Helmets Used to Reduce Clinicians Workload and improve NIV
When Prof. Giacomo Bellani started clinical practice and research, he thought using helmets for patients in respiratory distress was standard practice because they are so common in Italy.
After a few years, he realized that outside of Italy, and even in some regions in Italy, no one knew that helmets even existed. Bellani is an associate professor of Anesthesia and Critical Care Medicine of the University of Milan-Bicocca, in Monza, Italy, and a staff physician in the general Intensive Care Unit of San Gerardo Hospital.
(Video of the interview is coming soon on our Youtube channel)
Helmets are becoming better known, in part because of COVID-19, and in part because of people like Bellani, a proponent for them. He said helmets are “something I really believe works.”
A superior tool
Helmets are a tool to avoid intubation and, under several aspects, are superior to face masks for most patients, he said. They are part of the workflow – the first line of intervention and a reasonable way to manage patients early.
But for patients who respond, helmets used early in treatment offer a longer bridge for other therapies to work. In his hospital, the ratio of patients who use helmets to face mask users is probably 2-3 helmets for 1 face mask.
A “helmet is good when you don’t have the possibility to treat patients closely,” he said.
“The reason why helmets picked up so much here in Italy, we used to have an outrageously small number of ICU beds,” he said. It forced clinicians to use helmets outside of the ICU in both hospital settings and ambulances.
Clinicians who are new to helmets probably don’t know how much easier it is to set up a helmet than a face mask, he added.
“Because many times, a face mask is a pain in the neck,” he said. “There are all these leaks and you cannot use it easily with the high flow -- you need a ventilator.” If people used helmets a few times, it would convince them they are really easy to use, he said.
Difference between CPAP and NIV
People often don’t understand that helmet NIV and helmet CPAP are two very different things.
“Helmets are relatively easy to use with CPAP. You just need to have a good flow, and the PEEP valve will do the rest. I think that’s the key point to helmets. You drop the level of nursing assistance ... that you have to provide to the patient,” Bellani said.
With CPAP ventilation, you can diagnose if the patient is PEEP responsive. As long as the gas flows, the valve is connected and nothing is disconnected, it’s really hard for something to go wrong with the helmet, he said. It still works, even with leaks. “You know, that’s robust,” he said.
“NIV, it’s a different story,” he said. “You need to know how to set the ventilator. And if your goal is really to use it to reduce CO2, because the patient is hypercapnic, that’s not, honestly, as much as I love the helmet, that’s not the direction you want to go.”
Bellani also has seen more patients -- even in Italy, the “helmet capital” -- being treated with a high-flow nasal cannula.
Bellani helped develop a new Venturi flow generator, the EasyVEE, which allows the size of the port for ambient air to vary and provides continuous modulation of FiO2.
He also helped patent a closed-circuit system to recirculate oxygen, remove carbon dioxide and drop oxygen use by 60 to 70 percent. It is able to flush a helmet for CPAP with 60 to 70 liters per minute using only 15 liters of oxygen.
Presently, he’s working on a new flow generator, which may be available next year.
Few problems with helmets
A weakness of helmets, Bellani notes, is monitoring the helmet itself. Patients themselves are monitored, and if the helmet is disconnected from the airflow, there’s an anti-suffocation valve. The good news is that no patients have died from helmet failure to his knowledge.
Devices are available now to monitor flow and pressure. The PEEP-Alert, approved by the FDA EUA, measures flow and pressure inside a helmet and sounds an alarm if it drops.
Bellani is “very in favor of helmets, but if I was a detractor of helmets, I would see treatises of someone saying that’s too dangerous because you’re putting the patient’s head in a plastic bag, and there’s no alarm.”
Bellani suggests doctors and nurses try the helmet themselves. Then, when patients ask, they can honestly say it wasn’t bad. “After they have it on their heads, they see it’s not that bad,” he said. “They breathe better.”
Normally, patients find it’s easier to talk and look around. “It’s a little bit noisy (CPAP set up), but besides that, there’s nothing bad in it.”
Cost savings for helmet use
Many times, Bellani heard criticism that helmets are more expensive than face masks or high-flow nasal cannulas. Studies have shown better patient outcomes with helmet-based ventilation, fewer days in critical care, and less time hospitalized overall. During COVID, many patients in Italy were effectively managed outside of the ICU using helmets, which is a cost-saving that could be measured, he said.
Additionally, there’s less nursing time required with a helmet than a face mask. Alberto Lucchini, a nursing coordinator in the general Intensive Care Unit of San Gerardo Hospital, has published papers about the nursing aspects of helmets.
Hospitals that don’t use helmets lose the opportunity to start noninvasive ventilation early and to assess the patient to see if he or she is PEEP-responsive. Helmet CPAP can save money because there’s no ventilator, no knobs, no buttons, and no need for a respiratory therapist to be there at all times, Bellani said.
“You don’t have to give the feeling that you’re trying to avoid intubation at any cost,” Bellani said. “That is not good either. If you try everything before intubating, you keep postponing the intubation for the patient, which is really bad for the patient.”
Helmet use specifics
US hospitals don’t have Venturi systems, but they do have a lot of BiPAP machines and ventilators. Helmet CPAP can’t use CPAP mode on a ventilator, though. Most ventilators now allow the use of a flow generator, Bellani said, such as with a high-flow nasal cannula. He suggests using a respiratory branch with a continuous flow system. If that’s not possible, he wouldn’t use CPAP mode, he said. “You have to get some pressure support, and you’re stuck with it. At this point, I would put a relatively low PEEP, let’s say 5, and pressure support of 8- 10, so flow is washing out CO2.”
There’s also a problem with the flow that’s too high, he said. While you can go up to 80 to 90 liters for COVID, it’s not necessarily best for the patient, because the pressure is up during expiration. He suggests going to 60 liters.
With helmet CPAP, he’s seen cases of self-induced lung injury. He suggests a device from the US, ExSpiron, for noninvasive monitoring of tidal volume. “I was skeptical,” he said, but “it’s very accurate.”
Bellani commented on HelmetBasedVentilation.com and its new online course for clinicians, noting this educational offering can help medical professionals understand better how to use helmets for their patients.