and subsequent atropine requirements may be warranted.