Development and performance testing of the low-cost, 3D-printed, smartphone-compatible ‘Tansen Videolaryngoscope’ vs. Pentax-AWS videolaryngoscope vs. direct Macintosh laryngoscope

Abstract

BACKGROUND: While videolaryngoscopes help in the management of difficult airways, they remain too expensive for those with limited resources. We have developed a robust, re-usable, low-cost videolaryngoscope at United Mission Hospital Tansen, Nepal, by combining a smartphone-compatible endoscope capable of capturing still and video images with a three dimensional-printed, channelled, hyperangulated blade. The computer-aided design file for the videolaryngoscope blade was emailed and printed in London before evaluation of its performance on a difficult airway manikin. OBJECTIVE: To benchmark the intubation performance of the Tansen Videolaryngoscope (TVL) in a 'difficult airway' manikin (SimMan3G, tongue fully inflated, neck stiff), against a commercially available videolaryngoscope and a conventional Macintosh laryngoscope. DESIGN: A manikin study. SETTING AND PARTICIPANTS: Forty-three experienced videolaryngoscope users in two London teaching hospitals. INTERVENTION AND OUTCOME: Primary outcome: Intubation success rate. SECONDARY OUTCOMES: grade of laryngeal view, median time to intubation and intubator-rated 'ease of use'. RESULTS: Our device was equivalent to Pentax-AWS and superior to Macintosh laryngoscope (TVL vs. Pentax-AWS vs. Macintosh) in overall intubation success rate (88 vs. 98 vs. 67%, P < 0.05); grade of view (median Cormack-Lehane grade 1 vs. 1 vs. 3, P < 0.01); median time to intubation (17.5 vs. 15.5 vs. 27 s, P < 0.01). In subjective 'ease of use' scores, Pentax-AWS was superior to the TVL, which was superior to Macintosh laryngoscope (Likert-type 1 to 5 scale: 4 vs. 4 vs. 1, P < 0.00001). CONCLUSION: In this manikin simulation of a difficult airway, the 'TVL' was superior to the Macintosh laryngoscope, and noninferior to the Pentax-AWS videolaryngoscope in intubation success rate, grade of laryngeal view and time to intubation. Participants found the Pentax device easier to use, and their feedback has given us valuable insights for improving our device. The TVL is well suited to settings in which resources are limited, being inexpensive, simple and re-usable.