Comparison of dexmedetomidine and three different doses of midazolam in preoperative sedation

The influence of drugs used for sedation during mechanical ventilation on respiratory pattern during unassisted breathing and assisted mechanical ventilation: a physiological systematic review and meta-analysis

Background

Sedation management has a major impact on outcomes in mechanically ventilated patients, but sedation strategies do not generally consider the differential effects of different sedatives on respiration and respiratory pattern. A systematic review was undertaken to quantitatively summarize the known effects of different classes of drugs used for sedation on respiratory pattern during both spontaneous breathing and assisted mechanical ventilation.

Methods

This was a systematic review and meta-analysis conducted using Ovid MEDLINE, Embase, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials up to June 2020 to retrieve studies that measured respiratory parameters before and after the administration of opioids, benzodiazepines, intravenous and inhaled anaesthetic agents, and other hypnotic agents (PROSPERO #CRD42020190017). A random-effects meta-analytic model was employed to estimate the mean percentage change in each of the respiratory indices according to medication exposure with and without mechanical ventilation. Risk of bias was assessed using the Cochrane risk of bias assessment tools.

Findings

Fifty-one studies were included in the analysis. Risk of bias was generally deemed to be low for most studies. Respiratory rate decreased with the administration of opioids in both non-ventilated patients (18% decrease, 95% CI 12-24%) and ventilated patients (26% decrease, 95% CI 15-37%) and increased with inhaled anaesthetics in non-ventilated patients (83% increase, 95% CI 49-118%) and ventilated patients (50% increase, 28-72%). In non-ventilated patients, tidal volume decreased following administration of inhaled aesthetics (55% decrease, 95% CI 25-86%), propofol (36% decrease, 95% CI 20-52%), and benzodiazepines (28% decrease, 95% CI 17-40%); in patients receiving assisted mechanical ventilation, tidal volume was not significantly affected by sedation. Administration of other hypnotic agents was not associated with changes in respiratory rate or tidal volume.

Interpretation

Different classes of drugs used for sedation exert differential effects on respiratory pattern, and this may influence weaning and outcomes in mechanically ventilated patients.

Funding

This study did not receive any funding support.

Effect of virtual reality on preoperative anxiety in patients undergoing septorhinoplasty

BACKGROUND

The aim of this study was to evaluate the effect of a virtual reality video on preoperative anxiety, hemodynamic parameters, and patient satisfaction in patients undergoing septorhinoplasty.

METHODS

This was a prospective, observational cohort trial. Forty patients between the ages of 18...65 who were scheduled for elective septorhinoplasty, with an American Society of Anesthesiologists (ASA) physical status I...II were included in the study. Patients experienced a 15-minute virtual reality (VR) video via a phone using a VR device. A three-dimensional, 360.. video depicted the beauty of nature and was accompanied by meditation music.

PATIENTS

.. oxygen saturation values, heart rate, and blood pressure were monitored and recorded. Using the State-Trait Anxiety Inventory scale, anxiety scores and hemodynamic parameters were compared before and after VR application.

RESULTS

Median anxiety scores decreased significantly from 40.5 to 34 (p.ß<.ß0.001). VR also had positive effects on hemodynamic parameters.

CONCLUSIONS

VR reduces preoperative anxiety and has positive effects on hemodynamic parameters in patients undergoing septorhinoplasty. We anticipate that VR will be increasingly used as a non-pharmacological preoperative approach in the future.

A Randomized Control Trial of Three Intravenous Dexmedetomidine Doses for Procedural Sedation in Patients Undergoing Minor Gynaecological Surgery

Background: Minor gynaecological procedures are usually done in outpatient settings. Early discharge with minimal haemodynamic compromise is an essential requirement of these procedures. Many sedative drugs are being used for outpatient surgeries. Of the sedative agents available, dexmedetomidine, which has sedative and analgesic sparing effects, has the best safety profile in the cardiorespiratory system. Therefore, we evaluated the optimum dexmedetomidine dose for providing better procedural sedation.

Methodology: This randomized, double-blinded study included 120 ASA grade I and II patients aged 18-45 years who were undergoing short gynaecological procedures in a tertiary care hospital. Patients were randomly allocated into three groups of 40 each. After a loading dose of 1 µg/kg over 10 min, group A received dexmedetomidine infusion at a rate of 0.2 µg/kg/hr, group B at a rate of 0.4 µg/kg/hr, and group C at a rate of 0.6 µg/kg/hr. Perioperative hemodynamic changes, intraoperative adjuvant drug requirements, and postoperative recovery were also compared in the three different dexmedetomidine groups.

Results: Heart rate, blood pressure, oxygen saturation, and respiratory rate remained within the normal physiological range in all three groups at most perioperative time points. The time to achieve the Modified Aldrete Score and the post-anesthetic discharge scoring system was maximum in group C and minimum in group A. Ketamine had to be supplemented in almost half of the patients in group A and less than a quarter of the patients in group B. In group C, surgery was completed without any drug supplementation. Two patients in group B and four patients in group C had an episode of bradycardia. Oxygen saturation decreased in one patient in group C, necessitating oxygen supplementation.

Conclusions: Dexmedetomidine, at a dose of 0.4 µg/kg/hr with ketamine supplementation, provides the most appropriate procedural sedation and analgesia (PSA) without any significant hemodynamic compromise.

THE USE OF DEXMEDETOMIDINE IN PUNCTURE TECHNIQUES FOR DEGENERATIVE DISEASES OF THE LUMBAR SPINE

ABSTRACT Objective To analyze the results of the use of dexmedetomidine (D) in the treatment of patients with degenerative diseases of the lumbar spine using puncture techniques. Methods The study included 77 patients who underwent surgical puncture for degenerative diseases of the lumbar spine with the use of alpha-2-adrenomimetic D: percutaneous laser denervation of the facet joints (n = 46) and posterolateral transforaminal endoscopic discectomy (n = 31). We assessed: the level of sedation using the Ramsay Sedation Scale (RSS) and the Richmond Agitation Sedation Scale (RASS); intraoperative dynamics of the cardiovascular and respiratory system parameters; the level of pain syndrome according to VAS. Results A high intraoperative level of sedation was determined, with RASS -2, -3 and Ramsay III, IV; when transferring a patient to a department (in 90 minutes) this parameter was RASS 0 and Ramsay II. There were no significant changes in central hemodynamics and respiratory depression. The minimum level of pain was determined immediately after surgery, at 30 and 60 minutes after surgery, and before transfer to the department (90 minutes): 6 (4;9); 10 (8;12); 12 (9;13); 16 (13;19) respectively. The absence of the need for additional analgesia on the first postoperative day was verified. Conclusion The use of D significantly reduces the level of pain, while maintaining the necessary verbal contact with the patient, and provides the necessary neurovegetative protection without respiratory depression or lowered hemodynamic parameters during the perioperative period. Level of evidence II; Prognostic Studies - Investigating the Effect of a Patient Characteristic on Disease Outcome. Case series, retrospective study.

The Effect of Midazolam and Dexmedetomidine Sedation on Block Characteristic Following Spinal Bupivacaine: A Randomized Comparative Study

Background:

Dexmedetomidine is widely used as an adjunct to general as well as regional anesthesia.

Aims:

This study was conducted to compare and evaluate the synergistic effect of single intravenous (i.v.) bolus dose of dexmedetomidine with midazolam on spinal block duration, analgesia, and sedation in patients undergoing infra-umbilical surgeries.

Settings and Design:

Prospective, randomized, comparative, and double-blinded study.

Materials and Methods:

One hundred patients between 18 and 60 years of age of American Society of Anesthesiologists physical status I and II posted for elective infra-umbilical surgery under subarachnoid block were randomly divided into two groups (Group D and Group M). Patients of Group D received i.v. dexmedetomidine 0.5 μg.kg⁻¹ and of Group M received i.v. midazolam 0.05 mg.kg⁻¹ as premedication 5 min before spinal anesthesia over 10 min. Vital parameters, Ramsay sedation score, level of sensory and motor block, recovery time for sensory blockade, postoperative numerical rating scale, time of requirement of the first dose of postoperative rescue analgesic, and duration of analgesia were recorded and analyzed.

Statistical Analysis:

Chi-square test, t-test, and analysis of variance test were applied to analyze data using SPSS package for Windows.

Results and Conclusion:

Premedication with single i.v. dexmedetomidine prolonged the duration and increased the maximum upper level of only sensory component of spinal anesthesia (6.42 ± 3.21 vs. 4.8 ± 1.21 thoracic segments higher than with midazolam sedation). This property can be beneficial in preventing undesirable prolongation of motor block and facilitating early ambulation in shorter duration of infra-umbilical surgeries. In addition, dexmedetomidine slowed the regression of sensory block and increased the time of the first request of analgesic.

Preoperative education reduces preoperative anxiety in cancer patients undergoing surgery: Usefulness of the self-reported Beck anxiety inventory

Background and objectives

Methods

Results

Conclusions

Randomized controlled trial assessing the effectiveness of midazolam premedication as an anxiolytic, analgesic, sedative, and hemodynamic stabilizer

BACKGROUND

Midazolam premedication is widely used before general anesthesia, but lacks clinical evidence of effectiveness. The present study aimed to evaluate the effectiveness of midazolam premedication following 4 aspects: anxiety reduction, sedation, hemodynamic stabilization, and analgesia.

METHODS

In a randomized, single-blind, prospective study, a total of 128 women were allocated to the midazolam premedication group (Group P, n = 64) or the control group (Group N, n = 64). The patients were asked to complete the Beck anxiety inventory (BAI) 2 times: on the day before surgery (BS) and 30 minutes after midazolam premedication (T0). Depth of anesthesia using state entropy (SE), conventional hemodynamic data using heart rate (HR) and mean blood pressure (MBP), and analgesic profiles using surgical pleth index (SPI) were acquired at the following 4 points: T1-pre-induction, T2-prior to intubation, T3-intubation, and T4-20 minutes after intubation.

RESULTS

No change in BAI score was observed between BS and T0 in both groups P and N (median and interquartile range [IQR], Group P: BS-4.5 [2.0-7.0], T0-4.0 [1.0-9.0], P = .603; Group N: BS-4.0 [1.0-8.5], T0-3.5 [1.0-6.0], P = .066). Midazolam premedication reduced SE at T2-4 (mean difference with 95% confidence interval [95% CI], T2-7.1 [1.6-12.6], P = .012; T3-10.4 [6.5-14.4], P < .001; T4-9.2 [5.0-13.4], P < .001). Midazolam premedication also reduced HR (mean differences [95% CI], T1-7.3 [2.5-12.1], P = .003; T3-6.6 [1.1-12.2], P = .020) and MBP at T1 and T3 (mean differences [95% CI], T1-7.3 [2.5-12.1], P = .003; T3-8.6 [1.3-15.9], P = .021), and lowered SPI at T1-3 (mean differences [95% CI]: T1-12.7 [6.1-19.4], P < .001; T2-6.0 [0.5-11.5], P = .033; T3-7.9 [1.7-14.1], P = .012).

CONCLUSION

Midazolam premedication did not reduce the level of anxiety. However, midazolam premedication reduced the entropy values, stabilized hemodynamics, and provided analgesia during the induction of anesthesia. The purpose of midazolam premedication needs to be reconsidered.

Effect of Different Dosages of Intravenous Midazolam Premedication on Patients Undergoing Head and Neck Surgeries- A Double Blinded Randomized Controlled Study

INTRODUCTION

Benzodiazepines primarily acts on the central nervous system. Most patients are extremely anxious in the pre-operative period. Excessive anxiety adversely influences anaesthetic induction and often leads to functional impairment and poor recovery after surgery.

AIM

To determine whether amnesia, anxiety, sedation and cardio respiratory symptoms are affected while administering two different doses of intravenous midazolam (0.02 mg/kg & 0.06 mg/kg).

MATERIALS AND METHODS

Two forty patients posted for head and neck surgeries were involved in this double blinded prospective randomised controlled trial. The patients were randomized into two main groups, Group 1 receiving 0.02 mg/kg and Group 2 receiving 0.06 mg/kg midazolam intravenously as premedication. Visual recognition and recall were tested using eight laminated A4 size posters pre-operatively and four further images were shown at the postoperative interview. Anxiety was evaluated by a Visual Analogue Scale (VAS) and sedation depth was determined by the Observer's Assessment of Alertness/Sedation Scale (OAAS) scale. Vital signs including heart rate, respiratory rate, mean blood pressure and arterial oxygen saturation (SpO₂) were monitored. Statistical analysis was done using paired Student's t-test and Chi-square test.

RESULTS

VAS scores were lower in Group 2 (0.06 mg/kg) than in Group 1 (0.02 mg/kg) at T₁₅ (15 minutes after the injection of midazolam). Comparison of OAAS scores among Group 1 and Group 2 showed that more patients in Group 1 were alert at T15 compared to Group 2. Recall of events was significantly lower in Group 2 compared to Group 1. There was no significant statistical variation in haemodynamic parameters between the groups except for decreased diastolic blood pressure and room air saturation in Group 2.

CONCLUSION

A higher dosage of midazolam improves the quality of anxiolysis and sedation with lesser rates of intraoperative recall and maintains haemodynamic stability.

Monitored anaesthesia care - Comparison of nalbuphine/dexmedetomidine versus nalbuphine/propofol for middle ear surgeries: A double-blind randomised trial

Background and Aims:

Middle ear surgeries (MESs) are usually performed under sedation with local anaesthesia and can be well tolerated by the patient with minimal discomfort. In the present study, we compare the effect of nalbuphine/dexmedetomidine combination with nalbuphine/propofol on sedation and analgesia in monitored anaesthesia care.

Methods:

One hundred adult patients undergoing MESs under monitored anaesthesia care (MAC) were randomly allocated into two groups. All patients in both groups received injection nalbuphine 50 μg/kg intravenously (IV). Group D received a bolus dose of injection dexmedetomidine 1 μg/kg IV over 10 min followed by an infusion started at 0.4 μg/kg/h IV. Group P received a bolus dose of injection propofol 0.75 mg/kg followed by an infusion started at 0.025 mg/kg/min IV. Sedation was titrated to Ramsay Sedation Score (RSS) of 3. Patient's mean arterial pressure, heart rate, saturation peripheral pulse and need for intraoperative rescue sedation/analgesia were recorded and compared. The data analysis was carried out with Z test and Chi-square test.

Results:

Mean RSS was significantly more in Group D (4.24 ± 1.54) as compared to Group P (2.58 ± 0.95). Overall VAS score was also significantly less in Group D (3.5 ± 1.7) than in Group P (5.4 ± 1.8). In total, 16 patients (32%) in Group D had hypotension whereas 7 patients (14%) only in Group P had hypotension.

Conclusion:

Nalbuphine/dexmedetomidine combination is superior to nalbuphine/propofol in producing sedation and decreasing VAS in patients undergoing MESs under MAC. Better surgeon and patient satisfaction were observed with nalbuphine/dexmedetomidine. Haemodynamics need to be closely monitored.

A Prospective Randomized Trial Comparing Dexmedetomidine and Midazolam for Conscious Sedation During Oocyte Retrieval in An In Vitro Fertilization Program

Background:

Various sedative and analgesic techniques have been used for pain relief during oocyte retrieval which is the most painful part of in vitro fertilization (IVF) procedures.

Aim:

This study aimed at comparing dexmedetomidine and midazolam for conscious sedation in women undergoing transvaginal oocyte retrieval during an IVF program.

Settings and Design:

Prospective randomized double-blinded comparative study.

Patients and Methods:

Fifty-two patients undergoing oocyte retrieval in their first IVF cycle were randomly allocated into two equal groups. The intervention started with giving fentanyl1 mcg/kg intravenous (IV) followed by paracervical block in both groups. Then, subjects in group (D) received dexmedetomidine at a loading dose of 1 μg/kg IV over 10 min followed by 0.5 μg/kg/h infusion until Ramsay Sedation Scale (RSS) reached 3–4. Patients in group (M) received a loading dose of midazolam 0.06 mg/kg IV over 10 min followed by 0.5 mg incremental doses until RSS reached 3–4.

Statistical Analysis:

Statistical analysis was performed using SPSS program version 19 and EP 16 program.

Results:

Visual analog scale scores significantly decreased in group D than group M at 5 and 10 min during the procedure (P = 0.03 and 0.01, respectively), and at 20 min during postanesthesia care unit (PACU) time (P = 0.04). Intraoperative rescue sedation by propofol and postoperative rescue analgesia by acetaminophen showed a highly significant decrease (P < 0.01) in group D compared with group M. Furthermore, the time of PACU stay was significantly less (P < 0.01) in group D (49.03 ± 12.8 min) compared to group M (62.5 ± 18.34 min). Although significant bradycardia was noted in group D (23% of patients) during the procedure (P = 0.02), no cases were reported in group M. Patient satisfaction was significantly higher in group D (P < 0.1).

Conclusion:

Dexmedetomidine is an effective analgesic alternative to midazolam during oocyte retrieval for IVF. It offered not only a shorter PACU stay without significant side effects, but also better overall patient satisfaction scores.

The timing of administration of intravenous dexmedetomidine during lower limb surgery: a randomized controlled trial

Background

Dexmedetomidine, a selective alpha-2 agonist, has sedative, analgesic, and anxiolytic effects without respiratory depression. Dexmedetomidine can cause a biphasic cardiovascular response, and induce transient hypertension. Hypotension is a common complication of spinal anesthesia. Decreasing anxiety of patients before procedure is important for high quality of procedure. This study aimed to compare the incidence of hypotension and patients’ anxiety and comfort levels when dexmedetomidine was intravenously administered before and after spinal anesthesia.

Methods

Seventy-four patients with American Society of Anesthesiologists physical status classification I or II were randomly allocated into two groups. Spinal anesthesia was performed using 12 mg of 0.5% heavy bupivacaine. In Group A, 1 μg/kg of dexmedetomidine was intravenously administered for 10 min, followed by the maintenance infusion of dexmedetomidine 0.2 μg/kg/hr after 5 min of intrathecal bupivacaine injection. Patients in Group B received same dose of dexmedetomidine by intravenous administration before 5 min of intrathecal bupivacaine injection. Perioperative vital signs, anxiety (using the Spielberger’s State-Trait Anxiety Inventory) and comfort (using the numerical rating scale) were evaluated.

Results

The incidence of hypotension was significantly lower in Group A (16.1%) than in Group B (48.4%) during infusion of dexmedetomidine (p = 0.01). The need for treatment of hypotension is higher in Group B than Group A (p = 0.02). The incidence of bradycardia and desaturation did not significantly differ between the two groups. There were no statistically significant differences regarding the patients’ anxiety and comfort.

Conclusions

Hypotension is more frequently occurred, and the treatment of hypotension is more needed in Group B. The intravenously administration of dexmedetomidine before spinal anesthesia has no advantages in hemodynamic status and patients’ comfort compared to that after spinal anesthesia during lower limb surgery.

Trial registration

ClinicalTrials.gov number, NCT02155010. Retrospectively registered on May 22, 2014.

Single dose intravenous dexmedetomidine prolongs spinal anesthesia with hyperbaric bupivacaine

Background and Introduction:

Spinal block, a known technique to obtain anaesthesia for infraumblical surgeries. Now physician have advantage of using adjuvant to prolong the effect of intrathecal block, which can be given either intravenously or intrathecally, dexmedetomidine is one of them. We studied effect of intravenous dexmedetomidine for prolongation of duration of intrathecal block of 0.5% bupivacaine block.

Objective:

To evaluate the effect of intravenous dexmedetomidine on sensory regression, hemodynamic profile, level of sedation and postoperative analgesia.

Methodology:

60 patients of ASA grade I and II posted for elective infraumblical surgeries were included in the study and randomly allocated into two groups. Group D recieved intrathecal 0.5% bupivacaine heavy, followed by infusion of intravenous dexmedetomidine 0.5mic/kg over 10 min, patients in group C received intrathecal 0.5% bupivacaine heavy 3ml followed by infusion of same volume of normal saline as placebo.

Results:

Two segment regression of sensory block was achieved at 139.0 ± 13.797 in group D whereas in group C it was only 96.67 ± 7.649min, the total duration of analgesia achieved in both study groups was 234.67 ± 7.649min and 164.17 ± 6.170min respectively in group D and group C. The time at which first analgesic was given to the patients when VAS >3 achieved that is in group D at 234.67 ± 7.649min and in group C at 164.17 ± 6.170min. Inj diclofenac sodium 75mg intramuscular was used as rescue analgesic.

Is dexmedetomidine better than propofol and fentanyl combination in minor day care procedures? A prospective randomised double-blind study

Background and Aims:

The growing popularity and trend of day care (ambulatory) anaesthesia has led to the development of newer and efficient drug regimen. We decided to evaluate the efficacy of two drug regimens namely dexmedetomidine and propofol with midazolam and fentanyl for moderate sedation characteristics in minor surgical procedures in terms of analgesia, intra-operative sedation, haemodynamic stability and side effects related.

Methods:

Totally, 60 adult American Society of Anaesthesiologists class I-II patients posted for day care surgeries of duration <45 min divided into two groups; Group D, where dexmedetomidine loading dose at 1 μg/kg was administered over 10 min followed by maintenance infusion initiated at 0.6 μg/kg/h and titrated to achieve desired clinical effect with dose ranging from 0.2 to 0.7 μg/kg, Group P, where midazolam at 0.02 mg/kg and fentanyl at 2 μg/kg IV boluses were given followed by propofol infusion. Statistical analysis was done using student t-test, analysis of variance and Chi-square analysis. P < 0.05 was considered to be significant.

Results:

Degree of sedation (Observer's Assessment of Activity and Sedation Scale ≤3) was comparable in both groups (P > 0.05). Rescue analgesia with fentanyl was needed in 30% patients of Group D compared to 17.63% patients of Group P (P < 0.05). The level of arousal was faster and better in Group D at 5 min after the procedure (P < 0.05). Haemodynamics were stable in Group D as with Group P patients (P < 0.005). Dry mouth reported by 16.67% patients.

Conclusion:

Dexmedetomidine can be a useful adjuvant rather than the sole sedative-analgesic agent during minor surgeries and be a valuable alternative to propofol in terms of moderate sedation, haemodynamic stability with minimal transient side effects.

Comparison of dexmedetomidine-propofol versus fentanyl-propofol for insertion of laryngeal mask airway

Background and aims:

Laryngeal mask airway (LMA) insertion requires anesthesia and suppression of airway reflexes. In search of an optimal drug, we compared dexmedetomidine and fentanyl, in combination with propofol for insertion of LMA.

Material and Methods:

This study was a prospective double blind randomized study. Eighty patients of ASA class 1&2 were randomly divided into two groups of 40 each. Group D received dexmedetomidine 1 mcg/kg and group F received fentanyl 1 mcg/kg intravenously (IV) over 2 minutes. For induction, propofol 2mg/kg was given IV and 90 seconds later LMA was inserted. We observed apnea time, heart rate, respiratory rate, non invasive blood pressure and oxygen saturation before induction, 30 seconds after induction, 1, 3, 5, 10 and 15 minutes after insertion of LMA. Patient's response to LMA insertion like coughing, gagging or any movement were noted and scored. Statistical analysis of data was done using student t test for parametric data, Chi-square test for non parametric data and SPSS 15.0 for windows software.

Results:

37 (92.5%) patients of group D and 35 (87.5%) patients of group F had LMA insertion score of <2 and 5 (12.5%) patients of group F had score >2. Adverse events to insertion of LMA and hemodynamic variables were comparable in both the groups. Number of patients developing apnoea was larger and apnoea times were longer in group F compared to group D. When compared to group F, group D showed an increased respiratory rate.

Conclusion:

Dexmedetomidine can be a comparable alternative to fentanyl as an adjuvant to propofol for providing optimum insertion conditions for LMA and preservation of respiration.

Low-dose intramuscular dexmedetomidine as premedication: a randomized controlled trial

BACKGROUND

Dexmedetomidine-induced bradycardia or hypotension has recently attracted considerable attention because of potentially grave consequences, including sinus arrest and refractory cardiogenic shock. A route other than intravenous injection or a low dose may help minimize cardiovascular risks associated with dexmedetomidine. However, few studies have addressed the clinical effects of low-dose intramuscular dexmedetomidine as premedication.

MATERIAL AND METHODS

Forty American Society of Anesthesiologists physical status I adult patients undergoing suspension laryngoscopic surgery were randomized to receive intramuscular dexmedetomidine (1 µg·kg-1) or midazolam (0.02 mg·kg-1) 30 minutes prior to anaesthesia induction. The sedative, hemodynamic, and adjuvant anaesthetic effects of both premedications were assessed.

RESULTS

The levels of sedation (Observer's Assessment of Alertness/Sedation scales) and anxiety (visual analog score) at pre-induction, and the times to eye-opening and extubation, were not different between the groups. The heart rate response following tracheal intubation and extubation, and mean arterial pressure responses after extubation, were attenuated in the dexmedetomidine group compared to the midazolam group. No bradycardia or hypotension was noted in any patients. Propofol target concentrations at intubation and at start and completion of surgery were decreased in the dexmedetomidine group, whereas no difference in respective remifentanil levels was detected.

CONCLUSIONS

This study provides further evidence that dexmedetomidine premedication in low dose (1 μg·kg-1) by intramuscular route can induce preoperative sedation and adjuvant anaesthetic effects without clinically significant bradycardia or hypotension.

Does premedication with dexmedetomidine provide perioperative hemodynamic stability in hypertensive patients?

Background

Perioperative hemodynamic fluctuations are seen more often in hypertensive patients than in normotensive patients. The purpose of our study was to investigate the perioperative hemodynamic effects of dexmedetomidine and midazolam used for premedication in hypertensive patients relative to each other and in comparison to normotensive patients.

Methods

One-hundred-forty female, normotensive or hypertensive patients undergoing myomectomies or hysterectomies. They were randomly enrolled into the subgroups: Group ND (normotensive-dexmedetomidine); Group HD (hypertensive-dexmedetomine); Group NM (normotensive-midazolam); Group HM (hypertensive- midazolam). Dexmedetomidine was administered at a concentration of 0.5 μg.kg⁻¹, and midazolam was administered at a concentration of 0.025 μg.kg⁻¹ via intravenous (IV) infusion before the induction of anaesthesia. Haemodynamic parameters were recorded at several times (T_beginning, T_{preop5 min}, T_{preop 10 min}, T_induction, T_intubation, T_{intubation5 min}, T_{initial surgery}, T_{surgery 15 min}, T_{surgery 30 min}, T_extubation, T_{extubation 5 min}). Propofol amount for induction, time between induction and initial surgery, demand of antihypertensive therapy, rescue atropine were recorded. Quantitative clinical and demographic characteristics were compared using One Way ANOVA. The values were compared using One-way Analysis of Variance. Additionally periodic variations were examined by One way Repeated Measures Analysis of Variance for groups separately.

Results

SBP was significantly different between normotensive and hypertensive groups at the following time points: T_{preop 5 min}, T_{preop 10 min}, T_induction, T_intubation, T_{intubation 5 min} and T_{initial surgery}. MBP was significantly different in the hypertensive groups at T_induction, T_intubation, T_{intubation 5 min,} T_{initial surgery}, T_{surgery 15 min}, T_{surgery 30 min,} T_extubation and T_{extubation 5 min}. The perioperative requirements for antihypertensive drugs were significantly higher in Group HM.

Conclusion

In the hypertensive patients, dexmedetomidine premedication provides better hemodynamic stability compared with midazolam, and because it decreases the antihypertensive requirements, its use might be beneficial.

Trial registration

Trial registration: Clinicaltrials.gov identifier: NCT02058485.

Comparison of Dexmedetomidine and Midazolam in Sedation for Percutaneous Drainage of Hepatic Hydatid Cysts

OBJECTIVE

Hydatid cyst still continues to be a public health problem. The basic treatment for the disease is surgery, but ultrasound-guided percutaneous drainage has become an important treatment alternative. Agents preferred for sedation during drainage performed under local anaesthesia must also preserve respiration and hemodynamic stability while providing adequate sedation. We compared the sedative properties of midazolam, which has a short duration of action, and a selective α2 adrenergic receptor agonist, dexmedetomidine, and the intraoperative complications.

METHODS

After approval by the clinical trials ethics committee, 40 patients with similar demographic data were randomized into two groups. All patients received 10 mg metoclopramide and 45.5 mg pheniramine before the procedure. Then, midazolam (0.07 mg kg(-1) IV bolus followed by 0.01 mg kg(-1) h(-1) infusion) was administered to Group 1, and dexmedetomidine (1 μg kg(-1) loading dose in 10 minutes, followed by 0.2 μg kg(-1) h(-1) continuous infusion) was administered to Group 2 for sedation. Just before the surgical procedure, all patients received IV propofol in a subhypnotic dose of 0.5 mg kg(-1); the dose was repeated if adequate sedation could not be achieved. Observer's assessment of alertness/sedation (OAA/S) scale and Bispectral index (BIS) were used to evaluate the sedation level during the procedure. Heart rate (HR), mean arterial pressure (MAP), respiratory rate (RR), peripheral oxygen saturation (SpO2) and end-tidal carbon dioxide pressure (ETCO2) were monitored before and after induction and every 5 minutes thereafter. Propofol requirement was noted for each group.

RESULTS

Sedation in the dexmedetomidine group was as effective and adequate as that observed in the midazolam group. BIS values were significantly lower in the dexmedetomidine group, especially after 10 minutes and thereafter. RR, SpO2, and ETCO2 were similar in both groups, whereas clinically insignificant decreases in HR and MAP were observed in the dexmedetomidine group. Propofol requirements were similar in both groups.

CONCLUSION

We conclude that dexmedetomidine, providing adequate sedation without respiratory depression, can be considered as an appropriate agent for sedation in surgical procedures performed under local anaesthesia.

A prospective randomized double-blind study comparing dexmedetomidine vs. combination of midazolam-fentanyl for tympanoplasty surgery under monitored anesthesia care

Background:

Analgesia and sedation are usually required for the comfort of the patient and surgeon during tympanoplasty surgery done under local anesthesia. In this study, satisfaction scores and effectiveness of sedation and analgesia with dexmedetomidine were compared with a combination of midazolam-fentanyl.

Materials and Methods:

Ninety patients undergoing tympanoplasty under local anesthesia randomly received either IV dexmedetomidine 1 μg kg^-1 over 10 min followed by 0.2 μg kg^-1h^-1 infusion (Group D) or IV midazolam 0.06 mg kg^-1 plus IV fentanyl 1 μg kg^-1 over 10 min (Group MF) followed by normal saline infusion at 0.2 ml kg^-1h^-1. Sedation was titrated to Ramsay sedation score (RSS) of three. Vital parameters, rescue analgesics (fentanyl 1 μg kg^-1) and sedatives (midazolam 0.01 mg kg^-1), patient and surgeon satisfaction scores were recorded.

Results:

Patient and surgeon satisfaction score was better in Group D than Group MF (median interquartile range (IQR) 9 (8-10) vs. 8 (6.5-9.5) and 9 (8.5-9.5) vs. 8 (6.75-9.25), P = 0.0001 for both). Intraoperative heart rate and mean arterial pressure in Group D were lower than the baseline values and the corresponding values in Group MF (P < 0.05). Percentage of patients requiring rescue fentanyl was higher in Group MF than Group D (40% vs. 11.1%, P = 0.01). One patient in Group D while four in Group MF (8.8%) required rescue sedation with midazolam (P > 0.17). Seven patients in Group D had dry mouth vs. none in Group MF (P = 0.006). One patient in Group D had bradycardia with hypotension which was effectively treated.

Conclusion:

Dexmedetomidine is comparable to midazolam-fentanyl for sedation and analgesia in tympanoplasty with better surgeon and patient satisfaction. Hemodynamics need to be closely monitored.

Effects of different loading doses of dexmedetomidine on bispectral index under stepwise propofol target-controlled infusion

BACKGROUND AND PURPOSE

Stepwise propofol target-controlled infusion (TCI) can achieve a less disturbed condition of hemodynamics and respiration. Its combination with dexmedetomidine may have some advantages for patients. We studied the effects of different loading doses of dexmedetomidine on the bispectral index (BIS) under stepwise propofol TCI.

METHODS

Forty patients were randomly assigned into groups D(1.0), D(0.5), D(0.25) and D(0), in which dexmedetomidine at 1.0, 0.5, 0.25 or 0 µg•kg(-1) was infused over 10 min followed by 0.5 µg•kg(-1)•h(-1) and stepwise propofol TCI, which was administered with target effect site concentration (Ce) at 0.5 µg•ml(-1), and increased until 2.5 µg•ml(-1) by 1.0 µg•ml(-1) after 5 min reaching target Ce. BIS, heart rate, MAP, pulse oxygen saturation, RR and end-tidal carbon dioxide pressure were recorded before loading dose (T(0)), at 5 min (T(5 min)) and 10 min (T(10 min)) after starting infusion, after 5 min reaching Ce of 0.5, 1.5 and 2.5 µg•ml(-1) (T(p0.5), T(p1.5) and T(p2.5)).

RESULTS

BIS values in group D(1.0) were significantly lower compared with those in group D(0) since T(10 min) and those in groups D(0.5) and D(0.25) since T(p0.5). In group D(1.0), heart rate decreased significantly at T(5 min) and T(10 min), heart rate at T(10 min) was significantly lower compared with that in group D(0). MAP remained stable during the loading dose infusion and decreased to some degree after propofol infusion in all groups. Changes in pulse oxygen saturation, RR and end-tidal carbon dioxide pressurewere similar among the groups without respiration depression.

CONCLUSION

A loading dose of dexmedetomidine of 1.0 µg•kg(-1), not 0.5 µg•kg(-1) or less, over 10 min followed by 0.5 µg•kg(-1)•h(-1) can definitely decrease the BIS under stepwise propofol TCI with clinically stable blood pressure and without respiration depression, while attention should be paid to decreased heart rate.

Dexmedetomidine reduces emergence agitation after tonsillectomy in children by sevoflurane anesthesia: a case-control study

OBJECTIVE

To evaluate the efficacy and safety of dexmedetomidine for emergence agitation after tonsillectomy in children.

METHODS

120 ASA physical status I and II children, aged 5-14 years, undergoing anesthesia for tonsillectomy, were randomly divided into 3 groups: Placebo group, the low dexmedetomidine concentration group and the high dexmedetomidine concentration group. Before the entrance of the operating room (OR), all of the children received intravenous injection 40 μg kg(-1) midazolam to reduce anxiety at first, and then dexmedetomidine was given intravenously at an initial loading dose of 0.5 μg kg(-1) or 1 μg/kg over a 10-min period via a computer controlled infusion pump followed by a maintenance infusion of 0.2 μg kg(-1)h(-1) or 0.4 μg kg(-1)h(-1)over the surgery. The heart rate, SpO(2) and mean arterial blood pressure were recorded for each patient in both operation room and PACU. The designated time points: at the start of the anesthetic induction, at the discontinuation of inhalational agents, at first opening of eyes, at time to remove endotracheal tube were recorded. After patient arrival at the PACU, VAS score, RSS, the occurrence of emergence agitation were recorded every 5 min for the first 30 min and every 10 min for the next 30 min after endotracheal tube was removed.

RESULTS

There was significant difference in the incidence of emergence agitation between Placebo group and the high concentration group when endotracheal tube was removed (P<0.05). There was significant difference in the VAS pain scores and in the RSS between three groups at the time of extubation, as well as 5 min and 10 min after extubation (P<0.05).

CONCLUSIONS

Dexmedetomidine appears to be safe and effective to reduce the incidence of early emergence agitation in children after tonsillectomy. Initial loading dose of 1.0 μg kg(-1) followed by a maintenance infusion of 0.4 μg kg(-1)h(-1) is better choice for children received tonsillectomy.