A Comparative Study of Airtraq Versus Macintosh Laryngoscope for Endotracheal Intubation by First Year Resident

Study Overview
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Brief Summary
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This study evaluates the learning and performance of tracheal intubation by first year anaesthesia trainee in Nepalese population using either Airtraq or Macintosh laryngoscopes.

Detailed Description
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The airway is primarily a conduit for air to reach the lungs. Maintaining a stable, patent airway is a fundamental element of safe perioperative care for all anesthesiologists. Though maintaining airway patency seems conceptually straightforward, a wide variety of clinical circumstances, patients, and tools can make the task of ensuring a stable, open airway under all clinical conditions extremely challenging. In spite of endotracheal intubation being a lifesaving skill, problems like delayed intubation, misplaced tracheal tube, or airway trauma are frequently encountered, and can cause death or hypoxic brain damage. The magnitude of problems during airway management constitute 17% of anaesthesia closed claims in UK, with difficult intubation being the most common at a rate of 5%.The American Society of Anesthesiologists' Closed Claims Project (ASACCP) reports that though the proportion of claims for respiratory complications decreased from 34% in the 1970s to 15% in the 1990s, the 'big three' (inadequate ventilation, oesophageal intubation, and difficult tracheal intubation) still accounted for >50% of claims leading to death or permanent brain damage. Direct laryngoscopy (DL) remains the gold standard technique for securing the airway. Successful DL involves the creation of a new (non-anatomic) visual axis, through maximal alignment of the axes of the oral and pharyngeal cavities and displacement of the tongue that requires manipulations of head, neck and larynx and other stressful movements. These manipulations of the airway have numerous adverse implications including significant hemodynamic disturbances, cervical instability, injury to oral and pharyngeal tissues, and dental damage. It is thus, a complicated technical skill with a variable learning curve and requires regular training, experience, and practice to acquire and maintain. The video laryngoscope (VL) is a recently developed device with a camera and light source on the tip of its blade that provides indirect glottic view. The Airtraq laryngoscope is a recently developed video laryngoscope. It has an anatomically shaped blade which contains two parallel channels, one, the guiding channel, for the insertion of the endotracheal tube (ETT) and the other, the optical channel, containing a series of lenses, prisms, and mirrors that transfer the image from the illuminated tip to a proximal viewfinder, giving a high-quality wide-angle view of the glottis and surrounding structures. As compared to DL, Airtraq VL requires the application of lesser force to the base of the tongue and is thus less likely to stimulate stress response and induce local tissue injury, produces less cervical movement, and has a faster learning curve relative to DL. It has also been demonstrated to be beneficial in the difficult airway scenario, when compared with the Macintosh laryngoscope, by reducing the number of failed intubations, the duration of intubation attempts and the amount of airway manipulation required, making them suitable for use by medical personnel who intubate infrequently. The purpose of this study is to evaluate learning and performance of tracheal intubation by first year anaesthesia trainee using either Airtraq VL or Macintosh laryngoscopes.

Official Title
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Airtraq Video Laryngoscope Versus Macintosh Laryngoscope for Endotracheal Intubation by First Year Anaesthesia Trainee in Nepalese Population: A Comparative Study

Conditions
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Intubation; Difficult or Failed, Intubation Complication

Intervention / Treatment
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* Device: Orotracheal intubation with either Macintosh laryngoscope versus Airtraq video laryngoscope


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA physical status I and II Age group 16-65 years of either gender Patient requiring orotracheal intubation under general anaesthesia. Exclusion Criteria: Patient having respiratory tract (oropharynx, larynx) pathology, Patient with predicted difficult airway (such as mouth opening <2 cm), Patient having gastroesophageal reflux disease, hiatus hernia, and pregnancy.

Ages Eligible for Study
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Minimum Age: 16 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Health Services Research
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: First year anaesthesia trainee are those residents in their first year of anaesthesia training and has not had any prior experience using either laryngoscope. They will be given adequate training and instructions before intubation on patients. On the day of surgery, the baseline airway variables and the baseline hemodynamic values will be recorded. An investigator not involved in assessing the patient outcome will open the sealed envelope according to the serial number of the patient enrolled into the study. Following standard induction technique of preoxygenation with 100% oxygen, injection fentanyl, injection propofol, injection veruronium and mixture of isoflurane and oxygen, tracheal intubation will then be performed by first year anaesthesia trainee using either Airtraq or Macintosh laryngoscope according to the randomization sequence supervised by an experienced anaesthesiologist and data recorded by an independent observer.
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Orotracheal intubation with macintosh laryngoscope<br>Following standard intubation protocol, tracheal intubation will be performed by first year anaesthesia trainee using Macintosh laryngoscope according to the randomization sequence supervised by an experienced anaesthesiologist and data recorded by an independent observer on one group of patients. Duration of intubation attempt, failed intubation, optimization maneuvers required to perform tracheal intubation, glottic view according to the Cormack and Lehane grading will be evaluated. Similarly, the maximum fall in oxygen saturation during intubation, HR, SBP and DBP will be documented immediately following intubation and then every 5 minutes till the end of surgery. The occurrence of minor complications (visible trauma to lip or oral mucosa, and presence of blood on laryngoscope blade), and the postoperative sore throat and hoarseness will be evaluated at the end of surgery in the postoperative recovery room. | |
| Active Comparator: Orotracheal intubation with Airtraq Video Laryngoscope<br>Following standard intubation protocol, tracheal intubation will be performed by first year anaesthesia trainee using Airtraq video laryngoscope according to the randomization sequence supervised by an experienced anaesthesiologist and data recorded by an independent observer on one group of patients. Duration of intubation attempt, failed intubation, optimization maneuvers required to perform tracheal intubation, glottic view according to the Cormack and Lehane grading will be evaluated. Similarly, the maximum fall in oxygen saturation during intubation, HR, SBP and DBP will be documented immediately following intubation and then every 5 minutes till the end of surgery. The occurrence of minor complications (visible trauma to lip or oral mucosa, and presence of blood on laryngoscope blade), and the postoperative sore throat and hoarseness will be evaluated at the end of surgery in the postoperative recovery room. | Device: Orotracheal intubation with either Macintosh laryngoscope versus Airtraq video laryngoscope<br>* Tracheal intubation will be performed by first year anaesthesia trainee using either Macintosh laryngoscope or Airtraq video laryngoscope according to the randomization sequence supervised by an experienced anaesthesiologist and data recorded by an independent observer on one group of patients.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time required for tracheal intubation. | Duration of intubation attempt will be defined as the time elapsed from insertion of the blade of laryngoscope between the dental arches until the endotracheal tube is placed through the vocal cords and confirmed by chest rise, auscultation, and square wave capnography | From the time of randomization and insertion of the blade of the laryngoscope between the dental arches until the endotracheal tube is placed through the vocal cords upto start of surgery, assessed upto 15 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intubation difficulty scale (IDS) score18 for each device. | Number of attempts >1: N1; Each additional attempts add 1 point Number of operators >1: N2; Each additional operators add 1 point Number of alternative techniques: N3; Each techniques add 1 point Cormack Lehane grade: N4; 0 if successful blind intubation; 1 if grade at first attempt is 1 Lifting force required : N5; 0 if normal force required; 1 if increased force required Laryngeal pressure : N6; 0 if not applied; 1 if applied Vocal cord mobility : N7; 0 if abduction 1 if adduction Total IDS : Sum of scores = N1+N2+N3+N4+N5+N6+N7 | From the time of randomization and insertion of the blade of the laryngoscope between the dental arches until the endotracheal tube is placed through the vocal cords upto start of surgery, assessed upto 15 minutes | 
| Rate of successful placement of endotracheal tube. | Successful placement will be confirmed by chest rise, auscultation, and square wave on capnography. | From the time of randomization and insertion of the blade of the laryngoscope between the dental arches until the endotracheal tube is placed through the vocal cords upto start of surgery, assessed upto 15 minutes | 
| Number of optimization maneuvers required to perform tracheal intubation. | Optimization maneuvers required to perform tracheal intubation will be assessed on a score of 0 to 2: 0. No maneuvers required. External laryngeal pressure. Use of stylet. | From the time of randomization and insertion of the blade of the laryngoscope between the dental arches until the endotracheal tube is placed through the vocal cords upto start of surgery, assessed upto 15 minutes | 
| Changes in heart rate before and immediately following intubation. | The blood pressure will be recorded before intubation and assessed again immediately after intubation, and every 5 minutes till the end of the surgery | From the randomization and before intubation to immediately following intubation and every 5 minutes till the end of surgery, upto 1 hour | 
| Incidence of trauma to the airway. | The occurrence of minor complications (visible trauma to lip or oral mucosa, and presence of blood on laryngoscope blade), and the postoperative sore throat and hoarseness will be evaluated at the end of surgery in the postoperative recovery room. | From the time of randomization and insertion of the blade of the laryngoscope between the dental arches until the endotracheal tube is placed through the vocal cords upto start of surgery, assessed upto 15 minutes | 
| Changes in systolic, diastolic and mean blood pressure before and immediately following intubation | The blood pressure will be recorded before intubation and assessed again immediately after intubation, and every 5 minutes till the end of the surgery | From the randomization and before intubation to immediately following intubation and every 5 minutes till the end of surgery, upto 1 hour | 
| Changes in oxygen saturation before and immediately following intubation | The oxygen saturation will be recorded before intubation and assessed again immediately after intubation, and every 5 minutes till the end of the surgery | From the randomization and before intubation to immediately following intubation and every 5 minutes till the end of surgery, upto 1 hour | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Macintosh laryngoscope, Airtraq video laryngoscope