Intubation; Difficult
Conditions
Brief summary
Tracheal intubation requires alignment of oro-pharyngeal-laryngeal axes. When these three axes are not aligned, intubation becomes difficult. In the researchers' study, the investigators simulated difficult laryngoscopy situation by using a rigid neck collar. This neck collar renders intubation difficult not only by restricting neck movement, but also reducing mouth opening. The investigators compared the performance of Macintosh, MacCoy and Airtraq laryngoscope in simulated difficult laryngoscopy using a rigid neck collar.
Detailed description
Airtraq laryngoscope is an optical laryngoscope which allows visualization of vocal cord as a reflected image through multiple lenses and prisms. MacCoy laryngoscope is a modification of Macintosh laryngoscope. It has a lever which, when pressed, moves its flexible tip. In the investigators' study, the researchers compared the performances of Airtraq laryngoscope with MacCoy and Macintosh laryngoscopes in simulated difficult laryngoscopy using a rigid neck collar. The researchers recruited 120 patients and randomly divided those patients into three equal groups i.e. 30 patients in each group. These three groups are 1-Airtraq, 2-MacCoy and 3-Macintosh. The researchers compared efficacy and safety in these three laryngoscopes. The researchers compared efficacy in terms of time of intubation, ease of intubation, overall success, Intubation difficulty score, visualization of vocal cord in terms of POGO (percentage of Glottic Opening) score. The researchers compared safety in terms of hemodynamic pressor response and airway trauma.
Interventions
DEVICEIntubation- Macintosh laryngoscope
Difficult intubation was simulated by using rigid neck collar. Then patients were intubated according to the assigned laryngoscopes. In Macintosh group, tip of the laryngoscope blade was placed in the vallecula and epiglottis was lifted. After visualization of the vocal cord, patients were intubated.
DEVICEIntubation- MacCoy laryngoscope
In MacCoy group, tip of the laryngoscope blade was placed in the vallecula and lever was pressed to flex the tip. After visualization of the vocal cord, patients were intubated.
DEVICEIntubation- Airtraq laryngoscope
In Airtraq group, the laryngoscope was loaded with endotracheal tube. Airtraq laryngoscope was inserted through midline and after visualization of image of vocal cord through its eyepiece, endotracheal tube was passed.
Sponsors
Government Medical College, Haldwani
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
No
Inclusion criteria
* American Society of Anesthesiologists (ASA) physical status I and II. * Posted for elective surgery requiring general anesthesia and tracheal intubation
Exclusion criteria
* patients with anticipated difficult airway * obese (body mass index (BMI)\>30) patients * patients with risk of pulmonary aspiration of gastric contents * pregnant patients * patients with airway distortion or trauma.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Time of Intubation | up to 10 minutes | Time of intubation is defined as the time from passing the device beyond the incisors to the confirmation of endotracheal tube placement by square wave capnograph tracings. |
Participant flow
Recruitment details
120 patients were recruited for the study. Recruitment process started in January 2014 and the study ended in December 2014. patients were recruited in the operating rooms of a tertiary care teaching hospital.
Pre-assignment details
30 patients were excluded from the study for not meeting the inclusion criteria.
Participants by arm
| Arm | Count |
|---|---|
| Intubation With Macintosh Laryngoscope After randomization, 40 patients were included in this group. After application of rigid neck collar, all patients were intubated with Macintosh laryngoscope. We observed and documented ease of intubation, time of intubation, overall success, number of attempts, Intubation Difficulty Score and POGO score. We also observed hemodynamic response in terms blood pressure and pulse rate. We assessed airway trauma after extubation.
Intubation- Macintosh laryngoscope: Difficult intubation was simulated by using rigid neck collar. Then patients were intubated according to the assigned laryngoscopes. In Macintosh group, tip of the laryngoscope blade was placed in the vallecula and epiglottis was lifted. After visualization of the vocal cord, patients were intubated. | 40 |
| Intubation With MacCoy Laryngoscope After randomization, 40 patients were included in this group. After application of rigid neck collar, all patients were intubated with MacCoy laryngoscope. We observed and documented ease of intubation, time of intubation, overall success, number of attempts, Intubation Difficulty Score and POGO score. We also observed hemodynamic response in terms blood pressure and pulse rate. We assessed airway trauma after extubation.
Intubation- MacCoy laryngoscope: In MacCoy group, tip of the laryngoscope blade was placed in the vallecula and lever was pressed to flex the tip. After visualization of the vocal cord, patients were intubated. | 40 |
| Intubation With Airtraq Laryngoscope After randomization, 40 patients were included in this group. After application of rigid neck collar, all patients were intubated with Airtraq laryngoscope. We observed and documented ease of intubation, time of intubation, overall success, number of attempts, Intubation Difficulty Score and POGO score. We also observed hemodynamic response in terms blood pressure and pulse rate. We assessed airway trauma after extubation.
Intubation- Airtraq laryngoscope: In Airtraq group, the laryngoscope was loaded with endotracheal tube. Airtraq laryngoscope was inserted through midline and after visualization of image of vocal cord through its eyepiece, endotracheal tube was passed. | 40 |
| Total | 120 |
Baseline characteristics
| Characteristic | Total | Intubation With Airtraq Laryngoscope | Intubation With MacCoy Laryngoscope | Intubation With Macintosh Laryngoscope |
|---|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 120 Participants | 40 Participants | 40 Participants | 40 Participants |
| Age, Continuous | 37.88 years STANDARD_DEVIATION 9.88 | 35.47 years STANDARD_DEVIATION 10.1 | 38.82 years STANDARD_DEVIATION 9.62 | 39.35 years STANDARD_DEVIATION 9.92 |
| BMI | 22.29 kg/m^2 STANDARD_DEVIATION 1.1 | 22.03 kg/m^2 STANDARD_DEVIATION 1.13 | 22.43 kg/m^2 STANDARD_DEVIATION 1.07 | 22.41 kg/m^2 STANDARD_DEVIATION 1.11 |
| Mallampati grade | 2 units on a scale | 1 units on a scale | 2 units on a scale | 2 units on a scale |
| Sex: Female, Male Female | 45 Participants | 15 Participants | 16 Participants | 14 Participants |
| Sex: Female, Male Male | 75 Participants | 25 Participants | 24 Participants | 26 Participants |
| Thyromental distance | 6.21 cm STANDARD_DEVIATION 0.41 | 6.28 cm STANDARD_DEVIATION 0.44 | 6.16 cm STANDARD_DEVIATION 0.4 | 6.19 cm STANDARD_DEVIATION 0.4 |
| Weight | 58.30 Kg STANDARD_DEVIATION 6.05 | 57.62 Kg STANDARD_DEVIATION 5.65 | 58.62 Kg STANDARD_DEVIATION 6.46 | 58.65 Kg STANDARD_DEVIATION 6.03 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — |
| other Total, other adverse events | 0 / 40 | 0 / 40 | 0 / 40 |
| serious Total, serious adverse events | 3 / 40 | 5 / 40 | 8 / 40 |
Outcome results
Primary
Time of Intubation
Time of intubation is defined as the time from passing the device beyond the incisors to the confirmation of endotracheal tube placement by square wave capnograph tracings.
Time frame: up to 10 minutes
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Intubation With Macintosh Laryngoscope | Time of Intubation | 41.22 seconds | Standard Deviation 4.72 |
| Intubation With MacCoy Laryngoscope | Time of Intubation | 37.62 seconds | Standard Deviation 3.45 |
| Intubation With Airtraq Laryngoscope | Time of Intubation | 27.80 seconds | Standard Deviation 3.87 |