European Journal of Cardiovascular Medicine

Airway management is crucial for the safe practice of general anesthesia, as failure to secure the airway can lead to catastrophic events. ⁽¹⁾ Supraglottic airway devices (SAD) are now widely used in surgeries requiring general anesthesia, replacing endo tracheal tubes in elective surgeries and reducing complications. SAD is easy to use and quick to place, even for less experienced personnel in emergency settings. The ideal SAD must meet criteria such as high airway seal pressure, low gas flow resistance, lower pulmonary aspiration incidence, and complications. These devices are also used in difficult airway algorithms as per current recommendations. ⁽²⁾ SAD (supraglottic airway device) is a method of intubation that is associated with stable haemodynamics, intracranial and intraocular pressure. However, it can lead to incomplete airway sealing, potentially causing gastric insufflation at pressures above 20cmH2O. Newer SADs aim to decrease aspiration risk and increase oropharyngeal leak pressure (OLP), improving airway seal during intermittent positive pressure ventilation without significant gastric inflation. The Baska mask, designed by Kanag and Meena Baska in 2012, is a newer generation SAD with an oesophageal drainage inlet, a non-inflatable cuff, side channels for gastric content aspiration, and an integrated bite-block.^(3,4) The cuff is continuous with the central channel, self-inflated as pressure increases with positive pressure ventilation, improving seal and efficiency. The bite block reduces the risk of patient biting and blocking the airway. The Baska mask comes in four sizes, ranging from pediatrics to adults. ^(5,6)

Propofol is commonly used for the insertion of a supraglottic airway device (SAD) due to its rapid onset and smooth induction. However, its single induction dose requires large doses, which can lead to cardiovascular depression and prolonged apnea. To reduce adverse effects, drugs like opioids, benzodiazepines, ketamine, and neuromuscular blockers are used as co-induction agents with propofol. Dexmedetomidine, a selective alpha 2 agonist, is used as a co-induction agent with propofol for SAD insertion due to its sedative, hypnotic, sympatholytic, and analgesic activity.⁽⁷⁾ It reduces the dose of propofol during induction and maintenance, and is used in doses of 0.5 to 1 µ/kg as bolus dose and 0.2 to 0.7 µ/kg as maintenance dose. Butorphanol, an agonist antagonist opioid, can also be used as a co-induction agent with propofol for SAD insertion, with moderate affinity to µ and κ receptors without respiratory depression and used in doses of 20µ/kg. Limited literature exists on comparing dexmedetomidine and butorphanol as adjuvants to propofol for insertion of Baska masks in short elective surgeries.⁽⁸⁾ This study aims to compare these adjuvants for insertion conditions and hemodynamic stability.

Aim and Objectives

PRIMARY OBJECTIVE:

To compare Butorphanol and Dexmedetomidine as adjuvants to propofol on the insertion conditions of Baska Mask for short surgical procedures.

SECONDARY OBJECTIVES:

• The ease of insertion (assessed by the duration of time taken to insert them successfully and the number of insertion attempts).
• To assess the incidence of complications such as cough, laryngospasm during insertion.
• To detect the hemodynamic responses induced by airway insertion (blood pressure, heart rate, oxygen saturation).

A Prospective randomized double blind controlled study was conducted among Patients admitted in Pondicherry Institute of Medical Sciences who underwent short elective surgeries under general anaesthesia. The study was conducted during December 2019 to August 2021. Sample size: The insertion conditions was taken as outcome measure of interest for the purpose of sample size calculation from the previous study conducted by Chhabra et al.⁽¹⁵⁾ Based on the successful insertion of the airway device in the first attempt which was 93.33 % in Dexmedetomidine and 73.33% in Butorphanol group, with 80% power and 5% level of significance, sample size calculated is 40 patients in each group, taking 10% as dropout rate the sample size is raised to 44 in each group. Computer based block randomization was used to select the patients. In the present study patients were divided into two groups. Group A participants was received Propofol 2.5 mg/kg with Dexmedetomidine 0.5µ/kg and Group B was received Propofol 2.5 mg/kg with Butorphanol 20 µ/kg. The study participants were selected on the following Inclusion criteria. Patients admitted to the hospital posted for short surgical procedures coming under American Society of Anaesthesiologists grade I or II. Age: above 18 years and below 65 years, Mallampati Grade I & II and Surgeries lasting for 1 to 2 hours (like short gynaecologic procedures, Incision and drainage and fibroadenoma excision) and the exclusion criteria was Emergency surgeries, patients at the risk of aspiration (hiatus hernia, pregnancy, full stomach, intestinal ileus) Patients with known gastrointestinal reflux, sore throat, upper respiratory airway infections, patients suffering from pharyngeal pathology e.g. abscess, haematoma and tissue disruption, low pulmonary compliance e.g., morbid obesity, bronchospasm or pulmonary oedema and Patients undergoing oral surgery and those allergic to study drugs. Since it’s a clinical trial, registration with CTRI was done. Drugs used – Propofol, Butorphanol and Dexmedetomidine were used. These drugs were approved for these indications by Drug Controller General of India. Parameters like ease of insertion, dose of propofol required, Time taken for insertion, number of attempts, Blood pressure (systolic pressure, diastolic pressure, mean arterial pressure), Heart rate, SpO₂ and EtCO₂ was collected.

Procedure

Prior to the day of surgery, the patients were visited as per the pre anaesthetic check protocol. A fully informed written consent was taken. Patient were fasted for 8hrs prior to surgery. Premedication was given with Tab Pantoprazole 40mg, Tab. Metoclopramide 10mg, Tab. Lorazepam 1mg - night before surgery and Tab Pantoprazole 40mg and Tab. Metoclopramide 10mg were administered to all patients - two hours prior to surgery with sips of water. On arrival into the operation theatre, the patient was made to lie down supine and intravenous access was secured and intravenous fluids were started. The baseline parameters (NIBP, SpO2, ECG and Heart rate) were recorded. Based on the computerized block randomization, the patients were divided into two groups, group A (Propofol - Dexmedetomidine) and group B (Propofol - Butorphanol). The structural integrity and standard pre use test for Baska mask was performed. Baska mask was lubricated on the posterior surface and the tip, using a water-based gel (Lignocaine Jelly), prior to the insertion of the device. Patients were pre oxygenated for 3 minutes, with 100% oxygen followed by iv Inj. midazolam 0.03 mg/kg and Inj. glycopyrrolate 0.01 mg/kg. Patients in Group A received inj. Dexmedetomidine 0.5 mcg/kg and patients in Group B received Inj. Butorphanol 20 mcg/ kg. Both the drugs were diluted in 20 ml of 0.9% normal saline and was given as slow iv using a infusion pump for 10 minutes. ⁽⁹⁾ In both the groups, 60 secs later, propofol 2.5 mg/kg was given for induction. The trapezius squeeze test was performed to assess the depth of anaesthesia. Negative test is defined as when the response to squeezing trapezius muscle produced no body or toe movement. ⁽¹⁰⁾ If necessary, an additional dose of propofol 0.5 mg/kg IV was given till the trapezius squeeze test became negative. The Baska Mask was inserted after a negative squeeze test without use of muscle relaxant by an anaesthesiologist who was blinded to the adjuvant anaesthetic agents. The correct placement of the mask was confirmed with expansion of the chest wall with bag compression and consecutive 3 EtCO₂ traces.

If it was difficult to insert the airway device in first attempt, the following manoeuvres were done; a Chin lift, to open the airway, along with a jaw thrust and a head extension, or flexion of the neck. Also, the position was adjusted, by pushing up or pulling down the device by the tab provided on the ventral surface. If the insertion of Baska mask fails with the first attempt, two more attempts were allowed. After the failed third attempt, the procedure was abandoned, and the patient was intubated or awakened. Failure to place the Baska mask in position was recorded. Insertion time was defined as the time from end of propofol bolus to first EtCO₂. The ease of Baska mask insertion was qualitatively evaluated using the insertion conditions, number of attempts, need for manipulation and time taken for insertion. The insertion conditions were graded as excellent, good, poor and unacceptable according to the modified scheme of Lund and Stovner as detailed below.⁽¹²⁾

1. Excellent – No gagging or coughing, no patient movement, or no laryngospasm.
2. Good – Mild-to-moderate gagging, coughing, or patient movement with no laryngospasm.
3. Poor – Moderate-to-severe gagging, coughing, or patient movement with no laryngospasm.
4. Unacceptable – Laryngospasm with or without severe gagging, coughing, or patient movement.

Patients were maintained on spontaneous respiration and anaesthesia was maintained with Sevoflurane, Oxygen and Nitrous Oxide. Standard ASA monitoring were continuously monitored during the study period. At the completion of the surgery, the Baska mask was removed after the patient gains consciousness which was observed by resumption of the reflexes of the cornea, eyelash and gag reflex and the patients were monitored in the post-op holding area for the next thirty mins post extubation. If the hemodynamic parameters like HR & BP were reduced to more than 20% of the baseline, injection Atropine 20 mcg/ kg or injection ephedrine 6mg was given.

Statistical analysis:

Data was entered in MS Excel and analysis was done using SPSS version 20. Shapiro Wilk test was used to assess the normality of the data. Frequency & percentage was used to represent the qualitative data. Mean & standard deviation was used to represent the quantitative data if it followed normal distribution. Median & inter-quartile range was used to represent the quantitative data if it followed non normal distribution. Chi-square test / Fisher exact test was used to find the association between the qualitative data. Student’s unpaired‘t’ test was used to find the association between the quantitative data if it followed normality. Mann Whitney U test was used to find the association between the quantitative data if it followed non normal distribution. Repeated measures ANOVA was used to compare three or more group means where the participants were same in each group. Appropriate graphs like bar charts and line diagrams were used to represent the data. P Value <0.05 was considered as significant.

Table 1: Basic characteristics of the study population

The mean age of patients in group A was found to be 31.66 ± 10.79 yrs. and the mean age of patients in group B was found to be 35.51 ± 11.26 yrs. There was no statistically significant difference between the two groups (p value 0.112) and both the groups were comparable. Out of 85 patients, 73 were female and 12 were male among both the groups. The sex distribution was comparable between the two groups (p Value=0.082) and both the groups were comparable. In group A, 32 belonged to ASA-I and 12 belonged to ASA-II. In group B, 27 belonged to ASA-I and 14 belonged to ASA-II. ASA Physical status was similar and comparable between two groups (P Value=0.492). The mean weight of the patients in group A was 56.57 ± 9.82 kg and in group B was 60.32 ± 9.52 kg. There was no statistically significant difference between the two groups (p value = 0.078) and both the groups were comparable. The mean height of the patients in group A was 154.73 ± 17.25 cm and in group B was 159.15 ± 5.53 cm. There was no statistically significant difference between the two groups (p value = 0.113) and both the groups were comparable. Mean BMI was 22.90 ± 3.49 kg/m2 in group A and 23.779 ± 3.43 kg/m2 in group B. There was no statistically significant difference between the two groups (p value = 0.25) and both the groups were comparable.

Table 2: Comparative Efficacy of Dexmedetomidine versus Butorphanol on Propofol Requirements, Baska Mask Insertion Ease, and Patient Response:

In group A, 5 had MPG 1 while 39 had MPG 2 and in group B, 5 had MPG 1 while 36 had MPG 2. MPG was similar and comparable between two groups (P Value=1.000). The trapezius squeeze test was performed to assess the depth of anaesthesia. Negative test is defined as when the response to squeezing trapezius muscle produced no body or toe movement. In group A, 10 out of 44 patients had positive squeeze test while in group B, 4 out of 44 had positive squeeze test. There was no statistically significant difference between the two groups. (P Value=0.080). However, the response to trapezius squeezing was less in Butorphanol group. Mild movements observed during the insertion of Baska mask in 14 out of 44 patients in the Dexmedetomidine group and 7 out of 41 patients in the Butorphanol group. There was no statistically significant difference between the two groups (P Value=0.115). However, the incidence of movements was least with Butorphanol group. Additional dose of propofol was required in 17 out of 44 patients (38.63%) in Dexmedetomidine group and only 4 out of 41 (9.75%) patients in Butorphanol group. There was a statistically significant difference between the two groups (P Value=0.002). The additional dose of propofol - 0.5mg/kg was given after positive Trapezius squeeze test in both groups. The mean additional dose of propofol required was 10.09 ± 13.53 mg in Dexmedetomidine group whereas 2.71 ± 8.5 mg in Butorphanol group. Using Mann-Whitney U test, (IQR – 24.4) there was a statistically significant difference between the requirement of additional dose of propofol between two groups, P Value= (0.003). The mean total dose of propofol required was 149.85 ± 29.68 mg in Dexmedetomidine group whereas 151.59 ± 24.66 mg in Butorphanol group. There was no statistically significant difference between the two groups (P value = 0.770).

Insertion time is defined as the time from end of propofol bolus to first EtCO2. The duration of insertion in Dexmedetomidine group was 30.56 ± 10.66 secs and in Butorphanol group was 33.63 ± 11.93 secs. There was no statistically significant difference between the two groups (P value = 0.217). Baska mask was inserted in the first attempt in 38 out of 41 patients (92.7%) in Butorphanol group, 34 out of 44 patients (77.3%) in Dexmedetomidine group. There was a statistically significant difference in the number of attempts between the two groups (P Value=0.049). The overall insertion conditions were graded using the modified score of Lund and Stovner. The insertion conditions were graded as excellent in 36 out of 41 patients (87.8%) in butorphanol group, 30 out of 44 patients (68.2%) in Dexmedetomidine group. There was a statistically significant difference in the ease of insertion between the groups (p value= 0.030). The failure of insertion of Baska mask in the third attempt was considered as failed insertion. Three patients in the Butorphanol group had failed insertion and excluded from the study. There was no statistically significant difference between the two groups. (P = Value=0.241).

Table 3: Vital status distribution between the groups

There was a statistically significant difference noted between different time points of the 2 groups. There was a fall in the mean HR from the preinduction values at 10th minute (78.25 + 11.92) and 15th minute (76.07 + 11.99) in the Dexmedetomidine group , but this fall was less than 20% from the baseline HR. There were no fall in the HR noted in the Butorphanol group. There was a statistically significant difference noted between different time points of the 2 groups. There was a fall in the mean SBP (102.3 + 10.503) from the preinduction values at 15th minute in the Dexmedetomidine group and no fall was noted in the Butorphanol group. The fall in SBP was less than 20% from the baseline SBP. There was a statistically significant difference noted between different time points of the 2 groups. There was a fall in the mean DBP (63.82 + 8.732) from the preinduction values at 15th minute in the Dexmedetomidine group and no fall was noted in the Butorphanol group. The fall in DBP was less than 20% from the baseline DBP. There was a statistically significant difference noted between different time points of the 2 groups. There was a fall in the mean MAP from the preinduction values at 15th minute in the Dexmedetomidine group and no fall was noted in the Butorphanol group. The fall in MAP was less than 20% from the baseline MAP. There was no statistically significant obserwed in SPO2 between different time points of the two groups. There is no significant mean end tidal carbon dioxide difference observed between the groups.

Figure 2: Mean EtCO2 among the groups

Supra glottic Airway devices can be considered as an effective alternative to endo tracheal tubes in elective surgeries as it abets the use of endo tracheal tube and its complications. It is easy to use and quick to place even in the hands of less experienced personnel in emergency setting in management of difficult airway. ⁽²⁾ Second generation supraglottic airway devices like Proseal LMA, I gel are designed to reduce the risk of aspiration and to increase the oropharyngeal leak pressure thereby improving the airway seal at higher airway pressures. These second generation SADs can be safely used for IPPV without significant gastric inflation for long hours.⁽³⁾ Baska mask is a newer addition in the family of SAD. It was designed by Kanag and Meena Baska. It is made up of medical grade silicon with a self-sealing membranous cuff which does not require any inflation. It has a sump and two drains which avoids the need for an orogastric tube. Baska mask also has an integral bite-block and brings together features of LMA – Proseal, LMA – Supreme, I-gel and SLIPA. ⁽⁴⁾ Propofol is conventionally used for easier insertion of SAD as it provides rapid onset and smooth induction because of its ability to suppress pharyngeal and airway reflex. Propofol as a single induction agent requires large doses for achieving optimal SAD insertion conditions, which may lead to cardiovascular depression and prolonged apnoea. In order to reduce the adverse effects of propofol, the drugs like opioids, benzodiazepines, ketamine, neuromuscular blockers are used as co-induction agents with propofol.⁽⁸⁾

The present study was carried out to compare the Dexmedetomidine and Butorphanol as adjuvants to Propofol for insertion of Baska mask in short elective surgeries. Our primary objective was to compare the insertion conditions of Baska Mask for short surgical procedures using butorphanol and dexmedetomidine as adjuvants to propofol. Secondary objectives were to assess the ease of insertion, the incidence of complications and detect the hemodynamic responses induced by Baska mask insertion. The study included 88 adult patients who belonged to ASA I or II of either sex, scheduled for elective surgery under general anaesthesia. All were allocated randomly either to receive dexmedetomidine 0.5µ/kg IV (Group A) or butorphanol 20µ/kg IV (Group B). All patients were uniformly pre-medicated, induced and Baska mask was inserted as per standard protocol. Ease of insertion score was determined by Modified scheme of Lund & Stovner grading & time taken for insertion was noted in seconds. ⁽¹²⁾ Intra operative monitoring of HR, systemic arterial pressures, oxygen saturation & EtCO2 were recorded at baseline, after induction, 1, 3,5,10 and15 mins after insertion of Baska mask. Three had failed insertion and hence excluded from the study and 85 were included for statistical analysis. (Consort Diagram)

The demographic variables such as age, sex and BMI were compared. The mean age of patients in group A was found to be 31.66 ± 10.79 yrs. and the mean age of patients in group B was found to be 35.51 ± 11.26 yrs. The mean weight of the patients in group A was 56.57 ± 9.82 kg and in group B was 60.32 ± 9.52 kg. The mean height of the patients in group A was 154.73 ± 17.25 cm and in group B was 159.15 ± 5.53 cm. Mean BMI was found to be 22.90 ± 3.49 kg/m² in group A and 23.779 ± 3.43 kg/m² in group B. The demographic data among two groups were comparable and there was no statistically significant difference. The distribution of patients according to ASA physical status and Modified Mallampati grade (MPG) were also comparable between the two groups. ASA and MPG were similar between the two groups. In Dexmedetomidine group, 32(72.72%) belonged to ASA-I and 12(27.27%) belonged to ASA-II and in Butorphanol group, 27 (65.85%) belonged to ASA-I and 14(34.14%) belonged to ASA-II. In Dexmedetomidine group, 5(11.36%) had MPG 1 while 39(88.63%) had MPG 2 and in Butorphanol group, 5(12.19%) had MPG 1 while 36(87.8%) had MPG 2. Adequate depth of anaesthesia for relaxation of jaw muscles and suppression of airway reflexes are required for smooth insertion of supra glottic airway devices. We assessed the insertion conditions of Baska mask based on various parameters as number of attempts, time required for its insertion, any movement during insertion, coughing/gagging and occurrence of laryngospasm during insertion of device. After induction with study drugs, propofol @ 2.5 mg/ kg and after the negative trapezius test, Baska mask was inserted. The trapezius squeeze test was performed to assess the depth of anaesthesia. Negative test is defined as when the response to squeezing trapezius muscle produced no body or toe movement. We adopted this method as an indirect indicator for assessing the depth of anaesthesia for insertion of SAD from a study conducted by Hooda et al. where they used the trapezius squeeze test as an indicator for insertion of laryngeal mask airway in children.⁽¹⁰⁾ In group A, 10 out of 44 patients had positive trapezius squeeze test while in group B, 4 out of 44 had positive trapezius squeeze test. There was no statistically significant difference between the two groups (Table 1). We observed mild movements during the insertion of Baska mask in 14 out of 44 patients in the Dexmedetomidine group and 7 out of 41 patients in the Butorphanol group. There was no statistically significant difference between the two groups. However, there was less response to squeeze test in the Butorphanol group.

Patient who had movements during the trapezius squeezing were administered with additional dose of 0.5mg/kg propofol and Baska mask was inserted. In our study, the mean additional dose of propofol required was 10.09 ± 13.53 mg in Dexmedetomidine group whereas 2.71 ± 8.5 mg in Butorphanol group. We also observed about the number of patients requiring additional dose of propofol, where 17 out of 44 patients (38.63%) in Dexmedetomidine group and only 4 out of 41 (9.75%) patients in Butorphanol group required additional dose (Table 2). There was a statistically significant difference between the two groups (p value = 0.02). But there was no statistically significant difference noted in the mean total dose of propofol required. The mean total dose of propofol required was 149.85 ± 29.68 mg in Dexmedetomidine group whereas 151.59 ± 24.66 mg in Butorphanol group. Insertion time was defined as the time from end of propofol bolus to first EtCO_2. The duration of insertion in Dexmedetomidine group was 30.56 ± 10.66 secs and in Butorphanol group was 33.63 ± 11.93 secs. There was no statistically significant difference between the two groups (p value =0.217). The mean duration of insertion between the groups were comparable.

Baska mask was inserted in the first attempt in 38 out of 41 patients (92.7%) in butorphanol group, 34 out of 44 patients (77.3%) in Dexmedetomidine group. The overall insertion conditions were graded using the modified score of Lund and Stovner.⁽¹²⁾ The insertion conditions were graded as excellent in 36 out of 41 patients (87.8%) in butorphanol group, 30 out of 44 patients (68.2%) in Dexmedetomidine group. There was a statistically significant difference in the ease of insertion grading and number of attempts between the groups. The better insertion conditions and first pass success rate in the butorphanol group may be due to the better jaw relaxation and easy insertion. Similar Observation was made by Nagalakshmi et al. ⁽¹¹⁾, where they assessed the insertion conditions of laryngeal mask airway in 90 patients divided into three groups with each group constituting 30 participants using butorphanol, fentanyl and ketamine as co induction agents with propofol. They observed excellent insertion conditions in 25 (83.3%) patients in Butorphanol group, 25 (83.3%) patients in Fentanyl group, and 15 (50%) patients in Ketamine group. Similarly. Gupta et al. ⁽¹⁶⁾ assessed the jaw relaxation and LMA insertion conditions in 90 patients using the Ketamine, fentanyl, or butorphanol as an adjuvant to propofol and found that the incidence of absolute jaw relaxation was observed to be excellent in patients on Butorphanol (93.33%), intermediate in Fentanyl (53.33%) and lowest in ketamine (36.66%) patients. Excellent insertion conditions were observed in 12 (40%) patients in Ketamine and 13 (43.33%) patients in Fentanyl and in 26 (86.67%) patients in Butorphanol group, respectively. Our results are also consistent with the results of Chari et al. ⁽⁷⁾ where they found that the insertion conditions were better in butorphanol group when used as induction agent with thiopentone for laryngeal mask airway insertion vs fentanyl and thiopentone in 104 patients. The incidence of jaw relaxation at first attempt was higher in the butorphanol group 48 Vs 35 patients in the fentanyl group (p value = 0.003). The insertion was easy in 48 patients in Butorphanol group and 37 patients in Fentanyl group (p value = 0.017).

In contrast to our study, Chhabra et al. ⁽¹⁵⁾ observed that Dexmedetomidine with propofol as adjuvant agent for insertion of I-gel provided better insertion characteristics when compared with Butorphanol with propofol. The Insertion conditions of I-gel were assessed in 120 female patients using Propofol with adjuvants of either dexmedetomidine or butorphanol in day care diagnostic laparoscopic gynecological surgeries. I gel was inserted in the first attempt in 44 out of 60 patients (73.33%) in butorphanol group and 56 out of 60 patients (93.33%) in Dexmedetomidine group (p value = 0.03). There was a significant difference in the requirement of additional dose of propofol (p value < 0.01) noted, which was more in the Butorphanol group 21 out of 60 patients (32%) whereas in Dexmedetomidine group only 3 out of 60 patients (5%). The ease of insertion was better in the Dexmedetomidine group than the Butorphanol group (p value < 0.001). It was observed that successful insertion of I-gel was appreciably higher in propofol-dexmedetomidine as compared to propofol–butorphanol (P < 0.001).

SGA device insertion is associated with less hemodynamic changes as compared to endotracheal intubation.⁽¹⁴⁾ Hemodynamic parameters such as HR, SBP, DBP, MAP were monitored at the following time interval - pre insertion of device, post insertion of device, 1 min, 3 mins, 5 mins, 10 mins and 15 mins. Propofol causes decrease in the heart rate and blood pressure when it is used along with Dexmedetomidine/ Opioids. When used along with Dexmedetomidine as co adjuvant which also causes bradycardia because of stimulation of presynaptic α2 receptors leading to decreased release of nor adrenaline. In our study, Dexmedetomidine group showed a statistically significant difference in the mean HR at different time points from the baseline. There was a fall in HR from baseline following insertion of Baska mask only at 10^th min (78.25 + 11.92) and 15^th minute (76.07 + 11.99) (P < 0.05) and a fall in SBP (102.3 + 10.50), DBP (63.82 + 8.73) and MAP (76.39 + 8.50) only at 15 mins while in the butorphanol group, there were no changes in HR, SBP, DBP and MAP up to 15 mins after insertion of device. Clinically also no patients in both groups showed a significant fall of more than 20% from baseline values requiring any intervention. The fall in the heart rate and BP were attributed to the action of dexmedetomidine on post‑synaptic receptors and activation of α2 adrenoreceptors in central nervous system which inhibits sympathetic activity and thus decreases BP and HR. Similar findings were observed in a study by Chhabra et al. ⁽¹⁵⁾ where they had a considerable fall in the HR from baseline to 15 min after I-gel insertion (88.65 ± 14.84 to 71.90 ± 12.15 bpm) in Dexmedetomidine Group as compared to Butorphanol group (87.60 ± 12.71 to 83.52 ± 10.91 bpm, P < 0.001). There was also a fall in MAP from baseline values after induction up to 15 min following insertion in Dexmedetomidine Group (96.72 ± 13.54 to 86.96 ± 11.03), while in Butorphanol fall in MAP from baseline was observed only up to 1 and 2 min of I-gel insertion (96.27 ± 9.53 to 89.42 ± 9.03) (P < 0.001). Whereas, in a study by Amin et al.⁽¹³⁾ where they assessed the condition for I-gel insertion by using dexmedetomidine with propofol versus nalbuphine with propofol in 100 patients belonging to ASA I and II scheduled for elective surgery under general anaesthesia, They found MAP and HR were increased significantly in propofol–nalbuphine group at 1, 5, and 10 min after insertion of I-gel as compared to the hemodynamically stable parameters in propofol–dexmedetomidine group (P < 0.05). In the present study, there was no statistically significant difference between two groups in respect to oxygen saturation and EtCO2. There was no desaturation in any of the participants. The EtCO2 did not show obstructed trace at any time. Three patients in the Butorphanol group had failed insertion and excluded from the study. We observed that our patients required a smaller size Baska than that recommended by the manufacturer. This was only a clinical observation and further studies are required to confirm the observation. All three patients were intubated with endotracheal tube and procedure was safely completed. There were no intra-operative complications observed between the groups.

Measurement of oropharyngeal airway leak pressure was not performed in our study. We did not assess the post-operative complications like post-operative sore throat, post-operative hoarseness of voice, post-operative nausea and vomiting. Sedation scores were not noted in our study. The study concludes that addition of Butorphanol to propofol as adjuvant compared to Dexmedetomidine reduces the dose of propofol required and provides superior insertion conditions and good jaw relaxation for ease of insertion of Baska mask. The first pass success rate was greater in Butorphanol group than Dexmedetomidine group. We recommend Butorphanol at 20µ/kg as an adjuvant to propofol for Bask mask insertion without hemodynamic compromise when compared to Dexmedetomidine at 0.5µ/kg.

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