Primary objective
1) Comparison of the OLP (Oropharyngeal Leak Pressure) of AMBUAURA and I-gel after insertion in patient undergoing Laparoscopic appendicectomy under general anesthesia
Secondary objectives
1) Assessment of first attempt success rate and the number of attempts, as well as the time to insert the both SGDs and compare them.
2) Ease of SGD insertion will be subjectively assessed by the investigator on an objective scale
3)Observe the ease of gastric tube insertion through gastric tube channel with 3-point scale
4)Observe whether Airway manipulation required to maintain the airway patency during the surgery or not
5) Observation of obstruction after insertion and also intraoperatively
6)Observation of complication after removal of SGDs and compare them
METHODOLOGY
Ethical consideration: This study will be conducted after getting approval from local ethical committee (IHEC) of GMERS Medical College, Gotri, Vadodara and it will be registered under Clinical Trial Registry of India. Written and informed consent will be obtained from all the participants. Data collected will be kept confidential.
Settings: Tertiary care teaching hospital (GMERS Medical College & Hospital, Gotri, Vadodara)
Study design: Prospective randomized open label study
Study Period: over the period of 1 year after ethics approval and CTRI registration
Study population : Patients undergoing laparoscopic appendicectomy under general anesthesia
Inclusion criteria:
1) Age 18 years to 60 years
2) American Society of Anesthesiology grade I & II patients
3) Mouth opening ≥ 2.5 cm
4) Patients who are willing to participate and give consent
Exclusion criteria:
1) Patient who didn’t comply to minimum 8 hour fasting before surgery
2) Patients with potentially difficult airway
3) Patients with active upper respiratory tract infection
4) Patients with high risk of aspiration
Study procedure
Randomization and allocation : Patients who require an SGDs and will be scheduled for elective laparoscopic appendicectomy surgery will be allocated to the Ambu Aura group or the I-gel group by simple randomization 1:1 allocation for Ambu Aura group and the I-gel group. That randomization sealed in opaque envelope. The study investigator will open this envelope on day of surgery after taking consent from the eligible participants.
Intervention
Patients will be randomized in 2 groups
Group A : Ambu Aura group
Group I : I-GEL group
The pre anesthetic visit of patients will be done along with airway assessment including mouth opening, dentition, neck movement etc. Each attending anesthesiologist will be having the experience of SGDs insertion of more than 20 times including insertion of the Ambu Aura and i-gel and insertion of both devices will be done by same anaesthetist only during whole study period.
Standard fasting guidelines (8 h for solid food, 4 h for milk and 2 h for clear water) will be followed. In the operating room, electrocardiography, Noninvasive blood pressure, pulse oximeter, capnography will be attached. Intravenous line will be placed. Both devices will be checked thoroughly for their function.
Premedication: Injection Ondansetron 0.08 mg/kg will be given 30 minutes before induction and Injection Glycopyrrolate 4 ug/kg, Injection Midazolam 0.02 mg/kg, , Injection Tramadol 2 mg/kg will be given 10 minutes before induction. All patients will be preoxygenated with 100% oxygen. All patients will be induced with intravenous agents Injection Propofol 2 to 2.5 mg/kg. Muscle relaxant succinyl choline 2mg/kg will be given. Adequate anesthetic depth will be confirmed by lack of a motor response to jaw thrust. Both devices will be selected according to weight of the patients as recommended by the manufacturers. Both devices will be inserted with the head in the sniffing position and without a laryngoscope. If resistance will be encountered during insertion, the SGD will be turned gently, or the chin-lift maneuver will be performed. For Ambu Aura, the cuff will be inflated according to manufacturer’s recommendations. Correct placement will be confirmed by observing the chest rise, bilateral air entry with stethoscope and the square waveform in the capnography. Muscle relaxant Injection Atracurium (0.5 mg/kg) will be given to all the patient after confirming the placement of SGDs. Appropriate size of gastric tube will be inserted via gastric port given in the devices.
Data collection and Outcome measures
Primary outcome
1)Oropharyngeal leak pressure (OLP) will be measured after the loss of spontaneous ventilation after insertion. OLP will be measured by transiently stopping ventilation and providing a fresh gas flow of 3 L/min. The pressure-limiting valve (APL) of the anesthetic circuit will be closed and adjusted at 40cm of H2O, and the plateau airway pressure will be monitored. If reading of plateau pressure sustained for >10 seconds, that Plateau pressure will be considered as the Oropharyngeal Leak Pressure (OLP). (Maximum peak airway pressure should not reach above 40 cm of H2O, if it goes then APL valve will be opened.)
Secondary outcome
1)First attempt success rate and the number of attempts, as well as the Time to insert the both SGDs will be noted.
2)Ease of SGD insertion will be subjectively assessed by the investigator on an objective scale from 1 to 4. (1=no resistance, 2= moderate resistance,3=high resistance, 4=inability to place the device)
3)Ease of gastric tube insertion through gastric tube channel will be assessed with 3-point scale (1=Passed easily, 2=Passed with difficulty,3=Impossible to pass)
4)The number and type of Airway manipulation if required to maintain the airway patency during the surgery like Jaw thrust, Head extension, Adjustment of the device. If can’t maintain the saturation then the exchange for an endotracheal tube will be recorded.
5)If airway obstruction [abnormal chest/abdominal movement, occlusion sound, inadequate ventilation (tidal volume <6 ml kg), oxygen desaturation (SpO2 < 90%) or changes in the capnography curve] occurs then we will attempt to re-insert the SGA, maximum up to 2 times.
6)Complication after removal of SGDs (i.e., cough, sore throat, dyspnea, laryngospasm, bronchospasm, aspiration or blood staining on the device after removal) will be recorded.
Anesthesia will be maintained with sevoflurane, Nitrous oxide and oxygen. At the end of the surgery residual blockade will be antagonized by intravenous Injection Neostigmine 0.05mg/kg and Injection Glycopyrrolate 0.01mg/kg. The device will be removed after achieving response to verbal commands, adequate spontaneous breathing.