DIY - A helmet NIV CAN BE USED with WALL OXYGEN alone to help COVID-19 patients
Updated: May 6
As of April 2, 2020, this is the most reliable and comprehensive training video about the use of a Helmet connected to wall gases or to BiPAP V60. detailed assembly instructions for a helmet from Dr. Bhakti Patel, The University of Chicago Medical Center (UChicago Medicine).
With some simple parts, a helmet can be set up to connect to airflow from the hospital wall oxygen or medical air wall outlet to help patients with COVID-19.
A mechanical ventilator, or non-invasive positive pressure ventilation (NIPPV) (corrected by the editor 02/27) is not needed when the helmet is used in this fashion. The oxygen and medical air flowing into the helmet produces positive pressure to recruit alveoli.
“Certainly many people won’t tolerate this” John P. Kress, MD said when he explained the process to Aurika Savickaite. Patients with more advanced in respiratory distress may need to go directly to mechanical ventilation. Dr. Kress is a professor of medicine, specializing in pulmonary medicine and critical care medicine. He is the director of the Medical Intensive Care Unit at the University of Chicago Medicine.
“But the experience in Italy suggests that about 20% of people can be managed this way. If there is a shortage of ventilators, this could prove to be very useful”, he said.
Using a helmet with wall oxygen/air could be the first step for caregivers to use with patients. A second step would be to connect a helmet to a mechanical ventilator or CPAP. (Based on what we know today about COVID-19 patients - we should not try to go from CPAP via helmet off the wall to a ventilator, instead, you have to act fast and intubate. If you have a ventilator you can hook it up to the helmet and set it to pressure support - but if it fails in 1-2 hours - intubate the patient. Update from Dr. Kress 03/27). The final step would be intubation.
Dr. Kress explained the parts needed to connect a helmet to wall oxygen:
Updated video 3/21/2020
The helmet looks like this. It has two connecting ports (see red arrows below):
On one of the helmet ports, you connect a standard bacterial/virus filter (blue device below) in between the helmet and a PEEP valve to prevent virus spread. The PEEP valve is the black device below.
On the other helmet port you make the following connections:
One clear end “nipple connector” (nipple for oxygen tubing connection is at the end of the connector).
Then two blue side “nipple connectors” (nipple for oxygen tubing connection is on the side of the connector).
One blue connector is placed between the two nipple connectors (connects the smaller diameter part of the blue nipple [see red arrows above])
“It’s basically like Legos. You just connect one after another,” Dr. Kress said. “It literally would take you just a few minutes to hook everything up.”
Here is the full setup. There is one missing piece—the bacterial/virus filter needs to be connected between the helmet and the PEEP valve (see red arrow in the picture below):
Then, turn the gas flow from the three flow meters on the wall as high as they will go. “That’s an important message to people,” Kress said. Turn the air and gas flow as high as it will go. The meter will stop at 15 l/min (see flow meters below), but if you turn the meter knob as high as it will go, the flow will be more than that.
“If you just bury the needle, so to speak, turn it up as high as it will go, you get way more than 15 liters per minute,” he said. If you turn the flow up as high as it will go, you get 40-50 liters per minute from each flow meter. This means if you have three flow meters connected (see above) you can get ~ 120-150 liters per minute of total flow. This is important because it is best to have ~100 liters per minute of the fresh gas flow in order to prevent CO2 rebreathing in the helmet.
If all three meters are at maximal flow, the FiO2 is 73.67% (100% + 100% + 21%/3). If you turn the oxygen flow meters down a bit, you can reduce the FiO2 closer to 60%. If you need 100% FiO2, just substitute the medical airflow meter with a third oxygen flow meter.
Helmet-based ventilation most often is used with a ventilator. This alternative use of noninvasive ventilation (NIV) via helmet is another way medical staff can help patients with COVID-19 while trying to keep ICU beds for those who are most ill.