Second generation supraglottic airway devices (SADs) provide many advantages over endotracheal intubation. It includes reduced haemodynamic response, decreased anaesthetic requirement for airway tolerance and lesser pharyngolaryngeal morbidity [1,2].

The AMBU AURAGAIN laryngeal mask airway (Ambu A/S, Ballerup Denmark) is a newer second-generation supraglottic airway device launched in June 2014. It is a single use SAD which promises to provide high seal pressures. It has an integrated gastric access, a     bite      block    and    a   wider   airway   tube  [1,2].

Laparoscopic surgeries are widely done nowadays which involve generation of pneumoperitoneum and positioning with head up and head down tilt, which effects cardiovascular and respiratory system by causing an alteration in location of intestinal contents and the additional effect of CO2 insufflation which elevates the diaphragm and intra thoracic pressure which affects the overall compliance of lung. SAD is used to maintain a reliable airway for various type of anaesthesia. Laparoscopic surgeries are done under general anaesthesia which institute the use of nitrous oxide, oxygen and volatile anaesthetic agents along with pneumoperitoneum. SAD cuff is highly permeable to nitrous oxide  and  carbon dioxide  through  the cuff  wall. 

Hence nitrous oxide and carbon dioxide are expected to diffuse into the air filled cuff of the SAD [3,4].

Various studies have been conducted to assess the efficacy of supraglottic airway devices for maintaining airway during general anaesthesia. But there is paucity of literature comparing clinical and haemodynamic performance of Ambu AuraGain during laparoscopic surgeries under general anaesthesia. Hence, the present study was aimed to determine hemodynamic Changes in different positions in laparoscopic surgeries done using Ambu AuraGain. 

Aim and Objectives

To determine hemodynamic Changes in laproscopic surgeries in Trendenlenburg and Reverse Trendenlenburg position with the use of Ambu AuraGain SGA.

Study Design

Prospective cohort study. 

Study Site

Department of Anaesthesia, Dr RPGMC Kangra at Tanda.

Study Duration

The study was conducted over the period of 18 months including data collection, data organization, presentation, analysis, and interpretation from January, 2020 to June 2021.

Sample Size

Total of 46 patients were included which were categorized into two groups.

In the first arm of study less number of patients participated than calculated sample size due to COVID-19 pandemic containment restrictions. Further research is needed with adequate sample to rule out effect of chance if any from obtained results or power analysis to check adequacy of sample size. 

Group A

Comprised of 16 patients who underwent Surgeries in Trendelenburg position including gynaecological surgeries like Diagnostic Laparoscopy for infertility and ectopic pregnancy, Laparoscopic cystectomy, TAP surgery for hernia and Laparoscopic appendicectomy.

Group B

Comprised of 30 patients who underwent surgeries in Reverse Trendelenburg position including Laparoscopic surgery for gall bladder disease, i.e. Laparoscopic cholecystectomy.

Inclusion criteria 

•      Patients (age 18 to 60 years) of either sex 

•      Body Mass Index 18.5 to 30 kg/m2 

•      American Society of Anesthesiologists physical status I or II 

•      Undergoing elective laparoscopic surgery involving Trendelenburg and Reverse Trendelenburg position with an anticipated duration of 30-120 minutes will be included in the study

Exclusion criteria 

•      Obesity (Body Mass Index >30) 

•      All the contraindications for supraglottic airway 

•      Oropharyngeal diseases 

•      If Laparoscopic surgery was converted into open surgery in any of cases 

•      If in any case supraglottic airway had to be replaced by endotracheal tube 

•      Limited mouth opening (inter-incisor gap < 20 mm) 

•      Patients at risk of aspiration (full stomach, previous upper gastrointestinal surgery, hiatus hernia)

•      Refusal to participate in the study

The study was commenced after obtaining Institutional Ethics Committee approval---dated 21-12-2019, NO-HFW- H DRPGMC/Ethics/2019/239. The patients were classified into Trendelenburg and Reverse Trendelenburg position depending upon the laparoscopic surgeries they were scheduled for. 

• Group A: Trendelenburg position (Head Down 20-300), n = 16

• Group B: Reverse Trendelenburg position (Head Up 20-300), n = 30

In Group A

All patients were explained the procedure and written, well informed consent was taken. All patients were instructed to remain fasting for 8 hours prior to surgery and medicated night before surgery with Tablet Alprazolam 0.25 mg and Tablet Ranitidine 150 mg. In Operation theater, intravascular fluid (Normal Saline) was started with 18G cannula. A multichannel monitor showing pulse rate, electrocardiogram, oxygen saturation, non-invasive blood pressure (NIBP) was connected and baseline readings were recorded. 

All patients of group A were given Inj.glycopyrrolate 0.2 mg, Inj. midazolam 0.02 mg/kg, and Inj. fentanyl 2 μg/kg IV. Pre-oxygenation was done for 3-5 minutes and induction was done with Inj. Propofol 2mg/kg IV in slow incremental dose till the loss of verbal command, eyelash reflex and ease of mask ventilation was noted. After confirming adequate mask ventilation Inj. Atracurium 0.5 mg/kg IV was administered to facilitate insertion of Ambu AuraGain. Once the jaw relaxation was achieved, the supraglottic device was inserted in supine position. 

Size selection of Ambu AuraGain was done according to weight of the patients,  SGA size 4 (weight 50-70 kg). For the lubrication, water based lubricating jelly was applied on the dorsum of the device. Initially, the handle (Shaft) was kept approximately parallel to the patient’s chest and then the device was pushed along the hard palate after. Its placement might require higher tangential force due to bulky and acute angle of the device. It was straightened like of classical LMA before insertion to avoid any complication. 

Ambu AuraGain was inflated by recommended amount of air i.e. not more than 30 ml. If any leak around the Ambu AuraGain was found clinically, cuff was inflated with more air up to recommended limits. Adequate ventilation was confirmed by auscultation, chest movements, and EtCO2 waveforms. The pilot balloon was attached to cuff manometer, and cuff pressure was measured with cuff manometer, which further helped in getting an effective oropharyngeal seal and keep peak airway pressure and tidal volume within normal limits. 

After the completion of procedure, when the patient showed initial sign of respiratory efforts, the neuromuscular block was reversed with Inj. neostigmine 0.05 mg/kg and Inj. glycopyrrolate 0.02 mg/kg. When extubation criteria was met the Ambu AuraGain was removed with the cuff deflated. Post-operatively, the patients were assessed over 24 hours for sore throat (constant pain, independent of swallowing), hoarseness of voice, dysphonia (difficulty in or pain on speaking) and numbness of the tongue.

In Group B 

Reverse Tredenlenburg position (head up 20- 30o) all patients were monitored for same parameters at same time interval as in Group A.

Haemodynamics Parameters 

Haemodynamics parameters such as heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure and SpO2 were also measured 1 min. and 5 min. after SGA placement and thereafter every 10 min till the end of surgery. 

After the completion of procedure, when the patient showed initial sign of respiratory efforts, the neuromuscular block was reversed with Inj. neostigmine 0.05 mg/kg and Inj. glycopyrrolate 0.02 mg/kg. When extubation criteria was met the Ambu AuraGain was removed with the cuff deflated. Post-operatively, the patients were assessed over 24 hours.

Statistical analysis 

Statistical analyses were performed using IBM SPSS Statistics for Windows, Version 25.0. Armonk, NY: IBM Corp. Results on continuous measurements were presented on Mean±SD (Min-Max) and categorical as Frequency (Percentage). Inferential statistics like Chi-square test/Fischer Exact test, Independent t test was applied. The significance of level adopted was 5%. 

The present study was conducted on 46 patients in Department of Anaesthesia, Dr RPGMC Kangra at Tanda, Himachal Pradesh to determine Haemodynamics changes in laparoscopic surgeries in Trendelenburg and Reverse. Trendelenburg position with the use of Ambu AuraGain. The patients were categorised into Trendelenburg and Reverse. Trendelenburg position depending upon the laparoscopic surgeries they were scheduled for.

• Group A: Trendelenburg position (n = 16) 

• Group B: Reverse Trendelenburg position (n = 30)

The mean age of patients in Group A was 44.44±11.11 years whereas the mean age of patients in Group B was 45.50±11.78 years. The comparison of mean age of two groups was not found to be statistically significant (p>0.05). The mean BMI of patients in Group A was found to be 22.28±1.58 kg/m2 and mean BMI of patients in Group B was 45.50±11.78 years. The comparison of mean age of two groups was not found to be statistically significant  (p>0.05).  The  mean BMI of patients in Group A   was   found   to   be 22.28±1.58 kg/m2 and mean BMI of patients in Group B was 22.57±2.54 kg/m2. Upon statistical analysis, this was not found to be significant (p>0.05).

Table 1: Comparison of Mean Age of Study Participants.

Table 2: Distribution of Study Participants According To Gender, Asa Status and Duration of Surgery.

Table 3: Comparison of Heart Rate (Bpm) of Study Participants at Different Intervals.

Table 4: Comparison of Sbp (Mmhg) of Study Participants at Different Intervals.

Table 5: Comparison of Dbp (Mmhg) of Study Participants at Different Intervals.

Group A comprised of 2 (12.5%) males and 14 (87.5%) females whereas Group B comprised of 12 (40%) males and 18 (60%) females. The comparison of number of males and females between two groups was not found to be statistically significant (p>0.05). Group A comprised of 11 (68.8%) patients with ASA status I and 5 (31.2%) patients with ASA status II. On the other hand, Group B had 15 cases each with ASA status    I    and   II. This   was not found to be statistically significant (p>0.05). The average duration of surgeries  in Group  A  was 80-90   minutes   whereas  the  average  duration  of surgeries in Group B was 70-80 minutes.

Table 6: Comparison of Map (Mmhg) of Study Participants at Different Intervals.

Table 7: Comparison of Spo2 (%) of Study Participants at Different Intervals.

The Mean Diastolic Blood Pressure for Group A at baseline, 1 min after placement of SGA, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min and 90 min was found to be 76.19±7.34, 73.88±3.95, 74.69±7.69, 76.81±6.87, 76.25±6.58, 74.13±6.67, 74.06±7.51, 74.31±7.04, 75.69±6.24, 71.00±8.79, 74.13±7.42 and 77.17±6.63mm Hg respectively. The Mean Diastolic Blood Pressure for Group B at baseline, 1 min after placement of SGA, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min and 90 min was found to be 74.27±6.17, 75.93±7.66, 74.43±7.73, 76.60±6.40, 77.00±8.49, 74.40±7.39, 76.07±7.63, 72.77±7.24, 75.27±7.00, 73.47±7.11, 75.94±7.41 and 76.00±2.92mm Hg respectively. The comparison between Mean Diastolic Blood Pressure of two groups was not found to be statistically significant at any time interval (p>0.05).

The mean heart rate for Group A at baseline, 1 min after placement of SGA, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min and 90 min was found to be 77.31±9.81, 80.06±9.49, 73.25±7.88, 78.19± 8.00, 80.06± 6.94, 78.13±7.76, 77.81±9.96, 76.63± 8.21, 78.56± 7.55, 79.44±9.49, 77.94± 7.31 and 74.83± 8.47 respectively. The mean heart rate for Group B at baseline, 1 min after placement of SGA, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min and 90 min was found to be 75.13±8.70, 78.93±8.22, 77.73±8.66, 76.27±8.68, 79.80±7.71, 78.07±7.98, 76.43±7.66, 79.93±7.57, 76.70±6.81, 76.37±8.91, 76.67±9.65 and 76.00±6.04 respectively. The comparison between mean heart rates of two groups was not found to be statistically significant at any time interval (p>0.05).

The Mean Systolic Blood Pressure for Group A at baseline, 1 min after placement of SGA, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min and 90 min was found to be 130.31±5.95, 127.19±6.73, 130.13±5.32, 127.38±6.66, 126.75±6.74, 127.44±7.93, 129.06±5.80, 127.06±6.76, 126.69±6.75, 128.69±7.34, 126.75±5.81 and 129.08±7.15mm Hg respectively. The Mean Systolic Blood Pressure for Group B at baseline, 1 min after placement of SGA, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min and 90 min was found to be 126.50±6.72, 126.77±6.11, 128.67±6.92, 128.53±6.91, 128.47±6.44, 128.30±7.01, 128.30±6.08, 128.17±6.78, 128.20±7.58, 126.33±6.18, 126.17±6.90 and 131.00±3.08mm Hg respectively. The comparison between Mean Systolic Blood Pressure of two groups was not found to be statistically significant at any time interval (p>0.05).

The mean of MAP (Mean Arterial Pressure) for Group A at baseline, 1 min after placement of SGA, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min and 90 min was found to be 102.94±4.39, 100.53±3.81, 101.78±4.06, 103.41±5.05, 101.88±6.58, 100.06±5.74, 99.59±5.95, 101.47±4.52, 102.59±3.76, 98.69±4.42, 101.31±5.76 and 76.46±4.37mm Hg respectively. The mean of MAP (Mean Arterial Pressure) for Group B at baseline, 1 min after placement of SGA, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min and 90 min was found to be 101.47±4.32, 102. 57±4.81, 101.23±5.71, 101.93±4.88, 102. 62±5.95, 101.03±4.91, 101.98±4.59, 100.5±4.66, 100.82±4.65, 100.23±4.35, 101.92±5.90 and 76.70±3.90 mm Hg respectively. The comparison between MAP of two groups was not found to be   statistically   significant   at  any time interval (p>0.05).

The mean SPO2 for Group A at baseline, 1 min after placement of SGA, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min and 90 min was found to be 98.44±1.03, 99.81±0.54, 99.81±0.54, 99.88±0.34, 99.94±0.25, 99.94±0.25, 99.81±0.54, 99.81±0.54, 99.81±0.54, 99.88±0.34, 99.88±0.34 and 99.83±0.39respectively. The mean SPO2 for Group B at baseline, 1 min after placement of SGA, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min and 90 min was found to be 99.47±0.51, 99.47±0.51, 99.40±0.50, 99.53±0.51, 99.53±0.51, 99.53±0.51, 99.40±0.50, 99.57±0.51, 99.67±0.48, 99.43±0.50, 99.72±0.46 and 99.80±0.45respectively. The comparison between mean SPO2 of two groups was not found to be statistically significant (p>0.05). There is small rise in SPO2 in both groups. This could be due to effect of preoxygenation and positive pressure ventilation through SGA.

The position of the patient in the laparoscopic surgery has an effect on cardiovascular and respiratory functions. In this study, we evaluated and compared the hemodynamic parameters in Trendelenburg and Reverse Trendelenburg position. To the best of our knowledge, this is the first study to evaluate and compare hemodynamic parameters in two positions with the use of Ambu AuraGain.

In our study, we didn’t find any significant changes in haemodynamic parameters of two groups. The comparison between mean heart rate, mean systolic blood pressure, mean Diastolic Blood Pressure and Mean arterial blood pressure of patients in Trendelenburg and Reverse Trendelenburg Position was not found to be statistically significant at any time interval (p>0.05). This is in accordance with study done by Kihara et al [5] who had demonstrated that LMA insertion has no significant haemodynamic effect compared to base line. Ubale P et al [6] conducted a study to evaluate the hemodynamic changes between endotracheal intubation and laryngeal mask airway insertion and they found that haemodynamic response consisting of an increase in Heart rate, SBP, DBP and MAP was significantly greater with ETT than that caused by LMA insertion. In Md. Harun-Or-Rashid [7] study, hemodynamic parameter i.e. pulse rate, systolic blood pressure, diastolic blood pressure and presence of any dysrhythmias were monitored after 1,3,5 & 10 minutes after LMA insertion and ETT intubations. There were statistically significant changes in pulse rate, systolic blood pressure, diastolic blood pressure and (appearance of dysrhythmia in some patients) in ETT patients whereas there were less changes in pulse rate, systolic blood pressure, diastolic blood pressure whose airway was maintained by LMA insertion. They concluded that LMA insertion causes less haemodynamic changes than that of endotracheal intubation. Our study also didn’t find any significant change in haemodynamic parameters with use of Ambu AuraGain.

Limitations

The COVID-19 pandemic led to the decreased sample size of our study as there were less number of elective surgical procedures performed during this period. Studies with larger sample size are required to validate the findings of the present study.

We concluded that two groups of patients in Trendelenburg and Reverse Trendelenburg Position were comparable in  respected to various haemodynamic parameters like mean heart rates, Mean Systolic Blood Pressure, Mean Diastolic Blood Pressure, Mean arterial blood pressure and Spo2 at any time interval.

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