Proseal LMA vs Air-Q LMA vs Ambu AurGain LMA Clinical Trial
Official title:
"A Randomized Controlled Study Comparing ProSeal Laryngeal Mask Airway, Air-Q LMA and Ambu AuraGain in Mechanically Ventilated Patients"
The present study entitled, "A Randomized Controlled Study Comparing ProSeal Laryngeal Mask
Airway, Air-Q LMA and Ambu AuraGain in mechanically ventilated patients." was conducted in
during the period Nov 2016 - Aug 2018.
The Aim of the study was to compare the clinical performance of ProSeal-LMA (P-LMA) ,Air-Q
and Ambu AuraGain in terms of efficacy and safety in anaesthetized and paralyzed patients on
mechanical ventilation undergoing elective surgical procedures.
Objective was to study the three supraglottic devices with respect to following
parameters:-number of insertion attempts and overall success rate, ease of insertion of
device, time taken for placement of device, airway sealing pressure, glottic view, number of
attempts of gastric tube placement, hemodynamic parameters: heart rate and mean arterial
pressure: pre-insertion and 0,1,3,5 and 10 minutes post insertion and complications noted if
any: blood staining of device and tongue, lip and dental trauma, laryngospasm ,sore throat,
dysphagia, hoarseness of voice.
It was a randomized prospective single blind comparative study comprised of 150 ASA I - II
patients, aged 18-65 years of either sex who weighed between 40 to 60 kg scheduled for
elective surgical procedure of duration not more than 90 mins. After a thorough
pre-anaesthetic check-up, informed written consent was obtained and the patients were
randomized into 3 groups of 50 patients each as Group P(Proseal), Group Q (Air Q) and Group A
(AuraGain) by computer generated randomization sequence.
In this study PLMA, Air-Q® and Ambu AuraGain were compared undergoing elective surgeries
under general anaesthesia. Primary outcome measure was insertion time. Airway sealing
pressure,ease of insertion, number of attempts,overall success rate, glottis view,number of
attempts of gastric tube placement , hemodynamic parameters and complications were also
compared.
After approval from the institutional ethical committee, 150 patients were studied in a
randomised prospective study, designed to compare PLMA , Air-Q® and Ambu AuraGain .The period
of the study was from nov 2016 to aug 2018. This study was conducted according to Good
Clinical Practice standards and the Helsinki Declaration.
The American Society of Anesthesiologists (ASA) physical status I and II patients, between
18-65 years of age, weighing from 40 to 60 kg of either sex, undergoing elective surgical
procedures of duration not more than 90 minutes were selected for the study. The exclusion
criteria included patients with anticipated difficult airway (mouth opening of <2 finger,
Mallampati Score 4, limited neck extension, history of previous difficult intubation), upper
respiratory tract infections,airway related conditions such as trismus, trauma or mass,
cervical spine disease, obese with body mass index (BMI) ≥25kg/m2 ,pregnant females, patients
at risk of aspiration (full stomach, hiatus hernia, gastro-oesophageal reflux disease,
emergency surgery)and laparoscopic surgeries. Neck movement was assessed as Class: I-No
reduction in movement, II-1/3rd reduction, III-2/3rd reduction, IV-Complete reduction.
Following detailed pre-anaesthetic check-up, informed written consent was obtained from all
patients fulfilling the required criteria.Patients were randomly allocated into three groups
namely Group P(ProSeal,n=50) ,Group Q (Air-Q®, n = 50) and Group A (AuraGain™, n = 50) using
computer-generated randomisation sequence. Participants were assigned to specific groups by
the operating room nurse in charge.
After attaching the standard monitors(ASA recommended), patients were pre-medicated with
injection midazolam 0.05 mg/kg, glycopyrrolate 0.2 mg, dexamethasone 4 mg and nalbuphine
0.02mg/kg intravenously. All patients were pre-oxygenated for 3 min, and anaesthesia was
induced with injection propofol 2 mg/kg. Injection vecuronium 0.1 mg/kg was given for
neuromuscular blockade.
PLMA or Air-Q® or AuraGain™ appropriate for weight or/and height was inserted as per the
manufacturers guidelines.After successful insertion, the cuff was inflated with air according
to the size and type of LMA as per manufacturers guidelines, to prevent audible and palpable
air leak. An effective airway was confirmed by bilateral symmetrical chest expansion on
manual ventilation, auscultation of breath sounds, square waveform on capnography. Devices
were fixed with adhesive tape applied to the maxilla on one side of the patient's face and
passed over and under the tube in a single loop before fixing to the opposite maxilla.
Anaesthesia was maintained with oxygen, nitrous oxide and isoflurane and intermittent
positive pressure ventilation. Haemodynamic parameters[heart rate(HR), mean arterial
pressure(MAP)]were monitored before and after the insertion of the device. A lubricated
gastric tube was placed in the stomach through the gastric channel. At the end of surgical
procedure, anaesthesia was discontinued and residual neuromuscular blockade reversed with
injection neostigmine and glycopyrrolate, followed by device removal. Complication if any was
noted.
Insertion time, number of insertion attempts, overall success rate, ease of insertion, airway
sealing pressure, glottis view, number of attempts of gastric tube insertion, hemodynamic
parameters (HR and MAP) preinduction, induction and 1,3,5 and 10mins post induction and
complications were noted. One attempt was defined as insertion of the LMA between the teeth
until the LMA will be deemed to be correctly placed and its cuff will be properly inflated.
In case of insertion attempts, maximum of three attempts were allowed. An attempt was
considered unsuccessful, if there was failure to negotiate the device beyond oropharynx,
significant leak present (both audible and auscultatory) or inadequate ventilation with
EtCO2>45 mmHg. Failure of a device was defined as three unsuccessful insertion attempts or
inadequate ventilation. After failure of three attempts, intubation was performed using
conventional rigid laryngoscopy and case was recorded as failed and also deleted from the
study. The ease of insertion of device based on Visual Analogue Scale(VAS) was recorded.0 was
considered the easiest insertion of device and 10 being the most difficult
insertion.Insertion time was defined as time interval (in seconds) elapsed from insertion of
LMA between the dental arches until the confirmation of successful ventilation determined by
chest wall movement, auscultation of breath sounds and square wave capnographic curves and no
oropharyngeal leak with peak airway pressure ≥ 20cmH2O, which was recorded by an independent
observer.The airway sealing pressure was measured by closing the expiratory valve of the
circle system at a fixed gas flow of 3 L/min and recording the airway pressure at which
equilibrium is reached. At this stage, a leak at mouth and stomach was ascertained. Glottic
viewing was assessed by insertion of the fibreoptic bronchoscope through the airway channel
of the respective LMA.A maximum of two attempts were allowed for gastric tube placement. Its
correct placement was confirmed by injection of air and epigastric auscultation or aspiration
of gastric contents. Failure was defined as inability to advance the orogastric tube into the
stomach within two attempts. Blood staining of the device and tongue, lip or dental trauma
was noted. Incidence of laryngospasm or hypoxia (defined as oxygen saturation <92%), if any,
in intra-operative period was noted and managed accordingly. In post-operative period, an
investigator blinded to study asked the patients about the signs of sore throat, dysphagia
and hoarseness of voice. Incidence of hoarseness and sore throat, whether present or absent,
were enquired in 24 h post-operatively.
The primary outcome measure of the study was insertion time. Based on a previous study
investigators found mean insertion time in PLMA group was 23.43 seconds and SD of 3.54. Based
on that, taking alpha 0.05, β =0.90 and 25% difference between the means as significant,
investigators calculated 47 patients were required in each group; hence, the sample size was
increased to 50 patients each.
The data were recorded in a Microsoft Excel Spreadsheet and analysed using SPSS statistics
software version 24 (IBM SPSS Inc., Chicago, IL, USA). Continuous numerical variables were
presented as mean (standard deviation) and intergroup differences were compared using one-way
analysis of variance with post hoc correction. Categorical variables were presented as ratio
or as n (%) and inter-group differences were compared using Kruskall-Wallis test. The P< 0.05
was considered statistically significant.
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