Israeli doctors are increasingly sparing in the use of ventilators for coronavirus treatment, with some expressing fears that the breathing machines can cause harm.
“There’s a sentiment that we’re trying to delay ventilation unless we really have to,” Eyal Zimlichman, chief medical officer at Sheba Medical Center in Ramat Gan, told The Times of Israel, adding that this has been the case since mid-April.
It’s an unexpected twist in a health crisis that began with worries that Israel wouldn’t have enough ventilators. In the early days of the pandemic, doctors tried to connect patients to the machines as early as possible if they showed signs of deterioration, and suggested then that Israel’s success fighting the pandemic hinged to a large extent on its ability to find enough ventilators. The country even deployed the Mossad intelligence agency to help — and the feared ventilator shortage didn’t materialize.
As the novel coronavirus tends to cause respiratory illness, doctors often intubate patients, which means sedating them and inserting a tube into their windpipe through which pressured oxygen is supplied to mimic breathing. The pipe is hooked up to a ventilator. In Israel, some 50 patients are currently receiving this kind of breathing support.
In Zimlichman’s hospital, as in many others, doctors are increasingly trying to use ventilation methods that don’t require instruments to be inserted into the body. These noninvasive methods include BiPAP machines that push air into the lungs via a mask, and high flow oxygen therapy, which delivers oxygen via a mask at a higher than normal rate.
Philip Levin, director of intensive care at Shaare Zedek Medical Center in Jerusalem, said there is a growing push to support breathing without ventilators.
“I think the general attitude seems to be changing towards more liberal use of noninvasive techniques,” he said.
This reflects an international shift. In China, America and elsewhere there are now reports of doctors approaching ventilation with more caution. Ron Daniels, a specialist in UK intensive care units, told the Financial Times that doctors have “migrated” from ventilating as a matter of course based on oxygen levels to a more conservative use of ventilators based on symptoms.
In Israel, while more conservative use of invasive breathing support has become common, doctors sharply disagree about the logic for this — a dispute that stems from very different understandings of how the disease plays itself out in patients.
Yoav Yehezkeli, a public health expert at Tel Aviv University, said that doctors have been baffled as they attempt to understand better how the virus affects people differently. And he believes there are two distinct types of patients, one of which is ventilator-averse.
“In some types of patients you need more positive pressure like ventilation, but in others, this type of pressure becomes harmful, and there’s no certain way to know who has which condition,” he said. Research doesn’t help as it’s too soon for there to be a body of reliable literature, Yehezkeli added. “Formally this is something that does not exist but informally, at hospitals with experience, we’re discussing it.”
Zimlichman, like Yehezkeli, subscribes to a belief that there are two types of patients. Zimlichman said that some patients respond to COVID-19 in a way that gives doctors little scope to help them, and can make ventilation by machine harmful, adding that for this subgroup of coronavirus patients, “nothing we’ve been doing so far seems to help them.”
He said that patients whose symptoms reflect familiar acute respiratory distress syndrome, or ARDS, are often helped by ventilation, while others show a pattern of respiratory distress that is unfamiliar, and find that ventilators harm their lungs.
“This is different, and for this group it seems everything we’re doing fails to improve outcome, and the mortality with them is 70% to 80%,” Zimlichman said.
When patients respond with these unfamiliar respiratory patterns, there can be extensive damage to the lungs and other organs such as the heart, Zimlichman reported, adding that kidneys can start shutting down. He thinks that a key to better treatment and reducing mortality is working out a way to identify which patient has which condition, and said Sheba is deploying artificial intelligence to attempt this.
But despite efforts like these, many doctors dismiss the notion that there are two categories of patients, and say there is a range of similar responses with every illness. Ventilators, they insist, vary in effectiveness from patient to patient, but they aren’t causing harm.
“I wouldn’t say that I see damage from the ventilators,” said Margarita Mashavi, who oversees coronavirus care at the Wolfson Medical Center in Holon.
She tries not to use ventilators and places emphasis on noninvasive methods because she believes they are effective, but said this is across the board. She thinks that coronavirus patients are “all the same” in terms of their condition, and said that when it comes to treatment “the approach is the same approach.”
Levin, of Shaare Zedek, said that patients have very different needs when it comes to breathing support. “Our experience here has been that there are patients who require ventilation, and once they do, they need it for many days, and recovery is very slow,” he said. “But quite a large proportion of patients can be supported with noninvasive means, and these are generally patients who recover faster.”
However, Levin insisted, the difference in patients’ needs just reflects a normal variation in response to treatment. He doesn’t support the notion that there are two conditions, or that ventilators harm some.
“There are patients who are helped by ventilation more than others, but that’s the way with many diseases, it’s the way that people respond to intervention,” he said.
In his view, sparing use of ventilators made sense all along, though initially there was a push for early intubation out of fears that delaying it would cause worse results. Levin said that this clashed with a belief, common in intensive care, “that less is more, and we have to be cautious with interventions.”
Shaare Zedek was “more willing than others in the beginning to go with noninvasive ventilatory support and I’m thankful for this,” Levin said. “We saw several amazing successes. The use of noninvasive ventilation support in select cases, with careful monitoring, may lead to earlier recovery and less need [in the long run for] invasive ventilation.”
But he stressed that there are many unknown factors.
“The amount we don’t know about coronavirus far exceeds what we do know,” he said.