Retromolar Route Access With and Without A Retromolar Gap

Airway Management Clinical Trial

Official title:

Retromolar Route Access With and Without A Retromolar Gap - A Visualization Study Of The Vocal Cords

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02611141
• Other study ID #: 1848/2015
• Status: Completed
• Phase: N/A
• First received: November 7, 2015
• Last updated: March 21, 2018
• Start date: November 2015
• Est. completion date: July 2017

Study information

• Verified date: March 2018
• Source: Medical University of Vienna
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Retromolar Intubation is a successful option for intubation in patients with an existing retromolar gap in the case that the conventional method fails.

Therefore the investigators want to test if the retromolar gap is essential for performing the retromolar intubation technique.

Description:

For successful endotracheal intubation an optimal visualisation of the vocal cords is essential. A study comparing retromolar and conventional laryngoscopy showed in patients with an existing retromolar gap, that the retromolar technique is superior for endotracheal intubation especially in patients with a failed 'conventional' intubation attempt. The aim of the following study is to test if a retromolar gap at the right mandible is necessary for the successful performance of the retromolar laryngoscopy technique.

Therefore, 20 patients with and 20 patients without a retromolar gap will be investigated.

The anesthesiologist will visually determine the view of the vocal cords and score it according to Cormack & Lehane. For an improved view a backward, upward, right-ward pressure (BURP) will be performed, if needed, and scored again.

Finally, endotracheal intubation will be performed by the 'conventional' intubation method. If, however, intubation is not possible, then the retromolar technique will be used. In the case that both methods fail, then any (other) intubation method will (can) be used.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 40
• Est. completion date: July 2017
• Est. primary completion date: July 2017
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 99 Years

Eligibility

Inclusion Criteria:

• BMI < 35kg/m2

• Elective surgery

• Absence of at least one molar of the right mandible in arm I (20 patients)

Exclusion Criteria:

• Emergency patients

• Prevalence of reflux disease

• Toothless patients

• Diaphragmatic hernia

• Patient is not sober

• Ventilation problems during induction of anaesthesia

• Patient with a tracheostomy

Related Conditions & MeSH terms

• Airway Management

Intervention

Procedure:
• Retromolar laryngoscopy and scoring of the visualisation of the vocal cords according to Cormack & Lehane
To facilitate the insertion of the straight blade laryngoscope (Miller #4) the head of the patient will be turned to the left side. The blade will be inserted and then pushed laterally rightwards until the retromolar space will be finally reached. Thereafter the epiglottis will be lifted up in order to achieve the best direct view to the vocal cords and scored according to Cormack & Lehane . This score will be assessed at least 2 minutes after muscle relaxation: Once without a backward, upward, rightwards pressure maneuver (=BURB) and immediately thereafter (i.e. 5-10 seconds later): If 100% visualization of the vocal cords is not possible a BURP maneuver will be performed and the scored again. Intubation will then be performed by the conventional method using a Macintosh blade #3. In the case that intubation with the conventional method is not successful the retromolar technique will be used.

Locations

Country	Name	City	State
Austria	Medical University of Vienna	Vienna

Sponsors (1)

Lead Sponsor	Collaborator
Medical University of Vienna

Country where clinical trial is conducted

Austria, 

References & Publications (8)

Behringer EC, Kristensen MS. Evidence for benefit vs novelty in new intubation equipment. Anaesthesia. 2011 Dec;66 Suppl 2:57-64. doi: 10.1111/j.1365-2044.2011.06935.x. Review. — View Citation

Bonfils P. [Difficult intubation in Pierre-Robin children, a new method: the retromolar route]. Anaesthesist. 1983 Jul;32(7):363-7. German. — View Citation

De Jong A, Molinari N, Conseil M, Coisel Y, Pouzeratte Y, Belafia F, Jung B, Chanques G, Jaber S. Video laryngoscopy versus direct laryngoscopy for orotracheal intubation in the intensive care unit: a systematic review and meta-analysis. Intensive Care Med. 2014 May;40(5):629-39. doi: 10.1007/s00134-014-3236-5. Epub 2014 Feb 21. Review. — View Citation

Henderson JJ. Questions about the macintosh laryngoscope and technique of laryngoscopy. Eur J Anaesthesiol. 2000 Jan;17(1):2-5. — View Citation

Levitan RM, Heitz JW, Sweeney M, Cooper RM. The complexities of tracheal intubation with direct laryngoscopy and alternative intubation devices. Ann Emerg Med. 2011 Mar;57(3):240-7. doi: 10.1016/j.annemergmed.2010.05.035. Epub 2010 Jul 31. Review. — View Citation

Martinez-Lage JL, Eslava JM, Cebrecos AI, Marcos O. Retromolar intubation. J Oral Maxillofac Surg. 1998 Mar;56(3):302-5; discussion 305-6. — View Citation

Ranieri D Jr, Filho SM, Batista S, do Nascimento P Jr. Comparison of Macintosh and Airtraq™ laryngoscopes in obese patients placed in the ramped position. Anaesthesia. 2012 Sep;67(9):980-5. doi: 10.1111/j.1365-2044.2012.07200.x. Epub 2012 Jun 1. — View Citation

Scott J, Baker PA. How did the Macintosh laryngoscope become so popular? Paediatr Anaesth. 2009 Jul;19 Suppl 1:24-9. doi: 10.1111/j.1460-9592.2009.03026.x. Review. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Cormack & Lehane score (without a backward, upward, rightwards pressure maneuver)	After ensuring sufficient bag-mask ventilation, the scoring of the vocal cords according to Cormack & Lehane will be performed at least 2 minutes after administration of the muscle relaxant rocuronium without a backward, upward, rightwards pressure maneuver (=BURB)	At least 2 minutes after muscle relaxation
Primary	Cormack & Lehane score (with a backward, upward, rightwards pressure maneuver)	If the Outcome Measure 1 does not reveal a 100% visualization of the vocal cords, a backward, upward, rightwards pressure maneuver (BURP) maneuver will be applied and scored again according to Cormack & Lehane .; Usually each of the two scoring procedures lasts approximately 5-10 seconds.	Approximately 5-10 seconds after the collection of the Outcome Measure 1