Manikin studies are essential in airway research.
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.’ This conclusion causes us concern as simulation is a standard in almost all industry that involves experts at work.
In medicine all simulation is preparation for safe practice without exposing patients to harm. Such work is to be applauded and the results can be utilised to develop a portfolio as is the case with our work on the Tulip® supraglottic airway. Our initial work involved both bench testing (MeDEC; Department of Anaesthetics and Intensive Care Medicine, Cardiff University) and manikin studies (TRUCORP AirSim) [2]. This yielded important information regarding the performance of this new airway device without exposing any patients to possible harm.
Our subsequent clinical findings contradict the editorial statement that suggests that there is no correlation between man and manikin. We have found there is a good correlation between man and manikin in a number of parameters including ease and speed of insertion, intra-cuff pressures, maximum ventilation pressures and bronchoscopic laryngeal views. There were no significant differences between man and manikin in our initial studies which also suggests that manikin simulation is a good adjunct for anaesthetic research, at least with the Tulip® airway.
We also found that simulation was not only necessary but essential in a number of conditions where new technology was being tested. For example, it is not desirable to measure the maximum ventilation pressure that the Tulip® supraglottic airway can generate in-vivo as this exceeds 100cm H20 in mannequins. This would clearly be dangerous to test in human subjects. It can thus be seen that there are circumstances where the results from assessment in manikins may provide better information than human evaluations and in a safe fashion.
Currently, we are supporting a safe manikin study with a clinical pilot study. The value of the manikin cannot be replaced or dismissed as this forms part of the constructed sequence of safe research for any airway device. We have found that the accuracy of the results depends on the quality of the simulation tests performed.
P. N. Robinson
Northwick Park Hospital
North West London Hospitals NHS Trust
Middlesex UK
A. Shaikh
St. Andrew’s Cottage
3 North Burlingham
Norwich Norfolk
NR13 4TA
Email: pnrfmt@msn.com
Dr Shaikh is the inventor of the Tulip® airway. No external funding and no competing interests are declared.
References
1 Popat MT, Rai MR. Evaluation of airway equipment: man or manikin. Anaesthesia 2011; 66: 1-3.
2 Harrison S, Robinson NP, Shaikh A, Yentis SM. Manikin evaluation of the Tulip®, a new supraglottic airway. Anaesthesia 2009; 64: 807.