As the coronvirus continues to intensify, and hospitals around the world struggle to find enough equipment, an emergency physician is seen explaining how modify one ventilator to be used for up to four patients in a video published by the Daily Mail.
"Due to the COVID-19 pandemic, many health care providers are struggling with the situation where they may have more than one patient needing ventilation, and not enough ventilators to go around," Dr. Charlene Irvin Babkok.
The design is based off of a feasibility study that was published in 2006 in emergency medicine called a single ventilator from multiple simulated patients to meet disaster surge, in a joint study by Dr. Babkok another emergency physician Dr. Greg Namis.
The design is based off of equipment that can easily be found in emergency rooms and hospitals, accounting for the possibility of different equipment available to different hospitals.
In this design they use a 'T-tube' taken from an emergency respiration kit from an respiratory therapist's cart, as well as 22mm adapters making an 'H' formation. One end of the ventilation tube is hooked up to a port on each end of the small 'H' device, which is inserted into the one ventilator machine. The other ends of the tubes can then be hooked up to the patients. The H device may be halved, to only be used for two patients.
Despite only lung simulators being used in the study, and not real patients, the device was successfully used on patients during the Las Vegas mas shooting incident by Dr. Kevin Mannis. During the incident the hospital received an influx of patients needing respiratory therapy greater than the number of ventilators on hand. Dr. Mannis was able to successfully use the device for many hours before ventilators from outside sources were brought into the hospital.
"Dr. Mannis trained with Dr. Namis, and remembered the study from their time together," Dr. Babkok in the video. "so when the respiratory therapist came up to him and said 'we've run out of ventilators' he remembered the study."
In that particular case, he used to patients per ventilator rather than four.
The study did not cover the possibility of potential cross contamination risk, although they assumed it to be low given, "this is a one way circuit and the air only travels one way," however this has yet to be proven.
"If you envision this during a COVID-19 pandemic, everyone has the same infection, mitigating the concern for cross contamination," she notes.
The physician emphasizes that this is an off label use, and that the ventilators are designed for only one patient, "I hope that you don't need to use this, but you can never predict what's going to happen in a disaster."
"If it were me in this situation, and I had four patients and one ventilator, I would have a shared discussion with all four patients' families, and say, we could pick one to live, or all four to live, but this is off label use, and would only be used in dire circumstances.
Dr. Babkok explains in the video how the device works in, and goes on to give recommendations on how to use it to treat real patients. "Some things are intuitive. You want to make sure that the lung sizes are the same in all four portions of the circuit, you wouldn't wanna put a pediatric patient with an adult patient," she explains.
"Likewise you wanna make sure that the resistance is the same, you want to make sure the severity of the patients is similar, this would ensure that equal volumes would be delivered to everyone. Additionally the same length tubing should be used for all four patients."