The effect of dexmedetomidine continuous infusion as an adjuvant to general anesthesia on sevoflurane requirements: A study based on entropy analysis

Effects of dexmedetomidine combined with etomidate on postoperative cognitive function in older patients undergoing total intravenous anaesthesia: a randomized, double-blind, controlled trial

BACKGROUND

Etomidate has been advocated for anesthesia in older and critically ill patients because of its hemodynamic stability. Clinical studies have shown that dexmedetomidine has neuroprotective and anti-inflammatory properties and improves postoperative cognitive dysfunction in older patients. The present study was to evaluate the effects of the combination of etomidate and dexmedetomidine with different anaesthesia time on postoperative cognitive function in older patients.

METHODS

A total of 132 older patients undergoing ureteroscopic holmium laser lithotripsy were randomly divided into EN group and ED group equally. Patients whose surgery time was less than or equal to 1 h in each group were allocated to short-time surgery group (EN1 group and ED1 group), and whose surgery time was more than 1h were allocated to long-term surgery group (EN2 group and ED2 group). The primary outcome was the score of the Mini-Mental State Examination. The secondary outcomes were State-Trait Anxiety Inventory scores, Riker sedation agitation scores, Zung Self-Rating Depression Scale scores, the memory span for Arabic numerals, the plasma concentrations of S-100 calcium-binding protein B and neuron specific enolase, the time to spontaneous respiration, recovery, and extubation.

RESULTS

The MMSE scores at t2-3 were higher in ED1 and ED2 groups than in EN1 and EN2 groups (p<0.05). Compared with ED1 and ED2 groups, the ZSDS scores, the S-AI scores and the T-AI scores at t1-2 were higher in EN1 and EN2 groups (p<0.05), respectively. The recalled Arabic numbers at t1-3 were higher in ED2 group than in EN2 group (p<0.05). The plasma concentration of S-100β at t1-2 in EN1 group and t1-3 in EN2 group were higher than that in ED1 and ED2 groups (p<0.05), respectively. Compared with ED1 and ED2 groups, the plasma concentrations of NSE were higher at t1-3 in EN1 group and t1-4 in EN2 group (p<0.05), respectively.

CONCLUSION

The administration of dexmedetomidine could improve postoperative cognitive dysfunction, emergence agitation, depression and anxiety, attenuate the plasma concentrations of S-100β and NSE in older patients undergoing total intravenous anaesthesia with etomidate.

TRIAL REGISTRATION

Registration number: ChiCTR1800015421, Date: 29/03/2018.

Towards a potent and rapidly reversible Dexmedetomidine-based general anesthetic

IN CONCLUSION

Our results suggest that Dex supplemented with a low dose of a second agent creates a potent anesthetic that is rapidly reversed by atipamezole and caffeine.

Comparison of the Efficacy of Opioid-Free Anesthesia With Conventional Opioid-Based Anesthesia for Nasal Surgeries - A Prospective Randomized Parallel Arm Triple-Blinded Study

Introduction In the setting of nasal surgeries, the use of opioid-free anesthesia involving the use of dexmedetomidine, and lignocaine is being investigated as a potential alternative to opioids. This combination of drugs provides sympatholysis, pain relief, and sedative properties, thereby aiming at reducing the negative effects commonly associated with opioid usage. The objective of this study is to evaluate and compare the effectiveness of opioid-free anesthesia using dexmedetomidine and lignocaine versus conventional opioid anesthesia with fentanyl for nasal surgeries. The comparison will be based on the primary outcome of postoperative visual analog scale (VAS) scores. Secondary outcomes assessed were the amount of rescue analgesic consumption, intraoperative sevoflurane usage, intraoperative blood loss, hemodynamic stability, postoperative nausea and vomiting (PONV) scores, and postoperative Ramsay Sedation Scores. Methods A triple-blind, prospective, randomized, parallel arm study in which 48 patients planned for elective nasal surgery were allocated randomly to one of two groups. In the study, the population labeled as Group D, comprising 24 participants, received dexmedetomidine at a dosage of 1 mcg.kg^-1 via intravenous infusion lasting for a duration of 10 minutes prior to the induction of anesthesia. This was followed by a continuous infusion of 0.6 mcg.kg^-1 h^-1 throughout the intraoperative period, and intravenous Lignocaine 1.5 mg.kg^-1 was administered three minutes prior to induction, subsequently an intraoperative infusion of 1.5 mg.kg^-1 h^-1. In Group F, consisting of 24 participants, intravenous fentanyl of 2 mcg.kg^-1 was administered three minutes before the induction. This was subsequently followed by a fentanyl infusion of 0.5 mcg.kg^-1h^-1 in the intraoperative period. Results The study findings indicate that Group D had considerably lower postoperative VAS scores from 30 minutes to two hours compared to Group F (p<0.05). The utilization of sevoflurane during the intraoperative period was comparatively reduced in Group D in order to achieve the desired bispectral index (BIS) range of 40-60 (p<0.01). Mean intraoperative blood loss was also lower in Group D (85 ml) compared to Group F (115 ml )(p<0.01). Additionally, Group D had significantly lower rescue analgesic consumption and lower incidence of PONV up to 60 minutes compared to Group F (P-value <0.01). A statistically significant difference was observed between Group D and Group F in terms of lower mean values of both mean arterial pressure (MAP) and heart rate in Group D (p<0.01). The results indicate that the postoperative sedation scores within the first two hours were significantly greater in Group D compared to Group F (p<0.01). Conclusion The usage of opioid-free anesthesia has been found to be superior to a traditional opioid-based approach in various aspects, including the provision of sufficient pain relief after surgery, maintenance of stable hemodynamics during the operation, and reduction in occurrences of postoperative nausea and vomiting.

Sevoflurane Exposure in Neonates Perturbs the Expression Patterns of Specific Genes That May Underly the Observed Learning and Memory Deficits

Exposure to commonly used anesthetics leads to neurotoxic effects in animal models-ranging from cell death to learning and memory deficits. These neurotoxic effects invoke a variety of molecular pathways, exerting either immediate or long-term effects at the cellular and behavioural levels. However, little is known about the gene expression changes following early neonatal exposure to these anesthetic agents. We report here on the effects of sevoflurane, a commonly used inhalational anesthetic, on learning and memory and identify a key set of genes that may likely be involved in the observed behavioural deficits. Specifically, we demonstrate that sevoflurane exposure in postnatal day 7 (P7) rat pups results in subtle, but distinct, memory deficits in the adult animals that have not been reported previously. Interestingly, when given intraperitoneally, pre-treatment with dexmedetomidine (DEX) could only prevent sevoflurane-induced anxiety in open field testing. To identify genes that may have been altered in the neonatal rats after sevoflurane and DEX exposure, specifically those impacting cellular viability, learning, and memory, we conducted an extensive Nanostring study examining over 770 genes. We found differential changes in the gene expression levels after exposure to both agents. A number of the perturbed genes found in this study have previously been implicated in synaptic transmission, plasticity, neurogenesis, apoptosis, myelination, and learning and memory. Our data thus demonstrate that subtle, albeit long-term, changes observed in an adult animal's learning and memory after neonatal anesthetic exposure may likely involve perturbation of specific gene expression patterns.

Electroencephalogram Mechanism of Dexmedetomidine Deepening Sevoflurane Anesthesia

Dexmedetomidine, as an α2-adrenoceptor agonist, plays anti-sympathetic, sedative and analgesic roles in perioperative period. Also, dexmedetomidine can reduce the minimal alveolar concentration (MAC) of sevoflurane and the risk of postoperative cognitive dysfunction (POCD) induced by sevoflurane anesthesia. But so far, the electroencephalogram (EEG) mechanism of dexmedetomidine deepening sevoflurane anesthesia is not clear. In this study, by analyzing the changes of the power spectrum and bicoherence spectrum of EEG before and after dexmedetomidine infusion, the EEG mechanism of dexmedetomidine deepening sevoflurane anesthesia was studied. We analyzed dexmedetomidine-induced changes in power spectrum and bicoherence spectrum in 23 patients under sevoflurane anesthesia. After anesthesia induction, the sevoflurane concentration was maintained at 0.8 MAC for 15 min, and then dexmedetomidine was administered at a loading dose of 0.8 μg/kg in 10 min, followed by a maintenance rate of 0.5 μg⋅kg^–1⋅h^–1. Frontal EEG data from 5 min before and 10 min after dexmedetomidine infusion were compared. After dexmedetomidine infusion, the mean α power peak decreased from 6.09 to 5.43 dB and shifted to a lower frequency, the mean θ bicoherence peak increased from 29.57 to 41.25% and shifted to a lower frequency, and the median α bicoherence peak increased from 41.49 to 46.36% and shifted to a lower frequency. These results demonstrate that dexmedetomidine deepens sevoflurane anesthesia, and enhances α and θ bicoherences while shifting peak values of these bands to lower frequencies through regulating thalamo-cortical reverberation networks probably.

Time course of psychomotor recovery after intravenous dexmedetomidine infusion as a part of balanced anaesthetic technique: A randomised, double-blind study

Background and Aims:

Dexmedetomidine is a drug that is being widely used as an adjuvant to anaesthesia because of its unique pharmacodynamic and pharmacokinetic properties. We aimed to assess the recovery of psychomotor function from balanced anaesthesia including intravenous dexmedetomidine infusion as adjunct.

Methods:

Ninety American Society of Anesthesiologists I and II patients were randomised to group D (n = 45), to receive 1 μg/kg of dexmedetomidine loading dose over 10 min, with maintenance infusion of 0.5 μg/kg/h, and group S (n = 45), to receive an equal volume of 0.9% normal saline. Objective parameters were recovery of psychomotor function assessed by Trieger dot test (TDT), digit symbol substitution test (DSST) and intraoperative opioid requirement. the total fentanyl used intraoperatively in the two groups. Statistical analysis was performed using unpaired Student's t-test, Chi-squareor Fisher's exact test.

Results:

Psychomotor recovery assessed by TDT showed statistically significant early recovery in group D compared with group S. This was seen in the maximum distance of dots missed at 30 min, 60 min, 90 min and 120 min as well as in the average distance of dots missed at identical time points. Similarly, DSST revealed early recovery at 30 min (12.4 ± 5.3 vs. 10.4 ± 3.9 P = 0.04) postoperative interval but not at other time intervals. There was significant decrease in the intraoperative opioid requirement in group D compared with group S.

Conclusion:

The addition of dexmedetomidine to balanced anaesthetic technique significantly hastened the psychomotor recovery compared with placebo.

Male requires a higher median target effect-site concentration of propofol for I-gel placement when combined with dexmedetomidine

OBJECTIVE

The supraglottic airway device (SAD) can be used for airway management of spontaneous breathing patients, and propofol is commonly applied for the SAD placement. This study was designed to assess the effect of gender on median target effect-site concentration (Ce₅₀) of propofol for I-gel placement when combined with dexmedetomidine.

MATERIAL AND METHOD

19 males and 18 females, aged 18 to 59 and undergoing elective surgery, were enrolled. After intravenous infusion of dexmedetomidine 1.0μg/kg over 10min followed by continuous infusion of 0.4μg/kg/h, target-controlled infusion of propofol under Marsh model was started and the initial Ce of propofol was set at 4.79μg/mL and 4.35μg/mL in the male and female patients, respectively. The I-gel was inserted when the Ce of propofol reached the pre-set concentration and bispectral index value was less than 60. The Ce of propofol required for I-gel placement was determined by the Dixon up-and-down method.

RESULTS

The Ce₅₀ (95% confidence interval) of propofol required for I-gel placement were 4.082μg/mL (3.798-4.332μg/mL) and 3.509μg/mL (3.266-3.749μg/mL) in male and female patients, respectively, with a significantly higher Ce₅₀ in males.

CONCLUSION

When combined with dexmedetomidine, males require a higher Ce₅₀ of propofol for I-gel placement compared to females.

Effect of adjunctive dexmedetomidine on anesthesia and analgesia requirement and recovery characteristics during Bispectral Index-guided anesthesia for cerebello-pontine angle surgeries: A randomized clinical trial

Background and Aims

The study was conceived to elucidate the effects of dexmedetomidine as an anesthetic adjunct to propofol (total intravenous anesthesia) on anesthetic dose reduction and anesthesia recovery parameters in cerebello-pontine angle (CPA) surgeries.

Material and Methods

This prospective randomized study was conducted on 49 patients (25 with dexmedetomidine, 24 without). After standardized anesthetic induction, anesthesia was maintained using propofol (via target controlled infusion, titrated to maintain BIS between 40 and 60), fentanyl (0.5 μg/kg/hour) and either dexmedetomidine (0.5 μg/kg/hour) or a sham infusion. Neuromuscular blocking agents were excluded to allow cranial nerve EMG monitoring. Adverse hemodynamic events, recovery parameters (time to opening eyes, obeying commands, and extubation) and postoperative sedation score, shivering score, nausea, and vomiting score were recorded.

Results

Propofol and fentanyl utilization (as total dose, adjusted for duration of surgery and body weight, and number of extra boluses) was significantly lower in the dexmedetomidine group. There was no difference in any of the recovery parameters between the two groups. Incidence of bradycardia was significantly higher with dexmedetomidine, while no difference was found for hypotension, hypertension, and tachycardia.

Conclusion

Dexmedetomidine-fentanyl-propofol anesthesia compares favorably with fentanyl-propofol anesthesia during CPA neurosurgical procedures with regard to anesthesia recovery times, but with lower intraoperative opioid and hypnotic utilization rates.

Entropy as an Indicator to Measure Depth of Anaesthesia for Laryngeal Mask Airway (LMA) Insertion during Sevoflurane and Propofol Anaesthesia

INTRODUCTION

Assessment of the depth of anaesthesia is fundamental to the anaesthetic practice. Entropy measurement is an objective monitoring and is of two types- Response Entropy (RE) and State Entropy (SE) indicating analgesic and hypnotic levels during general anaesthesia.

AIM

The aim of our study was to assess the depth of anaesthesia for LMA placement using entropy as a tool. The assessment of entropy as an indicator of depth of anaesthesia in the form of haemodynamic variations and success rate of LMA placement.

MATERIALS AND METHODS

A prospective study was carried out after ethical committee approval in 100 patients, aged 20-50 years, with ASA grade I and II of either gender undergoing elective surgery lasting less than two hours under general anaesthesia. Anaesthesia was induced with sevoflurane 2.5% and IV propofol at 6 ml/min until entropy value fell from baseline values to 30-40 and then LMA insertion was performed. SE and RE values were noted every 30 seconds for five minutes. Mean blood pressure and heart rate were recorded every minute after induction for 5 minutes.

RESULTS

There was a significant change in RE and SE values within 30 seconds from start of induction. Desired values of RE (40.10±2.52) and SE (39.2±2.47) were achieved at 120 seconds to 150 seconds. Mean dose of propofol used during surgery was 86.5±3.5 mg and mean insertion time was 110±12 seconds Patients in study group had a stable haemodynamics throughout the procedure, (p-value -0.8).

CONCLUSION

Entropy is a reliable indicator to assess depth of anaesthesia for LMA placement during sevoflurane and propofol anaesthesia.

A Comparative Evaluation of Intravenous Dexmedetomidine and Fentanyl in Breast Cancer Surgery: A Prospective, Randomized, and Controlled Trial

Background and Aim:

Recent studies have advised narcotic less anaestheic techniques for breast cancer surgeries due to altered immune system by use of opioids. So we planned this study to compare the efficacy of dexmedtomidine with fentanyl in breast cancer surgery in terms of haemodynamic stability, anaesthetic sparing effects, recovery profile and postoperative analgesia.

Material and Methods:

In this randomized prospective controlled trial, a total of 60 female patients were randomly assigned into two groups. Patients in group F (n = 30) received a loading dose of fentanyl 2 μg/kg with maintenance dose of 0.5 μg/kg/h and in group D (n = 30) received dexmedetomidine 1 μg/kg as loading dose with maintenance dose of 0.25 μg/kg/h till the end of surgery. Hemodynamic parameters, desflurane requirement, recovery profile and postoperative analgesia were monitored and compared in both the groups.

Results:

Mean HR was less in group D compared to group F intraoperatively, before and after extubation with a significant p value. The mean MAP was also lower in group D compared to group F at all the time points. MAC requirements were found lower in group D compared to group F with a significant P < 0.001. Cognitive recovery in the form of time to respond to verbal commands, time to extubation, time to orientation was early in dexmedetomidine group.

Conclusion:

Dexmedtomidine can be used as suitable alternative to fentanyl in breast cancer surgeries due to better hemodynamic stability, anaesthetic sparing effects and better recovery profile.

Intraoperative effect of dexmedetomidine infusion during living donor liver transplantation: A randomized control trial

BACKGROUND

Dexmedetomidine hydrochloride (Dex) is a useful adjuvant for general anesthesia. The aim was to evaluate the effects of Dex infusion during living donors liver transplantation (LDLT) on the general anesthetic requirements, hemodynamics, oxygen consumption (VO2), and CO2 production (VCO2).

MATERIALS AND METHODS

Forty LDLT recipients were allocated randomly to receive either Dex (0.2-0.7 μg/kg/h) or placebo (control [C]). Patient state index (PSI), SEDLine monitored anesthesia depth (25-50) with desflurane (Des) % and fentanyl altered accordingly. Transesophageal Doppler (TED), invasive mean arterial blood pressure (MAP) and heart rate (HR) were monitoring any Dex side effects and altering infusion rate accordingly; TED was used for fluid optimization. Metabolic gas monitoring (VO2, VCO2) and Des consumption were recorded.

RESULTS

Dex reduced Des and fentanyl consumption versus C (120.0 ± 30.2 vs. 248.0 ± 38.8) ml, (440.0 ± 195.74 vs. 1300.0 ± 32) μg, respectively (P < 0.01). Dex was delivered for 11.35 ± 2.45 h with comparable HR, MAP, and TED variables versus C and with similar mean noradrenaline support (5.63 ± 2.44 vs. 5.83 ± 2.57 mg, P = 0.81). VO2 was reduced with Dex vs. C during anhepatic, 30 min postreperfusion and end of surgery (193.2 ± 26.78 vs. 239 ± 14.93) (172.1 ± 28.14 vs. 202.7 ± 18.03) and (199.7 ± 26.63 vs. 283.8 ± 14.83) ml/min/m(2) respectively (P < 0.01). VCO2 was also reduced with Dex versus C during the same periods (195.2 ± 46.41 vs. 216.7 ± 29.90, P = 0.09), (210.6 ± 60.71 vs. 253.9 ± 32.51, P = 0.01), and (158.7 ± 49.96 vs. 209.7 ± 16.78, P < 0.01), ml/min/m(2) respectively.

CONCLUSION

TED and PSI guided Dex infusion helped to reduce Des and fentanyl consumption as well as VO2 and VCO2 at a lower cost with no adverse effects on hemodynamics.

Effect of dexmedetomidine bolus dose on isoflurane consumption in surgical patients under general anesthesia

Background and Objective:

Various adjuvants have been introduced to decrease the dose of volatile agents and their side effects. Dexmedetomidine a potent alpha-2 adrenoreceptor agonist is one such agent. Our objective is to assess the effect of preanesthetic dexmedetomidine on isoflurane consumption and its effect on intraoperative hemodynamic stability and recovery profile.

Setting and Design:

This prospective, randomized controlled, double-blind study was done in a tertiary care hospital.

Materials and Methods:

One hundred patients were randomly allocated into two groups. Group 1 received saline infusion and Group 2 received dexmedetomidine infusion in a dose of 1 μg/kg over 10 min given 15 min before induction. Vital parameters and bispectral index (BIS) values were noted throughout the surgery. Patients were induced and intubated as per the standard protocol and maintained with N₂O: O₂ = 1:1 mixture at 2 L/min and isoflurane concentration adjusted to achieve BIS values of 45–60. Demographic profile, hemodynamic variables, total isoflurane consumption, and recovery profile data were collected.

Statistics:

Independent t-test and Mann–Whitney U-test were used to compare the average anesthetic consumption, hemodynamics, and recovery profile between two groups.

Results:

End-tidal concentration and total isoflurane consumption in Group 2 were 0.56 ± 0.11 and 10.69 ± 3.01 mL, respectively, with P < 0.001 which was statistically significant compared to Group 1 which were 0.76 ± 0.14 and 13.76 ± 3.84 mL. Postintubation and intraoperative mean arterial pressure values were significantly lower in dexmedetomidine group with P < 0.001.

Conclusion:

Preanesthetic bolus dose of dexmedetomidine is a useful adjuvant to reduce isoflurane consumption.

Effects of dexmedetomidine on smooth emergence from anaesthesia in elderly patients undergoing orthopaedic surgery

BACKGROUND

Intraoperative dexmedetomidine may decrease postoperative emergence agitation in elderly patients due to its sedative effect. In this study, we evaluated the effect of adjuvant dexmedetomidine on smooth emergence from anaesthesia after orthopaedic surgery in elderly patients.

METHODS

A total 115 patients (ASA I-II, aged over 65 years) were randomly allocated into four groups. Anaesthesia was maintained with either sevoflurane or total intravenous anaesthesia (TIVA) comprising propofol and remifentanil. Patients were also administered either dexmedetomidine (0.4 μg kg(-1) hr(-1); SD and TD) intraoperatively or normal saline (SN or TN) as a control. The bispectral index (BIS) score was maintained from 40-60 intraoperatively. All anaesthetics and dexmedetomidine were discontinued at surgical conclusion, and the recovery times (durations to a BIS = 60, 70, and 80; eye opening; and extubation) were measured. The mean arterial pressure, heart rate, Ricker's agitation-sedation scale (RSAS), visual analogue scale (VAS) for pain, and incidences of emergence agitation and postoperative nausea and vomiting (PONV) were measured in the recovery room.

RESULTS

Dexmedetomidine significantly decreased the RSAS score in the SD and TD groups, and a calm state postoperatively occurred more frequently in these groups than in the control groups. The heart rate and incidence of emergence agitation were lower in the dexmedetomidine groups. Recovery time was higher in the SD group than in the SN group, and no significant differences occurred between the TN and TD groups. The VAS score was lower in the SD group than in the SN group, and the PONV did not differ regardless of the use of dexmedetomidine.

CONCLUSIONS

Dexmedetomidine may be an effective intraoperative adjuvant for a reducing emergence agitation and smooth emergence from anaesthesia after orthopaedic surgery in elderly patients.

TRIAL REGISTRATION

Current Controlled Trials NCT01851005 .

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.

A priming dose of intravenous ketamine-dexmedetomidine suppresses fentanyl-induced coughing: a double-blind, randomized, controlled study

OBJECTIVE

This study was designed to investigate whether a priming dose of ketamine-dexmedetomidine can effectively suppress fentanyl-induced coughing (FIC).

METHODS

Altogether 400 patients of ASA I and II, aged 18-70 years, undergoing various elective surgical procedures, were randomly allocated into four groups of 100 patients each. Patients in the placebo group received volume-matched normal saline 0.15 mL/kg + normal saline 0.05 mL/kg. One group of patients was given ketamine 0.15 mg/kg + normal saline 0.05 ml/kg (KET), and another group dexmedetomidine 0.5 μg/kg + normal saline 0.05 ml/kg (DEX). Finally, one group of patients received ketamine 0.15 mg/kg + dexmedetomidine 0.5 μg/kg (KETODEX). After fentanyl administration, the onset time and severity of cough for 1 min were recorded. Cough severity was graded as mild (grade 1-2), moderate (grade 3-5), or severe (grade >5).

RESULT

The incidence of FIC was 53%, 34%, 20%, and 9% in the placebo, DEX, KET, and KETODEX groups, respectively. The incidence of cough was significantly lower in the KETODEX group. Likewise, the onset time of cough was significantly delayed in the KETODEX group. Only nine patients in the KETODEX group had either mild (6%) or moderate (3%) cough, with none suffering from severe cough.

CONCLUSION

A priming dose of KETODEX effectively suppressed the cough reflex induced by fentanyl and delayed the onset time of cough. Therefore, treatment with KETODEX may be a clinically useful method for preventing FIC.