Ventilator Splitting: What's Been Done for COVID19 Coronavirus

In 2006 a paper was published; suggesting that in a time of crisis a single ventilator could be used to supply oxygenation and ventilation to a set of patients:

A Single Ventilator for Multiple Simulated Patients to Meet Disaster Surge Greg Neyman, MD, Charlene Babcock Irvin, MD

https://onlinelibrary.wiley.com/doi/pdf/10.1197/j.aem.2006.05.009

In this study they experimentally demonstrate on test lungs that on both pressure and volume control mode you can sync up to 4 lungs and deliver reasonable ventilation and pressures required to sustain life -- at least for a couple of hours. 

 

They stack their patients up in PARALLEL. That is; all patients get inhalation at the same time, and exhale at the same time. 

 

A simple figure I drew is here:

 

 

 

They do this using a serial of 3 way junctions. 

 

 

However, this system only functions if all the patients are supposed to get the same volume or pressure -- specifically they need to have similar compliance (stiffness) and volumes (usually based on their body weight). 

 

People have described this process; and ways to optimize it; even though some societies are recommending against it -- however if the alternative is death I think ICU and ER docs are going to have to be a bit more flexible in the face of guidelines. 

 

Check out EMCRIT's take on it with some FUNCTIONAL thoughts on the process; and counters to guidelines that recommend against it

https://emcrit.org/pulmcrit/split-ventilators/

 

Also check out the "how-to" guide with parameters from Columbia

https://www.gnyha.org/wp-content/uploads/2020/03/Ventilator-Sharing-Protocol-Dual-Patient-Ventilation-with-a-Single-Mechanical-Ventilator-for-Use-during-Critical-Ventilator-Shortages.pdf

 

Also, some schematics and how-do's done in video format:

https://medium.com/@pinsonhannah/a-better-way-of-connecting-multiple-patients-to-a-single-ventilator-fa9cf42679c6

 

However -- I'm going to take a sharp left turn and suggest a completely different way of doing things in another blog. 

 

https://yourdesignmedical.com/blogs/ventilator-splitting-the-theory/vent-splitting-a-better-way