Humidicare – an implementation study of a novel HME safety device designed to prevent ventilator circuit occlusion due to inadvertent dual humidification

Abstract

Mechanical ventilation bypasses the protective mechanisms of the upper respiratory tract which are designed to heat and humidify inspired air to 37 °C and 44 mg H₂O/L respectively. Artificial humidification systems are therefore incorporated into ventilation circuits to condition cold and dry medical gases before they reach the lower respiratory tract and cause patient harm. Commonly either a heat and moisture exchanger (HME) or a heated humidifier (HH) are utilised for this purpose, however the inadvertent simultaneous use of both devices within the same circuit can cause critical airway occlusion within 24 h. The Humidicare HME (Medovate, Cambridge, UK) is a safety engineered temperature-dependent warning system designed to activate when inadvertently placed into a warm circuit containing a HH. This study aimed to determine the efficacy of the Humidicare HME warning system in simulated clinical conditions. The threshold temperature for activation of the device was determined in a digital incubator, and the device was tested for efficacy with a HH present or absent from the breathing circuit. The device performed reliably and activated rapidly when required across all simulations. The Humidicare HME warning system is a simple and unobtrusive device which can effectively alert the operator to the error of dual humidification.

Keywords:

• Patient safety
• safety engineered device
• artificial humidification
• anaesthesia
• intensive care

Acknowledgements

None.

Author contributions

All authors (i) made a substantial contribution to the concept or design of the work; or acquisition, analysis or interpretation of data, (ii) drafted the article or revised it critically for important intellectual content, (iii) approved the version to be published and (iv) participated sufficiently in the work to take public responsibility for appropriate portions of the content.

Disclosure statement

Dr Young is the owner of a patent (WO2019141978A1) for the HME safety warning system discussed in this paper belonging to Medovate. The remaining authors declare no competing interests.