Evaluation of six videolaryngoscopes in 720 patients with a simulated difficult airway: a multicentre randomized controlled trial.
BACKGROUND
Videolaryngoscopes are aggressively marketed, but independent evaluation in difficult airways is scarce. This multicentre, prospective randomized controlled trial evaluates six videolaryngoscopes in patients with a simulated difficult airway.


METHODS
With ethics committee approval and written informed consent, 12 senior anaesthetists intubated the trachea of 720 patients. A cervical collar limited mouth opening and neck movement, making intubation difficult. We evaluated three unchannelled (C-MAC™ D-blade, GlideScope™, and McGrath™) and three channelled videolaryngoscopes (Airtraq™, A.P. Advance™ difficult airway blade, and KingVision™). The primary outcome was first-attempt intubation success rate. Secondary outcomes included overall success rate, laryngeal view, intubation times, and side-effects. The primary hypothesis for every videolaryngoscope was that the 95% confidence interval of first-attempt success rate is ≥90%.


RESULTS
Mouth opening was decreased from 46 (sd 7) to 23 (3) mm with the cervical collar. First-attempt success rates were 98% (McGrath™), 95% (C-MAC™ D-blade), 87% (KingVision™), 85% (GlideScope™ and Airtraq™), and 37% (A.P. Advance™, P<0.01). The 95% confidence interval of first-attempt success rate was >90% only for the McGrath™. Overall success, laryngeal view, and intubation times differed significantly between videolaryngoscopes (all P<0.01). Side-effects were minor.


CONCLUSIONS
This trial revealed differences in the performance of six videolaryngoscopes in 720 patients with restricted neck movement and limited mouth opening. In this setting, first-attempt success rates were 85-98%, except for the A.P. Advance™ difficult airway blade. Highest success and lowest tissue trauma rates were achieved by the McGrath™ and C-MAC™ D-blade, highlighting the importance of the videolaryngoscope blade design.


BACKGROUND
ClinicalTrials.gov: identifier NCT01692535.
Department of Anaesthesiology and Pain Therapy, Inselspital, University Hospital Bern and University of Bern, Switzerland Department of Anaesthesia and Intensive Care, Barts Heart Centre, London, UK maren.kleine-brueggeney@insel.ch.
M
M
Kleine-Brueggeney
Department of Anaesthesiology and Pain Therapy, Inselspital, University Hospital Bern and University of Bern, Switzerland.
R
R
Greif
Department of Anaesthesiology, University Hospital Centre and University of Lausanne, Lausanne, Switzerland.
P
P
Schoettker
Division of Anaesthesiology, University Hospitals of Geneva and Faculty of Medicine, University of Geneva, Geneva, Switzerland.
G L
GL
Savoldelli
Department of Anaesthesiology and Pain Therapy, Inselspital, University Hospital Bern and University of Bern, Switzerland.
S
S
Nabecker
Department of Anaesthesiology and Pain Therapy, Inselspital, University Hospital Bern and University of Bern, Switzerland.
L G
LG
Theiler
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000768:Anesthesia, General / Q000379:methods; D004311:Double-Blind Method; D004867:Equipment Design; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D020704:Laryngoscopes / Q000009:adverse effects; D007828:Laryngoscopy / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014741:Video Recording; D055815:Young Adult
anaesthetic techniques, laryngoscopy; equipment, airway; intubation, tracheal tube