See a need, fill a need: medical invention in the 21st century

Dr. A. Shaikh

Introduction

The historical article on the development by Dr Brain of the laryngeal mask airway [1] shows for the first time what the processes were for the introduction of a new airway device some 30 years ago. The authors of the paper state that it would be ‘interesting to speculate whether such research would be possible under today’s more stringent conditions’.

Literature search for studies with supraglotic devices and manikin studies or comparison studies

Manikin evaluation of the Tulip – a new supraglottic airway
Anaesthesia, 2009, 64, pages 793–813
S. Harrison,1 N. P. Robinson,2 A. Shaikh3 and S. M. Yentis4

What it’s about:
3 operators inserted 3 devices (LMA, iGel, Tulip) in manikins.
Each device inserted 3 times in total.

Reflux/Regurgitation

Historically, the publications show that Laryngeal Masks have a higher incidence of methylene blue dye regurgitation than Guedel airways when used with Facemasks in live patients. This seems counter-intuitive but when a capsule of blue dye is ingested by the patient 10 minutes before induction and the airway is visualized after the end of surgery in patients at no known risk of regurgitation Barker P states “Dye was observed within the Laryngeal Mask in 7 of 28 patients (25%). No patients in the Facemask-Guedel airway group regurgitated dye (p=0.005)”.

Clearing and maintaining an airway

Clearing and maintaining an airway is one of the first priorities for emergency personnel called to an out of hospital cardiac arrest, and many are trained to intubate or place supraglottic devices such as a laryngeal mask airway. Evidence has begun to emerge that these advanced techniques may do more harm than good in the prehospital setting.

Supraglottic airways and oesophageal insufflation

by rfdsdoc on September 21, 2012

This months anaesthesia journal reading revealed this gem from German authors.
In a cadaver model of simulated complete airway obstruction, ventilation pressures of 20mBar did not produce any oesophageal insufflation in any of the 4 supraglottic airways but at higher presssures 40mBar and greater, there was air leak into the oesophagus and this was more so in the laryngeal tube airway devices. iGel and LMA Supreme devices performed well.

Man and Manikin

Dear Editor,

New anaesthetic equipment and it’s pathway to introduction has been a topic of discussion over the past few years and this is a conversation in which we have participated. The ADEPT recommendations were noted to reflect the processes through which the Tulip airway had been developed, tested and researched ultimately producing level 1 evidence with a randomized controlled trial being submitted to Anaesthesia in December 2014 for consideration.

Manikin studies are essential in airway research.

The editorial ‘evaluation of airway equipment: man or manikin?’ [1] states, in negative terms, that increasing numbers of publications use manikins as surrogate research subjects and concludes that ‘it is time for serious researchers to move on to study patients rather than manikins.’