Trial Outcomes & Findings for Force and Pressure Distribution Using Macintosh and GlideScope Laryngoscopes in Normal Airway: an in Vivo Study (NCT NCT01685320)

Results Overview

The pressure distribution exerted upon the tissues by the blade was measured (in Newton)through pressure film transducers put on the blade of both direct and indirect laryngoscopes, in order to compare the two devices.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

30 participants

Primary outcome timeframe

Force measurement is referred to an average of 45 seconds in patients scheduled to undergo elective surgery under general anaesthesia

Results posted on

2021-02-11

Participant Flow

Date of recruitment period: January-October 2011. Type of location: Dept. of Anaesthesia, University School of Medicine Campus Bio-Medico, Rome, Italy.

After written consent, thirty adult patients scheduled for elective surgery under general anaesthesia (age between 18 and 65 years, body-mass index between 18 and 30, classified as ASA-PS class 1 or 2), were included in this study. Subjects likely to be difficult to intubate, according to the SIAARTI Recommendations, were excluded.

Participant milestones

Participant milestones
Measure	Direct Laryngoscope Includes cases in which the forces applied by McIntosh direct laryngoscope onto soft tissue of the pharynx during glottis visualization and intubation were measured using film pressure transducers.	Indirect Laryngoscope Includes cases in which the forces applied by GlideScope indirect laryngoscope onto soft tissue of the pharynx during glottis visualization and intubation were measured using film pressure transducers.
Overall Study STARTED	15	15
Overall Study COMPLETED	15	15
Overall Study NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Force and Pressure Distribution Using Macintosh and GlideScope Laryngoscopes in Normal Airway: an in Vivo Study

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Direct Laryngoscope n=15 Participants Includes cases in which the forces applied by McIntosh direct laryngoscope onto soft tissue of the pharynx during glottis visualization and intubation were measured using film pressure transducers.	Indirect Laryngoscope n=15 Participants Includes cases in which the forces applied by GlideScope indirect laryngoscope onto soft tissue of the pharynx during glottis visualization and intubation were measured using film pressure transducers.	Total n=30 Participants Total of all reporting groups
Age, Categorical <=18 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	15 Participants n=5 Participants	15 Participants n=7 Participants	30 Participants n=5 Participants
Age, Categorical >=65 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Age, Continuous	41 years STANDARD_DEVIATION 12 • n=5 Participants	44 years STANDARD_DEVIATION 11 • n=7 Participants	42.5 years STANDARD_DEVIATION 12 • n=5 Participants
Sex: Female, Male Female	7 Participants n=5 Participants	7 Participants n=7 Participants	14 Participants n=5 Participants
Sex: Female, Male Male	8 Participants n=5 Participants	8 Participants n=7 Participants	16 Participants n=5 Participants
Region of Enrollment Italy	15 participants n=5 Participants	15 participants n=7 Participants	30 participants n=5 Participants

PRIMARY outcome

Timeframe: Force measurement is referred to an average of 45 seconds in patients scheduled to undergo elective surgery under general anaesthesia

Population: We have utilized our previous in vitro study on manikin (Carassiti et al. Br J Anaesth 2012; 108: 146-151) as basis for the calculus of sample size in this research, considering 95% confidence interval (2-sided), power of 80%, ratio of sample size (Group B/Group A) = 1.

The pressure distribution exerted upon the tissues by the blade was measured (in Newton)through pressure film transducers put on the blade of both direct and indirect laryngoscopes, in order to compare the two devices.

Outcome measures

Outcome measures
Measure	Direct Laryngoscope n=15 Participants Includes cases in which the forces applied by McIntosh direct laryngoscope onto soft tissue of the pharynx during glottis visualization and intubation were measured using film pressure transducers.	Indirect Laryngoscope n=15 Participants Includes cases in which the forces applied by GlideScope indirect laryngoscope onto soft tissue of the pharynx during glottis visualization and intubation were measured using film pressure transducers.
Force Applied and Pressure Distribution Upon the Blade of Laryngoscopes During Tracheal Intubation. Measurements during intubation	40 Newton Standard Deviation 14	8 Newton Standard Deviation 4
Force Applied and Pressure Distribution Upon the Blade of Laryngoscopes During Tracheal Intubation. Measurements during glottis visualization	16 Newton Standard Deviation 6	10 Newton Standard Deviation 3

SECONDARY outcome

Timeframe: On average 20 seconds

Population: We have utilized our previous in vitro study on manikin (Carassiti et al. Br J Anaesth 2012; 108: 146-151) as basis for the calculus of sample size in this research, considering 95% confidence interval (2-sided), power of 80%, ratio of sample size (Group B/Group A) = 1.

Since the time needed for laryngoscopy and intubation could represent one of the major contributors to the stress response during these procedures, times to achieve the glottis visualization and to perform the entire intubation were recorded.

Outcome measures

Outcome measures
Measure	Direct Laryngoscope n=15 Participants Includes cases in which the forces applied by McIntosh direct laryngoscope onto soft tissue of the pharynx during glottis visualization and intubation were measured using film pressure transducers.	Indirect Laryngoscope n=15 Participants Includes cases in which the forces applied by GlideScope indirect laryngoscope onto soft tissue of the pharynx during glottis visualization and intubation were measured using film pressure transducers.
Time Required to Visualize the Glottis and Complete Oro-tracheal Intubation Time measured during glottis visualization	13 seconds Standard Deviation 1	7 seconds Standard Deviation 1
Time Required to Visualize the Glottis and Complete Oro-tracheal Intubation Time measured during intubation	22 seconds Standard Deviation 3	20 seconds Standard Deviation 1

Adverse Events

Direct Laryngoscope

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Indirect Laryngoscope

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Prof. Massimiliano Carassiti

Campus Bio-medico University

Phone: +39-06-225411952

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place