Comparison of dexmedetomidine–propofol vs. fentanyl–propofol for laryngeal mask insertion:

Comparison of Intra and Post-operative Sedation efficacy of Dexmedetomidine-Midazolam and Dexmedetomidine-Propofol for Major Abdominal Surgery

BACKGROUND

The effectiveness and side effects of dexmedetomidine (DEX) in combination with midazolam and propofol have not been comparatively studied in a single clinical trial as sedative agents to general anesthesia before.

OBJECTIVE

The objective of this study is to compare intra and post-operative sedation between DEX-Midazolam and DEX-Propofol in patients who underwent major abdominal surgery on the duration of general anesthesia, hemodynamic and sedation effect.

METHOD

This prospective, randomized, double-blinded clinical trial included 50 patients who were 20 to 60 years of age and admitted for major abdominal surgery. The patients were randomly assigned by a computer-generated random numbers table to sedation with DEX plus midazolam (DM group) (n=25) or DEX plus propofol (DP group) (n=25). In the DM group, patients received a bolus dose of 0.1 mg/kg of midazolam and immediately initiated the intravenous (i.v.) infusion of DEX 1 µg/kg over a 10 min and 0.5 µg/kg/hr by continuous i.v. infusion within operation period. In the DP group, patients received pre-anesthetic i.v. DEX 1 µg/kg over 15 min before anesthesia induction and 0.2-1 µg/kg/hr by continuous i.v. infusion during the operative period. After preoxygenation for at least 2 min, during the surgery, patients received propofol infusion dose of 250 μg/kg/min for 15 min then a basal infusion dose of 50 μg/kg/min. The bispectral index (BIS) value, as well as mean arterial pressure (MAP), heart rate (HR), respiratory rate (RR), oxygen saturation (SaO2), percutaneous arterial oxygen saturation (SpO2) and end-tidal carbon dioxide tension (ETCO2) were recorded before anesthesia (T0), during anesthesia (at 15-min intervals throughout the surgical procedure), by a blinded observer. Evidence of apnea, hypotension, hypertension and hypoxemia were recorded during surgery.

RESULTS

The hemodynamic changes, including HR, MAP, BIS, VT, SaO2, and RR had a downward tendency with time, but no significant difference was observed between the groups (P>0.05). However, the two groups showed no significant differences in ETCO2 and SPO2 values in any of the assessed interval (P>0.05). In this study, the two groups showed no significant differences in the incidence of nausea, vomiting, coughing, apnea, hypotension, hypertension, bradycardia and hypoxemia (P>0.05). Respiratory depression and serious adverse events were not reported in either group. Extubation time after surgery was respectively 6.3 ± 1.7 and 5.8 ± 1.4 hr. in the DM and DP groups and the difference was not statistically significant (P= 0.46).

CONCLUSION

Our study showed no significant differences between the groups in hemodynamic and respiratory changes in each of the time intervals. There were also no significant differences between the two groups in the incidence of complication intra and post-operative. Further investigations are required to specify the optimum doses of using drugs which provide safety in cardiovascular and respiratory system without adverse disturbance during surgery.

Comparative evaluation of i-gel® insertion conditions using dexmedetomidine-propofol versus fentanyl-propofol - A randomised double-blind study

Background and Aims:

i-gel^® insertion necessitates adequate depth of anaesthesia to prevent laryngospasm, gagging or limb movements. We aimed to compare i-gel^® insertion conditions with propofol induction after pre-treatment with dexmedetomidine or fentanyl.

Methods:

Eighty ASAI/II patients undergoing general anaesthesia were randomised into Groups D (n = 40) and F (n = 40). Group D received 1 μg/kg dexmedetomidine over 10 minutes followed by 5ml of 0.9%normal saline (NS) over 2 minutes. Group F received 10 ml of 0.9%NS over 10 minutes followed by fentanyl 1 μg/kg over 2 minutes. Thirty seconds after study drugs, propofol 2 mg/kg was given. Ninety seconds after propofol, i-gel^® was inserted. Overall insertion conditions were assessed by Modified Scheme of Lund and Stovener. Heart-rate (HR) and mean arterial pressure (MAP) were noted at baseline, after study drug, propofol induction and 1,3,5,10 minutes after i-gel^® insertion. Respiratory rate and apnoea times were recorded.

Results:

Insertion conditions were comparable between both groups. Moderately relaxed jaw, coughing and movement was observed in more patients of Group F. Incidence of apnoea was significantly higher (P < 0.0001) in group F (18/40) than group D (3/40).Mean duration of apnoea in group F (284.5 ± 11.19 sec) was significantly higher than group D (217.17 ± 16.48 sec). Percentage drop in MAP from baseline after propofol was more in group F (10.3%) than group D (5.6%). MAP after induction was significantly lower in group F compared to group D (P = 0.002), but similar after i-gel^® insertion, 1,3,5 and 10 minutes after insertion. After propofol (P = 0.003) and i-gel^® insertion (P < 0.001), HR was significantly lower with dexmedetomidine.

Conclusion:

Dexmedetomidine and fentanyl provide comparable conditions for i-gel^® insertion with propofol.

Dexmedetomidine with propofol versus fentanyl with propofol for insertion of Proseal laryngeal mask airway: A randomized, double-blinded clinical trial

Background and Aims:

Successful insertion of the proseal laryngeal mask airway (PLMA) requires much greater doses of propofol as compared to classic laryngeal mask (CLMA). Dexmedetomidine and fentanyl are equally effective adjuvants for CLMA insertion. We designed this study to compare the efficacy of these two drugs as sole adjuvant in PLMA insertion.

Material and Methods:

Seventy four American Society of Anesthesiologists (ASA) I and II patients were randomly allocated to receive either dexmedetomidine 1 μg/kg [Group PD] or fentanyl 1 μg/kg [Group PF]. Study drugs were diluted in 10 ml NS and administered over 10 min prior to induction of anesthesia with 2.5 mg/kg propofol. PLMA insertion condition was measured according to the Muzi scoring system. Score ≤2 was considered optimal for PLMA insertion. Patient's cardio-respiratory parameters, emergence time, and postoperative pain were also recorded.

Results:

In our study 83.8% patients in the group PF and 91.9% in the group PD achieved optimal insertion condition (not significant). Hemodynamic stability was maintained in both the groups but the incidence of apnea was significantly higher in the PF group (P = 0.011). We also observed that emergence time was prolonged but postoperative pain scores were significantly lower in the PD group (P < 0.001).

Conclusion:

We conclude that both dexmedetomidine and fentanyl in a dose of 1 μg/kg when used before induction with propofol provide comparable conditions for successful PLMA insertion. Dexmedetomidine has additional advantage of preserving spontaneous respiration and providing better analgesia.

Low-dose Succinylcholine to Facilitate Laryngeal Mask Airway Insertion: A Comparison of Two Doses

Background and Aims:

Around the world, the use of the laryngeal mask airway (LMA) is becoming more common for different surgeries accounting for it being the dominant choice of airway in numerous surgeries. Although propofol is known to blunt the laryngeal reflexes often patient movement, coughing, and gagging occur on insertion. This study aims to identify the optimum dose of succinylcholine required to facilitate LMA insertion comparing placebo, 0.1 mg/kg and 0.25 mg/kg of succinylcholine. Further objectives were to compare (a) the overall insertion conditions of the LMA, (b) the number of insertion attempts, (c) the amount of propofol consumption, and (d) the hemodynamics in the three groups.

Setting and Design:

This is a prospective, double-blinded, randomized control trial of 283 patients randomized into three groups-placebo, 0.1 mg/kg and 0.25 mg/kg of succinylcholine. It was done in the day case theatres of a tertiary hospital in Southern India.

Subjects and Methods:

Patients were induced with 2 mg/kg of propofol, after 2 μg/kg of fentanyl. The study drug was given after loss of consciousness. After 60 s, a classic LMA was inserted by the standard method by a single investigator. Jaw relaxation, coughing, gagging, movement, laryngospasm, ease of insertion, number of attempts, propofol usage, and hemodynamics were assessed.

Statistical Analysis:

Statistical methods used were analysis of variance with Bonferroni's t-test, Chi-square test, and Fisher's test. P < 0.05 was considered statistically significant.

Results:

Jaw relaxation was significantly better in the 0.25 mg/kg succinylcholine group. There was no significant difference in coughing and gagging in the groups, but patient movement was more in the placebo group. Two patients in the placebo group experienced partial laryngospasm. Overall insertion conditions were significantly better in the 0.25 mg/kg group compared to the other two groups. Propofol consumption was significantly more in the placebo group.

Conclusions:

The study concludes that 0.25 mg/kg succinylcholine facilitates insertion of the LMA.

Optimum end-tidal concentration of sevoflurane to facilitate supraglottic airway device insertion with propofol at induction allowing spontaneous respiration in obese patients: A prospective observational study

Obese patients are more likely to encounter with difficult airway management, and supraglottic airway device has been adopted to facilitate tracheal intubation. The optimum anesthetic concentration for obese patients to insert a supraglottic airway device with spontaneous respiration has not been investigated. This study was designed to determine the end-tidal concentration of sevoflurane that would provide acceptable condition for supraglottic airway device insertion with propofol at induction in obese patients without using neuromuscular blockade.Thirty elective obese patients [body mass index (BMI) 30-50 kg/m] scheduled for bariatric surgery were enrolled in this study. Sevoflurane was inhaled at a concentration of 5% after infusion of 1 mg/kg propofol (within 1 minute) according to lean body weight. The target concentration of sevoflurane was initiated at 2.5% with 0.5% as a step size using a modified Dixon up-and-down method. Five minutes after target concentration achieved, the insertion of supraglottic airway device was attempted.The minimum alveolar concentration of sevoflurane for successful insertion of supraglottic airway device calculated using up-and-down method were 2.25 (0.53) % for obese patients. The values of the effective concentration of sevoflurane for successful supraglottic airway device insertion in 50% (EC50) and 95% (EC95) of the obese patients obtained by probit regression analysis were 2.09% (95% confidence interval 1.48-2.68) and 3.31% (95% confidence interval 2.70-8.12), respectively.We conclude that sevoflurane at a minimum alveolar concentration of 2.25% can provide optimal conditions for insertion of supraglottic airway device with spontaneous respiration in obese patients with 1 mg/kg propofol at induction.

Comparison of dexmedetomidine and propofol for conscious sedation in inguinal hernia repair: A prospective, randomized, controlled trial

Objective The ideal agents for conscious sedation during ambulatory inguinal hernia repair are still unclear. We aimed to compare the analgesic, sedative, haemodynamic, and side effects of dexmedetomidine with those of propofol in combination with fentanyl for conscious sedation in patients undergoing inguinal hernia repair. Methods Eighty patients undergoing unilateral inguinal hernia repair were prospectively randomized to receive either dexmedetomidine (n = 40) or propofol (n = 40). Dexmedetomidine and propofol dosages were adjusted to maintain the targeted level of sedation. Results After administration of sedative drugs, patients who received dexmedetomidine had a significantly lower heart rate. The intraoperative requirement of fentanyl was significantly lower in patients who received dexmedetomidine compared with patients who received propofol. Administration of dexmedetomidine was associated with a reduced postoperative pain score, longer time for onset of sedation, and a slightly longer recovery time. No serious adverse events occurred in either group. The patients' overall satisfaction score was comparable between the two groups. Conclusion Dexmedetomidine is an effective adjuvant when co-administered with fentanyl for conscious sedation in patients who undergo inguinal hernia repair. Administration of dexmedetomidine decreases the requirement of fentanyl and the pain score, but slightly prolongs the time to sedation and recovery.

Comparison of Dexmedetomidine-Propofol versus Fentanyl-Propofol on Insertion Conditions of Proseal Laryngeal Mask Airway

INTRODUCTION

Proseal Laryngeal Mask Airway (PLMA) is a newer supraglottic airway device that requires adequate depth of anaesthesia and suppression of upper airway reflexes thereby providing optimal insertion conditions.

AIM

To compare dexmedetomidine and fentanyl for co-induction with propofol with respect to PLMA insertion conditions, haemodynamic variation and the total dose requirement of propofol.

MATERIALS AND METHODS

This was a prospective randomized double-blinded study conducted in 60 cases of American Society of Anaesthesiologists (ASA) class I/II undergoing elective surgery under general anaesthesia. They were randomly divided into two equal groups, D and F, each receiving 1μg/kg of dexmedetomidine and fentanyl respectively followed by Propofol 2.5mg/kg as per protocol. The ease of PLMA insertion was Young's Criteria and Modified scheme of Lund and Stovener. The haemodynamic parameters (mean heart rate, mean arterial pressure, Respiratory rate, SPO₂) were monitored at: Baseline, Pre-medication, Pre PLMA, Post LMA (at insertion), 1, 3, 5, 10, 15 and 20 minutes.

RESULTS

PLMA insertion conditions and haemodynamics were comparable between the dexmedetomidine-propofol and fentanyl-propofol groups according to the Young's criteria and Modified scheme of Lund and Stovener. Total induction dose of propofol and its increments were significantly reduced in the dexmedetomidine group.

CONCLUSION

Dexmedetomidine and fentanyl when both used individually for co-induction with propofol for PLMA insertion give excellent overall insertion conditions with haemodynamic stability. Dexmedetomidine also significantly reduces the requirements of induction dose propofol for PLMA insertion.

The effect of dexmedetomidine pretreatment on the median effective bolus dose of propofol for facilitating laryngeal mask airway insertion

BACKGROUND

We designed this study to investigate the effect of dexmedetomidine (1 μg/kg) pretreatment on the median effective dose (ED50) of propofol for facilitating successful laryngeal mask airway (LMA) insertion compared to propofol alone.

METHODS

Forty patients were randomized to either the control group (n = 21) or the dexmedetomidine group (n = 19). After infusion of normal saline or dexmedetomidine 1 µg/kg over 10 min, 1 % lidocaine 0.5 mg/kg, followed by propofol 2.5 mg/kg was administered and the laryngeal mask airway was inserted without muscle relaxants. The ED50 of propofol for successful LMA insertion was determined by the modified Dixon's up-and-down method. The ED50 and ED95 were also calculated using an isotonic regression method, based on the pooled adjacent-violators algorithm-adjusted response rate, and the confidential interval (CI) was estimated using a bootstrap approach.

RESULTS

The ED50 of propofol for smooth insertion of the LMA was significantly higher in the control group than in the dexmedetomidine group (3.1 ± 0.4 vs 1.9 ± 0.3 mg/kg, P < 0.001). From isotonic regression analysis using a bootstrap approach, the ED50 and ED95 of propofol was 2.9 mg/kg (83 % CI 2.5-3.3 mg/kg) and 3.9 mg/kg (95 % CI 3.5-4.0 mg/kg) in the control group, and 1.8 mg/kg (83 % CI 1.8-2.1 mg/kg) and 2.4 mg/kg (95 % CI 2.0-2.5 mg/kg) in the dexmedetomidine groups, respectively. The apnea time was not significantly different between the two groups.

CONCLUSIONS

Pretreatment with dexmedetomidine 1 μg/kg could reduce the propofol requirement by 38 % for facilitating LMA insertion without prolonged respiratory depression and hemodynamic instability.

Comparison of the effects of patient controlled analgesia (PCA) using dexmedetomidine and propofol during septoplasty operations: a randomized clinical trial

Introduction

Septoplastical surgery to correct septum deviation can be performed under either local or general anesthesia. During local anesthesia, sedation helps to provide minimum anxiety/discomfort. Our aim was to evaluate the effects of patient-controlled analgesia using dexmedetomidine and propofol on sedation level, analgesic requirement, and patient satisfaction.

Study design

A prospective, randomized-parallel clinical study.

Methods

Fifty patients undergoing septoplastical surgery at our university hospital were randomized into two groups. A nasopharyngeal cotton tampon soaked in 0.25 % adrenaline solution was placed, and 1 mg midazolam and 1 mcg/kg fentanyl were applied 5 min before the injections of a surgical local anesthetic. Loading dose was 0.5 mg/kg propofol (Group I) and 1 mcg/kg dexmedetomidine (Group II). The sedation was sustained by a bolus dose of 0.2 mg/kg and continuous basal infusion dose of 0.5 mg/kg/h propofol in Group I, or by a bolus dose of 0.05 µg/kg and continuous basal infusion dose of 0.4 mcg/kg/h dexmedetomidine in Group II. The primary outcomes were patient satisfaction via patient-controlled anesthesia and analgesic demand. Secondary outcomes were sedation level of patients under local anesthesia.

Results

In Group II, SpO₂ levels were significantly higher than in Group I. Intraoperative and postoperative analgesic requirements were lower in Group II than in Group I. There were no statistically significant differences in patient satisfaction, hemodynamic parameters, nausea and vomiting between the two groups.

Conclusion

Dexmedetomidine can be used safely as an analgesic and sedation drug in septoplastic surgery.

Non-intubated anesthesia in thoracic surgery-technical issues

Performing awake thoracic surgery (ATS) is technically more challenging than thoracic surgery under general anesthesia (GA), but it can result in a greater benefit for the patient. Local wound infiltration and lidocaine administration in the pleural space can be considered for ATS. More invasive techniques are local wound infiltration with wound catheter insertion, thoracic wall blocks, selective intercostal nerve blockade, thoracic paravertebral blockade and thoracic epidural analgesia, offering the advantage of a catheter placement which can also be continued for postoperative analgesia.

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.

The median effective dose of dexmedetomidine for laryngeal mask airway insertion with propofol 2.0 mg/kg

BACKGROUND

Dexmedetomidine can be used as a co-induction agent to facilitate laryngeal mask airway (LMA) insertion with minimal effect on respiratory function. The purpose of the study was to determine the median effective dose (ED50) of dexmedetomidine to facilitate LMA insertion during anaesthesia induction with propofol 2.0 mg/kg without neuromuscular blockade.

METHODS

Twenty-two patients, whose American Society of Anesthesiologists physical status was I or II with ages between 18 and 60 years undergoing minor orthopaedic or gynaecological surgery, were enrolled. After an injection of pre-determined bolus dose of dexmedetomidine over 2 min, anaesthesia was induced with propofol 2.0 mg/kg. The modified Dixon's up-and-down method was used to determine the bolus dose of dexmedetomidine, starting from 0.5 μg/kg (step size; 0.1 μg/kg). LMA insertion was conducted 90 s after the propofol injection, and the response of patients was categorized as either 'success' or 'failure.'

RESULTS

Insertion of the LMA was unsuccessful in 12 of 22 patients. The ED50 (95% confidence interval) of dexmedetomidine for successful LMA insertion with propofol 2.0 mg/kg was 0.55 (0.44-0.66) μg/kg. Bradycardia occurred in four patients, and seven patients had an apneic episode.

CONCLUSION

The single dose of dexmedetomidine for successful LMA insertion to be feasible in 50% of patients was 0.55 μg/kg during anaesthesia induction with propofol 2 mg/kg.

A comparison of dexmedetomidine versus midazolam for sedation, pain and hemodynamic control, during colonoscopy under conscious sedation

OBJECTIVE

The intent of our study was to compare the effects of dexmedetomidine versus midazolam on perioperative hemodynamics, sedation, pain, satisfaction and recovery scores during colonoscopy.

MATERIAL AND METHODS

A total of 60 ASA I-II patients, between 20 and 80 years of age were included in the study. Patients were randomly assigned to two groups. Midazolam 0.05 mg kg(-1) and fentanyl citrate 1 microg kg(-1) were administered intravenously to cases in Group I (n = 30). An initial loading dose of 1 microg kg(-1) dexmedetomidine was administered intravenously in 10 min to cases in Group II (n = 30) before the procedure and as a continuous infusion dose of 0.5 microg kg(-1) h(-1) just before the procedure started. Also 1 microg kg(-1) fentanyl citrate was administered intravenously immediately before the procedure. Peripheral oxygen saturation (S(pO2)), mean arterial pressure (MAP), heart rate (HR), Ramsay Sedation Scale (RSS), Numeric Rating Scale (NRS) scores and colonoscopist satisfaction scores of the cases were recorded.

RESULTS

Although statistically significant values were not detected between the two groups with regard to mean arterial pressure, in Group I heart rates were higher and S(pO2) scores were lower in a statistically significant manner. When the groups were compared with regard to RSS, the RSS scores of Group I at the 10th and 15th minutes were significantly lower than Group II. There was no statistically significant difference between the two groups when compared with regard to NRS scores. Satisfaction scores were significantly lower in Group II.

CONCLUSION

Dexmedetomidine provides more efficient hemodynamic stability, higher Ramsay sedation scale scores, higher satisfaction scores and lower NRS scores in colonoscopies. According to our results we believe that dexmedetomidine can be used safely as a sedoanalgesic agent in colonoscopies.

An Updated Focused Review of Dexmedetomidine in Adults

Objective:

To evaluate recent comparative studies regarding the safety and efficacy of dexmedetomidine in adults.

Data Sources:

Articles evaluating safety and efficacy of dexmedetomidine were identified from an English-language MEDLINE search (1996–July 2009), with a focus on data published since our previous review in 2007 to the present. MeSH terms included dexmedetomidine, medetomidine, α2:-agonist, and sedation. References from selected articles were also reviewed for additional material.

Study Selection and Data Extraction:

Experimental and observational English-language studies that focused on the efficacy, safety, and pharmacoeconomics of dexmedetomidine in humans were selected.

Data Synthesis:

Dexmedetomidine is an α2-agonist used for sedation during procedures and in critical illness. Compared with placebo, use of dexmedetomidine during procedures was associated with decreased use of rescue midazolam and a similar degree of sedation compared with various agents used during surgery or for procedures. Use of long-term (>24 h) dexmedetomidine sedation is comparable to sedation with benzodiazepines in critically ill patients. In a Phase 4 study, dexmedetomidine was safe in dosages up to 1.4 μg/kg/hour for greater than 24 hours and did not produce rebound tachycardia or hypertension when abruptly discontinued. One small randomized controlled trial demonstrated decreased incidence of delirium, the primary endpoint, with dexmedetomidine compared with midazolam or propofol for sedation after cardiac valve surgery. Many, but not all, studies suggest that dexmedetomidine has a promising role in prevention and treatment of delirium in critically ill patients when delirium was studied as a secondary endpoint.

Conclusions:

Dexmedetomidine is an alternative for procedural sedation and can be used long-term (>24 h) in critically ill patients, in dosages up to 1.5 μg/kg/hour. More studies are needed to better define the role of dexmedetomidine in preventing and treating delirium.