Epiglottic Downfolding During Endotracheal Intubation

Epiglottic Downfolding During Endotracheal Intubation - An Alternative Technique to Improve Glottic Exposure and Facilitate Intubation?

Usually videolaryngoscopy using a videolaryngoscope with a classic Macintosh design is performed with the blade in the vallecula and the epiglottis elevated from the vocal cords indirectly, as in direct laryngoscopy. However, during an audit of videolaryngoscopic practice we noticed that, in obtaining the best view, clinicians frequently and inadvertently advanced the blade into the vallecula to get a better view, such that the epiglottis was downfolded and elevated directly from the vocal cords. However, a better view does not necessarily lead to higher intubation success.

In this randomized, controlled trial, we want to determine the efficacy of videolaryngoscope-guided tracheal intubation using an alternative position for the blade in patients with normal airways.

Study Overview

• Status: Withdrawn
• Conditions: Intubation Complication; Injury of Epiglottis
• Intervention / Treatment: Device: C-MAC® videolaryngoscope (Karl Storz, Tuttlingen, Germany)

Detailed Description

Anaesthesia will be induced in the conventional matter. For patients randomized to the intervention group, when the anaesthesiologist considers the depth of anaesthesia to be sufficient, a C-MAC® videolaryngoscope (Karl Storz, Tuttlingen, Germany), will be placed into the patients mouth. The best possible view of the vocal cords will be obtained with the blade positioned normally in the vallecula anterior to the epiglottis. The epiglottis will be elevated from the vocal cords indirectly, identical with direct laryngoscopy. After this, the best possible view of the vocal cords will be obtained with the blade positioned alternatively in the vallecula posterior to the epiglottis, such that the epiglottis is downfolded and elevated directly from the vocal cords. Views will be scored in both positions using the Cormack and Lehane classification system. When correct laryngoscope positioning can't be achieved with a size 3 blade, a size 4 blade will be used.

For patients not randomized to the intervention group, anaesthesia will also be induced in the conventional matter. When the anaesthesiologist considers the depth of anaesthesia to be sufficient, a C-MAC® videolaryngoscope (Karl Storz, Tuttlingen, Germany), will be placed into the patients mouth. The best possible view of the vocal cords will be obtained with the blade positioned normally in the vallecula anterior to the epiglottis. The epiglottis will be elevated from the vocal cords indirectly, identical with direct laryngoscopy. The view will be scored in this position using the Cormack and Lehane classification system. After this, the patient will be intubated.

Patients will be interviewed 2 and 24 hours postoperatively about sore throat, dysphonia, dysphagia and coughing.

• Study Type: Interventional
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Netherlands
  • Eindhoven, Netherlands, 5623 EJ
    • Catharina Ziekenhuis Eindhoven

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Informed patient consent
• ASA I-III
• Age > 18 years
• Elective surgery, other than head and/or neck surgery
• Elective surgery, duration < 1 hour in supine position
• Pre-operative Mallampati I-II-III

Exclusion Criteria:

• No informed patient consent
• ASA IV
• Age < 18 years
• Preoperative complaints of sore throat, dysphagia, dysphonia and coughing
• Emergency surgery, surgery of head and/of neck
• Surgery during > 1 hour in other than supine position
• Locoregional anaesthesia
• Preoperative Mallampati IV
• Known difficult airway
• Bad dentition
• Dental crowns and/or fixed partial denture
• Risk of aspiration (fasted < 6 hours, gastroesophageal reflux)

Study Plan

How is the study designed?

Design Details

• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Control group; In the control group, anaesthesia will be induced in the same way as mentioned above for the intervention group. Also in this group, intubation will be achieved using a C-MAC® videolaryngoscope (Karl Storz, Tuttlingen, Germany) with a size 3 Macintosh blade. The best possible view of the glottic inlet will be scored with the blade tip positioned in the vallecula. The glottic view will be scored in this position using the Cormack and Lehane classification system. If correct laryngoscope positioning cannot be achieved with a size 3 blade, a size 4 blade will be used. Hereafter, the patient's trachea will be intubated once the optimal view of the larynx had been obtained. Intubation attempts will be scored in the same way as mentioned above for the intervention group.
Experimental: Epiglottic downfolding; Endotracheal intubation will be achieved using a C-MAC® videolaryngoscope (Karl Storz, Tuttlingen, Germany) with a size 3 Macintosh blade. The best possible view of the glottic inlet will be scored with the blade tip positioned in the vallecula. Next, the view of the glottic inlet will be scored with the blade advanced further into the vallecula, until the epiglottis flips infero-posteriorly and becomes downfolded into the trachea. The glottic view will be scored in both positions using the Cormack and Lehane classification system. After successful intubation, the blade will slowly be withdrawn into the vallecula to elevate the epiglottis back to its normal position.	Device: C-MAC® videolaryngoscope (Karl Storz, Tuttlingen, Germany); Endotracheal intubation will be achieved using a C-MAC® videolaryngoscope (Karl Storz, Tuttlingen, Germany) with a size 3 Macintosh blade. The best possible view of the glottic inlet will be scored with the blade tip positioned in the vallecula. Next, the view of the glottic inlet will be scored with the blade advanced further into the vallecula, until the epiglottis flips infero-posteriorly and becomes downfolded into the trachea. The glottic view will be scored in both positions using the Cormack and Lehane classification system. After successful intubation, the blade will slowly be withdrawn into the vallecula to elevate the epiglottis back to its normal position.; Other Names: Epiglottic downfolding during endotracheal intubation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Cormack and Lehane grade	The Cormack and Lehane grade scored in both positions of the C-MAC® videolaryngoscope and consequent success of intubation	Patients will be followed for the duration of induction of anaesthesia, an average of 10 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Discomfort	Sore throat, dysphonia, dysphagia and coughing reported by patients 2 and 24 hours postoperatively	Patients will be followed for 24 hours postoperatively
Use of adjuncts	Frequency of use of a stylet, gum elastic bougie or BURP manoeuvre.	Patients will be followed for the duration of induction of anaesthesia, an average of 10 minutes

Collaborators and Investigators

• Sponsor: Catharina Ziekenhuis Eindhoven
• Investigators: Principal Investigator: Barbe MA Pieters, MD, Catharina Ziekenhuis Eindhoven

Publications and helpful links

General Publications

• van Zundert A, van Zundert T, Brimacombe J. Downfolding of the epiglottis during intubation. Anesth Analg. 2010 Apr 1;110(4):1246-7. doi: 10.1213/ANE.0b013e3181ce716f. No abstract available.
• Kaplan MB, Hagberg CA, Ward DS, Brambrink A, Chhibber AK, Heidegger T, Lozada L, Ovassapian A, Parsons D, Ramsay J, Wilhelm W, Zwissler B, Gerig HJ, Hofstetter C, Karan S, Kreisler N, Pousman RM, Thierbach A, Wrobel M, Berci G. Comparison of direct and video-assisted views of the larynx during routine intubation. J Clin Anesth. 2006 Aug;18(5):357-62. doi: 10.1016/j.jclinane.2006.01.002.
• Merli G. Videolaryngoscopy: is it only a change of view? Minerva Anestesiol. 2010 Aug;76(8):569-71. Epub 2010 Apr 23. No abstract available.

Study record dates

Study Major Dates

• Study Start: April 1, 2013
• Primary Completion (Actual): January 1, 2016
• Study Completion (Actual): January 1, 2016

Study Registration Dates

• First Submitted: September 19, 2012
• First Submitted That Met QC Criteria: September 24, 2012
• First Posted (Estimate): September 25, 2012

Study Record Updates

• Last Update Posted (Estimate): January 28, 2016
• Last Update Submitted That Met QC Criteria: January 27, 2016
• Last Verified: January 1, 2016

More Information

Terms related to this study

• Keywords: Intubation; Laryngoscopy; Epiglottis
• Other Study ID Numbers: M12-1233; NL40875.060.12 (Other Identifier: Medisch Ethische Commissie Catharina Ziekenhuis Eindhoven)