Clinical trial NCT02934347: Comparison of Glottic Views and Intubation Times in the Supine and 25 Degree Back-up Positions
Official title: Comparison of Glottic Views and Intubation Times in the Supine and 25 Degree Back-up Positions
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Elective Surgical Patients
Keywords: Intubation, Back-up position; Glottis, View
Lead sponsor: Betsi Cadwaladr University Health Board
Sponsor class: OTHER_GOV
First posted: 2016-10-17
Enrollment: 781
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Adult patients who required intubation as part of their routine anaesthesia

Brief summary: Our hypothesis is that the view of the glottis may be improved by putting all patients requiring intubation in the ramped or back up position while maintaining the classic sniffing position.

Detailed description: The sniffing position has traditionally been considered the optimal head position for direct laryngoscopy and is the usual patient position preferred by most anaesthetists. In theory, neck flexion aligns the pharyngeal and laryngeal axes, and head extension at the atlanto-occipital joint aligns the oral axis with these two axes allowing the line of sight to fall on the glottis. It is recognized as the starting head position for direct laryngoscopy because it provides the best chance of adequate exposure.

However the sniffing position does not guarantee adequate exposure in all patients because many other anatomical factors control the final degree of visualization.

To achieve a proper sniffing position in obese patients, the "ramped" (or the back-up) position has been used as this produces better neck flexion and head extension in these patients when compared to the horizontal supine position. Also the forces required to elevate and move the tongue and other tissues out of the line of sight are less when the patients are ramped.

Our hypothesis is that the view of the glottis may be improved by putting all (ie not only obese) patients requiring intubation in the ramped or back up position while maintaining the classic sniffing position.

Eligibility criteria: Inclusion Criteria:

* Adult surgical patients who required intubation as part of their routine anaesthesia

Exclusion Criteria:

1. Patients less than 18 years old,
2. Patients recognised to have difficult airways where an alternative method of intubation (e.g. fibre optic) was the method of choice,
3. Patients undergoing emergency surgery where patient positioning and data collection might cause delay (e.g. exsanguinating patients) or where the supine position is not optimal (e.g. brisk bleeding into the upper airway),
4. Patients requiring rapid sequence induction of anaesthesia

Primary outcomes:
measure: The Best Glottic View Obtained During Laryngoscopy
timeFrame: The view of the glottis was measured once while the patient was being intubated
Secondary outcomes:
measure: The Number of Attempts at Both Laryngoscopy and Tracheal Intubation
timeFrame: Once at intubation
measure: The Use of Ancillary Equipment
timeFrame: Once at intubation
measure: The Time Between the Beginning of Laryngoscopy and Detection of Carbon Dioxide on the End-tidal Carbon Dioxide Monitor
timeFrame: Once at intubation
Other outcomes:
Locations:
Study officials:
affiliation: Anaesthetic Department, Glan Clwyd Hospital, Betsi Cadwaladr University Health Board
name: Raj M Reddy, FRCA
role: PRINCIPAL_INVESTIGATOR
References:
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citation: Collins JS, Lemmens HJ, Brodsky JB, Brock-Utne JG, Levitan RM. Laryngoscopy and morbid obesity: a comparison of the "sniff" and "ramped" positions. Obes Surg. 2004 Oct;14(9):1171-5. doi: 10.1381/0960892042386869.
citation: Lane S, Saunders D, Schofield A, Padmanabhan R, Hildreth A, Laws D. A prospective, randomised controlled trial comparing the efficacy of pre-oxygenation in the 20 degrees head-up vs supine position. Anaesthesia. 2005 Nov;60(11):1064-7. doi: 10.1111/j.1365-2044.2005.04374.x.
citation: Dixon BJ, Dixon JB, Carden JR, Burn AJ, Schachter LM, Playfair JM, Laurie CP, O'Brien PE. Preoxygenation is more effective in the 25 degrees head-up position than in the supine position in severely obese patients: a randomized controlled study. Anesthesiology. 2005 Jun;102(6):1110-5; discussion 5A. doi: 10.1097/00000542-200506000-00009.
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citation: Reddy RM, Adke M, Patil P, Kosheleva I, Ridley S; Anaesthetic Department at Glan Clwyd Hospital. Comparison of glottic views and intubation times in the supine and 25 degree back-up positions. BMC Anesthesiol. 2016 Nov 16;16(1):113. doi: 10.1186/s12871-016-0280-4.